[FFmpeg-devel] [PATCH 1/2] Optimization of AC3 floating point decoder for MIPS

[Babic, Nedeljko]

>> FFT in MIPS implementation is working iteratively instead
>>  of "recursively" calling functions for smaller FFT sizes.
>> Some of DSP and format convert utils functions are also optimized.
>[...]
>> diff --git a/libavcodec/mips/fmtconvert_mips.c b/libavcodec/mips/fmtconvert_mips.c
>> new file mode 100644
>> index 0000000..9e45ba1
>> --- /dev/null
>> +++ b/libavcodec/mips/fmtconvert_mips.c
>> @@ -0,0 +1,336 @@
>> +/*
>> + * Format Conversion Utils for MIPS
>> + *
>> + * Copyright (c) 2012
>> + *      MIPS Technologies, Inc., California.
>> + *
>> + * Redistribution and use in source and binary forms, with or without
>> + * modification, are permitted provided that the following conditions
>> + * are met:
>> + * 1. Redistributions of source code must retain the above copyright
>> + *    notice, this list of conditions and the following disclaimer.
>> + * 2. Redistributions in binary form must reproduce the above copyright
>> + *    notice, this list of conditions and the following disclaimer in the
>> + *    documentation and/or other materials provided with the distribution.
>> + * 3. Neither the name of the MIPS Technologies, Inc., nor the names of is
>> + *    contributors may be used to endorse or promote products derived from
>> + *    this software without specific prior written permission.
>> + *
>> + * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND
>> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
>> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
>> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE
>> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
>> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
>> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
>> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
>> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
>> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
>> + * SUCH DAMAGE.
>> + *
>> + * Author:  Zoran Lukic (zoranl at mips.com)
>> + * Author:  Nedeljko Babic (nbabic at mips.com)
>> + *
>> + * This file is part of FFmpeg.
>> + *
>> + * FFmpeg is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * FFmpeg is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with FFmpeg; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>> + */
>> +#include "config.h"
>> +#include "libavcodec/avcodec.h"
>> +#include "libavcodec/fmtconvert.h"
>> +
>> +#if HAVE_INLINE_ASM
>
>if all code in the whole file depends on HAVE_INLINE_ASM then it
>would be easiest to change the Makefile to only compile it in that
>case instead of the #ifs
>

To tell the truth, I am not sure how to do this in elegant way...
Only place that something similar is done in ffmpeg is in optimizations for x86
and there it is done in the same way as it is done here (file 
libavcodec/x86/cavsdsp_mmx.c for example). 
I am thinking of using ifeq in Makefile, but I am not sure this is a 
right way of doing this...
Is there a better way?

>
>> +static void float_to_int16_mips(int16_t *dst, const float *src, long len) {
>
>you might want to look at libswresample/audioconvert
>as well as libswresample/x86/audio_convert.asm (which is the x86
>optimized variant of it)
>
>libswresample is what ffmpeg primarely uses to convert between
>sample formats and packings (as well as sample rates & channel layouts)
>the fmtconvert code is likely going to be used less and might totally
>disappear as codecs should read & write their "native" format and
>not convert internally ...
>

The fmtconvert code was optimized as part of ac3 decoder optimization. 
Do we need to optimize functions from libswresample/audioconvert in order for 
patch for ac3 decoder to be accepted?

-Nedeljko
________________________________________
From: Michael Niedermayer [michaelni at gmx.at]
Sent: Saturday, July 07, 2012 23:32
To: FFmpeg development discussions and patches
Cc: Babic, Nedeljko; Lukac, Zeljko
Subject: Re: [FFmpeg-devel] [PATCH 1/2] Optimization of AC3 floating point decoder for MIPS

On Tue, Jun 26, 2012 at 01:13:20PM +0200, Nedeljko Babic wrote:
> FFT in MIPS implementation is working iteratively instead
>  of "recursively" calling functions for smaller FFT sizes.
> Some of DSP and format convert utils functions are also optimized.
[...]
> diff --git a/libavcodec/mips/fmtconvert_mips.c b/libavcodec/mips/fmtconvert_mips.c
> new file mode 100644
> index 0000000..9e45ba1
> --- /dev/null
> +++ b/libavcodec/mips/fmtconvert_mips.c
> @@ -0,0 +1,336 @@
> +/*
> + * Format Conversion Utils for MIPS
> + *
> + * Copyright (c) 2012
> + *      MIPS Technologies, Inc., California.
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *    notice, this list of conditions and the following disclaimer in the
> + *    documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of the MIPS Technologies, Inc., nor the names of is
> + *    contributors may be used to endorse or promote products derived from
> + *    this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE MIPS TECHNOLOGIES, INC. ``AS IS'' AND
> + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
> + * ARE DISCLAIMED.  IN NO EVENT SHALL THE MIPS TECHNOLOGIES, INC. BE LIABLE
> + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
> + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
> + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
> + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
> + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
> + * SUCH DAMAGE.
> + *
> + * Author:  Zoran Lukic (zoranl at mips.com)
> + * Author:  Nedeljko Babic (nbabic at mips.com)
> + *
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +#include "config.h"
> +#include "libavcodec/avcodec.h"
> +#include "libavcodec/fmtconvert.h"
> +
> +#if HAVE_INLINE_ASM

if all code in the whole file depends on HAVE_INLINE_ASM then it
would be easiest to change the Makefile to only compile it in that
case instead of the #ifs


> +static void float_to_int16_mips(int16_t *dst, const float *src, long len) {

you might want to look at libswresample/audioconvert
as well as libswresample/x86/audio_convert.asm (which is the x86
optimized variant of it)

libswresample is what ffmpeg primarely uses to convert between
sample formats and packings (as well as sample rates & channel layouts)
the fmtconvert code is likely going to be used less and might totally
disappear as codecs should read & write their "native" format and
not convert internally ...

except these, the fmtconvert changes look good to me

thanks

[...]
--
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Complexity theory is the science of finding the exact solution to an
approximation. Benchmarking OTOH is finding an approximation of the exact