Codec feature comparission



divx5 supports 3point GMC, Thanks to Robert Norberg for the info


xvid supports 3point GMC (since mid july), Thanks to Edouard Gomez for the info


sklmp4 supports trellis quantization, Thanks to Thomas for the info


xvid supports trellis quantization, info from xvid-dev mailinglist


added sklmp4 codec, thanks to skal for the info


new ffmpeg features: rvlc decoding
new xvid features: 1 & 2 warp point GMC de/encoding. Thanks to Christoph Lampert for the info


new ffmpeg features: qpel encoding, chroma Motion estimation, trellis quantization
Added 3ivx D4 PR2. Thanks to Capt. Stux *-Jedi for the info.


Added envivo decoder, xvid decoder supports slices. Thanks to suxen drol for the info.
Added "*" for unverified entries. ffmpeg supports dynamic b frames for encoding now.


Divx5 doesnt seem to support decoding of gmc with more then 1 warp point (it just crashed)
Xvid has GMC support, now
adding text, instead of just colors, so broken browsers like netscape 4.x & lynx display at least someting


Divx5 does support RVLC decoding. Thanks to Andrea Graziani for the info.


Divx5 does support adaptive quantization (the psychovisual enhancements stuff activates it). Thanks to Eugene Kuznetsov for that info.

Mpeg4 Decoder features:

ffmpeg/libavcodec divx5 xvid envivo v1.2.46 3ivx D4 PR2 sklmp4
ac/dc prediction Sup Sup Sup Sup Sup* Sup*
mpeg quantizer Sup Bug, rounding? Sup Sup* Sup* Sup*
B-Vop Sup Bug, B before I Sup Sup* Sup* Sup*
4-MV Sup Sup Sup Sup* Sup* Sup*
quarter pel MC Sup Bug, 1. chroma rounding
2. 4mv
Sup* Sup* Sup* Sup*
Global MC Sup Sup* Sup* Sup* Part, 1 warp point is supported* Sup*
interlacing Sup No Part, only DCT* No* No* Sup*
reduced res VOP No No* Sup* Sup* No* Sup*
slices Sup Sup Sup* Sup* Sup* Sup*
data partitioning Sup Sup No Unk* No* No*
reversible vlc Sup Sup No Unk* No* No*

Mpeg4 Encoder features:

ffmpeg/libavcodec divx5 xvid sklmp4
ac/dc prediction Sup Sup Sup Sup*
mpeg quantizer Sup No Sup Sup*
B-Vop Sup Sup Sup No*
dynamic b frame decision Sup No Sup* No*
4-MV Sup No Sup Sup*
quarter pel MC Sup Bug, chroma rounding Sup Sup*
Global MC No Part, 1 warp point only Sup* Sup*
interlacing Part, only DCT No Part, only DCT Sup*
reduced res VOP No No Sup* Sup*
slices Sup Sup No Unk
data partitioning Sup Sup No No*
reversible vlc No No No No*
adaptive quantization Sup Sup Sup Sup*
custom quantizer matrixes No No Sup Sup*
Chroma Motion Estimation Sup Unk Sup Unk
Trellis Quantization Sup Unk Sup Sup*
not supported
not verified by me

if u notice ANY errors in the tables then please send me an email. if u dont want the codec of ur company listed here then tell me and ill remove it. patches / additions with codecs listed not here are very welcome too.

Note: i did not do extensive tests with the codecs except ffmpeg so there might be errors
some of the bugs mentioned might be corrected allready, if u do know about one then tell me so i can fix the table
features which are supported but where it is not known if the support is complete are marked as unknown
for all "buggy/partial" entries the exact reason is mentioned

copyleft 2002-2003 Michael Niedermayer

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