1/* 2 * ADTS muxer. 3 * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com> 4 * Mans Rullgard <mans@mansr.com> 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23#include "libavcodec/get_bits.h" 24#include "libavcodec/put_bits.h" 25#include "libavcodec/avcodec.h" 26#include "avformat.h" 27#include "adts.h" 28 29int ff_adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, uint8_t *buf, int size) 30{ 31 GetBitContext gb; 32 PutBitContext pb; 33 34 init_get_bits(&gb, buf, size * 8); 35 adts->objecttype = get_bits(&gb, 5) - 1; 36 adts->sample_rate_index = get_bits(&gb, 4); 37 adts->channel_conf = get_bits(&gb, 4); 38 39 if (adts->objecttype > 3U) { 40 av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1); 41 return -1; 42 } 43 if (adts->sample_rate_index == 15) { 44 av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n"); 45 return -1; 46 } 47 if (get_bits(&gb, 1)) { 48 av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n"); 49 return -1; 50 } 51 if (get_bits(&gb, 1)) { 52 av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n"); 53 return -1; 54 } 55 if (get_bits(&gb, 1)) { 56 av_log_missing_feature(s, "Signaled SBR or PS", 0); 57 return -1; 58 } 59 if (!adts->channel_conf) { 60 init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE); 61 62 put_bits(&pb, 3, 5); //ID_PCE 63 adts->pce_size = (ff_copy_pce_data(&pb, &gb) + 3) / 8; 64 flush_put_bits(&pb); 65 } 66 67 adts->write_adts = 1; 68 69 return 0; 70} 71 72static int adts_write_header(AVFormatContext *s) 73{ 74 ADTSContext *adts = s->priv_data; 75 AVCodecContext *avc = s->streams[0]->codec; 76 77 if(avc->extradata_size > 0 && 78 ff_adts_decode_extradata(s, adts, avc->extradata, avc->extradata_size) < 0) 79 return -1; 80 81 return 0; 82} 83 84int ff_adts_write_frame_header(ADTSContext *ctx, 85 uint8_t *buf, int size, int pce_size) 86{ 87 PutBitContext pb; 88 89 init_put_bits(&pb, buf, ADTS_HEADER_SIZE); 90 91 /* adts_fixed_header */ 92 put_bits(&pb, 12, 0xfff); /* syncword */ 93 put_bits(&pb, 1, 0); /* ID */ 94 put_bits(&pb, 2, 0); /* layer */ 95 put_bits(&pb, 1, 1); /* protection_absent */ 96 put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */ 97 put_bits(&pb, 4, ctx->sample_rate_index); 98 put_bits(&pb, 1, 0); /* private_bit */ 99 put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */ 100 put_bits(&pb, 1, 0); /* original_copy */ 101 put_bits(&pb, 1, 0); /* home */ 102 103 /* adts_variable_header */ 104 put_bits(&pb, 1, 0); /* copyright_identification_bit */ 105 put_bits(&pb, 1, 0); /* copyright_identification_start */ 106 put_bits(&pb, 13, ADTS_HEADER_SIZE + size + pce_size); /* aac_frame_length */ 107 put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */ 108 put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */ 109 110 flush_put_bits(&pb); 111 112 return 0; 113} 114 115static int adts_write_packet(AVFormatContext *s, AVPacket *pkt) 116{ 117 ADTSContext *adts = s->priv_data; 118 ByteIOContext *pb = s->pb; 119 uint8_t buf[ADTS_HEADER_SIZE]; 120 121 if (!pkt->size) 122 return 0; 123 if(adts->write_adts) { 124 ff_adts_write_frame_header(adts, buf, pkt->size, adts->pce_size); 125 put_buffer(pb, buf, ADTS_HEADER_SIZE); 126 if(adts->pce_size) { 127 put_buffer(pb, adts->pce_data, adts->pce_size); 128 adts->pce_size = 0; 129 } 130 } 131 put_buffer(pb, pkt->data, pkt->size); 132 put_flush_packet(pb); 133 134 return 0; 135} 136 137AVOutputFormat adts_muxer = { 138 "adts", 139 NULL_IF_CONFIG_SMALL("ADTS AAC"), 140 "audio/aac", 141 "aac,adts", 142 sizeof(ADTSContext), 143 CODEC_ID_AAC, 144 CODEC_ID_NONE, 145 adts_write_header, 146 adts_write_packet, 147}; 148