[FFmpeg-devel] [FFmpeg-devel-irc] IRC log for 2010-03-28

[Michael Niedermayer]

On Wed, Mar 31, 2010 at 09:17:47AM +0000, Carl Eugen Hoyos wrote:
> Michael Niedermayer <michaelni <at> gmx.at> writes:
> 
> > dont forget that we only support 1 out of 4 h264 files thanks to ivan
> > implementing only 1 out of 4 mandatory ways to handle timestamps
> > i dont know if that is related to what you "discuss" here.
> 
> While I know it is true that ffmpeg does not output correct time stamps for some
> H264 streams (see reference suite), the real-life H264-and-audio samples we have
> (all) play fine with ffplay and are transcoded fine with ffmpeg. It's mplayer
> -demuxer mpegts that fails horribly for ALL streams containing PAFF.

ffplay is quite forgiving, it can use dts or pts and it will figure out which
are better and use that.
and both ffplay and ffmpeg can handle missing timestamps by just assuming
constant framerate. This works fine with when it actually is constant
framerate but with things like telecine or paff frame/field mixes it can
fail unless the container stores timestamps for each frame OR falls in the
25% of h264 timestamp handling that was implemented.
I do not know how many of the real world h264 + audio files fall in the
category. But if i belive the reports ive seen at least h264 in matroska
does not fall in the implemented 25%.

incorrect or missing timestamps can only be recognized by looking at the
timestamps not by just checking if ffmpeg/ffplay can play it

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Incandescent light bulbs waste a lot of energy as heat so the EU forbids them.
Their replacement, compact fluorescent lamps, much more expensive, dont fit in
many old lamps, flicker, contain toxic mercury, produce a fraction of the light
that is claimed and in a unnatural spectrum rendering colors different than
in natural light. Ah and we now need to turn the heaters up more in winter to
compensate the lower wasted heat. Who wins? Not the environment, thats for sure
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