[MPlayer-DOCS] CVS: main/DOCS/xml/en faq.xml,1.82,1.83

[Guillaume POIRIER]

Hi,

On 7/5/05, Guillaume POIRIER <poirierg at gmail.com> wrote:
> Hi,
> 
> On 7/5/05, The Wanderer <inverseparadox at comcast.net> wrote:
> > Guillaume Poirier CVS wrote:
[...]
> If no one has additional comments, that's what I'd commit.

Following Rich's comment, here's what I propose:

<qandaentry>
<question><para>
Since 1.0pre7, DivX encoded by <application>MPlayer</application>
cannot be watched on third party players because it sets 'FMP4' as a
FourCC.
</para></question>

<answer><para>
<systemitem class="library">libavcodec</systemitem>, the native MPEG-4
encoding library usually shipped with <application>MEncoder</application>,
used to set the FourCC to 'DIVX' when encoding MPEG-4 videos
(the FourCC is an AVI tag to identify the software used to encode and
the intended software to use for decoding the video).
This led many people to think that
<systemitem class="library">libavcodec</systemitem>
was a DivX encoding library, when in fact it is a completely different
MPEG-4 encoding library whose MPEG-4 support is much better than DivX's.
Therefore, the new default FourCC used by
<systemitem class="library">libavcodec</systemitem> is 'FMP4', but you
may override this behavior using <application>MEncoder</application>'s
<option>-ffourcc</option> option.
You may also change the FourCC of existing files in this same way:
<screen>
  mencoder <replaceable>input.avi</replaceable> -o
<replaceable>output.avi</replaceable> -ffourcc XVID
</screen>
Note that this will set the FourCC as XVID rather than as DIVX.
This is recommended as DIVX FourCC means DivX4, which is a very basic
MPEG-4 codec, whereas DX50 and XVID both mean full MPEG-4 (ASP).
Therefore, if you change the FourCC to DIVX, some bad software or
hardware players may choke on some advanced features that
<systemitem class="library">libavcodec</systemitem> supports, but DivX
doesn't, whereas <systemitem class="library">XviD</systemitem> closer
to <systemitem class="library">libavcodec</systemitem> in terms of
functionalities, and is supported but all decent players.
</para></answer>
</qandaentry>