/* * 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> 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, };