third_party_ffmpeg/libavcodec/mlpdsp.c
Ramiro Polla 13bd2044d3 mlp: Simplify adressing of state and coeffs arrays for both filters by making
the arrays sequential.

Originally committed as revision 18841 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-05-15 15:34:22 +00:00

62 lines
2.1 KiB
C

/*
* Copyright (c) 2007-2008 Ian Caulfield
* 2009 Ramiro Polla
*
* 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 "libavcodec/mlp.h"
#include "dsputil.h"
static void ff_mlp_filter_channel(int32_t *state, const int32_t *coeff,
int firorder, int iirorder,
unsigned int filter_shift, int32_t mask, int blocksize,
int32_t *sample_buffer)
{
int32_t *firbuf = state;
int32_t *iirbuf = state + MAX_BLOCKSIZE + MAX_FIR_ORDER;
const int32_t *fircoeff = coeff;
const int32_t *iircoeff = coeff + MAX_FIR_ORDER;
int i;
for (i = 0; i < blocksize; i++) {
int32_t residual = *sample_buffer;
unsigned int order;
int64_t accum = 0;
int32_t result;
for (order = 0; order < firorder; order++)
accum += (int64_t) firbuf[order] * fircoeff[order];
for (order = 0; order < iirorder; order++)
accum += (int64_t) iirbuf[order] * iircoeff[order];
accum = accum >> filter_shift;
result = (accum + residual) & mask;
*--firbuf = result;
*--iirbuf = result - accum;
*sample_buffer = result;
sample_buffer += MAX_CHANNELS;
}
}
void ff_mlp_init(DSPContext* c, AVCodecContext *avctx)
{
c->mlp_filter_channel = ff_mlp_filter_channel;
}