[FFmpeg-devel] [PATCH] configure option for 32-bit MPEG audio output

Mike Melanson mike
Thu Feb 12 04:31:17 CET 2009

Michael Niedermayer wrote:
> On Wed, Feb 11, 2009 at 08:08:54PM +0100, Aurelien Jacobs wrote:
>> Michael Niedermayer wrote:
>>> On Wed, Feb 11, 2009 at 11:46:07AM +0100, Diego Biurrun wrote:
>>>> On Tue, Feb 10, 2009 at 10:52:45PM -0800, Mike Melanson wrote:
>>>>> I want to start doing automated testing of MPEG-1 audio conformance  
>>>>> vectors via FATE using the officially sanctioned RMS method. To that  
>>>>> end, FFmpeg needs to have configure-time support for 32-bit audio  
>>>>> output. The code is already in FFmpeg but it requires setting  
>>>>> CONFIG_AUDIO_NONSHORT manually in libavcodec/mpegaudio.h. I want to  
>>>>> remedy that with this patch.
>>>> Looks fine, but..
>>>>> --- libavcodec/mpegaudio.h	(revision 17146)
>>>>> +++ libavcodec/mpegaudio.h	(working copy)
>>>>> @@ -65,7 +63,7 @@
>>>> ..why not just
>>>> ?

That's just how it was when I go there. And CONFIG_MPEGAUDIO_HP is 
enabled by default anyway. Per the docs, disabling it sacrifices quality 
for better speed.

>>>> Otherwise you have to pass two configure options to enable this..
>>> is there any advantage of not enabling CONFIG_AUDIO_NONSHORT?
>> Last time I proposed to enable CONFIG_AUDIO_NONSHORT by default
>> the issue that was raised was the PSNR drop in regtest.
>> It is still here:
> right i remember now :(

Meanwhile, I have a method (several, really) for testing MPEG-1 audio in 
FATE that does not rely on long audio. But it would be nice to have so 
that FATE can use the more accurate and sanctioned method.

     -Mike Melanson

More information about the ffmpeg-devel mailing list