[FFmpeg-devel] [PATCH] AAC: [PATCH] AAC: Add support for 7350Hz sampling rates

[Michael Niedermayer]

On Tue, Mar 10, 2015 at 12:37:34AM -0300, Claudio Freire wrote:
> On Mon, Mar 9, 2015 at 3:31 PM, Claudio Freire <klaussfreire at gmail.com> wrote:
> > On Mon, Mar 9, 2015 at 1:38 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> >> On Mon, Mar 09, 2015 at 01:31:26PM -0300, Claudio Freire wrote:
> >>> On Mon, Mar 9, 2015 at 1:26 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> >>> > doesnt help
> >>> > but
> >>> > this does:
> >>> > -fate-aac-s7350-encode: CMD = enc_dec_pcm adts wav s16le $(REF) -strict -2 -c:a aac -b:a 256k
> >>> > +fate-aac-s7350-encode: CMD = enc_dec_pcm adts wav s16le $(REF) -strict -2 -c:a aac -b:a 88k
> >>> >
> >>> > this seems to fix it, didnt ivestigate why ...
> >>>
> >>> 88k is the maximum allowed bitrate at 7350hz, but it shouldn't make
> >>> any difference given that lavc/aacenc.c:775 already clamps the bitrate
> >>> to that number.
> >>
> >> i think it clamps to 88200 while 88k sets 88000
> >> i can reproduce the difference with -b:a 88200
> >
> > Oh... I see.
> >
> > There's a specific implementation for mips, I had completely
> > overlooked it on all patchesets.
> >
> > I'll have to look into it more thoroughly, most earlier patches should
> > be applied to that implementation as well when applicable.
> 
> Ok, try the attached patch on top of the previous ones, see what it
> does.

stddev:  443.22 PSNR: 43.40 MAXDIFF: 5038 bytes:   176400/   180224
stddev: |443.22 - 414| >= 5

    Duration: 00:00:06.89, bitrate: 57 kb/s
    Stream #0:0: Audio: aac (LC), 7350 Hz, stereo, fltp, 57 kb/s


> I cannot test myself yet (cannot build against mips, it will
> probably take me a long while before I can set up qemu for that), but
> the patch should bring both implementations in sync, at least enough
> for the test to pass without the -b:a 88k

if you use a debian based distro then the packages from
http://www.emdebian.org/
can probably be used to cross compile to mips
(you might need to force some versions manually during install, at
 least in the past the binary packages referred to many non existing
 package versions so only some versions of the packages had all
 dependancies available)

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

It is what and why we do it that matters, not just one of them.
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