diff options
Diffstat (limited to 'libavcodec/ac3dec_fixed.c')
| -rw-r--r-- | libavcodec/ac3dec_fixed.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/libavcodec/ac3dec_fixed.c b/libavcodec/ac3dec_fixed.c new file mode 100644 index 0000000000..c6cbeb9b28 --- /dev/null +++ b/libavcodec/ac3dec_fixed.c @@ -0,0 +1,176 @@ +/* + * 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: Stanislav Ocovaj (socovaj@mips.com) + * + * AC3 fixed-point decoder for MIPS platforms + * + * 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 + */ + +#define FFT_FLOAT 0 +#define USE_FIXED 1 +#define FFT_FIXED_32 1 +#include "ac3dec.h" + + +/** + * Table for center mix levels + * reference: Section 5.4.2.4 cmixlev + */ +static const uint8_t center_levels[4] = { 4, 5, 6, 5 }; + +/** + * Table for surround mix levels + * reference: Section 5.4.2.5 surmixlev + */ +static const uint8_t surround_levels[4] = { 4, 6, 7, 6 }; + +int end_freq_inv_tab[8] = +{ + 50529027, 44278013, 39403370, 32292987, 27356480, 23729101, 20951060, 18755316 +}; + +static void scale_coefs ( + int32_t *dst, + const int32_t *src, + int dynrng, + int len) +{ + int i, shift, round; + int16_t mul; + int temp, temp1, temp2, temp3, temp4, temp5, temp6, temp7; + + mul = (dynrng & 0x1f) + 0x20; + shift = 4 - ((dynrng << 24) >> 29); + round = 1 << (shift-1); + for (i=0; i<len; i+=8) { + + temp = src[i] * mul; + temp1 = src[i+1] * mul; + temp = temp + round; + temp2 = src[i+2] * mul; + + temp1 = temp1 + round; + dst[i] = temp >> shift; + temp3 = src[i+3] * mul; + temp2 = temp2 + round; + + dst[i+1] = temp1 >> shift; + temp4 = src[i + 4] * mul; + temp3 = temp3 + round; + dst[i+2] = temp2 >> shift; + + temp5 = src[i+5] * mul; + temp4 = temp4 + round; + dst[i+3] = temp3 >> shift; + temp6 = src[i+6] * mul; + + dst[i+4] = temp4 >> shift; + temp5 = temp5 + round; + temp7 = src[i+7] * mul; + temp6 = temp6 + round; + + dst[i+5] = temp5 >> shift; + temp7 = temp7 + round; + dst[i+6] = temp6 >> shift; + dst[i+7] = temp7 >> shift; + + } +} + +/** + * Downmix samples from original signal to stereo or mono (this is for 16-bit samples + * and fixed point decoder - original (for 32-bit samples) is in ac3dsp.c). + */ +static void ac3_downmix_c_fixed16(int16_t **samples, int16_t (*matrix)[2], + int out_ch, int in_ch, int len) +{ + int i, j; + int v0, v1; + if (out_ch == 2) { + for (i = 0; i < len; i++) { + v0 = v1 = 0; + for (j = 0; j < in_ch; j++) { + v0 += samples[j][i] * matrix[j][0]; + v1 += samples[j][i] * matrix[j][1]; + } + samples[0][i] = (v0+2048)>>12; + samples[1][i] = (v1+2048)>>12; + } + } else if (out_ch == 1) { + for (i = 0; i < len; i++) { + v0 = 0; + for (j = 0; j < in_ch; j++) + v0 += samples[j][i] * matrix[j][0]; + samples[0][i] = (v0+2048)>>12; + } + } +} + +#include "ac3dec.c" + +static const AVOption options[] = { + { NULL}, +}; + +static const AVClass ac3_decoder_class = { + .class_name = "Fixed-Point AC-3 Decoder", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + +AVCodec ff_ac3_fixed_decoder = { + .name = "ac3_fixed", + .type = AVMEDIA_TYPE_AUDIO, + .id = AV_CODEC_ID_AC3, + .priv_data_size = sizeof (AC3DecodeContext), + .init = ac3_decode_init, + .close = ac3_decode_end, + .decode = ac3_decode_frame, + .capabilities = CODEC_CAP_DR1, + .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"), + .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P, + AV_SAMPLE_FMT_NONE }, + .priv_class = &ac3_decoder_class, +}; |