[FFmpeg-devel] [RFC/PATCH] matroska timestamps not always pts

elupus elupus
Wed Nov 21 00:03:04 CET 2007

"elupus" <elupus at ecce.se> wrote in message 
news:fhvobt$snf$1 at ger.gmane.org...
> "Uoti Urpala" <uoti.urpala at pp1.inet.fi> wrote in message
> news:1195598562.18396.9.camel at symbol.nonexistent.invalid...
>> On Sun, 2007-11-18 at 23:11 +0100, elupus wrote:
>>> Apperently the timestamps stored in matroska container can mean 
>>> different
>>> things. For native tracks they normally mean pts, while for others this
>>> isn't always the case.
>>> The case i'm trying to nail here is the ms compatibility case. In this
>>> case,
>>> timestamps should correspond to the frame numbers in avi. This patch
>>> makes
>>> demuxer only set the correct timestamp (dts/pts) in the packet.
>> Does some spec say they "should correspond" to frame numbers? Or are you
>> only saying this because you've seen (invalid?) files generated by
>> someone which do this?
> Well, i didn't get that exact wording from Haali, what I got was that
> "timestamps should be treated as timestamps are treated in avi." And since
> there is no such thing as timestamps in avi, the closes thing you got is
> frame number. (hmm or is it packet number in stream perhaps, don't 
> remember
> how vfr files in avi are encoded) .
> In ms compatibility mode the stream is apperently copied raw from avi, so 
> I
> guess no real parsing of what's in the actual stream is done.
> /Joakim

On a different note. This might be usueful in figuring out how to set dts 
properly in the case of native coding where timestamps are pts.


More information about the ffmpeg-devel mailing list