[XviD-devel] ref bitstreams

[peter ross]

>From: skal <skal@planet-d.net>
>	Hi,
>
>	I'm trying to decode some reference bitstream with 'xvid_decraw'
>	but failing (amongst others) with this one:
>
>ftp://ftp.tnt.uni-hannover.de/pub/MPEG/video/conformance/version_2/
>vcon-ge11-ACEL1.bits
>
>	Did someone already try decoding the reference bitstreams too,
>	and could have a hint about what's going on before I dive into
>	the code?
>
>	later,
>		Skal
>

hi,

its an ACE (advanced coding efficiency) bitstream, the
"video_object_type_indication" header field is set to 12.
xvid currently halts if the object type isnt core,simple, or main.

to enable it, edit src/bitstream/bitstream.c ...

	if (BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_SIMPLE &&
		BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_CORE &&
		BitstreamShowBits(bs, 8) != VIDOBJLAY_TYPE_MAIN &&
		BitstreamShowBits(bs, 8) != 0)	// BUGGY DIVX

... and add "BitstreamShowBits(bs, 8) != 12", or just remove the
if() statement completetly.

the video decodes correctly xvid; although it is a rather blocky
encoding.

also, the decoder has debug output which ive found to be most
useful when decoding proprietary encoded (or test) streams.
debug output is enabled by editing src/portab.h, and setting
DPRINTF_LEVEL macro to 0xf.

-- pete

_________________________________________________________________
Get faster connections -- switch to MSN Internet Access! 
http://resourcecenter.msn.com/access/plans/default.asp