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adtsenc.c
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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 "libavcodec/mpeg4audio.h"
27 #include "libavutil/opt.h"
28 #include "avformat.h"
29 #include "apetag.h"
30 #include "id3v2.h"
31 
32 #define ADTS_HEADER_SIZE 7
33 
34 typedef struct {
35  AVClass *class;
40  int pce_size;
41  int apetag;
42  int id3v2tag;
43  uint8_t pce_data[MAX_PCE_SIZE];
44 } ADTSContext;
45 
46 #define ADTS_MAX_FRAME_BYTES ((1 << 13) - 1)
47 
49 {
50  GetBitContext gb;
51  PutBitContext pb;
52  MPEG4AudioConfig m4ac;
53  int off;
54 
55  init_get_bits(&gb, buf, size * 8);
56  off = avpriv_mpeg4audio_get_config(&m4ac, buf, size * 8, 1);
57  if (off < 0)
58  return off;
59  skip_bits_long(&gb, off);
60  adts->objecttype = m4ac.object_type - 1;
61  adts->sample_rate_index = m4ac.sampling_index;
62  adts->channel_conf = m4ac.chan_config;
63 
64  if (adts->objecttype > 3U) {
65  av_log(s, AV_LOG_ERROR, "MPEG-4 AOT %d is not allowed in ADTS\n", adts->objecttype+1);
66  return -1;
67  }
68  if (adts->sample_rate_index == 15) {
69  av_log(s, AV_LOG_ERROR, "Escape sample rate index illegal in ADTS\n");
70  return -1;
71  }
72  if (get_bits(&gb, 1)) {
73  av_log(s, AV_LOG_ERROR, "960/120 MDCT window is not allowed in ADTS\n");
74  return -1;
75  }
76  if (get_bits(&gb, 1)) {
77  av_log(s, AV_LOG_ERROR, "Scalable configurations are not allowed in ADTS\n");
78  return -1;
79  }
80  if (get_bits(&gb, 1)) {
81  av_log(s, AV_LOG_ERROR, "Extension flag is not allowed in ADTS\n");
82  return -1;
83  }
84  if (!adts->channel_conf) {
85  init_put_bits(&pb, adts->pce_data, MAX_PCE_SIZE);
86 
87  put_bits(&pb, 3, 5); //ID_PCE
88  adts->pce_size = (avpriv_copy_pce_data(&pb, &gb) + 3) / 8;
89  flush_put_bits(&pb);
90  }
91 
92  adts->write_adts = 1;
93 
94  return 0;
95 }
96 
98 {
99  ADTSContext *adts = s->priv_data;
100  AVCodecContext *avc = s->streams[0]->codec;
101 
102  if (adts->id3v2tag)
104  if (avc->extradata_size > 0 &&
105  adts_decode_extradata(s, adts, avc->extradata, avc->extradata_size) < 0)
106  return -1;
107 
108  return 0;
109 }
110 
112  uint8_t *buf, int size, int pce_size)
113 {
114  PutBitContext pb;
115 
116  unsigned full_frame_size = (unsigned)ADTS_HEADER_SIZE + size + pce_size;
117  if (full_frame_size > ADTS_MAX_FRAME_BYTES) {
118  av_log(NULL, AV_LOG_ERROR, "ADTS frame size too large: %u (max %d)\n",
119  full_frame_size, ADTS_MAX_FRAME_BYTES);
120  return AVERROR_INVALIDDATA;
121  }
122 
123  init_put_bits(&pb, buf, ADTS_HEADER_SIZE);
124 
125  /* adts_fixed_header */
126  put_bits(&pb, 12, 0xfff); /* syncword */
127  put_bits(&pb, 1, 0); /* ID */
128  put_bits(&pb, 2, 0); /* layer */
129  put_bits(&pb, 1, 1); /* protection_absent */
130  put_bits(&pb, 2, ctx->objecttype); /* profile_objecttype */
131  put_bits(&pb, 4, ctx->sample_rate_index);
132  put_bits(&pb, 1, 0); /* private_bit */
133  put_bits(&pb, 3, ctx->channel_conf); /* channel_configuration */
134  put_bits(&pb, 1, 0); /* original_copy */
135  put_bits(&pb, 1, 0); /* home */
136 
137  /* adts_variable_header */
138  put_bits(&pb, 1, 0); /* copyright_identification_bit */
139  put_bits(&pb, 1, 0); /* copyright_identification_start */
140  put_bits(&pb, 13, full_frame_size); /* aac_frame_length */
141  put_bits(&pb, 11, 0x7ff); /* adts_buffer_fullness */
142  put_bits(&pb, 2, 0); /* number_of_raw_data_blocks_in_frame */
143 
144  flush_put_bits(&pb);
145 
146  return 0;
147 }
148 
150 {
151  ADTSContext *adts = s->priv_data;
152  AVIOContext *pb = s->pb;
154 
155  if (!pkt->size)
156  return 0;
157  if (adts->write_adts) {
158  int err = adts_write_frame_header(adts, buf, pkt->size,
159  adts->pce_size);
160  if (err < 0)
161  return err;
162  avio_write(pb, buf, ADTS_HEADER_SIZE);
163  if (adts->pce_size) {
164  avio_write(pb, adts->pce_data, adts->pce_size);
165  adts->pce_size = 0;
166  }
167  }
168  avio_write(pb, pkt->data, pkt->size);
169 
170  return 0;
171 }
172 
174 {
175  ADTSContext *adts = s->priv_data;
176 
177  if (adts->apetag)
178  ff_ape_write_tag(s);
179 
180  return 0;
181 }
182 
183 #define ENC AV_OPT_FLAG_ENCODING_PARAM
184 #define OFFSET(obj) offsetof(ADTSContext, obj)
185 static const AVOption options[] = {
186  { "write_id3v2", "Enable ID3v2 tag writing", OFFSET(id3v2tag), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, ENC},
187  { "write_apetag", "Enable APE tag writing", OFFSET(apetag), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, ENC},
188  { NULL },
189 };
190 
191 static const AVClass adts_muxer_class = {
192  .class_name = "ADTS muxer",
193  .item_name = av_default_item_name,
194  .option = options,
195  .version = LIBAVUTIL_VERSION_INT,
196 };
197 
199  .name = "adts",
200  .long_name = NULL_IF_CONFIG_SMALL("ADTS AAC (Advanced Audio Coding)"),
201  .mime_type = "audio/aac",
202  .extensions = "aac,adts",
203  .priv_data_size = sizeof(ADTSContext),
204  .audio_codec = AV_CODEC_ID_AAC,
205  .video_codec = AV_CODEC_ID_NONE,
209  .priv_class = &adts_muxer_class,
211 };