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/codec_id.h" 26#include "libavcodec/codec_par.h" 27#include "libavcodec/packet.h" 28#include "libavcodec/mpeg4audio.h" 29#include "libavutil/opt.h" 30#include "avformat.h" 31#include "apetag.h" 32#include "id3v2.h" 33 34#define ADTS_HEADER_SIZE 7 35 36typedef struct ADTSContext { 37 AVClass *class; 38 int write_adts; 39 int objecttype; 40 int sample_rate_index; 41 int channel_conf; 42 int pce_size; 43 int apetag; 44 int id3v2tag; 45 int mpeg_id; 46 uint8_t pce_data[MAX_PCE_SIZE]; 47} ADTSContext; 48 49#define ADTS_MAX_FRAME_BYTES ((1 << 14) - 1) 50 51static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, const uint8_t *buf, int size) 52{ 53 GetBitContext gb; 54 PutBitContext pb; 55 MPEG4AudioConfig m4ac; 56 int off, ret; 57 58 ret = init_get_bits8(&gb, buf, size); 59 if (ret < 0) 60 return ret; 61 off = avpriv_mpeg4audio_get_config2(&m4ac, buf, size, 1, s); 62 if (off < 0) 63 return off; 64 skip_bits_long(&gb, off); 65 adts->objecttype = m4ac.object_type - 1; 66 adts->sample_rate_index = m4ac.sampling_index; 67 adts->channel_conf = m4ac.chan_config; 68 69 if (adts->objecttype > 3U) { 70 av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1); 71 return AVERROR_INVALIDDATA; 72 } 73 if (adts->sample_rate_index == 15) { 74 av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n"); 75 return AVERROR_INVALIDDATA; 76 } 77 if (get_bits(&gb, 1)) { 78 av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n"); 79 return AVERROR_INVALIDDATA; 80 } 81 if (get_bits(&gb, 1)) { 82 av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n"); 83 return AVERROR_INVALIDDATA; 84 } 85 if (get_bits(&gb, 1)) { 86 av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n"); 87 return AVERROR_INVALIDDATA; 88 } 89 if (!adts->channel_conf) { 90 init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE); 91 92 put_bits(&pb, 3, 5); //ID_PCE 93 adts->pce_size = (ff_copy_pce_data(&pb, &gb) + 3) / 8; 94 flush_put_bits(&pb); 95 } 96 97 adts->write_adts = 1; 98 99 return 0; 100} 101 102static int adts_init(AVFormatContext *s) 103{ 104 ADTSContext *adts = s->priv_data; 105 AVCodecParameters *par = s->streams[0]->codecpar; 106 107 if (par->codec_id != AV_CODEC_ID_AAC) { 108 av_log(s, AV_LOG_ERROR, "Only AAC streams can be muxed by the ADTS muxer\n"); 109 return AVERROR(EINVAL); 110 } 111 if (par->extradata_size > 0) 112 return adts_decode_extradata(s, adts, par->extradata, 113 par->extradata_size); 114 115 return 0; 116} 117 118static int adts_write_header(AVFormatContext *s) 119{ 120 ADTSContext *adts = s->priv_data; 121 122 if (adts->id3v2tag) 123 ff_id3v2_write_simple(s, 4, ID3v2_DEFAULT_MAGIC); 124 125 return 0; 126} 127 128static int adts_write_frame_header(ADTSContext *ctx, 129 uint8_t *buf, int size, int pce_size) 130{ 131 PutBitContext pb; 132 133 unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size; 134 if (full_frame_size > ADTS_MAX_FRAME_BYTES) { 135 av_log(NULL, AV_LOG_ERROR, "ADTS frame size too large: %u (max %d)\n", 136 full_frame_size, ADTS_MAX_FRAME_BYTES); 137 return AVERROR_INVALIDDATA; 138 } 139 140 init_put_bits(&pb, buf, ADTS_HEADER_SIZE); 141 142 /* adts_fixed_header */ 143 put_bits(&pb, 12, 0xfff); /* syncword */ 144 put_bits(&pb, 1, ctx->mpeg_id); /* ID */ 145 put_bits(&pb, 2, 0); /* layer */ 146 put_bits(&pb, 1, 1); /* protection_absent */ 147 put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */ 148 put_bits(&pb, 4, ctx->sample_rate_index); 149 put_bits(&pb, 1, 0); /* private_bit */ 150 put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */ 151 put_bits(&pb, 1, 0); /* original_copy */ 152 put_bits(&pb, 1, 0); /* home */ 153 154 /* adts_variable_header */ 155 put_bits(&pb, 1, 0); /* copyright_identification_bit */ 156 put_bits(&pb, 1, 0); /* copyright_identification_start */ 157 put_bits(&pb, 13, full_frame_size); /* aac_frame_length */ 158 put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */ 159 put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */ 160 161 flush_put_bits(&pb); 162 163 return 0; 164} 165 166static int adts_write_packet(AVFormatContext *s, AVPacket *pkt) 167{ 168 ADTSContext *adts = s->priv_data; 169 AVCodecParameters *par = s->streams[0]->codecpar; 170 AVIOContext *pb = s->pb; 171 uint8_t buf[ADTS_HEADER_SIZE]; 172 173 if (!pkt->size) 174 return 0; 175 if (!par->extradata_size) { 176 uint8_t *side_data; 177 size_t side_data_size; 178 int ret; 179 180 side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, 181 &side_data_size); 182 if (side_data_size) { 183 ret = adts_decode_extradata(s, adts, side_data, side_data_size); 184 if (ret < 0) 185 return ret; 186 ret = ff_alloc_extradata(par, side_data_size); 187 if (ret < 0) 188 return ret; 189 memcpy(par->extradata, side_data, side_data_size); 190 } 191 } 192 if (adts->write_adts) { 193 int err = adts_write_frame_header(adts, buf, pkt->size, 194 adts->pce_size); 195 if (err < 0) 196 return err; 197 avio_write(pb, buf, ADTS_HEADER_SIZE); 198 if (adts->pce_size) { 199 avio_write(pb, adts->pce_data, adts->pce_size); 200 adts->pce_size = 0; 201 } 202 } 203 avio_write(pb, pkt->data, pkt->size); 204 205 return 0; 206} 207 208static int adts_write_trailer(AVFormatContext *s) 209{ 210 ADTSContext *adts = s->priv_data; 211 212 if (adts->apetag) 213 ff_ape_write_tag(s); 214 215 return 0; 216} 217 218#define ENC AV_OPT_FLAG_ENCODING_PARAM 219#define OFFSET(obj) offsetof(ADTSContext, obj) 220static const AVOption options[] = { 221 { "write_id3v2", "Enable ID3v2 tag writing", OFFSET(id3v2tag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC}, 222 { "write_apetag", "Enable APE tag writing", OFFSET(apetag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC}, 223 { "write_mpeg2", "Set MPEG version to MPEG-2", OFFSET(mpeg_id), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC}, 224 { NULL }, 225}; 226 227static const AVClass adts_muxer_class = { 228 .class_name = "ADTS muxer", 229 .item_name = av_default_item_name, 230 .option = options, 231 .version = LIBAVUTIL_VERSION_INT, 232}; 233 234const AVOutputFormat ff_adts_muxer = { 235 .name = "adts", 236 .long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"), 237 .mime_type = "audio/aac", 238 .extensions = "aac,adts", 239 .priv_data_size = sizeof(ADTSContext), 240 .audio_codec = AV_CODEC_ID_AAC, 241 .video_codec = AV_CODEC_ID_NONE, 242 .init = adts_init, 243 .write_header = adts_write_header, 244 .write_packet = adts_write_packet, 245 .write_trailer = adts_write_trailer, 246 .priv_class = &adts_muxer_class, 247 .flags = AVFMT_NOTIMESTAMPS, 248}; 249