avcodec: encoder: Always provide frame dimension and pixel format
avcodec: encoder: Always provide frame dimension and pixel format

av_frame_unref will clear most of the frame fields, including dimension
& pixel format. This causes some encoders (at least the raw encoder) to
reject the frame.

xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc,xkfz007/vlc