libavformat/adtsenc.c

   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 "libavcodec/mpeg4audio_copy_pce.h"
  30 #include "libavutil/opt.h"
  31 #include "avformat.h"
  32 #include "apetag.h"
  33 #include "id3v2.h"
  34 #include "mux.h"
  35
  36 #define ADTS_HEADER_SIZE 7
  37
  38 typedef struct ADTSContext {
  39     AVClass *class;
  40     int write_adts;
  41     int objecttype;
  42     int sample_rate_index;
  43     int channel_conf;
  44     int pce_size;
  45     int apetag;
  46     int id3v2tag;
  47     int mpeg_id;
  48     uint8_t pce_data[MAX_PCE_SIZE];
  49 } ADTSContext;
  50
  51 #define ADTS_MAX_FRAME_BYTES ((1 << 14) - 1)
  52
  53 static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, const uint8_t *buf, int size)
  54 {
  55     GetBitContext gb;
  56     PutBitContext pb;
  57     MPEG4AudioConfig m4ac;
  58     int off, ret;
  59
  60     ret = init_get_bits8(&gb, buf, size);
  61     if (ret < 0)
  62         return ret;
  63     off = avpriv_mpeg4audio_get_config2(&m4ac, buf, size, 1, s);
  64     if (off < 0)
  65         return off;
  66     skip_bits_long(&gb, off);
  67     adts->objecttype        = m4ac.object_type - 1;
  68     adts->sample_rate_index = m4ac.sampling_index;
  69     adts->channel_conf      = m4ac.chan_config;
  70
  71     if (adts->objecttype > 3U) {
  72         av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1);
  73         return AVERROR_INVALIDDATA;
  74     }
  75     if (adts->sample_rate_index == 15) {
  76         av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n");
  77         return AVERROR_INVALIDDATA;
  78     }
  79     if (get_bits(&gb, 1)) {
  80         av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n");
  81         return AVERROR_INVALIDDATA;
  82     }
  83     if (get_bits(&gb, 1)) {
  84         av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n");
  85         return AVERROR_INVALIDDATA;
  86     }
  87     if (get_bits(&gb, 1)) {
  88         av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n");
  89         return AVERROR_INVALIDDATA;
  90     }
  91     if (!adts->channel_conf) {
  92         init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE);
  93
  94         put_bits(&pb, 3, 5); //ID_PCE
  95         adts->pce_size = (ff_copy_pce_data(&pb, &gb) + 3) / 8;
  96         flush_put_bits(&pb);
  97     }
  98
  99     adts->write_adts = 1;
 100
 101     return 0;
 102 }
 103
 104 static int adts_init(AVFormatContext *s)
 105 {
 106     ADTSContext *adts = s->priv_data;
 107     AVCodecParameters *par = s->streams[0]->codecpar;
 108
 109     if (par->extradata_size > 0)
 110         return adts_decode_extradata(s, adts, par->extradata,
 111                                      par->extradata_size);
 112
 113     return 0;
 114 }
 115
 116 static int adts_write_header(AVFormatContext *s)
 117 {
 118     ADTSContext *adts = s->priv_data;
 119
 120     if (adts->id3v2tag)
 121         ff_id3v2_write_simple(s, 4, ID3v2_DEFAULT_MAGIC);
 122
 123     return 0;
 124 }
 125
 126 static int adts_write_frame_header(AVFormatContext *s, ADTSContext *ctx,
 127                                    uint8_t *buf, int size, int pce_size)
 128 {
 129     PutBitContext pb;
 130
 131     unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size;
 132     if (full_frame_size > ADTS_MAX_FRAME_BYTES) {
 133         av_log(s, AV_LOG_ERROR, "frame size too large: %u (max %d)\n",
 134                full_frame_size, ADTS_MAX_FRAME_BYTES);
 135         return AVERROR_INVALIDDATA;
 136     }
 137
 138     init_put_bits(&pb, buf, ADTS_HEADER_SIZE);
 139
 140     /* adts_fixed_header */
 141     put_bits(&pb, 12, 0xfff);   /* syncword */
 142     put_bits(&pb, 1, ctx->mpeg_id); /* ID */
 143     put_bits(&pb, 2, 0);        /* layer */
 144     put_bits(&pb, 1, 1);        /* protection_absent */
 145     put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */
 146     put_bits(&pb, 4, ctx->sample_rate_index);
 147     put_bits(&pb, 1, 0);        /* private_bit */
 148     put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */
 149     put_bits(&pb, 1, 0);        /* original_copy */
 150     put_bits(&pb, 1, 0);        /* home */
 151
 152     /* adts_variable_header */
 153     put_bits(&pb, 1, 0);        /* copyright_identification_bit */
 154     put_bits(&pb, 1, 0);        /* copyright_identification_start */
 155     put_bits(&pb, 13, full_frame_size); /* aac_frame_length */
 156     put_bits(&pb, 11, 0x7ff);   /* adts_buffer_fullness */
 157     put_bits(&pb, 2, 0);        /* number_of_raw_data_blocks_in_frame */
 158
 159     flush_put_bits(&pb);
 160
 161     return 0;
 162 }
 163
 164 static int adts_write_packet(AVFormatContext *s, AVPacket *pkt)
 165 {
 166     ADTSContext *adts = s->priv_data;
 167     AVCodecParameters *par = s->streams[0]->codecpar;
 168     AVIOContext *pb = s->pb;
 169     uint8_t buf[ADTS_HEADER_SIZE];
 170
 171     if (!pkt->size)
 172         return 0;
 173     if (!par->extradata_size) {
 174         uint8_t *side_data;
 175         size_t side_data_size;
 176         int ret;
 177
 178         side_data = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
 179                                             &side_data_size);
 180         if (side_data_size) {
 181             ret = adts_decode_extradata(s, adts, side_data, side_data_size);
 182             if (ret < 0)
 183                 return ret;
 184             ret = ff_alloc_extradata(par, side_data_size);
 185             if (ret < 0)
 186                 return ret;
 187             memcpy(par->extradata, side_data, side_data_size);
 188         }
 189     }
 190     if (adts->write_adts) {
 191         int err = adts_write_frame_header(s, adts, buf, pkt->size,
 192                                              adts->pce_size);
 193         if (err < 0)
 194             return err;
 195         avio_write(pb, buf, ADTS_HEADER_SIZE);
 196         if (adts->pce_size) {
 197             avio_write(pb, adts->pce_data, adts->pce_size);
 198             adts->pce_size = 0;
 199         }
 200     }
 201     avio_write(pb, pkt->data, pkt->size);
 202
 203     return 0;
 204 }
 205
 206 static int adts_write_trailer(AVFormatContext *s)
 207 {
 208     ADTSContext *adts = s->priv_data;
 209
 210     if (adts->apetag)
 211         ff_ape_write_tag(s);
 212
 213     return 0;
 214 }
 215
 216 #define ENC AV_OPT_FLAG_ENCODING_PARAM
 217 #define OFFSET(obj) offsetof(ADTSContext, obj)
 218 static const AVOption options[] = {
 219     { "write_id3v2",  "Enable ID3v2 tag writing",   OFFSET(id3v2tag), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC},
 220     { "write_apetag", "Enable APE tag writing",     OFFSET(apetag),   AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC},
 221     { "write_mpeg2",  "Set MPEG version to MPEG-2", OFFSET(mpeg_id),  AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC},
 222     { NULL },
 223 };
 224
 225 static const AVClass adts_muxer_class = {
 226     .class_name     = "ADTS muxer",
 227     .item_name      = av_default_item_name,
 228     .option         = options,
 229     .version        = LIBAVUTIL_VERSION_INT,
 230 };
 231
 232 const FFOutputFormat ff_adts_muxer = {
 233     .p.name            = "adts",
 234     .p.long_name       = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"),
 235     .p.mime_type       = "audio/aac",
 236     .p.extensions      = "aac,adts",
 237     .priv_data_size    = sizeof(ADTSContext),
 238     .p.audio_codec     = AV_CODEC_ID_AAC,
 239     .p.video_codec     = AV_CODEC_ID_NONE,
 240     .p.subtitle_codec  = AV_CODEC_ID_NONE,
 241     .flags_internal    = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
 242                          FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
 243     .init              = adts_init,
 244     .write_header      = adts_write_header,
 245     .write_packet      = adts_write_packet,
 246     .write_trailer     = adts_write_trailer,
 247     .p.priv_class      = &adts_muxer_class,
 248     .p.flags           = AVFMT_NOTIMESTAMPS,
 249 };