[FFmpeg-devel] H264 Spatial Direct Mode

[Morfsta]

On Jan 31, 2008 9:22 PM, Mike Melanson <mike at multimedia.cx> wrote:
> Perhaps provide a sample that showcases the feature? Do you know if
> there are conformance vectors that exercise this feature in particular?
>
>  http://ftp3.itu.ch/av-arch/jvt-site/draft_conformance/
>

Hi Mike,

Thanks for such a swift response!

I'm not sure on the conformance vectors within that FTP site, however
I have uploaded a sample from a channel that exhibits extreme
artifacting and eventual segfault due to Spatial Direct Mode. Here's
what appears in the VDR output when replaying (I use xinelibout as the
display driver): -

[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]reference picture missing during reorder
[h264 @ 0x2aaaba3af420]reference picture missing during reorder
[h264 @ 0x2aaaba3af420]number of reference frames exceeds max
(probably corrupt input), discarding one
[h264 @ 0x2aaaba3af420]reference picture missing during reorder
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
[h264 @ 0x2aaaba3af420]Interlaced pictures + spatial direct mode is
not implemented
prebuffer=14400 pts
video: synced early
./testvdr: line 3: 24141 Segmentation fault      nice -n -15 ./vdr
-Psc -P"xineliboutput --local=sxfe --video=xv --audio=alsa"
-Pskinenigmang -Pvompserver -Pepgsearch -P'mp3 -i
/usr/local/bin/image_convert.sh' -Pmplayer -Protor -Pfemon -c
/video/config4 -E /video/config4

As Igor pointed out about 80% of channels utilise Spatial Direct mode
interlacing within Europe and I think that figure is probably about
right.

You can find the sample VDR recording here: -

http://rapidshare.com/files/88171133/Spatial_Direct.tar.html

I look forward to hearing more and hope that it might be something
that is of interest to the ffmpeg developers. I think quite a lot of
people would like to see this fixed, if there is anything I can do to
rally support then let me know.

Thanks a lot for your help,

Morfsta