Shutter slower than video FPS I'm trying to shoot low light video on my RX100 m3 and I want to make the best of it. So it would make sense that the ideal setting (in many cases) would be to open the shutter for as long as it can be open for that frame.
So if recording at 25 FPS video, then you would have the shutter open 1/25 seconds. That way you get max light in.

However I notice my camera doesn't mind having the shutter way slower than that number, I guess that means that it actually spills same information onto several frames?

If I set it to 1/25 does that mean absolute maximum. OR does the camera perhaps need a few milliseconds between each frame and therefor 1/25 for 25 fps video is too slow?

"If I set it to 1/25 (shutter speed) does that mean absolute maximum (or lowest setting)?"
Yes, if it was a non-digital video camera. This rule applied to the old non-digital (film) video cameras where you cannot set shutter speed lower than the frame rate.

Meaning that one celluloid was exposed for the full 1/25th of a second. Assuming 25fps.

For digital video cameras each frame can be blended with the other. This technique allows you to film in low light situations at the expense of motion blur. It can be used to create what some called a dream like sequence.

You should just view this as another creative control that you have to managing low light situations or adding motion blur to your videos.

See example below:


RTMP server using ffmpeg I'd like to use a Teradek Cube connected to a broadcast camera to push to a server running ffmpeg with an open RTMP port, and have ffmpeg re-stream that feed to a decoder using RTMP or RTSP.

Monaserver does this, but I need to duplicate this functionality using ffmpeg. I would use the Cube as a server, except it could be broadcasting anywhere so opening ports at every location the camera goes to is not an option. Our decoder is a Teradek Slice. Any other suggestions about how to do this would be greatly appreciated.

Thank you!

You can use FFmpeg as an RTMP server as following
ffmpeg -f flv -listen 1 -i rtmp://localhost:1935/live/app -c copy rtsp://YOUR_RTSP_HOST

Notes:

-listen 1 makes FFmpeg act as a RTMP server when used with RTMP protocol
Use rtmp://localhost:1935/live/app as the RTMP server url on the source
You can set any playpath rtmp://localhost:1935/any/thing and any port
The main advantage with this way is simplicity, the disadvantage is server stops if source stopped or had encoding errors
The other option is to use nginx with nginx-rtmp-module


If I delete a video from my computer after I've imported it, will it delete from the video I'm editing? If I delete a video from my computer after I've imported it, will it delete from the video I'm editing?

I've imported many video clips into a video project I'm currently working on (I'm using Vegas Pro 16). But I want to help clear up some space on my computer, so if I deleted those clips from their original location, would they still remain for me to work with in Vegas?

Thank you!

According to the on-line manual page 57 of this commercial software this is only true if you:

have selected the Copy media with project checkbox and
Clicked the Save button

for all your projects!
If you forgot to do that with just one, the answer is:

No, deleting the original file will delete it from all of the projects where you did not click that option.


How to work with desqueezed anamorphic footage in FCPX I have footage from an Array Alexa Mini, shot with anamorphic lenses. The footage was desqueezed in camera, so the resulting video resolution is 2944x2160. The codec is Timecode, Apple ProRes 4444, and the color profile is HD(1-1-1)
2944x1260 does not appear to be a standard format and I'm unsure how I should be working with these clips in FCPX.
I also need to sync up audio and video. When I try to synchronise clips, the automatic settings are:

720p HD 1280x720
Rec 709
automatic Audio Properties

Which seems too low a resolution to me. When I look at the options in custom settings, there is no format that matches the resolution of the source video.
So my question is, what setting should I be using for my synchronised clips and project?

Create a new library and then click on 'New Project'. Here you can change the format to any resolution you want.

In the sync dialogue your can also set a custom video format.


Can't browse Photos library in Final Cut Pro X I can't browse the Photos library from within FCPX. It just says "Open Photos to see your photos in this list". Yes, I've closed and reopened both Photos and FCPX.

I had everything working, but now I'm using a different Photos library on a different harddrive, and it has stopped working as before.

Any ideas?

In the Photos app (not FCPX), go to Preferences, then click "Use as System Photo Library". Then FCPX will be able to find the library file.


How to convert Dolby Vision HDR to HDR10+? I'd like to convert a file recorded from an iPhone 12 to a royalty-free version (for upload to Wikimedia, Flickr, etc). So the transfer involves:

Source (iPhone proprietary-encumbered)
Destination (royalty-free)

4k 60fps (UHD, not DCI)
4k 60fps

BT.2020 in HLG (WCG)
BT.2020 in HLG (WCG)

Frame-level dynamic HDR metadata in Dolby Vision profile 8.4
Frame-level dynamic HDR metadata in HDR10+

HEVC
VP9 (open to AV1 as well but that's likely more nascent)

Bitrate is 31 Mb/s
Fine with higher bitrate to maintain same SSIM/PSNR

Audio is in AAC
Audio to Vorbis/OGG

According to https://codecalamity.com/encoding-uhd-4k-hdr10-videos-with-ffmpeg/ it should be possible to do most of this.
Anyone can help me cook up the right command for this?

Sadly no, not without expensive specialist broadcast processing hardware.
From the Reddit link,

Dolby Vision is 100% proprietary. There is no incentive at all for
Dolby to convert anything to HDR10+ to help out Samsung users (and
pre-2019 Panasonics) when the only reason HDR10+ exists is because
Samsung didn’t want to pay Dolby for the license.
Dolby Vision is simply an enhancement layer on top of HDR10 which is
the base layer. There are a couple types of DV layers. The MEL
(minimum enhancement layer) and the FEL (full enhancement layer) which
reconstructs the original 12-bit signal. The FEL is what gives DV a
large advantage over HDR10 and HDR10+.
Page 12:
https://www.dolby.com/us/en/technologies/dolby-vision/dolby-vision-for-creative-professionals/dolby-vision-uhd-bluray-authoring-workflow.pdf


Presentation techniques for YouTube I watched some videos on YouTube and for not being professional in the area, I would like to know how I could denominate the track that shows the name of the presenter?

Is there a technical name for this kind of presentation?

In Russian we have term for them — плашка.

English name I personally don't like — Lower third

I was making them in After Effects. With animations, dynamic text, etc. There is a lot of tutorial (example), how you can make one.
But I believe that without animations you can make them in a lot of other video editing apps. It is basically a type of Title (Premiere Pro). Or art with alpha channel in any software, which allow to compose picture on top of the video.

You can achieve similar result directly on YouTube with annotations. Similar to this answer. It will not look so good, but can contain text information.


FFmpeg encode variable input framerate I have a Qt application running, i hijack the openGL frameBuffer when a new frame has been rendered. A new frame is drawned when only some changes appear in the scene, so no constant frameRate.

Now i want to send those raw rgba pixels value to ffmpeg, I use this wonderfull link http://blog.mmacklin.com/2013/06/11/real-time-video-capture-with-ffmpeg/ to encode my input stream, but in the end i have a video where each frame has been concatenate with a constant time between each.

To clarify, if i am not updating my application for 1 sec, this halt won't appear in the final video.

I use this command line to encode:

ffmpeg.exe -f rawvideo -vsync 1 -pix_fmt rgba -s 1172x768 -i - -threads 0 -y -pix_fmt yuv420p -b:v 8000K -vf vflip output.mp4

and i write in to my stream with:

uchar* buffer = (uchar*)malloc(count);
fwrite(buffer, sizeof(char), count, m_ffmpeg);
fflush(m_ffmpeg);

I saw the vsync option, i use it with different values as output and input options, but it seems to have no effect.

I might be able to store the delta time in a .txt file if it can help.

When receiving frames from a raw input i.e. one without embedded timestamps, ffmpeg will assign timestamps in serial order, thus losing the temporal relation between the incoming frames.

When the difference in times is important, you can add -use_wallclock_as_timestamps 1 before the input -i. This will assign the system time at time of receipt as the timestamp. Not perfect, as there may be jitter during the transport of the input, but better than the default behaviour.

vsync is somewhat of a misnomer. It takes effect after filtering and is generally used to select between generating a constant (cfr) or variable frame rate (vfr) stream.


Compress or convert .mov to lighter format My camera records videos in .mov format, what can I use to edit out the audio and lower it's size in a Windows environment?

You didn't mention whether you're using a Mac or Windows, but...

You could use a tool like MPEG Streamclip to change the format of the video, or strip off the audio.  Works on both Mac or Windows.


How can I make a slideshow with ffmpeg? I have a certain number of pictures that I want to repeat until the melody ends. The problem is that when I make settings it does not work.
the process goes on forever

ffmpeg  -pattern_type glob -loop 1 -r:v 1/4 -i "folder/*.jpg"  -i "folder/voice.mp3" -acodec libvo_aacenc -shortest  -c:v libx264  -preset veryslow -pix_fmt yuv420p -b 20M -pix_fmt yuv420p  -y /folder.avi

Your ffmpeg is old. Update it before doing anything else. See FFmpeg Downloads for links to builds for Linux, Windows, and macOS.
Use -framerate instead of -r for input.
Change -acodec libvo_aacenc to -c:a aac. libvoaac_enc is a low quality encoder and support for it has been removed from FFmpeg.
Some players do not like a low frame rate. Declare an output frame rate with -r or the fps filter when the input -framerate is below ~5 fps.
Use -crf instead of -b / -b:v.
Output MP4 instead of AVI.

Example command:

ffmpeg -y -pattern_type glob -loop 1 -framerate 1/4 -i "folder/*.jpg"  -i "folder/voice.mp3" -c:v libx264 -preset veryslow -crf 22 -pix_fmt yuv420p -r 25 -shortest -movflags +faststart folder.mp4


what software & How to Synchronize sequence pictures with audio and make it a video just like gif image I recently went on vacation with my family, and while capturing pictures I took some in sequence like in burst mode, for example, I took 4 pictures while the person turned his head from left to right. When I view then in sequence it looks like stop motion.

The real question is, how can I make use of those expressions of the person and synchronize it to music, it should look like he is shaking his head back and forth  reacting to the music.

You can use pretty much any movie editor that allows the import of single frames.

First line up your audio, work out where you want the key frames to be (eg for reversing the movement when shaking the head) and then fill in the other frames.

If your editor allows interpolation between frames, then you can use this to make the movie less jerky.

Or you can use one of the free online gif creators to join your images into a gif and then import that into a video editor - slightly more effort, but not much.


Technique: remove background by combining two images? I have two videos - both are on a tripod, so they are locked in place. First video has an empty background (no people or objects), the second video has a person walking through the scene.

Is there a technique that allows me to combine the two images - have the empty background remove the background from the person walking through it - and only keep the person with a transparent background?

I believe the effect you're after is Difference Matte. Keep in mind your clean plate needs to be exactly the same, pixel for pixel, as in your shots. You'll likely need to do some manual clean up as well.


mov to mp4 conversion produces grainy results I am using handbrake to compress 250mb of 3d animation stored in .mov. This is how the mov looks:

The compressed version has some artifacts. Like it doesn't have enough shades of grey:

How can I avoid that? Should I render in a .mov file in the first place?

You are indeed right about shades of grey. You're encoding in 8-bit 4:2:0 (standard h.264 settings) which means that there are only 256 possible shades of grey. Think about it. If your RGB* values go from [0, 0, 0] to [255, 255, 255] and the red green and blue channels are equal, because grey, then your pixels will be one of these values: [0,0,0], [1,1,1], [2,2,2]… [255,255,255]. Meaning 256 possible colours.

If your gradient went from full black to full white and was 256 pixels across there would be one pixel per colour, so you'd be fine. But if it was say, 1024px wide, then there would have to be four pixels of each colour next to each other, meaning bands. And that's a gradient going from full black to full white—a subtle gradient from 45% grey to 55% grey might only have 25 possible values available–it's going to be banding city.

And just to explain what is going on in your image–especially in the middle–there's an unfortunate optical illusion that makes those bands super obvious, by making the squares where the same colour is repeated look like gradients going the opposite way.

Two possible workarounds:

You can encode using 10 bit h.264, but a lot fewer people will be able to play it back, and you'll need to get a 10 bit build of ffmpeg or x.264 (I don't know of any other 10-bit h.264 software)
You can add some noise. Sounds crazy, but it will break up the bands into fuzz so they'll be less noticeable. Justify it to yourself by believing it gives it a more filmy look. It's called dithering, it was a big thing back in the days of 8-bit colour.

*Actually it's YUV, but that's not important right now.


How to create simple animation with transparent background? I'd like to create basically a HUD (head up display) using simple animations.  The following are three different videos:

animated checkmark
animated circle
animated underline

Each video just draws out the symbol.  I'd like transparent backgrounds so these small videos can be used in other videos for effects.

As an example, in some video, I can introduce the animated checkmark.  You'll see the checkmark next to something I want to emphasize but everything under the checkmark (in the host video) is still visible (because of transparency in the checkmark video).

How can this be done in AE?  I'm not sure how to create a checkmark that basically draws itself out.  Are there any tutorials (youtube) that show something like this?

All of the animations you want to do there are achievable with masks and the Stroke effect.

I suggest you start to generally learn to use After Effects, these are very simple things you want to do there and you shouldn't need any tutorial once you understand the very basics of After Effects.


Downloading earlier segments from a live m3u8 playlist I have an .m3u8 URI of type LIVE. As far as I know, live playlists use a sliding window instead of containing all the segments. My questions are,

1) Is it possible to find out what the length of the window is (time or frame-wise)? My intention is to use the playlist I have to download a live-stream starting from an earlier time.

2) If yes, how do I get the earlier segments, i.e., how do I specify where I want to start downloading from? I tried something like ffmpeg -ss -00:00:10 -i "in.m3u8" out.mp4, but it did not work.

I do not have much experience in video-encoding or live-streaming, and I would appreciate any direction!

You need to download the m3u8 itself, look at the entries and see if the individual TS filenames are entirely regular i.e. no signatures which vary with each entry, and the varying elements that are present can be deduced.

If so, then simply work backwards i.e. if the playlist you download has entries file_03532.ts, file_03533.ts, file_03534.ts..., then file_03529.ts, file_03530.ts, file_03531.ts.. would be the earlier entries. You can then use a download manager that lets you download a list of filenames generated using a pattern. IDM does this. There's probably others.


How to use the frame at 5s and replace all frames before it using ffmpeg? I have a video file a.flv. I want to use ffmepg to edit it. As I understand, each second of the video is a series of frames. What I want is to take the first frame of the fifth second and replace all frames before it. So the result video has exactly the same video data from the beginning to the first frame of the fifth second. Is it possible to do this using ffmpeg?

You can use a combination of the trim and tpad filters for this.
ffmpeg -i in.flv -vf "trim=4,setpts=PTS-STARTPTS,tpad=start_duration=4:start_mode=clone" -c:v libx264 -c:a copy out.flv


Connect GoPro Hero 7 Black to Macbook Pro 2017 via USB-C I have just bought a Hero 7 Black, which sports a USB-C port. I can use it to charge the battery etc. but I would expect it to also allow me to connect to another device, like my MacBook Pro, with a USB-C port.

I have tried a few configurations:

a few USB-C to USB-C cables, including one with Thunderbolt 3
the USB-C to USB-A cable that comes with my GoPro, and the USB-A side goes in an adapter that is then connected via USB-C to my Mac (works with a lot of other devices, so the adapter is fine)

No matter what I do, however, the only thing I succeed in doing is charging the camera.

Do GoPros support a direct USB-C connection to another device?

According to page 61 of the Hero7 Black manual, you can transfer files to your computer using USB-c.  The manual only mentions being able to do this with the Quik application on your computer.  Most likely your computer is missing the drivers necessary to exchange data with the camera due to either not using or not installing this application.


Does version control have a part in the video production workflow? I'm a software developer and I'm also interested in photography (for four years) and video production (for a few months only).

■ In software development, there is an important rule every developer follows on every project: everything should be under version control: source code, configuration files, database schema, documentation—everything which enables building the project from scratch. This has two pleasant consequences:

In an event of a disaster when you lose everything except the version control repository, you should be able to continue as if nothing happened.
In an event of some stupid change which negatively affects the project, the developer can come back to an earlier revision.

■ In photography, every change I make to photos is stored forever in Lightroom catalog, making it possible to revert to previous state at any moment. With virtual copies feature, Lightroom also enables to do what is called a branch in version control: the ability to test something different, and either keep both results or remove one of them later.

The catalog doesn't store the RAW photos themselves, but they don't change anyway.

■ In video production, things seem different. I work with Premiere Pro, After Effects and Soundbooth.

None seem to store history permanently: if I do an action by mistake and notice it only the next day, there is no way to recover the previous version.
Soundbooth also changes directly the WAV files, which requires an additional effort to keep separate the original recordings from the modified ones.
Version control is rarely mentioned, and I haven't found anyone telling how does he actually use version control in his workflow. Moreover, nobody mentions which version control should be used, and since most version control systems are optimized for text files, not binary ones, this creates an additional challenge.
Video.SE doesn't have version-control or revisions tags.

Thus, I have two questions:

Does version control have a part in the workflow of a person who works with video production? How is it integrated?
Would migrating to Adobe Creative Cloud help? Are there specific features which allow, in Creative Cloud, to track successive revisions of a Premiere Pro or After Effects project?

Remark: to avoid off-topic answers, I highlight that my question is unrelated to the backups, and is specifically about storing successive revisions of my work, not having an on-site/off-site backup of the data.

Version control in the sense of Git isn't very practical in the video world. You would need to make a specific version control tool for every audio and video tool out there as all work with their own project formats.
But being able to read these formats is just one thing, then you also need the render engine of that tool to show diff's.

Though all of these tools work in a non-destructive way unless you pre-render some stuff (compare that to compiling a dll/lib of a piece of your code and work with that from now on), so you ususally can just go back to an old revision by doing ctrl+z or using the history tool in some programs.

Though saving sub versions is usually the way to go. Like stib described in his answer or by doing it manually.

Something I like to do and works well with every software is putting my project files (no source footage) into Dropbox. If you have a somewhat fast upload speed (~1 Mbit/s) and your project file isn't 100MB+, you can upload your project before you save the next time. An average Premiere/AE/FCP project is around 10-20MB so your recently saved files will be uploaded in 1-2 minutes. Even faster if you have more upload bandwidth.

Then if you have to go back you can access Dropbox's history of your files and download or restore to that revision. Dropbox saves file revisions forever* on a paid account (*atleast when they had the pack rat option, now its a year I think) and for 30 days on a free account. I'm sure that there are other cloud hosters that offer similar features.
It's a bit like using a super limited version of git that handles binary files very well and is headache free.
This has the advantage that you don't clutter the folder with tons of files and have a backup at the same time.

Most cloud hosters also offer Team Memberships so you can work with multiple editors. Or you share the project folder with other team members.


Testing DaVinci Resolve on the cloud My computer is too old to run DaVinci Resolve, which hangs upon installing. I want to try the Chroma key feature of DaVinci and found this tutorial for launching a AWS EC2 instance running CentOS and installing DaVinci, TigerVNC, connecting to S3, etc. It seems too complicated for what I want, which is simply upload a clip, chroma key the green screen, and export. This case study sets up cloud post-production for a feature film and seems even more complicated.
What is the easiest way to test DaVinci Resolve on the cloud, with any cloud provider?

I would find a cloud provider that can offer full VNC access to dedicated hardware... Even so, your experience is going to be pretty unpleasant unless you've got a really fast connection. Latency is going to make it really fiddly to go frame by frame, and most VNC connections reduce the colour depth to a point where it's hard to tell what's going on.  I guess you can render and look at shots, but it's going to be laborious.


Trimming audio source in Adobe Premiere I want to actually trim out part of my audio in source window. I don't want a sub-clip which seems to be linked to actual full source audio, but rather to modify the source buy cutting out unnecessary part of it. Cannot find the tool to do that.

Adobe Premiere is Non-linear editing application. Any changes made in it don't have any influence on footage on your hard drive. Not audio, not video.

It is feature, which prevent damaging footage files.

It is based on trimming, not cutting. However, if you really want it, you can trim your audio, export it from Premiere, and then import back. But I can't find any reason, why you can need that.


How can one remove an image from a screenshare recording? I have a  screenshare recording: this is a typical academic presentation where some speaker  talks over a sequence of several slides. The video only shows the slides (screenshare). One slide contains an image for which I don't have the license.  How can I remove this image from a screenshare recording?

One way to do it is to overlay the relevant part of the presentation with another image (could be a blank image). This is called picture in picture, which is often used to overlay another video across part of a background video, but of course the same principle works for still images too.
You need a video editor that offers such a feature, any professional editor can do it and probably many free editors too.
Basically, you have the presentation video as one track and add the replacement image as a second track above it with the duration limited to the time segment where the problematic image is shown. This overlay track will hide the underlying image. You can resize the overlay image, so only the relevant portion of the presentation is covered.
The exact steps depend on the video editor you want to use. If you don't have a video editor yet, you could try the free version of DaVinci Resolve and check out YouTube tutorials on the picture in picture topic to see how it's done with this editor.


What does the Multi-Camera Record On/Off Toggle do in Premiere Pro? My experience
I'm currently creating a multi-camera sequence in Premiere Pro CC 2020 14.1.0 (build 116). I created my multicam sequence and everything is working fine.

When I press play, my sequence start playing and I can than switch between the multiple angles by clicking on a different angle or by pressing 1, 2 or 3 on my keyboard. After I've done that once I notice that the rectangle around the active angle becomes red and that the record button, the Multi-Camera Record On/Off Toggle, has a blue circle around it.

If I than pause playback, a cut has appeared in my sequence on the position where I switched angles, as expected. The rectangle is yellow again and the circle around the record button is gone. Everything works. But than what happens if I press this record button?

If I press it before I start playback, a blue circle appears around the button. If I than move my playhead the circle disappears. If after clicking the button I start playback or choose a different angle, the circle stays, but it doesn't appear to change the recording behaviour of the angles I can switch to at all.

If I press the record button during playback, but before I switched to a different angle, it makes a blue circle around the button appear. The rectangle around the active angle stays yellow though. I can than still switch to different angles and the switches I make are being recorded as usual.

If I press the button during playback after I switched to a different angle, the circle around the button disappears, but more noteworthy, the red rectangle around the active angle becomes yellow. If I than pause the playback, the angle switch is still recorded however. Once again this button doesn't seem to have any impact at all apart from UI appearance.

Research
I searched the web, checked multiple tutorial video's, searched Reddit, but no one mentions this button.
I searched this site and I found someone in 2015 mention this button in an answer. This user describes the button as a way to Toggle Multi-Cam recording. I believe he sees the pressing of this button as a required step before the angle-switches are recorded, however, as I described above, this doesn't seem to be in line with the behaviour I'm experiencing.
Over at Adobe's help website, there also is a tutorial that mentions pressing the button as a step in the Multi-camera editing workflow (step 6). It doesn't state though what the exact function of the button is.
My question
Could someone shine some light on what the purpose of this button is? Or to word it differently, what difference is there between state A and B?

The record button has three states:

Record is disabled
You're not selected on a multi-camera sequence, or you haven't enabled the Multi-camera View button, so you can't record camera cuts. (You can still change camera on a selected clip).

Record standby
If you have a clip selected, and select a different camera, the whole clip will be changed to the new camera. If you are playing a multi-camera clip, in multi-camera view and change cameras, the changes will be recorded as cuts, nothing will happen.

Record enabled
Does exactly the same as record standby, as far as I can tell.
At this point, I think the blue circle must only be there because they though it looks nice. It's like the close button on an elevator door....
The rectangles around the multi-view cameras show:
yellow - which cut is active
red - a new cut that you have just written
As soon as you stop playback, the red rectangle highlights become yellow highlights.


Delta Keyer not working with Clean Plate In DaVinci Resolve 16, in Fusion, I'm creating a Clean Plate and routing its output to a Delta Keyer to remove the background. While the Clean Plate works well, the Delta Keyer is not doing what I would expect (i.e. remove everything in the Clean Plate).

See screenshot below. What am I doing wrong?

With one exception (Garbage Matte), the Delta Keyer doesn't "remove" things.  What it does is create and/or apply masks and mattes so that keyed areas can be replaced by other things (either within the given Delta Keyer node or downstream in the Fusion composition).  Therefore, to get an effect you want, you need to provide the Delta Keyer with an image or a solid color that you want to use to replace the area of the key you have defined.


How to trim, crop, and concatenate a reverse into video at the same time I am using ffmpeg to first trim and crop the video, then take the output and concatenate a reverse of that onto the video. The way I'm doing it now requires me to run two commands. Is there a way to simplify it into a single command?

Currently, I'm running
        ffmpeg -i MVI_0289.mov -ss 00:00:10.50 -t 3 -vf "crop=720:720:600:80" -movflags +faststart -an OUTPUT.mp4

and then
        ffmpeg -i OUTPUT.mp4 -filter_complex "[0:v]reverse,fifo[r];[0:v][r] concat=n=2:v=1 [v]" -map "[v]" OUTPUT2.mp4

Update#1: Running ffmpeg -ss 00:00:10.50 -t 3 -i MVI_0289.mov
-filter_complex "reverse,fifo[r];[0:v][r] concat=n=2:v=1,crop=720:720:600:80[v]" -map "[v]" OUTPUT2.mp4
 gives the following error:
ffmpeg -ss 00:00:10.50 -t 3 -i MVI_0289.mov
ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers
  built with Apple LLVM version 9.0.0 (clang-900.0.38)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-ffplay --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libavresample   3.  7.  0 /  3.  7.  0
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MVI_0289.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 537331968
    compatible_brands: qt  CAEP
    com.apple.quicktime.make: Canon
    com.apple.quicktime.model: Canon EOS 70D
    com.apple.quicktime.rating.user: 0.000000
    creation_time   : 2017-12-09T23:42:21.000000Z
  Duration: 00:00:19.19, start: 0.000000, bitrate: 25320 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc, bt709), 1920x1080 [SAR 1:1 DAR 16:9], 25277 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 48k tbc (default)
    Metadata:
      creation_time   : 2017-12-09T23:42:21.000000Z
      timecode        : 00:16:56:04
    Stream #0:1(eng): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
    Metadata:
      creation_time   : 2017-12-09T23:42:21.000000Z
      timecode        : 00:16:56:04
At least one output file must be specified
-filter_complex "reverse,fifo[r];[0:v][r] concat=n=2:v=1,crop=720:720:600:80[v]" -map "[v]" OUTPUT2.mp4
-bash: -filter_complex: command not found

Run

ffmpeg -ss 00:00:10.50 -t 3 -i MVI_0289.mov -filter_complex "reverse,fifo[r];[0:v][r] concat=n=2:v=1,crop=720:720:600:80[v]" -map "[v]" OUTPUT2.mp4


After Effects: Increment a Variable over time I have following problem:
I am trying to tweak the speed of a Math.sin function. Therefore I need a variable that incerements over time with a combination of a keyframed speed variable.

Sounds complicated, I know.

Let's say I am using the global time variable and convert it with the timeToFrames() function I get an integer value for each frame.

myTime = timeToFrames(time);

This leads me to a value of 1 for Frame 1, a value of 2 for Frame 2, and so on.
But what if I want to manipulate the increment. For example:

//speed (gets tweened from a certain value range,for example: 10 - 1)
s = (some connected slider here)

myTime += s;

If I have a speed of 10 at Frame 1 I would get a value of 11. If I have a speed of 8 at Frame 2, I would expect a value of 11 + 2 + 8 = 21.

What I get is only 2 + 8;

So I need to store the value at every frame. Is this possible?

Please help.

You can loop over the range of frames from the start of the comp to the present and calculate the value along the way.

function myFuncf(theTime){
 //whatever the function you're using to create the value, e.g.
 t=theTime + s.valueAtTime(theTime); //s is the slider
 return t
}

firstFrame = timeToFrames(inPoint); //if you want it to calculate
                                    //from the beginning of the comp
                                    //change this to 0, or maybe 1?
                                    //I'd check but I'm rendering ATM

mytime=0; //initialise the mytime variable

currentFrame = timeToFrames(time);
for (int i=firstFrame; i <= currentFrame; i++){
  mytime += myFunc(framesToTime(i)); //need to convert frames back into seconds
}

after the loop myTime should be the sum of the results of function myFunc from all the previous frames up to and including the present one (I'm not 100% sure if the loop should end when i < cf or i <= cf, you might want to test).

note first time I posted this there was a mistake. Where I called the function I was giving it frames (from i the loop variable), but it uses valueAtTime which expects time in seconds, so you need to convert: mytime += myFunc(framesToTime(i));

If you have a long comp or this is applied to lots of layers, this expression may become slow to evaluate and cause lagginess. If it becomes a problem convert the expression to keyframes.


Merging two videos with hstack and play them back sequentially I am merging two mp4 files using hstack. I am using amix to merge the audio. Everything works perfectly.

Now I want that the hstacked videos should play sequentially, that is one after the other. Here is what I have done

ffmpeg -i left.mp4 -i right.mp4 -filter_complex [0:v]setpts=PTS-STARTPTS[l]; [1:v]setpts=PTS-STARTPTS+14/TB[r]; [l][r]hstack=inputs=2[stacked]; [0:a][1:a]amix=inputs=2[a] -map [stacked] -map [a] -c:a aac -preset superfast result.mp4

In the above example, I tried to delay the play back of the video on the right by 14 seconds (which happens to be the length of the left video). In essence I want the left video to play first and after it finishes the left video should play.

What I am getting instead from the command is, the left video remains still for 14 seconds with only displaying the first frame (the audio plays) and after 14 seconds the right video plays.

I am at my wits end trying to figure it out. What am I doing wrong ?

The h/vstack filters are designed to pair frames so they will hold the first frame of an input if the other input isn't active. Use the tpad filter to add blank frames for the required duration.

ffmpeg -i left.mp4 -i right.mp4 -filter_complex [0:v]setpts=PTS-STARTPTS[l]; [1:v]setpts=PTS-STARTPTS,tpad=start_duration=14:start_mode=add:color=black[r]; [l][r]hstack=inputs=2[stacked]; [0:a][1:a]amix=inputs=2[a] -map [stacked] -map [a] -c:a aac -preset superfast result.mp4

If you don't have the tpad filter available, a slightly longer approach is to use the drawbox filter with ffmpeg 4.0+.

ffmpeg -i left.mp4 -i right.mp4 -filter_complex [0:v]setpts=PTS-STARTPTS[l]; [1:v]setpts=PTS-STARTPTS,split[rb][rv];[rb]trim=0:14,drawbox=t=fill:c=black[rb];[rb][rv]concat=n=2:v=1:a0[r]; [l][r]hstack=inputs=2[stacked]; [0:a][1:a]amix=inputs=2[a] -map [stacked] -map [a] -c:a aac -preset superfast result.mp4


Fast forward the timelapse vedio clip I created a timelapse video from iMovie software and set the time to 0.1 second for every image. But the final output is not satisfying. It seems a bit slow video. I need the clouds to move faster, but they are moving slowly. It is total of 30 second video. I need it to be 15 second video, so that I can get a desired effect. But I cannot change the setting lower then 0.1 second in iMovie. Any suggestions?

In iMovie you can change the speed of a clip by selecting it in the timeline and then clicking on the icon that looks like a speedometer:

Then click on the "Speed:" popup menu and choose "Fast" or "Custom". The "Custom" setting lets you choose how much faster to make it (like 200%, or 50%).


Free songs for video production I would like to make a video with songs in the background. I'm mostly interested about classic music, but other genres as well. I know of Creative Commons. However, I was wondering if there are recordings of famous songs available for free (perhaps, old recordings?).

You can download royalty-free songs for video production or poems free for video production. It is no charge


How can I import subtitles/captions into a letterboxed video like this? How can I easily create captions that look like this?

(Click to see a video that shows a good example.)

I have a video that is 1280 x 720 pixels but converted to a square of 1280 x 1280 pixels so that there is empty space above and below.

Using Adobe Premiere Pro CC 2017, I've then added a "Default Still" Title to the top.

Given an .srt or other file of captions, how could I import them to be shown in the bottom band of the video at the appropriate time?

I want them "burned in" so that they are always visible regardless of the device used to play the video.

(So maybe they're called "open captions" instead of "closed captions".)

I want to be able to choose the font style and size.

I want to avoid creating a "Default Still Title" for each sentence of text manually—that would be a lot of hassle for a long video.

I have Adobe Premiere Pro CC 2017 but could buy other software if necessary or could use ffmpeg if that is capable.

You can use ffmpeg. Make your subtitles with Aegisub or manually with a text editor. ASS subtitles are fancier, but SRT are simpler if you want to manually make them.

Alignment & Margin

The default settings will likely work, but you can control the general location, or alignment, using the "keypad" coordinates. For example, 2 is bottom center. For more granular control you use the vertical margin. In Aegisub these options are available in Subtitles > Style Manager > Edit.

You can also choose the font and font size in this screen.

ffmpeg examples

Now run ffmpeg with the subtitles filter to make your hardsubs:

ffmpeg -i input -filter_complex "subtitles=subs.ass" output

Or if you want to avoid using Aegisub you can use the force_style option:

ffmpeg -i input -filter_complex "subtitles=subs.ass:force_style='Fontname=Arial,Fontsize=20,Alignment=2,MarginV=10'" output

Resulting in:

If you do want to use ffmpeg make sure to output from Premiere using a lossless format, such as UT video, because ffmpeg will re-encode it which is required when filtering.


What software can we use to create this slideshow video I am trying to create this video using adobe premier pro.

In each slide, I will have 3 different images slides in with different effect and timing.

However, it is a bit complex for me and I found difficult to change photos in slide, as I need to cater the motion effect, size, of other two images in the timeline.

I had tried window movie maker, it is very simple but it seems that it only allows transition of one whole image. I can't freely adjust the 3 different images to slide in with different angle, speed, stay on time, and fading effect, and stay on one screen.

May I know is there any other software that can produce the similar effect as in the video?

You should give a chance to Sony Vegas 8 or newer. In Sony Vegas you can place as many images as you wish and make it "fly in" or "fly out" over a background which can be a solid color, gradient (both self-generated) and/or a background image.

The process itself is quite easy. You set the background in the timeline for the duration that you need. Then simply add as many tracks as you need for each image that you wish to get animated over the background, place the item in the timeline, enter the "Pan and Crop" function of the timeline and create the movement that you wish.

See this video for a comprehensive explanation about the Pan and Crop function in Sony Vegas.

In Sony Vegas you can create per-track and/or per-event motion by using the proper tools.

If you are using Linux you may find KDEnlive as a good alternative for Sony Vegas.

Good luck!


Is possible to use ffmpeg to capture directly a DSLR streaming via USB? If i have an high end Canon or Nikon camera is possible to do what eos_movrec do but with a better quality? Could be useful to use this for streaming or recording purposes.

And in case of something available, is also possible to tune the config on the fly?

You can capture a live-view feed from your USB-connected Canon DSLR with gphoto2 (param: --capture-movie). The biggest limitation here is that the resulting mjpeg stream resolution is 1056x704, and that's the highest possible quality via USB. This mjpeg stream can be piped to ffmpeg. As an alternative, you could get yourself an USB<>Mini-HDMI recording dongle (e.g. "Elgato Cam Link"), this will give you a FullHD (1920x1080) resolution and you can use your Canon DSLR like any USB webcam, which can also be piped to ffmpeg.


Pixelate effect when converting MOV to FLV via FFMPEG I have a .MOV video -created with Final Cut Pro 7 - which I'm converting to .flv using FFMPEG. I'm very happy about the quality and the size of the output file, but whenever I have fade in/out transitions in the input video, I get a pixelate effect on the output file. Any advice on how to solve this, without increase too much the output file size?

FRAME_SIZE=720x576
BIT_RATE=1200k

ffmpeg -s $FRAME_SIZE -i $1 -g 250 -ar 44100 -deinterlace -b $BIT_RATE -minrate $BIT_RATE -maxrate $BIT_RATE -bufsize 10000k -qblur 0.3 $2

Where $1 and $2 are, respectively, the input and output file.

You should explicitly specify a video codec using -vcodec as well as quality settings.

The problem is that ffmpeg's defaults aren't very sensible when you only specify a container format for the output, often choosing a sub-standard video format by default.

If you want H.264 output, try using the presets, e.g. -vcodec libx264 -vpre max. (To see what presets are available, try ls /usr/share/ffmpeg/*.ffpreset.)


Need help finding plugins/techniques to recreate my magic system in After Effects This is my first time posting, but i'll try to stay concise
For the last 5 days, I've tried recreating my magic system in After Effects in order to make a guide explaining how it works. Because understanding the aestethics of my magic is important to this topic, i'll quickly talk about it:
The Logos is the art of drawing 3D objects using dots and lines. Pretty simple right? Well, here are some rules about the drawing:

First, you need to have a bunch of small, blue, semitransparent circles called Logya.
Then, you can connect the dots with blue lines, which is what allows object creation.
Every time you form a closed shape, a solid semitransparent layer forms. This lets the user create solid items like swords and shields.

In my guide i want to show off the two ways my magic system can look (a sword and a bunch of particles moving around), but i've had varying degrees of success on each. After a bit of googling, I found a plugin called Trapcode Particular that perfectly suited my needs for creating the particles and this is what i managed to create with it:

Unfortunately, i didn't have the same luck with the sword. My friend drew a sword for me to base myself, but as you'll see i wasn't able to replicate the desired effect.

I found a plugin named Plexus that excels in creating dot and line graphics, but one of the problems i found was that it lacked flexibility, seeing that i couldn't chose which lines connected to which dots or where i wanted the dots to spawn.

I created a mask and added the effect on top, but i could only 'fill' the mask's outline by creating a ton of dots and lines that i didn't want. The closest i got was creating a small trapezoid with my hands using motion tracking:

Note the semitransparent layer, the blue dots and lines that my system requires. However, there are still way too many lines for a simple trapezoid because i can't decide where the lines appear, same thing for the layers.
I thought of creating a bunch of dots and simply connecting them with lines, but i wouldn't know how to add the blue layer. That being said, i would appreciate any advice or links to techniques/plugins i could use to help me out!

I think you might be better off building the mesh for your sword using a 3D package, like Blender, Cinema 4D or Element 3D from Video CoPilot. Building hundreds of Beams can be very time consuming, and a true 3D renderer might be easier to achieve the look you're going for.


Typical size of one hour long mp4 video What is the typical size of a mp4 video, size 1280x720 encoded by ffmpeg libx264, and lasts for one hour? Currently my file is around 700Mb, is it too much?

There is no "typical" size.  It depends entirely on the quality level and level of motion in the video.  I could encode ten hours of video where there is no movement with very little space since the compression would work very well.

On the other hand, if I had a video where every frame was completely different from the last, it would take a huge amount of space to compress it with any kind of quality being left over.

Using Youtube as an example, uses a data rate of 2megabits per second for 720p video.  An hour of video has 3600 seconds, so that's 7200 megabits, which is 900 megabytes of video.  Bluray disks on the other hand often use much higher rates, such as 10 or even 25mbps which would take 4.5 gigabytes and 11.25 gigabytes respectively.

As you can see, there isn't a "standard" size and it can vary by orders of magnitude.  The best bet is to compress it to whatever level you need and see if the quality is sufficient for your purposes, though 700 megabytes for an hour of HD video is already pretty small.  Compressing further from such a highly compressed source is likely to obtain sub-standard results at any quality level.


Can I use Garageband on Mac to add harmony audio to a video? I'm thinking...
Import my video of me playing guitar and singing, into Garageband.
And then add new Garageband audio track with my backing vocal harmony.

Will this work?

If you're singing on the new track(s) you've added, definitely!  I've done it myself. You can even pan the new track(s) left or right to give your song more "space".

If you were thinking you'd duplicate your audio track in Garageband, and change the pitch of the new track, it's harder. Your harmonies probably won't stay the same number of half steps away from the main melody, so you'll have to adjust the pitch change on most notes. (As far as I know.)


FFmpeg: Getting this error while trying to add a logo to video (Unable to find a suitable output format for ..) Hey guys I want to add a logo to my video with ffmpeg but I am getting this error while running the below command. What is the reason? Please do help.
`Unable to find a suitable output format for 'overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01)' overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01): Invalid argument.`

I am using python subprocess to run ffmpeg commands.
subprocess.call([settings.VIDEO_ENCODING_FFMPEG_PATH, '-i', input_file_path,
                '-i', logo_path, '-filter_complex','scale=1920:1080',
                'overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01)',
                '-codec:v', 'libx264','-crf', '18',
                '-preset', 'slow', '-b:v', '1000k', '-maxrate', '2000k', '-bufsize', '2000k',
                "-pix_fmt", "yuv420p",
                '-codec:a', 'aac', '-b:a', '128k', '-strict', '-2', output_file_path])

Thanks

The entire filtergraph should be one argument.
'-filter_complex','scale=1920:1080[main];[main][1]overlay=x=main_w-overlay_w-(main_w*0.01):y=main_h-overlay_h-(main_h*0.01)',


Does anybody know any movies or stock footage with 1800's docks? For my school project I need footage of an 1800s dock with old-fashoined sailing ships at it. I've been searching for at least 2 hours already, but I found nothing useful. Does anybody know any good documentaries or movies that have footage of docks? Thanks!

so I wasn't able to find any footage from the 1800s (probably because video was very new and not too common back then) but I have found some old footage of docks which I think might be of interest.

London's Lost Docks DVD clip (1980s)

This is about a minute of a Documentary about the London docks and may be of use.

Britain's finest hours: The battle of Trafalgar

This is a recreation of a battle between the UK, Spain and France overseas in 1805.

Another video on the battle of Trafalgar and is using a game to try and recreate the visuals:

Lastly here is some footage from Liverpool docks in 1950

I hope this footage can help and if it doesn't I am sorry and I fully agree that finding the footage is hard XD

Have a nice day.


Audio can be heard only in VLC player, but not in the editor I have few files that I did retrieve from webpages, and saved as MKV files.

VLC play them without problems, but when I load the file either in the Windows video editor, or in Power director 13, the video play but there is no audio.

I am not sure why I can't even convert the file from VLC, since even using the conversion engine that is integrated in VLC, the resulting file has video but no audio.

My understanding is that if the video player can play it, then the system has the right codec, so why neither windows video editor nor Power director 13 are not able to play the audio?

.MKV files are not a friendly video format when working with NLE systems. And the non existent audio you're getting is probably due to the way audio  in .MKV files are wrapped.

I would suggest transcoding the .MKV file(s) to .mp4 if you're working with Windows Movie Maker. Alternatively you can follow this link for suitable formats: video files

A really good transcoder (free) is adaptor. It will read your .MKV file without problems and should convert to a .mp4 file just as easily.

Be sure to crank up the bit rate to get the best possible picture :)


Is there any similar function of photoshop " Actions .atn" in adobe after effect? I specifically looking for a plugin or function in After effect that is similar to photoshop actions " .atn" that allow me to record and play sequence of editing i recorded to apply with a one click play like button in Photoshop.

There is no Action function in Adobe After Effects. You would have to write a script to do the sequence for you.

I'm not versed enough to tell you if there's a Plugin or not.


Multiple Channels vs Playlists on YouTube Is it better to have multiple YouTube channels, effectively targeting specific audience for wildly different topics but also spreading the total subscribers thin, or to have multiple playlists all on one channel regardless if playlists have absolutely nothing to do with each other?

Additionally, if you have subscribers across various channels does YouTube count them cumulatively towards monetization?

Generally, you are much better having one channel and placing all your videos into this single channel, with different playlists targeting the different audiences.

However, I'm assuming the videos are somewhat related. If they are on completely different topics (for example Gardening and Software Programming) you may find that it's better to separate so the subscribers don't get overwhelmed by videos in the wrong category.

If perhaps you have a brand, say a magazine (Home World, for example) and you have separate categories (Home World: Gardening and Home World: Decorating) I'd say stick to a single channel for branding purposes.

And to answer your final question, no, generally YouTube will treat separate accounts as separate entities for the purpose of monetization.


Http Live Streaming for beginners I'm new to live streaming and it's quite hard to find good information for beginners. Could anyone recommend resources to HLS besides Apple's documentation?

I'm trying to make an app similar to LiveStream where videos can be broadcasted to multiple users in real-time.

I've run into some services like encoding.com, heywatchencoding.com, and wowza, but I'm having difficulties with what each platform provides as the documentations for each seem to be for more intermediate/experienced users.

By any chance, do anyone of you guys know if I can use wowza with Parse.com services?

Thanks

I would suggest you research a bit further and then refine your question. To me it seems that there is a bit of confusion in terms of the software components needed for creating a livestream. First you need to have a software component that acquires a live video from some device. This video needs to be encoded. Once it is encoded it can be streamed by a streaming server. There are a lot of softwares or software as service, that can do that. Also you should figure out what streaming protocol you want to use (rtmp, rtsp?) and how many concurrent streams you need to have.

Some pointers to check out:

Monaserver
https://github.com/MonaSolutions/MonaServer

Ffmpeg streaming guide
https://trac.ffmpeg.org/wiki/StreamingGuide

Nginx rtmp streaming
https://github.com/arut/nginx-rtmp-module/wiki/Getting-started-with-nginx-rtmp


App to rotate .mp4 video for Windows or Android I have an .mp4 format video filmed in portrait format, when currently played on any landscape format device the people appear sideways.

I would like a sipmle app for either Windows™ or Android OS to only rotate the video so it plays 'portrait format' on any 'landscape format' device, such as a Smart TV.

Any suggestions ?

If I've understood you correctly, your video appears upright when viewed in portrait orientation and rotated in landscape. This suggests the image is stored in a landscape matrix but with no rotation tag set. If so, there are two things you can try using ffmpeg, a free command line tool.

ffmpeg -i input.mp4 -c copy -metadata:s:v rotate=90 output.mp4

If your landscape devices don't understand or obey the rotation tag,

ffmpeg -i input.mp4 -c copy -vf transpose=2 -c:v libx264 -crf 20 output.mp4

The 2nd command will re-encode the video portion of your file. CRF controls the quality - lower is better but will produce bigger files.

In the commands, you may have to switch the 90 with -90 and 2 with 1 depending on how the video was stored.


How do you install Adobe Production Premium CS5 on a different hard drive in windows? Is there a way of installing Adobe Production Premium CS5 on a hard drive other than C:\? I tried changing the install path in the installer but after installing parts of the program don't work and it can't find any plug-ins I add. I have windows 7.

After a lot of messing around I figured out how to get it to work and will post the answer.

The reason I actually want to do this is because my main OS drive is an SSD and there's not really enough space to install the whole Adobe suite on it.

After a long time of messing aroung I got it to work by tricking the software into thinking it was actually in the default location it likes at 'C:\Program Files\Adobe' by creating directory junctions. In order for it to work the hard drive must be formatted with the NTFS filesystem.

I used http://code.google.com/p/symlinker/ to create the directory junctions. You need to map the following folders to folders on the other hard drive you want to install the suite on. Run the symlinker software as an administrator.

C:\Program Files\Adobe
C:\Program Files\Common Files\Adobe
C:\Program Files (x86)\Adobe
C:\Program Files (x86)\Common Files\Adobe

Make sure that you select Directory Junction in the dropdown for type of link otherwise it won't work.

In the symlink program the box which says 'give a name to the link' is the folder name. So for example to set up the first path you would enter 'C:\Program Files' in the top box. Then 'Adobe' as the link name and then '[New Drive]:\Adobe From Link' (as an example) in the third box and then do the same for the other 3 and they all need to go to different folders.

Then when you've done this and checked that the folders are being mapped correctly you can simply install the adobe suite into C:\Program Files\Adobe (where it wants to go) and it will actually set itself up on your other hard drive.

I know it's not common to even think about putting it on another hard drive but I had to and I hope this will be useful if there's someone else out there that ever needs to and will save a lot of time!


Adding screen flash (Hitfilm 3 Express) I want to use some kind of effect, to make the video flash for a short time, when something happens. (Example for a gaming video, when you get a kill the screen should flash for like a half a second)

I am using Hitfilm 3 Express. So far i found an effect, which looks pretty good, but i have no idea how to make it look a little more smooth. Is there a way to use effects over time in Hitfilm 3 Express?

You need to switch to the compositing timeline in HitFilm so that you can animate your effect (using keyframes). There are 2 timelines in HitFilm - one for editing your footage and another for layered animation work.

It's worth watching the tutorials on the HitFilm YouTube channel here > https://www.youtube.com/user/FXhomeHitFilm

This specific tutorial explains the difference between the two timelines > https://youtu.be/bawBXIhMxsM

This video explains animating with keyframes > https://youtu.be/jEPm2FPMZI8

I hope that helps! :D


What portion of m2t video file size is audio? What portion of a video file is audio information? I have a large number of m2t video files where the audio is worthless to me. I'm curious if removing the audio portion from these files will notably decrease the file size. Could someone give me a ballpark estimate of how much this will decrease file size? For example, how much will a 5 GB m2t video file be reduced?

There are variables you don't mention, but you can make a quick estimate based on the video bit rate and the audio bit rate. With (say) 4800Kb/s video and 48Kb/s audio, the audio represents 1% of the file.


Crop video in ffmpeg without re-encoding I have videos I want to split across multiple screens, so the solution I've found so far is to just crop the input video 4 times with ffmpeg (is this optimal? Is there some other way so I only need to use one command?)

Anyways, in ffmpeg crop is a video filter, and it seems that I can't specify the video codec as copy when using a video filter. Why is this the case? It seems like nothing should change if I just remove some of the video. I should be perfectly capable of just copying the same video over, with just part of it removed.

Is there any way for me to do a crop in ffmpeg without having to do a re-encode? The extra encoding time makes my processing times really long and the new bitrates caused by the re-encode makes the video parts out of sync and unable to be played properly.

Thanks

A videofilter in ffmpeg always has to modify pixel information hence the reason why you need to re-encode.
It seems logical at first that you wouldn't have to do this when cropping but the way lossy video codecs work makes this pretty impossible without re-encoding everything.
They usually don't see an array of pixel information but a much more complex representation of pixel blobs that are described in a way that takes up less space than the original pixel blob, you can't really "crop" that encoding, to do a crop you would first need to decode the information to know what you are dealing with but then you need to re-encode to have it compressed again. Thats the main stepping stone.
Then they also use things like motion estimation that depends on information before and after certain frames, if that information changes all of the sudden the whole thing is screwed up and you end up with tons of artifacts when decoding the video during playback.

tldr; no its not possible to crop without re-encoding in any tool.

Unless you deal with some very specific lossless non-consumer intermediate codecs that would enable it but in that case transcoding wouldn't be an issue.


Effective working at audio/video editing sessions (avoid fatigue making steady progress) Background

I've just completed an editing project to produce video highlights of an awards evening for my local community radio station. It was a voluntary non-paid project and I'm very pleased the results I achieved - and more importantly, the station are very pleased with it too. But, as with many other previous projects, have found editing can be tiring at times. I have a full time job in computing but unrelated to video editing (funds all the software and equipment that I learnt this stuff on!) and usual housekeeping commitments so I had to produce this work from a number of sessions, some into the early hours. When I know I have to resume the work to get it done I procrastinate and do other jobs sometimes before I finally get in the zone, once in the zone I get frustrated when I have to stop to meet other commitments: sleep, work etc.

Any top tips to bear in mind for a future project?

OK, I'll have a go. Here's my own answer (and advise I should take for myself - which I actually did do to some extent):

Avoid procrastination. Start small. Start with doing something. Don't hold up too high expectations to put yourself off. Good ideas here: http://zenhabits.net/dead-simple-guide-to-beating-procrastination/ (I succeed a bit with this advice, BTW I have no affiliation to zenhabits)
Regularly deliver draft work in a complete state to the customer. This rewards you. It gives them confidence that this is being done. It gives them opportunity to give feedback during the process (to avoid unnecessay work or deviation or disappointment). It gives them something to do on in the event you are delayed later, due to illness or other commitments.
Take breaks.
Track progress to help predict how long the remainder may take.

I'd welcome anyone else's input. I'm really answering here because no-one else has yet. I'd welcome some enlightenment from your own experiences.


How to prioritize subtitles in LAV Splitter? I'd like to default subtitles to English [Forced] (refer to Image 1) in MPC-HC, using LAV Splitter (refer to Image 2).

Also, if it'd be possible, I'd like to set the default Audio Track to Japanese [jpn].

Thanks in advance.

Image 1: Subtitles:

Image 2: LAV Splitter Settings:

I've managed to ensure the subtitles prioritise forced, then to choose non-forced English as a backup using this:

*|f,eng*
However, this does not guarantee it will always choose forced English (assuming this is your preferred language). So to ensure that you will always get English, I have found this seemingly works consistently

eng|f,eng*,*|f
This checks for forced subtitles in English, if not found, it checks for non-forced English subtitles, if neither are found, it chooses the forced subtitles.
As for setting the default audio track to Japanese, I found adjusting the order to preference did the trick.

NOTE: This is not guaranteed to work for every file, there are many variations to the way subtitles are setup. I have just found this way to be the most consistent.
If you want to learn what these symbols mean I suggest studying Regular Expressions or Formal Languages, or straight up do an online course on Theory of Computing.


Can AviSynth handle MTS files? I want to process MTS (MPEG Transport Stream) files from an AVCHD camcorder in AviSynth. Displaying with AviSource() says that the file couldn't be opened, displaying with DirectShowSource() says that the format is not supported.

I found no information about MTS on the AviSynth wiki. The list of source filters has nothing on MTS or TS. I found a thread about MTS and VirtualDub but I would prefer dealing only with the source file instead of converting to another format.

Can AviSynth handle MTS files?

Use cross-platform wrapper library FFmpegSource (around FFmpeg) — particularly, its filter FFmpegSource2() (instead of built-in AviSource() or DirectShowSource()).

See AviSynth Wiki about it.


Is the RCA camcorder output analog? Bear with me because I am very new to this topic.
I saw a setup where someone was recording using two cameras and sending the output to a laptop. The camera output was sent via a three pin cable which I now know is known as RCA. These outputs were sent to something known as a selector which allows you to select the camera by flipping a switch.
When reading online I see that the RCA cable is used to transport an analog signal. But these camcorders also have HDMI output. Does this mean that the cameras can output either analog or digital signal?
PS. In the above setup, the output of the selector was sent to a device named ADVC-55. Reading online I see that it is used to convert analog signal to digital. The problem is that the video observed on the laptop monitor seems lower quality than what is previewed in the camera. Hence my question to understand if this ADVC-55 device is needed at all for this purpose or if there is a different way to get better quality.

The best way to answer this definitively would be if you know the model of the camera.
RCA cables from video cameras are nearly always analogue signals.
It is possible for a camera to have both digital outputs such as HDMI and SDI, and analogue outputs such as component or composite video from RCA sockets.
The analogue outputs are almost always standard definition (ie 480 or 576 lines of video).
HDMI outputs are usually high definition 1080 lines (or possibly 720 on older cameras, higher on newer 4K cameras).
If you are asking how to capture video from a camera with HDMI output in high quality into a computer with USB3, I would use an adaptor such as the Elgato HD60 S Capture Card.


How to align two videos from different angles of the same event I have two videos of the same event. You can see people walking, making the same moves, from a different angle. There is music playing.

Now I want to edit both videos in FCP 10.4.3 and fade from one video into the other. I'll use one audio track and mute the other. Video 2 starts later and ends earlier. Video 2 is layered upon (overlaps) video 1.

Is there a way to move video 2 relative to video 1 with keys instead of the mouse? I need steps that are just 1 frame.
Is there a way to see both layers at the same time, video 1 and video 2, to sync the steps?
Is there a way to sync audio while keeping the video in sync with the audio? Like audio 1 in left ear, audio 2 in right ear or something like that?

Maybe there are excellent tutorials for this, but I'm probably using the wrong words for searching. I can't find them.

Sounds like you should try Multicam Multicam workflow - Apple support.
The cut you make between both angles can be anything e.g. dissolve or blend.

To move clips with the keyboard you need to select it and type comma or full stop. FCPX keyboard shortcuts - Apple support


How to make a video where an actor writes facing the camera? I'd like to know how to produce this kind of instructional video, where an actor is writing on an invisible wall facing the camera:

Introduction to Limits (mathbff)

What equipment/tools and which setup is required to shoot this video?

You need a few simple things to do this:

a camera
a large piece of glass or plexiglass
dry erase markers
editing software capable of basic transform controls

Record your actor writing on the glass.  To the camera, the writing will appear backwards.  Use your editing software to flip the image horizontally.  The writing will now appear normal*.  Most editing software is capable of this operation.  If there's not a "flip horizontal" command, try setting the horizontal scale to -100%.

*Pro tip:  Make sure your actor's clothes don't have any writing on them, or it will appear backwards in the final result.


Are there any good video editing apps for photographers? Photo editing apps like Lightroom have very intuitive ways (my opinion, of course) of performing operations on pictures.

I occasionally do small video projects that I edit either in Sony Vegas on Windows or Final Cut Pro 7 on Mac. These apps seem pretty lacking in some areas, when compared to Lightroom. For example, there is no option to show the EXIF data stored in DSLR clips, as far as I know, so I can't easily see what lens I've used for this or that shot, or what the aperture, shutter and ISO was. White balance is done by selecting a white area of the picture, which is fine, but then there is no slider to go warmer or cooler, instead I have to do this by hand using the full blown color correction filter.

I was wondering if there are any video editing applications that have a digital photography friendly workflow. I don't have any constraints on operating system or cost.

I don't have any personal experience with video, but Neil van Niekirk, a photographer whose articles have thrown lots of light into my understanding of event photography, is using iMovie. Even though he wished for something more powerful 8 months ago, it seems to have remained his tool of choice so far. Armin Defiesta, formerly videographer, now mostly photographer, has written a comparison of iMovie vs Final Cut Pro X.

I suspect part of the learning pain comes from the fact that video processing tools are based on heritage of movie film processing, not evolved from photography tools. The terminology and primary controls therefore have been evolving independently.

About EXIF info - are you sure your clips contain anything relevant in the first place? Most video file formats don't have any support for that. See what metainfo your camera can show you about a recorded clip.


Adding voiceover without video recompression I have some mp4 video files with pretty poor video quality. I need to add a voiceover translation. I have seen some video software programs that could do the job but unfortunately most of these programs recompress also the video stream, so it becomes worse.

Is there any (preferably, free) software, which would allow me to remix only audio part of my mp4 files and leave the video stream as is, without recompression?

Yes, it's possible. What you need to do is demux and remux. Check out free tools like VirtualDub and Any Video Converter to split the original into separate streams, add what you want using Audacity or similar, then re-multiplex them together using a tool like AviMux. The video can remain unchanged.


I want to have multiple streams (up to 4) on one YouTube Live broadcast, Is that possible? I want to have multiple streams (up to 4) on one YouTube Live broadcast, Is that possible ?

It would be a news cast report with up to 4 reporters from separate locations discussing the weather.

you can use something like a M/E switcher with a multiviewer to do this. Just feed the program out into the computer you are streaming from using an input card.

I have not used youtube streaming, but I know that justin.tv or other streaming services can use something like OBS to switch between scenes which you can setup with different video inputs in different configurations on the stream.

As these all rely on having external gear to get the camera feeds to the streaming location, the google hangout solution would be the best, as I am assuming you are on a low budget


Video sorting workflow In windows 7, I used to use windows explorer to click on a video, press the play button, and decide if it was worth keeping. If it was worth keeping, I'd move it to a "use" folder.

However, Windows 10 explorer doesn't seem to support this play feature. Without this function in Windows 10 explorer, I have to open many videos in a media player to view them, find the filename of the one I'm viewing, then go back to explorer to move to the "use" folder.

1) I've looked for a way of re enabling this feature in explorer, but don't seem to be able to do this. Is it possible?

2) Is there other software that's a file manager and viewer combined? I can not seem to find one.

what you are looking for is a DAM (Digital Asset Management) software. There are many many options available some free some paid.

Most NLE's have this built in, again there are free and paid versions


How could I recreate this stroke effect in After Effects and/or Sony Vegas? In the many Red Dead Redemption trailers, they use this cool effect were paint/brush strokes somewhat pan into the actual game-play and overlay it with an awesome drawn out piece from the previous frame - what I am trying to do, is recreate just that.

An example is :

             at 0:11 and 0:17

It's a lot of matte painting.  While the video is still running, they animate a semi-transparent shape (probably made in Illustrator or something similar) and animate the shape in over it.  As soon as the painting finishes, they switch to a frozen shot of the last frame and seem to transition to the painted version of that frame.  It's hard to tell exactly from the Youtube video since I can't frame advance, but that should get the general feel of it.


How to do a video live stream through a VPS? I've been looking at a million resources and I can't find a definitive answer to this.

I'm looking to do a small scale (max 50 viewers possibly), low quality live video stream, with nothing but my existing equipment (mac and firewire camera), a low end ubuntu vps and free software. Stream from the mac and host the stream on a website on the vps.

I don't want to use services like justin.tv or ustream because the advertising is very intrusive, and I'd also like to learn how to do it myself.
I have some server admin skills, but this is a new world to me, and I can't make sense of how all the pieces fit together. I spent all night reading about rtmp, rec5, wowza, ffmpeg and now i don't understand anything at all.

Can someone give me possible workflows to piece the 3 parts together?ie, streaming from local computer, receiving in vps, broadcasting on website.

It varies a little from one server to another, but the basic components are an encoder/streaming client on the local client that takes input from the camera and turns it in to a stream that can be sent to the stream server on the VPS.

The job of the stream server (such as Red5) is then to provide a publishing point that relays the stream to viewers.  The streaming server can either pull from the client or the client can push to a target location on the stream server in order to provide content to the publishing point.

Each viewer then connects to the published RTMP stream on the streaming server and is provided with a copy of the stream that is being uploaded.  Note that every copy has to be sent out separately unless you are on a private network where you can use multicast, so bandwidth needs rise quickly, though it should be possible to do 50 SD or lower quality streams from a single VPS provided it has a reliable 100Mbps connection.

The website simply contains a viewer that hooks up to the RTMP (or similar) stream and is actually operating client side, not server side.

So to quickly recap, client uploads to back end of streaming server, streaming server replicates out to every viewer requesting to watch it and the web server simply gives users a client side viewer that connects to the video stream.

To briefly hit on what each one of the component you mentioned.

RTMP is real time media protocol, which is a common streaming protocol used for actually relaying the video stream content.
Red5 is a fairly popular free streaming media server software used for replicating out RTMP and similar media streams to clients.
Wowza is another streaming media server software, however it is a commercial, paid software product.  If you are limited to free software, Wowza is not an option.
FFMpeg is a popular open source video encoder.  It runs on the client and can be configured to publish a stream that can be sent to Red5 or similar streaming media server.

Additionally, you will need an end-point viewer capable of consuming the stream.  Software like Windows Media Player or Quicktime should be able to view a stream, but it is often best to include an embedded cross platform player in the website that people are going to for the stream.  There are many options for this component with different strengths and weaknesses, but any should work for your purposes.


Slowing down video vs higher framerate recording What is the difference between slowing down the video in software compared to actual shooting at higher framerate?

For example, i have a camera that shoots at 60fps and want to slow it down to achieve the same effect as when shooting at 120fps. What would be the differences?

By shooting at higher frame rate, you can achieve great looking and frame accurate slow motion. Interpolation is not going to happen. But if you want to slow down your footage beyond the frames you have, you can use the right tools in your video editor, or Twixtor plugin, but of course it will not give you as good results as a dedicated high speed camera. Absent frames are digitally interpolated. There are some more affordable Twixtor alternatives, such as Respeeder. These tools will give your video a smooth, high-frame rate look.


Why videos taken in the dark has color artefacts (noise)? can someone tell me, why videos (taken in low light place) has noise (or i dont know what to call that, the pixels playing/blinking continuously) , for example:

My questions are:

1) Why that noise is added at all? why cant the image could be static, i mean, where is black color, there should be black without noise...  (same for other colors...) why colors are not static and why this annoying noise is added?

2) is there any method in photocameras (mobile, CANON etc..) , to force camera to record without noise (like professional videocameras do)?

The noise in dim-lit environments is a result of how digital cameras work. The exposure of a picture or video depends on three essential parameters: lens aperture, shutter speed and ISO. The first two are about how much light falls on the camera sensor. The larger the aperture, the more light can enter the camera. The slower the shutter speed (i.e. the longer the exposure), the more light can enter the camera. ISO/gain is a digital amplification of the digitalised sensor signal By amplifying the signal, the camera can essentially make it brighter. However, the noise that is captured is also amplified.

What's important to understand is that if you were to expose a light and a dark scene using the same aperture, shutter speed and ISO, the dark one wouldn't have more noise than the light one, it would just be darker. The noise is a result of the camera increasing the ISO/gain to achieve a well-exposed scene (which for the camera means a normally distributed histogram).

  1) Why that noise is added at all? why cant the image could be static, i mean, where is black color, there should be black without noise... (same for other colors...) why colors are not static and why this annoying noise is added?

What probably happened with your example video is that the camera noticed a dim-light environment and cranked up the ISO/gain to achieve a well-exposed video. This inadvertently increases the noise of the video as well. What you can do to circumvent this is to switch to a manual exposure mode where you set the aperture, shutter speed and ISO manually. This way, you can set your camera to underexpose the image. It will turn out rather dark, but less noisy. Keep in mind though that this does not mean you should just underexpose your video and just turn up the brightness in post-editing. This will once again increase the visible noise, because it's basically the same thing as increasing the ISO, only less efficient. So there's a tradeoff between noise and exposure as well.

  2) is there any method in photocameras (mobile, CANON etc..) , to force camera to record without noise (like professional videocameras do)?

High-quality lenses will usually be faster, meaning their minimum f-number (maximum aperture) will be lower. A larger aperture means more light entering the camera in the same amount of time, so with a larger aperture you will get a brighter image than with a smaller one (while shutter speed and ISO stay the same).

High-quality cameras will usually have slightly better low-light performance, meaning there will be less noise under the same circumstances with the same settings, but that difference is rather negligible in scenes as dark as the one in your video.

You can also use a tripod to steady your camera, allowing for slower shutter speed (meaning each individual frame of your video will be exposed for a longer time). However, the shutter speed can't be slower than the inverse of the framerate for obvious reasons, so that will only do so much to brighten up your scene.

What you really need to do to lower the noise is bring in more light. You can still darken the video in post-editing, but if you are able to shoot a well-exposed video with a low-ish ISO value (the meaning of low in this context depends on your camera model), the resultant video won't have much noise regardless of how you decide to edit it. Alternatively, if you want an underexposed video (if that is the style you're going for), you can just set your camera to manual and purposefully underexpose the scene as described above.


What are Grey Balls used for? I know that a Grey Card is used for the white balance of the camera, but whate are the Grey Balls used for?

On big Productions, there is usually a guy (what is his job?) that holds up a grey ball and a "mirror"-colored/reflective ball.
What is this used for? Is this for digital effects added in post and to see the light and the direction of light?
What is the purpose of them?

Also, sometimes, there is the use of a reference card (a paper with many little colored squares on there).
What is that used for?

Is this to adjust the color of the digitally added material?

This can't be added to adjust the images in post, because they should be the same (because of white balance), is it? Does dynamic range matter with these kind of things?

What are these balls called and what for are they used?
What Role/Job does the person holding them have? Does he has other duties or is he/her just holding them?

Yes, they are used for adding visual effects in post. The mirrored ball is for creating an environment map or reflection map. These maps provide the same lighting from the real scene to the virtual scene where graphics are created to composite into the existing scene.

I believe the grey ball is used for recording more diffuse lighting from all angles, though I'm not positive.

The cards with either black and white or colored square patterns on them are for motion tracking, image stabilization, and orientation. They're often used to replace computer or mobile phone screens, for example.


Scaling videos of variable size to a fixed aspect ratio I have 45 videos of varying aspect ratios and resolutions.
I need to scale all of them so that they fit neatly inside a 640x360 (16x9) container with the following specs:

16x9, 640x360, 1600kbps, H.264, MP4, progressive, 29.97

For example, some videos might be 512x12, others might be 480x320, but they all have to fit, scaled and centred, inside a new 640x360 output video.
If a video is not wide enough to fill that space, black bars should be added on the left and right.

Is this possible with ffmpeg?

Here's the code I've been toying with so far:

ffmpeg -i "input.mov"  -b:v 1600k -bufsize 1600k -r 29.97 -vf scale=640:360 -vcodec libx264 output.mp4

This seems to do everything I need, except for dynamically scaling to that fixed resolution.

Does anyone know how to achieve the result I'm looking for?

Thanks!

Use

ffmpeg -i "input.mov" -vf
          "scale='if(gt(a*sar,16/9),640,360*iw*sar/ih)':'if(gt(a*sar,16/9),640*ih/iw/sar,360)',
          pad=640:360:(ow-iw)/2:(oh-ih)/2,setsar=1"
       -vcodec libx264 -b:v 1600k -bufsize:v 1600k -r 30000/1001 output.mp4

The scale filters use the conditional if(a,b,c) expression i.e. if a then b else c. I check if the video is wider than 16:9. If yes, I scale the width to 640 and scale height to preserve proportion. If not, I scale height to 360, and keep width proportional. Then the result is padded out to 640x360. The setsar is used to make sure ffmpeg registers the video as square-pixel.


Why Doesn't Compound Clip With Effect in One Project Still Have Effect When Placed in Another Project? In project A I have grouped a number of clips into a compound clip called c1. While in project A I've added to the compound clip (e.g. so it affects the entire compound clip) a color board effect and some transformation adjustments.

Then when I go into project B and insert compound clip c1 it does not have the effect or transformation adjustments.

Is there a way for the adjustments I've made in project A to transfer over to project B? I have something like 200 compound clips along these lines that need to get reassembled in another project, and I don't want to lose all those adjustments.

Finally, is there anything else that doesn't transfer over I should be aware of?

It looks like you duplicated your project as a snapshot. Taking a snapshot of a project will duplicate the whole project but also a separate copy of the compound clips within a project. This way you can change anything on a compound clip in Project A, and it won't effect project B.

Here is a quote from the docs:

  When you duplicate a project as a snapshot, Final Cut Pro embeds copies of compound or multicam “parent” clips in the snapshot, so any changes to other instances of those clips do not affect the snapshot.


Do newly designed amateur video cameras still shoot interlaced footage by default? I have a relatively cheap video camera (one of the Sony HandyCam models). Even when the model is recent, I think it is essentially a variation of a hardware that has been around for some time. It shoots 59.94 interlaced fields per second by default (though it has also progressive 29.97 and 59.94 modes).

I don't know if the interlaced mode is there because of legacy reasons, or if it is really used and appreciated by amateurs. I see a lot of people taking progressive videos, specially with machines that resemble a traditional reflex camera instead of a video camera and apparently do not include an interlaced mode.

I like interlacing, though that is not the question because I can see a lot of discussing around this preference all over the internet. My question is, are the other manufacturers of newly designed camcorders still including interlacing modes by default in non-professional cameras like my HandyCam, or is it a format that is about to disappear from amateur machines? Is there any standard regulating this?

If you take a look at Bluray video codecs, you'll see that the 50+ fps HD formats at 1080 row resolution are all defined as interlaced formats.

That's a strong incentive for 1080 line interlaced formats not to go away fast in consumer grade cameras.


Resulting video is bad always on the same place I'm using Sony Vegas pro 10 and trying to render a small video for YouTube (3 min).
Resulting video is always slightly flushed, frozen, interrupted... on the same place - on about 1:18 till 1:36.

Original video is ok. I tried to render just this small problematic part - the same result. Something is wrong on that part. Playing in Vegas - no problem.

What could be the reason, pls.

Maybe important, on that place the audio track is the most loud.

Rendering another videos is ok.

Two possibilities that come to mind are that it could be a dropped frame that isn't that noticeable until an H.264 compression is applied or it could be that you are using an insufficient bit rate and that particular part of the video has enough going on that it couldn't compress well.

I would check the time code around the problem to make sure all the frames are there.  I would also try increasing the bit rate used and try VBR 2 pass and see if either of those fix it.


Lightroom-like software for video (categorizing & organizing footage) I use Lightroom's library system to organize my photos using tags and categories. Now I want to have the same functionality for video footage, especially for extracting and organizing the interesting sections of a clip.

Is there something like that, maybe even as an addon for lightroom?

Cheers,
fabs

I think the keywords your looking for is "media asset management" or "video asset management". Apart from the numerous commercial softwares around, this list of open source alternatives might give you a good overview.

http://www.opensourcedigitalassetmanagement.org


Do video re-encoding operations affect the container's audio file? Say I have a video file with contained audio file. So a container with audio and video codecs.

If I'm applying an operation in ffmpeg that will re-encode the video, such as applying filters or changing the container (assume it supports the audio codec) or video codec or whatever, does this also re-encode or affect the audio of the output file in any way?

Does the audio codec just automatically get a kinda pseudo -c copy command applied and translated over to new video file?

I'm trying to understand whether I need to specify a -c copy for the audio every-time I do an operation to the video part. Whether for the purpose of speeding up the operation or for avoiding quality-loss.

Like when setting an audio input and a video input and combining you need to specify a -c copy to get it to simply combine them. But I'm just a bit confused if you need to worry about it once the audio codec is already safely in the container and I'm applying operations to this video afterthefact.

In ffmpeg, copy mode for -codec / -c always needs to be expressly set.

So for

ffmpeg -i in -c copy out

ffmpeg will perform automatic stream selection and copy all those streams.

For

ffmpeg -i in -c:a copy out

ffmpeg will perform automatic stream selection and copy audio stream. Video stream will be transcoded.

I suggest you read the above link on stream selection fully. It covers stream handling.


privacy: the easiest way to blur out some location specific objects in a video My customer sent me a video, where she wishes to hide all location specific objects. The video viewer should not recognize where the video was filmed.

To blur out the location specific object, a human must decide what is privacy related and what not (it can't be done by algorithm). I wish to select an object (some tiny and some 50% of the resolution) and then some "magic" happens that this object is blurred in hole video. I wish to blur out only small portions of the video, that the result is enjoyable for our viewers.

I search for a very easy solution. I am not a Professional Video guy. I use macOS Sierra, did some basic stuff with ffmpeg and QuicktTime player (Trimming). For me it's possible to buy an extra software for about 100$. I prefer a very simple way to do this.

You are going to need to use; preferably After Effects to do this. You could also do it in Premiere; but AE is the way to go, because you can use the tracking feature to auto follow objects; combined with a custom mask (with a blur filter applied).

Other than that your options will be limited.

I believe Adobe CC allows a 30 day free trial; and it's monthly in terms of cost, you could always try it and see if it suits your needs, and go from there).


Professional text animation software In addition to Adobe Flash, what other tools people usually use to make text animations.
By text animation I mean, like animations that has a narration and word or letters from the narration dance on the screen, change in size and color, bump to each other, fall down or fly away.
I am looking for something that professionals would use, some like what is used to produce this video:

All of the pro video editors have a means of animating titles to some degree, some are better than others. I am only experienced with Sony Vegas Pro 10, but I have seen my colleagues use Adobe Premiere with Adobe After Effects to create some mind blowing 'dancing' titles. Vegas has plugins available to boost their basic package but the basic package can do most if not all the effects you have in your example while Adobe's Premiere and After Effects might be able to take this to another level as in more 3d attributes.

I recommend a pro video editor over power point as you have tons of flexibility (avi, mov, mp4, m2t, etc) vs. only a ppt file. However, there are many products available to convert ppt files into video such as this free version I just found:

http://www.effectmatrix.com/PowerPoint-Video-Converter/Free-PowerPoint-Video-Converter.htm

Caution: I have never tried this product so I am uncertain on quality.

I should mention that animating titles is not the only thing going on in your example, there is some degree of track motion control and pan/crop as well not to mention compositing.

If you are seriously looking for a pro product, I would seek advice from professionals that already use these products in conjunction with trying out the trail versions if available. I do know that Sony Vegas Pro 11 is available for free download for a 30 day trail. Most of these products will cost between $500 and $2500 and the learning curve can be heavy.

Sony Vegas trial version:
http://www.sonycreativesoftware.com/download/trials/vegaspro?keycode=64506

This is a serious product that costs you both time and money.

I would recommend posting on the appropriate forum on creative cow to seek more inside advice.

http://creativecow.com/

Hope this helps


How does MKV segment linking work? I downloaded a file vid1 that is in C:\dir1\ which links to another file vid2 in a subdirectory C:\dir1\dir2\ and it works if I move that file to dir1 (so both files are in dir1). I figure that it'll work as long as it's in the same directory or any subdirectory of dir1 but it also works if I move vid2 to C:\ or C:\dir3\ or C:\dir3\dir4..

So how does an MKV file look for other MKV file segments even when I move them all over the place in different directories?

It's not the container that 'knows' that, it is a player. And it is a good question how it managed to find the file in the different directory.

The only thing that the container does to help the player to identify the blocks is storing the Previous UID and Next UID for the files. It also stores the UID for the current file. So my guess would be that you have a player with some sort of 'library' capability, the player has scanned your drive and recorded the UIDs of the MKV files that it found, it then encounters the Next UID field in a file that it's playing and it will know where to look for the next one.


Magic Lantern follow focus Using Magic Lantern on a 600D. With Follow Focus and Rack Focus, the camera always misses the focus point I set. Sometimes it's just one or two movements too far but it's always too many. And if you focus back and forth a lot it drifts further and further. I've tried various settings and both a Canon 50mm f/1.8 as well as a Canon EFS 18-55mm f/3.5 (maybe slightly better).

Is there something wrong with my lenses? Or camera? Or is this normal?

The problem is that cheap lenses (and even some expensive ones) do not know where the focus ring is actually positioned. They only know if they are in focus and which way to run the motor to get more in focus. For focusing, they don't generally need access to this kind of information because they get feedback via the AF sensor about if they need to keep going.

When shooting video, the PDAF sensor is covered and the only way to verify positioning is to continue until contrast decreases. This is why you get the focus hunting issue with contrast based auto focus such as what is used on most LiveView modes (unless the camera has a hybrid sensor that includes PDAF pixels.)

What Magic Lantern is probably doing to get around this is running the motor for a fixed amount of time to approximate the movement, but in cheaper lenses, the motors are particularly imprecise, so it is going to often miss the mark. There might also be an option to have it use CBAF for confirmation, but that will result in at least a minimal amount of focus hunting.

There's still no real software fix for what is really a matter of needing to be able to move from position A to position B exactly unless you have a lens that actually provides exact position information back to the camera (in which case, this information may be able to be used by Magic Lantern for giving an exact follow or rack.)