[MEncoder-users] lavs encoding and divx compatibility

[Jakub Misak]

Stjepan Brbot <stjepan.brbot <at> zg.t-com.hr> writes:

> 
> Hi,
> 
> according to the specification my standalone DVD + DivX player Samsung
> DVD-V6500 does support:
> 
> * Supported CODEC formats: DivX3, DivX4, DivX5 (GMC 1WP)

The player vendors are very good at confusing people. The term "codec formats" 
per se is nonsense, as it confuses three different things - codecs (software 
products), formats (specifications) and FourCCs (four character codes in AVI 
files). Your player simply supports MPEG-4 (and MS MPEG-4) video with certain 
parameters.

> But it does not reproduce DivX created with mencoder when video codec is
> lavc (mencoder -ovc lavc).

Firstly, MEncoder does not produce DivX, because DivX is a company and a brand 
name. MEncoder does not produce a company or a brand name, MEncoder produces 
video files. In your case, it produces an AVI/MPEG-4 file, that is, AVI 
container with MPEG-4 ASP video inside.

Now, like Grozdan said, FourCC is important in AVI files, so try changing it. 
FMP4 is not widely supported.

> According to mencoder documentation lavc encoding actually produce DivX
> coded movies.

No, it does not produce DivX encoded movies and the documentation does not say 
that. Just like you can produce a MEncoder encoded movie only with MEncoder 
(and not with anything else, like Adobe Premiere, for example), you only 
produce DivX encoded movies with the DivX cocdec, which is a commercial 
software product (available for Windows and Mac OS X) made by DivX, Inc. 
libavcodec is not DivX and has absolutely nothing to do with DivX. The MPEG-4 
codec from libavcodec only uses the same video format the DivX codec uses, that 
is MPEG-4 ASP. Video encoded with libavcodec MPEG-4 (and DivX Pro Codec, Xvid, 
3ivx etc.) is MPEG-4 ASP video. Which can be played back using other MPEG-4-
compatible codecs like DivX, Xvid or standalone MPEG-4 players, if the 
particular MPEG-4 decoder supports the MPEG-4 features used during encoding. If 
you don't use GMC, Qpel (and maybe B-frames, too) plus you change the FourCC to 
DX50 or XVID, there should not be many compatibility problems.