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latmenc.c
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1 /*
2  * LATM/LOAS muxer
3  * Copyright (c) 2011 Kieran Kunhya <kieran@kunhya.com>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavcodec/get_bits.h"
23 #include "libavcodec/put_bits.h"
24 #include "libavcodec/avcodec.h"
25 #include "libavcodec/mpeg4audio.h"
26 #include "libavutil/opt.h"
27 #include "avformat.h"
28 #include "rawenc.h"
29 
30 #define MAX_EXTRADATA_SIZE 1024
31 
32 typedef struct LATMContext {
34  int off;
37  int counter;
38  int mod;
39  uint8_t buffer[0x1fff + MAX_EXTRADATA_SIZE + 1024];
40 } LATMContext;
41 
42 static const AVOption options[] = {
43  {"smc-interval", "StreamMuxConfig interval.",
44  offsetof(LATMContext, mod), AV_OPT_TYPE_INT, {.i64 = 0x0014}, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
45  {NULL},
46 };
47 
48 static const AVClass latm_muxer_class = {
49  .class_name = "LATM/LOAS muxer",
50  .item_name = av_default_item_name,
51  .option = options,
52  .version = LIBAVUTIL_VERSION_INT,
53 };
54 
56 {
57  MPEG4AudioConfig m4ac;
58 
59  if (size > MAX_EXTRADATA_SIZE) {
60  av_log(ctx, AV_LOG_ERROR, "Extradata is larger than currently supported.\n");
61  return AVERROR_INVALIDDATA;
62  }
63  ctx->off = avpriv_mpeg4audio_get_config(&m4ac, buf, size * 8, 1);
64  if (ctx->off < 0)
65  return ctx->off;
66 
67  if (ctx->object_type == AOT_ALS && (ctx->off & 7)) {
68  // as long as avpriv_mpeg4audio_get_config works correctly this is impossible
69  av_log(ctx, AV_LOG_ERROR, "BUG: ALS offset is not byte-aligned\n");
70  return AVERROR_INVALIDDATA;
71  }
72  /* FIXME: are any formats not allowed in LATM? */
73 
74  if (m4ac.object_type > AOT_SBR && m4ac.object_type != AOT_ALS) {
75  av_log(ctx, AV_LOG_ERROR, "Muxing MPEG-4 AOT %d in LATM is not supported\n", m4ac.object_type);
76  return AVERROR_INVALIDDATA;
77  }
78  ctx->channel_conf = m4ac.chan_config;
79  ctx->object_type = m4ac.object_type;
80 
81  return 0;
82 }
83 
85 {
86  LATMContext *ctx = s->priv_data;
87  AVCodecContext *avctx = s->streams[0]->codec;
88 
89  if (avctx->codec_id == AV_CODEC_ID_AAC_LATM)
90  return 0;
91 
92  if (avctx->extradata_size > 0 &&
93  latm_decode_extradata(ctx, avctx->extradata, avctx->extradata_size) < 0)
94  return AVERROR_INVALIDDATA;
95 
96  return 0;
97 }
98 
100 {
101  LATMContext *ctx = s->priv_data;
102  AVCodecContext *avctx = s->streams[0]->codec;
103  int header_size;
104 
105  /* AudioMuxElement */
106  put_bits(bs, 1, !!ctx->counter);
107 
108  if (!ctx->counter) {
109  /* StreamMuxConfig */
110  put_bits(bs, 1, 0); /* audioMuxVersion */
111  put_bits(bs, 1, 1); /* allStreamsSameTimeFraming */
112  put_bits(bs, 6, 0); /* numSubFrames */
113  put_bits(bs, 4, 0); /* numProgram */
114  put_bits(bs, 3, 0); /* numLayer */
115 
116  /* AudioSpecificConfig */
117  if (ctx->object_type == AOT_ALS) {
118  header_size = avctx->extradata_size-(ctx->off >> 3);
119  avpriv_copy_bits(bs, &avctx->extradata[ctx->off >> 3], header_size);
120  } else {
121  // + 3 assumes not scalable and dependsOnCoreCoder == 0,
122  // see decode_ga_specific_config in libavcodec/aacdec.c
123  avpriv_copy_bits(bs, avctx->extradata, ctx->off + 3);
124 
125  if (!ctx->channel_conf) {
126  GetBitContext gb;
127  int ret = init_get_bits8(&gb, avctx->extradata, avctx->extradata_size);
128  av_assert0(ret >= 0); // extradata size has been checked already, so this should not fail
129  skip_bits_long(&gb, ctx->off + 3);
130  avpriv_copy_pce_data(bs, &gb);
131  }
132  }
133 
134  put_bits(bs, 3, 0); /* frameLengthType */
135  put_bits(bs, 8, 0xff); /* latmBufferFullness */
136 
137  put_bits(bs, 1, 0); /* otherDataPresent */
138  put_bits(bs, 1, 0); /* crcCheckPresent */
139  }
140 
141  ctx->counter++;
142  ctx->counter %= ctx->mod;
143 }
144 
146 {
147  LATMContext *ctx = s->priv_data;
148  AVIOContext *pb = s->pb;
149  PutBitContext bs;
150  int i, len;
151  uint8_t loas_header[] = "\x56\xe0\x00";
152 
154  return ff_raw_write_packet(s, pkt);
155 
156  if (pkt->size > 2 && pkt->data[0] == 0xff && (pkt->data[1] >> 4) == 0xf) {
157  av_log(s, AV_LOG_ERROR, "ADTS header detected - ADTS will not be incorrectly muxed into LATM\n");
158  return AVERROR_INVALIDDATA;
159  }
160 
161  if (!s->streams[0]->codec->extradata) {
162  if(pkt->size > 2 && pkt->data[0] == 0x56 && (pkt->data[1] >> 4) == 0xe &&
163  (AV_RB16(pkt->data + 1) & 0x1FFF) + 3 == pkt->size)
164  return ff_raw_write_packet(s, pkt);
165  else
166  return AVERROR_INVALIDDATA;
167  }
168 
169  if (pkt->size > 0x1fff)
170  goto too_large;
171 
172  init_put_bits(&bs, ctx->buffer, pkt->size+1024+MAX_EXTRADATA_SIZE);
173 
174  latm_write_frame_header(s, &bs);
175 
176  /* PayloadLengthInfo() */
177  for (i = 0; i <= pkt->size-255; i+=255)
178  put_bits(&bs, 8, 255);
179 
180  put_bits(&bs, 8, pkt->size-i);
181 
182  /* The LATM payload is written unaligned */
183 
184  /* PayloadMux() */
185  if (pkt->size && (pkt->data[0] & 0xe1) == 0x81) {
186  // Convert byte-aligned DSE to non-aligned.
187  // Due to the input format encoding we know that
188  // it is naturally byte-aligned in the input stream,
189  // so there are no padding bits to account for.
190  // To avoid having to add padding bits and rearrange
191  // the whole stream we just remove the byte-align flag.
192  // This allows us to remux our FATE AAC samples into latm
193  // files that are still playable with minimal effort.
194  put_bits(&bs, 8, pkt->data[0] & 0xfe);
195  avpriv_copy_bits(&bs, pkt->data + 1, 8*pkt->size - 8);
196  } else
197  avpriv_copy_bits(&bs, pkt->data, 8*pkt->size);
198 
200  flush_put_bits(&bs);
201 
202  len = put_bits_count(&bs) >> 3;
203 
204  if (len > 0x1fff)
205  goto too_large;
206 
207  loas_header[1] |= (len >> 8) & 0x1f;
208  loas_header[2] |= len & 0xff;
209 
210  avio_write(pb, loas_header, 3);
211  avio_write(pb, ctx->buffer, len);
212 
213  return 0;
214 
215 too_large:
216  av_log(s, AV_LOG_ERROR, "LATM packet size larger than maximum size 0x1fff\n");
217  return AVERROR_INVALIDDATA;
218 }
219 
221  .name = "latm",
222  .long_name = NULL_IF_CONFIG_SMALL("LOAS/LATM"),
223  .mime_type = "audio/MP4A-LATM",
224  .extensions = "latm,loas",
225  .priv_data_size = sizeof(LATMContext),
226  .audio_codec = AV_CODEC_ID_AAC,
227  .video_codec = AV_CODEC_ID_NONE,
230  .priv_class = &latm_muxer_class,
232 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static const AVOption options[]
Definition: latmenc.c:42
static int latm_decode_extradata(LATMContext *ctx, uint8_t *buf, int size)
Definition: latmenc.c:55
AVOption.
Definition: opt.h:255
static void put_bits(Jpeg2000EncoderContext *s, int val, int n)
put n times val bit
Definition: j2kenc.c:167
#define LIBAVUTIL_VERSION_INT
Definition: version.h:62
static void skip_bits_long(GetBitContext *s, int n)
Definition: get_bits.h:217
int size
Definition: avcodec.h:1424
void avpriv_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
Copy the content of src to the bitstream.
Definition: bitstream.c:64
void avpriv_align_put_bits(PutBitContext *s)
Pad the bitstream with zeros up to the next byte boundary.
Definition: bitstream.c:48
static const AVClass latm_muxer_class
Definition: latmenc.c:48
static AVPacket pkt
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:87
Format I/O context.
Definition: avformat.h:1273
int counter
Definition: latmenc.c:37
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
uint8_t
AVOptions.
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1617
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1341
AVClass * av_class
Definition: latmenc.c:33
uint8_t * data
Definition: avcodec.h:1423
bitstream reader API header.
ptrdiff_t size
Definition: opengl_enc.c:101
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:178
#define av_log(a,...)
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:285
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
av_default_item_name
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
Libavcodec external API header.
static int put_bits_count(PutBitContext *s)
Definition: put_bits.h:85
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:861
int channel_conf
Definition: latmenc.c:35
const char * name
Definition: avformat.h:513
int ff_raw_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawenc.c:26
static int latm_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: latmenc.c:145
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:472
enum AVCodecID codec_id
Definition: avcodec.h:1519
AVIOContext * pb
I/O context.
Definition: avformat.h:1315
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:441
main external API structure.
Definition: avcodec.h:1502
int mod
Definition: latmenc.c:38
#define MAX_EXTRADATA_SIZE
Definition: latmenc.c:30
void * buf
Definition: avisynth_c.h:553
static int latm_write_header(AVFormatContext *s)
Definition: latmenc.c:84
int extradata_size
Definition: avcodec.h:1618
Describe the class of an AVClass context structure.
Definition: log.h:67
int object_type
Definition: latmenc.c:36
static int flags
Definition: cpu.c:47
Y Spectral Band Replication.
Definition: mpeg4audio.h:65
Main libavformat public API header.
int off
Definition: latmenc.c:34
static void flush_put_bits(PutBitContext *s)
Pad the end of the output stream with zeros.
Definition: put_bits.h:101
static void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
Initialize the PutBitContext s.
Definition: put_bits.h:48
int avpriv_mpeg4audio_get_config(MPEG4AudioConfig *c, const uint8_t *buf, int bit_size, int sync_extension)
Parse MPEG-4 systems extradata to retrieve audio configuration.
Definition: mpeg4audio.c:81
AVOutputFormat ff_latm_muxer
Definition: latmenc.c:220
Y Audio LosslesS.
Definition: mpeg4audio.h:93
int len
static void latm_write_frame_header(AVFormatContext *s, PutBitContext *bs)
Definition: latmenc.c:99
void * priv_data
Format private data.
Definition: avformat.h:1301
int avpriv_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
Definition: mpeg4audio.c:166
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:493
uint8_t buffer[0x1fff+MAX_EXTRADATA_SIZE+1024]
Definition: latmenc.c:39
This structure stores compressed data.
Definition: avcodec.h:1400
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: v4l2enc.c:86
GLuint buffer
Definition: opengl_enc.c:102
bitstream writer API