[FFmpeg-devel] [PATCH] avcodec: Remove libfaac, the internal AAC encoder is better

[Michael Niedermayer]

On Sun, Apr 10, 2016 at 09:24:21PM +0200, wm4 wrote:
> On Sun, 10 Apr 2016 21:13:13 +0200
> Michael Niedermayer <michael at niedermayer.cc> wrote:
> 
> > On Sun, Apr 10, 2016 at 07:29:05PM +0100, Rostislav Pehlivanov wrote:
> > > On 10 April 2016 at 17:42, Michael Niedermayer <michael at niedermayer.cc>
> > > wrote:
> > >   
> > > > On Sun, Apr 10, 2016 at 04:38:35PM +0100, Kieran Kunhya wrote:  
> > > > > ---
> > > > >  Changelog              |   1 +
> > > > >  configure              |   6 --
> > > > >  doc/encoders.texi      | 105 ---------------------
> > > > >  doc/ffserver.conf      |   2 +-
> > > > >  doc/general.texi       |   2 +-
> > > > >  doc/muxers.texi        |   4 +-
> > > > >  doc/platform.texi      |   2 +-
> > > > >  libavcodec/Makefile    |   1 -
> > > > >  libavcodec/allcodecs.c |   1 -
> > > > >  libavcodec/libfaac.c   | 248  
> > > > -------------------------------------------------  
> > > > >  libavcodec/version.h   |   2 +-
> > > > >  11 files changed, 7 insertions(+), 367 deletions(-)
> > > > >  delete mode 100644 libavcodec/libfaac.c  
> > > >
> > > > this is not possible currently libfaac is twice as fast than the
> > > > native encoder.
> > > >
> > > > time ./ffmpeg -v 0 -i matrixbench_mpeg2.mpg -vn -c:a libfaac -y test.aac
> > > > real    0m2.828s
> > > > user    0m2.776s
> > > > sys     0m0.048s
> > > >
> > > > time ./ffmpeg -v 0 -i matrixbench_mpeg2.mpg -vn -y test.aac
> > > > real    0m5.908s
> > > > user    0m5.856s
> > > > sys     0m0.048s
> > > >
> > > >
> > > >  
> > > FAAC isn't maintained, hasn't had any work done on it in who knows how many
> > > years, nobody but people who don't know that the native encoder/fdk is
> > > better use it (just a few thankfully), isn't particularly stable
> > > (segfaulted a few times when I was comparing it last year) and finally,
> > > it's not good at all.
> > > An argument that it's faster than the native encoder has as much weight as
> > > an argument that libaac_plus was also faster than the native encoder, which
> > > didn't matter as it was eventually removed
> > > The age where we needed a few different AAC encoders because there wasn't
> > > really a single good multipurpose one is gone now. The times have changed
> > > since FAAC was developed (Nokia sponsored at lot of its development, and
> > > you know what they used to make) and so have the computers. What was an
> > > acceptable speed back then for encoding a file at a given quality isn't
> > > necessarily the same now. And considering that fdk-aac can run as slow as
> > > our encoder I'd say we're doing pretty well as far as the balance between
> > > speed and quality goes.  
> > 
> > x264 can encode at really impressive speed and also at really
> > impressive quality, its the users choice by using teh preset option
> > 
> > for aac the user can choose speed through using the libfaac encoder
> > or quality through using the native encoder
> > speed matters for battery powered devices, not just for media servers
> > on phones but also for plain audio recording on phones which i think
> > is more common.
> 
> That's like grasping for straws. I very much doubt any phone uses the
> ffmpeg API to encode AAC.

i suspect some apps even pipe it into command line
ffmpeg and mencoder on phones.

some apps likely use the ffmpeg API, some likely will use multiple
libs directly to provide the various supported encoding formats
using ffmpeg (api or command line) is simpler than multiple libs
so it makes sense to use it instead if one is lazy


> 
> Even those dead Nokia phones are unlikely to have used it through
> ffmpeg.
> 
> > 
> > that said, to be blunt, make your encoder be capable to encode as fast
> > and as good quality as libfaac and after that remove libfaac support
> > if you want.
> 
> Our own AAC developer just said that faac is "not good at all".

yes


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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