FFmpeg/libavcodec/mpegvideoencdsp.c

/*
 * 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 <assert.h>
#include <stdint.h>

#include "config.h"
#include "libavutil/avassert.h"
#include "libavutil/attributes.h"
#include "avcodec.h"
#include "mpegvideoencdsp.h"

static int try_8x8basis_c(int16_t rem[64], int16_t weight[64],
                          int16_t basis[64], int scale)
{
    int i;
    unsigned int sum = 0;

    for (i = 0; i < 8 * 8; i++) {
        int b = rem[i] + ((basis[i] * scale +
                           (1 << (BASIS_SHIFT - RECON_SHIFT - 1))) >>
                          (BASIS_SHIFT - RECON_SHIFT));
        int w = weight[i];
        b >>= RECON_SHIFT;
        av_assert2(-512 < b && b < 512);

        sum += (w * b) * (w * b) >> 4;
    }
    return sum >> 2;
}

static void add_8x8basis_c(int16_t rem[64], int16_t basis[64], int scale)
{
    int i;

    for (i = 0; i < 8 * 8; i++)
        rem[i] += (basis[i] * scale +
                   (1 << (BASIS_SHIFT - RECON_SHIFT - 1))) >>
                  (BASIS_SHIFT - RECON_SHIFT);
}

av_cold void ff_mpegvideoencdsp_init(MpegvideoEncDSPContext *c,
                                     AVCodecContext *avctx)
{
    c->try_8x8basis = try_8x8basis_c;
    c->add_8x8basis = add_8x8basis_c;

    if (ARCH_X86)
        ff_mpegvideoencdsp_init_x86(c, avctx);
}