Hi,

since it is not documented I thought I'd ask what the semantics of 
AVIndexEntry.timestamp are? I assumed/guessed that it is the PTS (in Stream 
timebase units) of the frame starting at file byte offset AVIndexEntry.pos. 
However, the values I have for a concrete file (MPEG-2 in an MP4 container) 
from a camera do not agree with that assumption as the keyframe positions in 
the index do not match the ones I obtain when I simply decode the frames and 
before I file a bug report, I would like to know what the correct behaviour 
should be. In addition to that, looking at the code that builds the index in 
the mov demuxer, timestamps seem to be only set to dts values (which in my use 
case should not make a difference as I am currently only looking at keyframe 
index entries) but that of course does contradict my assumption.

Also, is the stored timestamp the PTS - AVStream.start_time or simply the PTS 
as read from the respective frame/packet?

Any insights would be greatly appreciated. If the outcome is that the correct 
semantics do not correspond to what happens with the mentioned file, I will 
file a bug report.

Thanks in advance,

Robert
 


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