[FFmpeg-devel] [PATCH] mpegaudio float default

Ronald S. Bultje rsbultje
Mon May 17 17:47:08 CEST 2010


On Mon, May 17, 2010 at 11:18 AM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Thu, May 13, 2010 at 06:23:46PM -0400, Ronald S. Bultje wrote:
>> Hi,
>> On Thu, May 13, 2010 at 6:12 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
>> > On Thu, May 13, 2010 at 10:56:36PM +0100, M?ns Rullg?rd wrote:
>> >> Michael Niedermayer <michaelni at gmx.at> writes:
>> >> 3x slower on Cortex-A8. ?We need to discuss betters way to choose
>> >> implementation. ?Ideally we should have something that extends well to
>> >> other codecs too. ?There are fixed-point versions of at least wma
>> >> floating about, and IMO we should be working towards merging them.
>> >
>> > someone is working on fixp wma ? :)
>> Rockbox (?) already has a fxp wma1/2 decoder, based on the FFmpeg one
>> from several years ago, that they'd like to backport into our tree if
>> we're interested.
> ive been pointed to
> http://www.mail-archive.com/rockbox-dev at cool.haxx.se/msg07388.html
> http://www.mail-archive.com/rockbox-dev at cool.haxx.se/msg07413.html
> This thread does not sound like the rockbox devels seriously intent to
> integrate fixed point support back into the ffmpeg codecs.
> But iam not on their ML so its easy for me to misinterrpret this.

I think you're right, and re-reading my original reply I was too
positive. Just alone looking at their reference to tremor, I don't
think they have any idea of how to do this in a good way (= code
sharing between fixp/float impls where possible, etc.), they simply
want to plumb a new codec in our tree called "wmafixed", which decodes
streams that are syntactically similar to wma1/2 but which shares 0%
code with any of the rest of the FFmpeg tree.

I don't think that's useful.


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