[FFmpeg-devel] [PATCH] MTH demuxer (Gamecube format)

Michael Montanye montanye
Tue Feb 3 20:58:28 CET 2009

Vitor Sessak wrote:

>> +static int mth_probe(AVProbeData *p)
>> +{
>> +    /* check file header */
>> +    if (AV_RL32(p->buf) == MKTAG('M', 'T', 'H', 'P'))
>> +        return AVPROBE_SCORE_MAX;
>> +    else
>> +        return 0;
>> +}
> This is a little false-positive prone (just four bytes). Something like 
> the following is better
> if (AV_RL32(p->buf) != MKTAG('M', 'T', 'H', 'P'))
>      return 0;
> if ({fps, width and weight are sane})
>     return AVPROBE_SCORE_MAX;
> else
>     return AVPROBE_SCORE_MAX/3;
Several other game-related formats already use this same four-byte 
check, including the THP demuxer this was based on, so I'm not sure this 
is that big a concern. (bethsoftvid, segafilm, smacker, and wc3movie 
also have the same or similar checks, and there may be others I missed 
on the first pass)

> Is there any reason to stop before EOF? If not, them you also don't need 
> all the frame counting logic...
Okay, that was mostly carryover from the THP demuxer, so it's all removed.
> -Vitor
The other fixes have been incorporated, and Diego's fixes are also 
added, new patch attached.

-Michael Montanye
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