libavcodec/mlpdsp.c

   1 /*
   2  * Copyright (c) 2007-2008 Ian Caulfield
   3  *               2009 Ramiro Polla
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavcodec/mlp.h"
  23 #include "dsputil.h"
  24
  25 static void ff_mlp_filter_channel(int32_t *state, const int32_t *coeff,
  26                                   int firorder, int iirorder,
  27                                   unsigned int filter_shift, int32_t mask, int blocksize,
  28                                   int32_t *sample_buffer)
  29 {
  30     int32_t *firbuf = state;
  31     int32_t *iirbuf = state + MAX_BLOCKSIZE + MAX_FIR_ORDER;
  32     const int32_t *fircoeff = coeff;
  33     const int32_t *iircoeff = coeff + MAX_FIR_ORDER;
  34     int i;
  35
  36     for (i = 0; i < blocksize; i++) {
  37         int32_t residual = *sample_buffer;
  38         unsigned int order;
  39         int64_t accum = 0;
  40         int32_t result;
  41
  42         for (order = 0; order < firorder; order++)
  43             accum += (int64_t) firbuf[order] * fircoeff[order];
  44         for (order = 0; order < iirorder; order++)
  45             accum += (int64_t) iirbuf[order] * iircoeff[order];
  46
  47         accum  = accum >> filter_shift;
  48         result = (accum + residual) & mask;
  49
  50         *--firbuf = result;
  51         *--iirbuf = result - accum;
  52
  53         *sample_buffer = result;
  54         sample_buffer += MAX_CHANNELS;
  55     }
  56 }
  57
  58 void ff_mlp_init_x86(DSPContext* c, AVCodecContext *avctx);
  59
  60 void ff_mlp_init(DSPContext* c, AVCodecContext *avctx)
  61 {
  62     c->mlp_filter_channel = ff_mlp_filter_channel;
  63     if (ARCH_X86)
  64         ff_mlp_init_x86(c, avctx);
  65 }