[Ffmpeg-devel] Apple h264 compatibility

Måns Rullgård mru
Sun Jun 19 19:41:34 CEST 2005

Gianluigi Tiesi <mplayer at netfarm.it> writes:

> On Sun, Jun 19, 2005 at 04:00:59PM +0200, M?ns Rullg?rd wrote:
>> Gianluigi Tiesi <mplayer at netfarm.it> writes:
>> > I've just tried some apple h264 samples, since the x264 decoder
>> > is internal to ffmpeg I'm posting here but I could forward the request
>> > directly to x264 ml if needed.
>> This is the right place.  The lavc h264 decoder is entirely separate
>> from x264, although some of the same people work on both.
>> > Anyway I've downloaded some great samples from:
>> > http://www.apple.com/quicktime/hdgallery/
>> >
>> > the quicktime decoder is very sloppy I think it need a cray to decode
>> > the video, but mplayer plays it very fast, the problem is some sort of
>> > incompatibilities but I think they are not so difficult to fix since
>> > the movie is almost played well, there are some glitches, the debug
>> > shows some errors for me:
>> Do all the trailers have those errors, or just some?
> It really seams that problems comes when the cpu has some difficult
> to decode the video, serenity_m1080p.mov is almost frozen,
> but fantastic_four_m420p.mov works fine,
> wildlifehd works untile the video becomes more complex,
> also if I move the mplayer window (blocking the decoder thread)
> a bunch of errors are displayed.
> Error are the same only values are different, at this point,
> I think it's not directly a decoder problem, but rather to the part
> of decoder that should handle dropped frames.

Mplayer with frame dropping doesn't work with H.264.  It appears that
it discards B frames without decoding them, in the belief that they
are not used as reference frames.  This used to be the case with older
codecs, but H.264 allows B frames as reference frames.  Try without
frame dropping.  If there are still decoding errors, there's a bug or
an unimplemented feature.

M?ns Rullg?rd
mru at inprovide.com

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