[ogg-dev] [Schrodinger-devel] ogg dirac granulepos in oggz tools

[David Schleef]

On Fri, Dec 05, 2008 at 06:34:41AM +0900, Conrad Parker wrote:
> So the last remaining tool to check is oggz-chop. I at first assumed it
> would not work with Dirac's granulepos, but it seems to do something
> vaguely useful:
> 
> conrad at chichai:~/share/oggz-chop$ oggz chop -s 7 -e 11 -o
> sage-7-11.ogv ../dirac/sage-640x360.ogg
> conrad at chichai:~/share/oggz-chop$ oggz dump sage-7-11.ogv |grep
> serialno | head -n 20
> 00:00:00.000: serialno 1762443388, granulepos 0, packetno 0 *** bos: 64 bytes
> 00:00:00.000: serialno 1763535876, granulepos
> (pt:0,dt:0,dist:0,delay:0), packetno 0 *** bos: 39 bytes
> 00:00:00.000: serialno 0719746932, granulepos 0, packetno 0 *** bos: 30 bytes
> 00:00:00.000: serialno 0719746932, calc. gpos 0, packetno 1: 75 bytes
> 00:00:00.000: serialno 0719746932, granulepos 0, packetno 2: 3.742 kB
> 00:00:00.000: serialno 1762443388, granulepos 0, packetno 1: 80 bytes
> 00:00:00.000: serialno 1762443388, granulepos 0, packetno 2: 81 bytes
> 00:00:00.000: serialno 1762443388, granulepos 0, packetno 3 *** eos: 0 bytes
> 00:00:06.923: serialno 1763535876, granulepos
> (pt:334,dt:332,dist:51,delay:2), packetno 2: 1.685 kB

The first picture should have a dist of 0, indicating that it's a place
you can start decoding from.

If you chopped an open GOP, you might get a few pictures after that
which depend on earlier pictures, but they have presentation times
before the key frame.  They will be ignored by the decoder.



dave...