[Ffmpeg-devel] [PATCH] movenc timecode track support

Baptiste Coudurier baptiste.coudurier
Wed Dec 13 13:38:53 CET 2006

Michael Niedermayer wrote:
> Hi
> On Wed, Dec 13, 2006 at 10:49:28AM +0100, Baptiste Coudurier wrote:
>> Hi
>> Michael Niedermayer wrote:
>>> Hi
>>> On Tue, Dec 12, 2006 at 06:30:51PM +0100, Baptiste Coudurier wrote:
>>>> Hi
>>>> Michael Niedermayer wrote:
>>>>> Hi
>>>>> On Tue, Dec 12, 2006 at 04:46:11PM +0100, Baptiste Coudurier wrote:
>>>>>> Baptiste Coudurier wrote:
>>>>>>> Hi
>>>>>>> $subject. Preliminary support for creating timecode track. Need to
>>>>>>> figure out a clean way to supply referenced track (video track).
>>>>>> Any problem with that patch ?
>>>>> what good does it do? / what is a timecode track good for?
>>>> Useful to specify start time of the media, used in editing systems
>>>> (Final Cut). Mov timestamps always start from 0. Basically same use as
>>>> mpeg2 gop headers timecode or h264 sei picture timing.
>>> except that these dont contain things with names like color, font face
>>> graphics mode, ... what the hell do these do in that "timecode track"?!
>> You can display time code in quicktime player, and those defines how to.
> ok and how now is that start time brought from the user into the final file?
> definitly not the same way as with mpeg and thats unacceptable, whatever the
> API it must be the same between different containers

A packet containing 32 bit int frame count start. What is unacceptable ?

Time code in mpeg is in elementary stream. Here time code is in
container, to specify it for codec not having that feature (mjpeg).
MXF/GXF/MKV also have time code tracks.

It provides the possibility to do it through libavformat, just create a
data track with codec_tag set to 'tmcd', set timebase correctly and
write an AVPacket. Now about how to set reference track...

Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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