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

elupus elupus
Tue Nov 20 23:50:32 CET 2007

"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.


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