[FFmpeg-devel] [PATCHSET] AAC decoder refactor

Lynne dev at lynne.ee
Sun Apr 21 15:39:49 EEST 2024


Apr 12, 2024, 11:12 by dev at lynne.ee:

> Apr 12, 2024, 00:45 by michael at niedermayer.cc:
>
>> On Thu, Apr 11, 2024 at 07:42:37AM +0200, Lynne wrote:
>>
>>> Apr 10, 2024, 23:57 by michael at niedermayer.cc:
>>>
>>> > On Wed, Apr 10, 2024 at 08:18:11PM +0200, Michael Niedermayer wrote:
>>> >
>>> >> On Wed, Apr 10, 2024 at 06:48:26PM +0200, Lynne wrote:
>>> >> > Apr 8, 2024, 09:36 by dev at lynne.ee:
>>> >> > 
>>> >> > > The following patchset refactors the AAC decoder step by step,
>>> >> > > removing all large-scale templating and abstracting away typed
>>> >> > > DSP functions from symbol parsing.
>>> >> > >
>>> >> > > This series saves 110Kib of binary data from libavcodec.so
>>> >> > > when compiled with Clang 18 with -O3, after stripping.
>>> >> > >
>>> >> > > The patchset can also be viewed here:
>>> >> > > https://github.com/cyanreg/FFmpeg/tree/aac_cleanup
>>> >> > >
>>> >> > > Fate passes on each step, and I've been running this patchset for
>>> >> > > a week with no issues.
>>> >> > >
>>> >> > > This also prepares the decoder for USAC support.
>>> >> > >
>>> >> > 
>>> >> > I've rebased the linked repo to current git master if anyone
>>> >> > wants to test.
>>> >>
>>> >> thanks, i will try to test it
>>> >>
>>> >
>>> > make fate-source
>>> >
>>> > TEST    source
>>> > --- ./tests/ref/fate/source	2024-04-08 18:26:00.670129617 +0200
>>> > +++ tests/data/fate/source	2024-04-10 23:56:18.032896853 +0200
>>> > @@ -22,6 +22,13 @@
>>> >  compat/djgpp/math.h
>>> >  compat/float/float.h
>>> >  compat/float/limits.h
>>> > +libavcodec/aac/aacdec.h
>>> > +libavcodec/aac/aacdec_fixed_coupling.h
>>> > +libavcodec/aac/aacdec_fixed_dequant.h
>>> > +libavcodec/aac/aacdec_fixed_prediction.h
>>> > +libavcodec/aac/aacdec_float_coupling.h
>>> > +libavcodec/aac/aacdec_float_prediction.h
>>> > +libavcodec/aac/aacdec_latm.h
>>> >  libavcodec/bitstream_template.h
>>> >  tools/decode_simple.h
>>> >  Use of av_clip() where av_clip_uintp2() could be used:
>>> > Test source failed. Look at tests/data/fate/source.err for details.
>>> > tests/Makefile:310: recipe for target 'fate-source' failed
>>> > make: *** [fate-source] Error 1
>>> >
>>>
>>> Thanks for testing. Fixed both issues in the repo.
>>> Was only testing with fate-aac while developing.
>>>
>>
>> mips:
>>
>> make  -k
>> LD	ffmpeg_g
>> libavcodec/libavcodec.a(aacsbr.o): In function `ff_aac_sbr_ctx_alloc_init':
>> aacsbr.c:(.text.unlikely+0x1d4): undefined reference to `ff_aacsbr_func_ptr_init_mips'
>> aacsbr.c:(.text.unlikely+0x200): undefined reference to `ff_aacsbr_func_ptr_init_mips'
>> libavcodec/libavcodec.a(sbrdsp.o): In function `ff_sbrdsp_init':
>> sbrdsp.c:(.text.unlikely+0x10): undefined reference to `ff_sbrdsp_init_mips'
>> sbrdsp.c:(.text.unlikely+0xb4): undefined reference to `ff_sbrdsp_init_mips'
>> libavcodec/libavcodec.a(aacpsdsp_float.o): In function `ff_psdsp_init':
>> aacpsdsp_float.c:(.text.unlikely+0x10): undefined reference to `ff_psdsp_init_mips'
>> aacpsdsp_float.c:(.text.unlikely+0x6c): undefined reference to `ff_psdsp_init_mips'
>> collect2: error: ld returned 1 exit status
>> Makefile:136: recipe for target 'ffmpeg_g' failed
>> make: *** [ffmpeg_g] Error 1
>> LD	ffprobe_g
>> libavcodec/libavcodec.a(aacsbr.o): In function `ff_aac_sbr_ctx_alloc_init':
>> aacsbr.c:(.text.unlikely+0x1d4): undefined reference to `ff_aacsbr_func_ptr_init_mips'
>> aacsbr.c:(.text.unlikely+0x200): undefined reference to `ff_aacsbr_func_ptr_init_mips'
>> libavcodec/libavcodec.a(sbrdsp.o): In function `ff_sbrdsp_init':
>> sbrdsp.c:(.text.unlikely+0x10): undefined reference to `ff_sbrdsp_init_mips'
>> sbrdsp.c:(.text.unlikely+0xb4): undefined reference to `ff_sbrdsp_init_mips'
>> libavcodec/libavcodec.a(aacpsdsp_float.o): In function `ff_psdsp_init':
>> aacpsdsp_float.c:(.text.unlikely+0x10): undefined reference to `ff_psdsp_init_mips'
>> aacpsdsp_float.c:(.text.unlikely+0x6c): undefined reference to `ff_psdsp_init_mips'
>> collect2: error: ld returned 1 exit status
>> Makefile:136: recipe for target 'ffprobe_g' failed
>> make: *** [ffprobe_g] Error 1
>> make: Target 'all' not remade because of errors.
>>
>
> Fixed. This should be all.
> On the Loongson machine I have access to, I can't compile FFmpeg
> due to missing asm/errno.h kernel header, while on the standard MIPS64
> machine I can access, compilation worked either way.
> Would you mind testing again the new version in the repo?
>

Ping. I'm probably the only one who'll touch the AAC code in the near
future, but I wouldn't push this branch without a review first.


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