[Ffmpeg-devel] Re: [PATCH] PKT_FLAG_B

[Baptiste Coudurier]

Hi

Michael Niedermayer wrote:
> [...]
> 
> knowledge of frame types of h.264 is not enough to calculate pts/ctts
> so your B_TYPE flag wont help, for example:
> 
> [...]
> 

OK for h264, there should be some way to figure that. For mpeg-4 in avi
It get no pts/dts differences at all when stream contains B frames, even
with -genpts.

>> Should demuxer set has_b_frame ?
> 
> if it has enough knowledge about the video then why not
> 

Say my mpeg-2 comes from mov, parser won't be invoked and has_b_frames
never set. Then gxf muxer won't ever set B frame :(
Are you ok if I implement a very simple frame type detection in gxf
muxer ? I think I need to detect closed gop also.

>> What about always invoking parser when stream copying ?
> 
> no

Ok, what's bad in it ?

>> [...]
>>
>> If you fake the number, it will be ingested and will crash the server
>> when trying to play. Same goes for Closed gop flag btw. That's the next
>> thing I need to figure out and detect.
> 
> well, then iam ok with trying to set the p/b count values to something
> approximately correct ...

Good.

> [...]

-- 
Baptiste COUDURIER                              GnuPG Key Id: 0x5C1ABAAA
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