[FFmpeg-devel] [PATCH 5/7] CrystalHD: Bring in h.264 parser to establish picture type.

[Michael Niedermayer]

On Sun, Mar 27, 2011 at 07:00:46PM +0200, Reimar Döffinger wrote:
> On Sun, Mar 27, 2011 at 09:33:59AM -0700, Philip Langdale wrote:
> > On Sun, 27 Mar 2011 10:43:40 +0200, Michael Niedermayer
> > <michaelni at gmx.at> wrote:
> > >On Sun, Mar 27, 2011 at 07:22:45AM +0200, Reimar Döffinger wrote:
> > >>
> > >>
> > >>On 26 Mar 2011, at 18:50, Philip Langdale <philipl at overt.org> wrote:
> > >>
> > >>> As the hardware is unreliable, we will have to use the h.264
> > >>parser
> > >>> to identify whether an input picture is a field or a frame. This
> > >>> change loads the parser and extracts the picture type.
> > >>
> > >>I think there is a way to tell the parser not to do any parsing
> > >>(in particular, not search for start codes) but only parse.
> > >>Libavcodec/avidec.c uses it like that.
> > >
> > >see AVSTREAM_PARSE_HEADERS and PARSER_FLAG_COMPLETE_FRAMES
> > 
> > But I don't see how this would work. The decoding of the picture
> > structure is done by parse_nal_units() in the
> > !PARSER_FLAG_COMPLETE_FRAMES
> > path.
> 
> Hm, that is suspicious, avidec.c has specifically:
> st->need_parsing = AVSTREAM_PARSE_HEADERS; // This is needed to get the pict type which is necessary for generating correct pts.
> If that does not actually parse headers I guess somethings are going wrong.

I confirm, this is a bug in the h264 parser

bugfix welcome, i suspect it should be relatively easy

[...]
-- 
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
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: Digital signature
URL: <http://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20110327/3a09ae00/attachment.asc>