[Ffmpeg-devel] global headers
Sun Mar 19 01:05:22 CET 2006
Michael Niedermayer <michaelni at gmx.at> writes:
> On Tue, Mar 14, 2006 at 12:08:50AM +0000, M?ns Rullg?rd wrote:
>> Loren Merritt <lorenm at u.washington.edu> writes:
>> > On Mon, 13 Mar 2006, Michael Niedermayer wrote:
>> >> what about letting encoders always generate global headers / set extradata?
>> >> currently it needs CODEC_FLAG_GLOBAL_HEADER to be set, which well, is
>> >> annoying from a encoder - muxer seperation POV
>> >> objections, comments?
>> > Then it would be the muxer's job to interleave the headers into the
>> > stream if it doesn't want global headers? Are there any codecs where
>> > that doesn't consist of "prepend a copy of extradata to each keyframe"?
>> Yes, AAC (what else?). The format of the global header is different
>> from the frame header used with any of the stream formats (ADTS, ...)
>> used either raw or in program/transport streams.
> hmm, what is the difference?
> could we use the same format and convert the global one in the mov/mp4
We're doing the opposite right now. I don't like this, since
whichever way it's done, several muxers will need to do the
conversion. E.g. ADTS format is required for raw ADTS, MPEG-TS and
MPEG-PS. MP4 requires the other format. Matroska, as is to be
expected, uses it's own bastardized variant.
mru at inprovide.com
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