[Ffmpeg-devel] mpeg4 avi, corrupted frames when CODEC_FLAG_TRUNCATED is set

[Michael Niedermayer]

Hi

On Sat, Oct 29, 2005 at 01:56:50PM -0400, Rich Felker wrote:
> On Sat, Oct 29, 2005 at 07:15:54PM +0200, Michael Niedermayer wrote:
> > Hi
> > 
> > On Wed, Oct 26, 2005 at 12:10:29PM -0400, Rich Felker wrote:
> > > On Wed, Oct 26, 2005 at 01:03:48PM +0200, Michael Niedermayer wrote:
> > > > Hi
> > > > 
> > > > On Tue, Oct 25, 2005 at 07:07:09AM +0200, Stefan Lucke wrote:
> > > > > On Samstag, 22. Oktober 2005 00:42, Stefan Lucke wrote:
> > > > > > On Freitag, 21. Oktober 2005 11:45, Stefan Lucke wrote:
> > > > > 
> > > > > > > I'll do some tests when I'm back home.
> > > > > > 
> > > > > > Done. The internal framer seems to be ok. But the number of consumed
> > > > > > byte is not. I changed the test sequence of get_consumed_bytes()
> > > > > > to first check CODEC_FLAG_TRUNCATED and than s->divx_packed.
> > > > > > By that this stream plays fine with and without CODEC_FLAG_TRUNCATED.
> > > > > > See attached diff.
> > > > > > 
> > > > > 
> > > > > No other comment from ffmpeg developer on that patch ?
> > > > 
> > > > rejected, dont use CODEC_FLAG_TRUNCATED, use a AVParser
> > > 
> > > hey michael,
> > > 
> > > on a related issue, is there any example/doc on how to use lavf/lavc
> > > to demux to a sequence of packets will full pts info? it's a common
> > > question on here it seems, and i think a lot of powerful stuff has
> > > been added to lavf/lavc to overcome the problems, but i don't know
> > > anything about it so i can't tell people who ask for help what to do,
> > > except for telling them it's a very difficult problem.
> > 
> > set AVFMT_FLAG_GENPTS, and if the code isnt buggy it should fill in the
> > missing pts values
> 
> how extensive is this? does it work for all known out-of-order codecs
> in avi?

it wont work with non trivial frame orderings in h264, but that could hardly
be expected, frame type + dts isnt enough there to generate pts, it would
require some changes to the h264 AVParser to either set the pts or to extract 
some info about the ordering


> 
> another question many users have been asking: when using lavc to
> decode frames, how do you copy the pts values from the input (coded)
> frames to the output (decoded) frames? i know it can be done with an
> ugly opaque data and get_buffer hack but surely there's a better
> way..? i probably just don't know it.

send a patch which adds some muxer_pts field to AVCodecContext and AVFrame 
maybe ...

[...]
-- 
Michael