3 * Copyright (c) 2006 Baptiste Coudurier <baptiste.coudurier@smartjog.com>
4 * Mans Rullgard <mans@mansr.com>
6 * This file is part of FFmpeg.
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.
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.
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
23 #include "libavcodec/get_bits.h"
24 #include "libavcodec/put_bits.h"
25 #include "libavcodec/avcodec.h"
26 #include "libavcodec/mpeg4audio.h"
27 #include "libavutil/opt.h"
31 #define ADTS_HEADER_SIZE 7
37 int sample_rate_index;
41 uint8_t pce_data[MAX_PCE_SIZE];
44 #define ADTS_MAX_FRAME_BYTES ((1 << 13) - 1)
46 static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, uint8_t *buf, int size)
50 MPEG4AudioConfig m4ac;
53 init_get_bits(&gb, buf, size * 8);
54 off = avpriv_mpeg4audio_get_config(&m4ac, buf, size * 8, 1);
57 skip_bits_long(&gb, off);
58 adts->objecttype = m4ac.object_type - 1;
59 adts->sample_rate_index = m4ac.sampling_index;
60 adts->channel_conf = m4ac.chan_config;
62 if (adts->objecttype > 3U) {
63 av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1);
66 if (adts->sample_rate_index == 15) {
67 av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n");
70 if (get_bits(&gb, 1)) {
71 av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n");
74 if (get_bits(&gb, 1)) {
75 av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n");
78 if (get_bits(&gb, 1)) {
79 av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n");
82 if (!adts->channel_conf) {
83 init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE);
85 put_bits(&pb, 3, 5); //ID_PCE
86 adts->pce_size = (avpriv_copy_pce_data(&pb, &gb) + 3) / 8;
95 static int adts_write_header(AVFormatContext *s)
97 ADTSContext *adts = s->priv_data;
98 AVCodecContext *avc = s->streams[0]->codec;
100 if (avc->extradata_size > 0 &&
101 adts_decode_extradata(s, adts, avc->extradata, avc->extradata_size) < 0)
107 static int adts_write_frame_header(ADTSContext *ctx,
108 uint8_t *buf, int size, int pce_size)
112 unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size;
113 if (full_frame_size > ADTS_MAX_FRAME_BYTES) {
114 av_log(NULL, AV_LOG_ERROR, "ADTS frame size too large: %u (max %d)\n",
115 full_frame_size, ADTS_MAX_FRAME_BYTES);
116 return AVERROR_INVALIDDATA;
119 init_put_bits(&pb, buf, ADTS_HEADER_SIZE);
121 /* adts_fixed_header */
122 put_bits(&pb, 12, 0xfff); /* syncword */
123 put_bits(&pb, 1, 0); /* ID */
124 put_bits(&pb, 2, 0); /* layer */
125 put_bits(&pb, 1, 1); /* protection_absent */
126 put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */
127 put_bits(&pb, 4, ctx->sample_rate_index);
128 put_bits(&pb, 1, 0); /* private_bit */
129 put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */
130 put_bits(&pb, 1, 0); /* original_copy */
131 put_bits(&pb, 1, 0); /* home */
133 /* adts_variable_header */
134 put_bits(&pb, 1, 0); /* copyright_identification_bit */
135 put_bits(&pb, 1, 0); /* copyright_identification_start */
136 put_bits(&pb, 13, full_frame_size); /* aac_frame_length */
137 put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */
138 put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */
145 static int adts_write_packet(AVFormatContext *s, AVPacket *pkt)
147 ADTSContext *adts = s->priv_data;
148 AVIOContext *pb = s->pb;
149 uint8_t buf[ADTS_HEADER_SIZE];
153 if (adts->write_adts) {
154 int err = adts_write_frame_header(adts, buf, pkt->size,
158 avio_write(pb, buf, ADTS_HEADER_SIZE);
159 if (adts->pce_size) {
160 avio_write(pb, adts->pce_data, adts->pce_size);
164 avio_write(pb, pkt->data, pkt->size);
169 static int adts_write_trailer(AVFormatContext *s)
171 ADTSContext *adts = s->priv_data;
179 #define ENC AV_OPT_FLAG_ENCODING_PARAM
180 #define OFFSET(obj) offsetof(ADTSContext, obj)
181 static const AVOption options[] = {
182 { "write_apetag", "Enable APE tag writing", OFFSET(apetag), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, ENC},
186 static const AVClass adts_muxer_class = {
187 .class_name = "ADTS muxer",
188 .item_name = av_default_item_name,
190 .version = LIBAVUTIL_VERSION_INT,
193 AVOutputFormat ff_adts_muxer = {
195 .long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"),
196 .mime_type = "audio/aac",
197 .extensions = "aac,adts",
198 .priv_data_size = sizeof(ADTSContext),
199 .audio_codec = AV_CODEC_ID_AAC,
200 .video_codec = AV_CODEC_ID_NONE,
201 .write_header = adts_write_header,
202 .write_packet = adts_write_packet,
203 .write_trailer = adts_write_trailer,
204 .priv_class = &adts_muxer_class,