[MPlayer-users] null codec(?)

[Loren Merritt]

On Tue, 12 Oct 2004, [ISO-8859-1] Carl Fûrstenberg wrote:
> On Tue, 12 Oct 2004 13:42:13 -0700 (PDT), Loren Merritt wrote:
>> On Tue, 12 Oct 2004, [ISO-8859-1] Carl Fûrstenberg wrote:
>>
>>> checked -vc help in semilatest cvs, and found this:
>>>
>>>    vc:         vfm:      status:   info:  [lib/dll]
>>>    (...)
>>>    null        null      crashing  NULL codec (no decoding!)
>>>
>>> Is this a easter-egg, or what?
>>
>> You might want a null codec if you don't want to decode the video.
>> For example, I sometimes use it to rip the audio track from a dvd:
>>    mplayer dvd://1 -dvd-device vobs/ -vc null -vo null -ao pcm -aofile foo.wav
>> Sure, it's not required, but it takes much less CPU time this way.
>>
>> (The status "crashing" is just to make sure that it's never selected
>> automatically.)
>
> so the label "crashing" is just a so called 'lousy hack'?
> But... if null does nothing, i.e. does what it should do, then, isn't
> it 'working' then?

Yes, it's a lousy hack, and -vc null really is working.
When selecting a codec to play a given file, MPlayer runs through the 
list of available codecs, and first tries all "untested" codecs, then the 
"working" codecs, then the "buggy" codecs, and uses the first one that 
accepts the stream (where "accept" may involve different tests depending 
on the format in question.)
"crashing" codecs are never selected, unless you explicitely specify them 
with -vc. Since null accepts anything, and we want MPlayer to complain 
about unhandled formats, not just use the null codec, null goes in the 
"crashing" category.

P.S. please reply to the list.

--Loren Merritt