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rtpdec_amr.c
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1 /*
2  * RTP AMR Depacketizer, RFC 3267
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 
23 #include "avformat.h"
24 #include "rtpdec_formats.h"
25 #include "libavutil/avstring.h"
26 
27 static const uint8_t frame_sizes_nb[16] = {
28  12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0
29 };
30 static const uint8_t frame_sizes_wb[16] = {
31  17, 23, 32, 36, 40, 46, 50, 58, 60, 5, 5, 0, 0, 0, 0, 0
32 };
33 
34 struct PayloadContext {
36  int crc;
38  int channels;
39 };
40 
41 static av_cold int amr_init(AVFormatContext *s, int st_index, PayloadContext *data)
42 {
43  data->channels = 1;
44  return 0;
45 }
46 
48  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
49  const uint8_t *buf, int len, uint16_t seq,
50  int flags)
51 {
52  const uint8_t *frame_sizes = NULL;
53  int frames;
54  int i;
55  const uint8_t *speech_data;
56  uint8_t *ptr;
57 
58  if (st->codecpar->codec_id == AV_CODEC_ID_AMR_NB) {
59  frame_sizes = frame_sizes_nb;
60  } else if (st->codecpar->codec_id == AV_CODEC_ID_AMR_WB) {
61  frame_sizes = frame_sizes_wb;
62  } else {
63  av_log(ctx, AV_LOG_ERROR, "Bad codec ID\n");
64  return AVERROR_INVALIDDATA;
65  }
66 
67  if (st->codecpar->channels != 1) {
68  av_log(ctx, AV_LOG_ERROR, "Only mono AMR is supported\n");
69  return AVERROR_INVALIDDATA;
70  }
72 
73  /* The AMR RTP packet consists of one header byte, followed
74  * by one TOC byte for each AMR frame in the packet, followed
75  * by the speech data for all the AMR frames.
76  *
77  * The header byte contains only a codec mode request, for
78  * requesting what kind of AMR data the sender wants to
79  * receive. Not used at the moment.
80  */
81 
82  /* Count the number of frames in the packet. The highest bit
83  * is set in a TOC byte if there are more frames following.
84  */
85  for (frames = 1; frames < len && (buf[frames] & 0x80); frames++) ;
86 
87  if (1 + frames >= len) {
88  /* We hit the end of the packet while counting frames. */
89  av_log(ctx, AV_LOG_ERROR, "No speech data found\n");
90  return AVERROR_INVALIDDATA;
91  }
92 
93  speech_data = buf + 1 + frames;
94 
95  /* Everything except the codec mode request byte should be output. */
96  if (av_new_packet(pkt, len - 1)) {
97  av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
98  return AVERROR(ENOMEM);
99  }
100  pkt->stream_index = st->index;
101  ptr = pkt->data;
102 
103  for (i = 0; i < frames; i++) {
104  uint8_t toc = buf[1 + i];
105  int frame_size = frame_sizes[(toc >> 3) & 0x0f];
106 
107  if (speech_data + frame_size > buf + len) {
108  /* Too little speech data */
109  av_log(ctx, AV_LOG_WARNING, "Too little speech data in the RTP packet\n");
110  /* Set the unwritten part of the packet to zero. */
111  memset(ptr, 0, pkt->data + pkt->size - ptr);
112  pkt->size = ptr - pkt->data;
113  return 0;
114  }
115 
116  /* Extract the AMR frame mode from the TOC byte */
117  *ptr++ = toc & 0x7C;
118 
119  /* Copy the speech data */
120  memcpy(ptr, speech_data, frame_size);
121  speech_data += frame_size;
122  ptr += frame_size;
123  }
124 
125  if (speech_data < buf + len) {
126  av_log(ctx, AV_LOG_WARNING, "Too much speech data in the RTP packet?\n");
127  /* Set the unwritten part of the packet to zero. */
128  memset(ptr, 0, pkt->data + pkt->size - ptr);
129  pkt->size = ptr - pkt->data;
130  }
131 
132  return 0;
133 }
134 
136  AVStream *stream, PayloadContext *data,
137  const char *attr, const char *value)
138 {
139  /* Some AMR SDP configurations contain "octet-align", without
140  * the trailing =1. Therefore, if the value is empty,
141  * interpret it as "1".
142  */
143  if (!strcmp(value, "")) {
144  av_log(s, AV_LOG_WARNING, "AMR fmtp attribute %s had "
145  "nonstandard empty value\n", attr);
146  value = "1";
147  }
148  if (!strcmp(attr, "octet-align"))
149  data->octet_align = atoi(value);
150  else if (!strcmp(attr, "crc"))
151  data->crc = atoi(value);
152  else if (!strcmp(attr, "interleaving"))
153  data->interleaving = atoi(value);
154  else if (!strcmp(attr, "channels"))
155  data->channels = atoi(value);
156  return 0;
157 }
158 
159 static int amr_parse_sdp_line(AVFormatContext *s, int st_index,
160  PayloadContext *data, const char *line)
161 {
162  const char *p;
163  int ret;
164 
165  if (st_index < 0)
166  return 0;
167 
168  /* Parse an fmtp line this one:
169  * a=fmtp:97 octet-align=1; interleaving=0
170  * That is, a normal fmtp: line followed by semicolon & space
171  * separated key/value pairs.
172  */
173  if (av_strstart(line, "fmtp:", &p)) {
174  ret = ff_parse_fmtp(s, s->streams[st_index], data, p, amr_parse_fmtp);
175  if (!data->octet_align || data->crc ||
176  data->interleaving || data->channels != 1) {
177  av_log(s, AV_LOG_ERROR, "Unsupported RTP/AMR configuration!\n");
178  return -1;
179  }
180  return ret;
181  }
182  return 0;
183 }
184 
186  .enc_name = "AMR",
187  .codec_type = AVMEDIA_TYPE_AUDIO,
188  .codec_id = AV_CODEC_ID_AMR_NB,
189  .priv_data_size = sizeof(PayloadContext),
190  .init = amr_init,
191  .parse_sdp_a_line = amr_parse_sdp_line,
193 };
194 
196  .enc_name = "AMR-WB",
197  .codec_type = AVMEDIA_TYPE_AUDIO,
198  .codec_id = AV_CODEC_ID_AMR_WB,
199  .priv_data_size = sizeof(PayloadContext),
200  .init = amr_init,
201  .parse_sdp_a_line = amr_parse_sdp_line,
203 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
static int amr_parse_sdp_line(AVFormatContext *s, int st_index, PayloadContext *data, const char *line)
Definition: rtpdec_amr.c:159
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static int amr_parse_fmtp(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *attr, const char *value)
Definition: rtpdec_amr.c:135
RTP/JPEG specific private data.
Definition: rdt.c:83
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3921
int index
stream index in AVFormatContext
Definition: avformat.h:877
int size
Definition: avcodec.h:1580
static AVPacket pkt
RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler
Definition: rtpdec_amr.c:195
Format I/O context.
Definition: avformat.h:1325
static const uint8_t frame_sizes[]
Definition: rtpdec_qcelp.c:24
uint8_t
#define av_cold
Definition: attributes.h:82
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1393
static int amr_handle_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_amr.c:47
uint8_t * data
Definition: avcodec.h:1579
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4023
#define av_log(a,...)
static const uint8_t frame_sizes_nb[16]
Definition: rtpdec_amr.c:27
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
Definition: graph2dot.c:48
audio channel layout utility functions
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:109
AVFormatContext * ctx
Definition: movenc.c:48
int frames
Definition: movenc.c:65
Stream structure.
Definition: avformat.h:876
int frame_size
Definition: mxfenc.c:1821
static const uint8_t frame_sizes_wb[16]
Definition: rtpdec_amr.c:30
void * buf
Definition: avisynth_c.h:553
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:860
const char * enc_name
Definition: rtpdec.h:116
static int flags
Definition: cpu.c:47
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
Main libavformat public API header.
static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
Parse a packet, add all split parts to parse_queue.
Definition: utils.c:1332
int len
int channels
Audio only.
Definition: avcodec.h:4027
AVCodecParameters * codecpar
Definition: avformat.h:1006
int stream_index
Definition: avcodec.h:1581
static av_cold int amr_init(AVFormatContext *s, int st_index, PayloadContext *data)
Definition: rtpdec_amr.c:41
#define AV_CH_LAYOUT_MONO
RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler
Definition: rtpdec_amr.c:185
This structure stores compressed data.
Definition: avcodec.h:1556