FFmpeg  4.4.5
rtpdec_latm.c
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1 /*
2  * RTP Depacketization of MP4A-LATM, RFC 3016
3  * Copyright (c) 2010 Martin Storsjo
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 "avio_internal.h"
23 #include "rtpdec_formats.h"
24 #include "internal.h"
25 #include "libavutil/avstring.h"
26 #include "libavcodec/get_bits.h"
27 
28 struct PayloadContext {
30  uint8_t *buf;
31  int pos, len;
32  uint32_t timestamp;
33 };
34 
36 {
37  ffio_free_dyn_buf(&data->dyn_buf);
38  av_freep(&data->buf);
39 }
40 
42  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
43  const uint8_t *buf, int len, uint16_t seq,
44  int flags)
45 {
46  int ret, cur_len;
47 
48  if (buf) {
49  if (!data->dyn_buf || data->timestamp != *timestamp) {
50  av_freep(&data->buf);
51  ffio_free_dyn_buf(&data->dyn_buf);
52 
53  data->timestamp = *timestamp;
54  if ((ret = avio_open_dyn_buf(&data->dyn_buf)) < 0)
55  return ret;
56  }
57  avio_write(data->dyn_buf, buf, len);
58 
59  if (!(flags & RTP_FLAG_MARKER))
60  return AVERROR(EAGAIN);
61  av_freep(&data->buf);
62  data->len = avio_close_dyn_buf(data->dyn_buf, &data->buf);
63  data->dyn_buf = NULL;
64  data->pos = 0;
65  }
66 
67  if (!data->buf) {
68  av_log(ctx, AV_LOG_ERROR, "No data available yet\n");
69  return AVERROR(EIO);
70  }
71 
72  cur_len = 0;
73  while (data->pos < data->len) {
74  uint8_t val = data->buf[data->pos++];
75  cur_len += val;
76  if (val != 0xff)
77  break;
78  }
79  if (data->pos + cur_len > data->len) {
80  av_log(ctx, AV_LOG_ERROR, "Malformed LATM packet\n");
81  return AVERROR(EIO);
82  }
83 
84  if ((ret = av_new_packet(pkt, cur_len)) < 0)
85  return ret;
86  memcpy(pkt->data, data->buf + data->pos, cur_len);
87  data->pos += cur_len;
88  pkt->stream_index = st->index;
89  return data->pos < data->len;
90 }
91 
92 static int parse_fmtp_config(AVStream *st, const char *value)
93 {
94  int len = ff_hex_to_data(NULL, value), i, ret = 0;
95  GetBitContext gb;
96  uint8_t *config;
97  int audio_mux_version, same_time_framing, num_programs, num_layers;
98 
99  /* Pad this buffer, too, to avoid out of bounds reads with get_bits below */
101  if (!config)
102  return AVERROR(ENOMEM);
103  ff_hex_to_data(config, value);
104  init_get_bits(&gb, config, len*8);
105  audio_mux_version = get_bits(&gb, 1);
106  same_time_framing = get_bits(&gb, 1);
107  skip_bits(&gb, 6); /* num_sub_frames */
108  num_programs = get_bits(&gb, 4);
109  num_layers = get_bits(&gb, 3);
110  if (audio_mux_version != 0 || same_time_framing != 1 || num_programs != 0 ||
111  num_layers != 0) {
112  avpriv_report_missing_feature(NULL, "LATM config (%d,%d,%d,%d)",
113  audio_mux_version, same_time_framing,
114  num_programs, num_layers);
115  ret = AVERROR_PATCHWELCOME;
116  goto end;
117  }
118  ret = ff_alloc_extradata(st->codecpar, (get_bits_left(&gb) + 7)/8);
119  if (ret < 0) {
120  goto end;
121  }
122  for (i = 0; i < st->codecpar->extradata_size; i++)
123  st->codecpar->extradata[i] = get_bits(&gb, 8);
124 
125 end:
126  av_free(config);
127  return ret;
128 }
129 
131  AVStream *stream, PayloadContext *data,
132  const char *attr, const char *value)
133 {
134  int res;
135 
136  if (!strcmp(attr, "config")) {
137  res = parse_fmtp_config(stream, value);
138  if (res < 0)
139  return res;
140  } else if (!strcmp(attr, "cpresent")) {
141  int cpresent = atoi(value);
142  if (cpresent != 0)
144  "RTP MP4A-LATM with in-band configuration");
145  }
146 
147  return 0;
148 }
149 
150 static int latm_parse_sdp_line(AVFormatContext *s, int st_index,
151  PayloadContext *data, const char *line)
152 {
153  const char *p;
154 
155  if (st_index < 0)
156  return 0;
157 
158  if (av_strstart(line, "fmtp:", &p))
159  return ff_parse_fmtp(s, s->streams[st_index], data, p, parse_fmtp);
160 
161  return 0;
162 }
163 
165  .enc_name = "MP4A-LATM",
166  .codec_type = AVMEDIA_TYPE_AUDIO,
167  .codec_id = AV_CODEC_ID_AAC,
168  .priv_data_size = sizeof(PayloadContext),
169  .parse_sdp_a_line = latm_parse_sdp_line,
170  .close = latm_close_context,
172 };
static double val(void *priv, double ch)
Definition: aeval.c:76
uint8_t
int avio_close_dyn_buf(AVIOContext *s, uint8_t **pbuffer)
Return the written size and a pointer to the buffer.
Definition: aviobuf.c:1427
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:225
int avio_open_dyn_buf(AVIOContext **s)
Open a write only memory stream.
Definition: aviobuf.c:1382
void ffio_free_dyn_buf(AVIOContext **s)
Free a dynamic buffer.
Definition: aviobuf.c:1457
#define flags(name, subs,...)
Definition: cbs_av1.c:572
#define s(width, name)
Definition: cbs_vp9.c:257
#define NULL
Definition: coverity.c:32
double value
Definition: eval.c:98
bitstream reader API header.
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:849
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:467
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
@ AV_CODEC_ID_AAC
Definition: codec_id.h:426
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
Definition: avcodec.h:215
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:99
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:237
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:34
int i
Definition: input.c:407
int ff_hex_to_data(uint8_t *data, const char *p)
Parse a string of hexadecimal strings.
Definition: utils.c:4917
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0.
Definition: utils.c:3314
static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index, int flush)
Parse a packet, add all split parts to parse_queue.
Definition: utils.c:1423
common internal API header
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
const char data[16]
Definition: mxf.c:142
int ff_parse_fmtp(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *p, int(*parse_fmtp)(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *attr, const char *value))
Definition: rtpdec.c:926
#define RTP_FLAG_MARKER
RTP marker bit was set for this packet.
Definition: rtpdec.h:93
static void latm_close_context(PayloadContext *data)
Definition: rtpdec_latm.c:35
static int parse_fmtp_config(AVStream *st, const char *value)
Definition: rtpdec_latm.c:92
static int parse_fmtp(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *attr, const char *value)
Definition: rtpdec_latm.c:130
const RTPDynamicProtocolHandler ff_mp4a_latm_dynamic_handler
Definition: rtpdec_latm.c:164
static int latm_parse_sdp_line(AVFormatContext *s, int st_index, PayloadContext *data, const char *line)
Definition: rtpdec_latm.c:150
static int latm_parse_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
Definition: rtpdec_latm.c:41
int extradata_size
Size of the extradata content in bytes.
Definition: codec_par.h:78
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
Format I/O context.
Definition: avformat.h:1232
Bytestream IO Context.
Definition: avio.h:161
This structure stores compressed data.
Definition: packet.h:346
int stream_index
Definition: packet.h:371
uint8_t * data
Definition: packet.h:369
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
int index
stream index in AVFormatContext
Definition: avformat.h:874
RTP/JPEG specific private data.
Definition: rdt.c:83
AVIOContext * dyn_buf
Definition: rtpdec_latm.c:29
uint32_t timestamp
current frame timestamp
Definition: rtpdec_ac3.c:31
uint8_t * buf
the temporary storage buffer
Definition: rtpdec_asf.c:183
const char * enc_name
Definition: rtpdec.h:116
Definition: graph2dot.c:48
#define av_free(p)
#define avpriv_request_sample(...)
#define av_freep(p)
#define av_log(a,...)
AVPacket * pkt
Definition: movenc.c:59
AVFormatContext * ctx
Definition: movenc.c:48
int len