demux/mp4: make sure we have enough data remaining in ExtractIntlStrings
demux/mp4: make sure we have enough data remaining in ExtractIntlStrings

The previous implementation would assume that we would always have at
least 4 bytes of data left in the pending buffer, which can cause us
to read more bytes than available inside the loop.

This change make sure that we do not continue parsing if this happens.

Signed-off-by: Francois Cartegnie <310f1db38de807b64012eea4bc0bd91d9d7c874e@free.fr>

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