Hi Thomas, On 05/30/2011 02:03 PM, Thomas Worth wrote:
I noticed that encoding a DNxHD encoded MOV with FFmpeg results in some extra data in the stsd atom for the video track. This data isn't there after encoding to other codecs, say Apple Animation/qtrle for example. At its most basic structure, stsd is 102 bytes, but with DNxHD material is is I think 275 bytes. Furthermore, this data is apparently needed to render the video correctly, because if I truncate stsd to 102, the resulting video is black in the QuickTime player (it still plays in VLC, though).
This is some of what I'm seeing (as text):
ACLRACLR0001 APRGAPRG0001 ARESARES0001
What is this data and what is referencing it? I have some additional stsd parameters I need to insert, but I don't know if putting stuff in before the "DNxHD extra data" (what we'll call it) will confuse whatever is looking for this extra data.
Baptiste?
It's extradata not completely deciphered yet, these parameters are required for decoding by the avid decoders for some reason. Some colorspace information, resolution information. -- Baptiste COUDURIER Key fingerprint 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA FFmpeg maintainer http://www.ffmpeg.org