[FFmpeg-devel] [PATCH 3/4] avformat/libopenmpt: Update file extensions list for libopenmpt 0.3

[Jörn Heusipp]

On 01/08/2018 12:48 AM, Carl Eugen Hoyos wrote:
> 2018-01-07 15:40 GMT+01:00 Jörn Heusipp <osmanx at problemloesungsmaschine.de>:
>> On 01/06/2018 04:06 PM, Carl Eugen Hoyos wrote:
>>> 2018-01-06 11:07 GMT+01:00 Jörn Heusipp
>>> <osmanx at problemloesungsmaschine.de>:


>>>> -    .extensions     =
>>>> "669,amf,ams,dbm,digi,dmf,dsm,far,gdm,imf,it,j2b,m15,mdl,med,mmcmp,mms,mo3,mod,mptm,mt2,mtm,nst,okt,plm,ppm,psm,pt36,ptm,s3m,sfx,sfx2,stk,stm,ult,umx,wow,xm,xpk",
>>>> +#if OPENMPT_API_VERSION_AT_LEAST(0,3,0)
>>>> +    .extensions     =
>>>> "669,amf,ams,dbm,digi,dmf,dsm,dtm,far,gdm,ice,imf,it,j2b,m15,mdl,med,mmcmp,mms,mo3,mod,mptm,mt2,mtm,nst,okt,plm,ppm,psm,pt36,ptm,s3m,sfx,sfx2,st26,stk,stm,stp,ult,umx,wow,xm,xpk",
>>>> +#else
>>>> +    .extensions     =
>>>> "669,amf,ams,dbm,digi,dmf,dsm,far,gdm,ice,imf,it,j2b,m15,mdl,med,mmcmp,mms,mo3,mod,mptm,mt2,mtm,nst,okt,plm,ppm,psm,pt36,ptm,s3m,sfx,sfx2,st26,stk,stm,ult,umx,wow,xm,xpk",
>>>> +#endif
>>>
>>>
>>> I believe this change can be made without the version check.
>>
>> Why would that be better?
> 
> Only because of the simplification:
> Other parts of FFmpeg will not support the files anyway, and I am sure
> we can find a real-world files that have one of above extensions but are
> not supported by libopenmpt (because they are completely different
> files).

Absolutely. Without doing any further research, I know at least of .mod 
(also used by JVC camcorders and others for some MPEG variant (I do not 
know the details)) and .umx (which can also contain wav or mp3 or 
similar instead of module music files). Also, .sfx is probably used by a 
ton of games as a generic extension for any sound effects.
Given the sheer amount of file extensions, there are likely even more 
conflicts that I am not aware of.

> Can't libopenmpt be configured to support only some of above file
> types?

No, that is not possible.

> But feel free to ignore my suggestion.

Listing too many file extensions increases the chance of false-positives 
which I think warrants listing as few as possible depending on 
libopenmpt version.
In any case, I do not have a particularly strong opinion on that matter.
So maybe someone else wants to comment on that?


Regards,
Jörn