[FFmpeg-devel] [PATCH 1/5] libavutil: Add fixed_dsp

[James Almer]

On 01/04/14 11:31 AM, Nedeljko Babic wrote:
> From: Nedeljko Babic <nbabic at mips.com>
> 
> Signed-off-by: Nedeljko Babic <nbabic at mips.com>
> ---
>  libavutil/Makefile    |   1 +
>  libavutil/fixed_dsp.c |  98 ++++++++++++++++++++++++++++++++++
>  libavutil/fixed_dsp.h | 144 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  libavutil/version.h   |   2 +-
>  4 files changed, 244 insertions(+), 1 deletion(-)
>  create mode 100644 libavutil/fixed_dsp.c
>  create mode 100644 libavutil/fixed_dsp.h
> 
> diff --git a/libavutil/Makefile b/libavutil/Makefile
> index 2fe3e15..a90347c 100644
> --- a/libavutil/Makefile
> +++ b/libavutil/Makefile
> @@ -89,6 +89,7 @@ OBJS = adler32.o                                                        \
>         file.o                                                           \
>         file_open.o                                                      \
>         float_dsp.o                                                      \
> +       fixed_dsp.o                                                      \
>         frame.o                                                          \
>         hash.o                                                           \
>         hmac.o                                                           \
> diff --git a/libavutil/fixed_dsp.c b/libavutil/fixed_dsp.c
> new file mode 100644
> index 0000000..6aceaac
> --- /dev/null
> +++ b/libavutil/fixed_dsp.c
> @@ -0,0 +1,98 @@
> +/*
> + * 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 its
> + *    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:  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 "fixed_dsp.h"
> +
> +static void vector_fmul_window_fixed_scaled_c(int16_t *dst, const int32_t *src0,
> +                                       const int32_t *src1, const int32_t *win,
> +                                       int len, uint8_t bits)
> +{
> +    int32_t s0, s1, wi, wj, i,j, round;
> +
> +    dst += len;
> +    win += len;
> +    src0+= len;
> +    round = bits? 1 << (bits-1) : 0;
> +
> +    for (i=-len, j=len-1; i<0; i++, j--) {
> +        s0 = src0[i];
> +        s1 = src1[j];
> +        wi = win[i];
> +        wj = win[j];
> +        dst[i] = av_clip_int16_c(((((int64_t)s0*wj - (int64_t)s1*wi + 0x40000000) >> 31) + round) >> bits);
> +        dst[j] = av_clip_int16_c(((((int64_t)s0*wi + (int64_t)s1*wj + 0x40000000) >> 31) + round) >> bits);
> +    }
> +}
> +
> +static void vector_fmul_window_fixed_c(int32_t *dst, const int32_t *src0,
> +                                       const int32_t *src1, const int32_t *win,
> +                                       int len)
> +{
> +    int32_t s0, s1, wi, wj, i, j;
> +
> +    dst += len;
> +    win += len;
> +    src0+= len;
> +
> +    for (i=-len, j=len-1; i<0; i++, j--) {
> +        s0 = src0[i];
> +        s1 = src1[j];
> +        wi = win[i];
> +        wj = win[j];
> +        dst[i] = ((int64_t)s0*wj - (int64_t)s1*wi + 0x40000000) >> 31;
> +        dst[j] = ((int64_t)s0*wi + (int64_t)s1*wj + 0x40000000) >> 31;
> +    }
> +}
> +
> +AVFixedDSPContext * avpriv_alloc_fixed_dsp(int bit_exact)
> +{
> +    AVFixedDSPContext * fdsp = (AVFixedDSPContext*)av_malloc(sizeof(AVFixedDSPContext));
> +    fdsp->vector_fmul_window_scaled = vector_fmul_window_fixed_scaled_c;
> +    fdsp->vector_fmul_window = vector_fmul_window_fixed_c;
> +
> +    return fdsp;

I didn't catch this before, but why allocate the struct during init? Why not doing it the 
same way as AVFloatDSPContext?
Having the fixed and float versions so different is weird. And having to call av_free() is 
annoying.

Can this be changed at this point? It's been in the tree for a few hours so it shouldn't 
be a problem.