Libav
rtpdec_mpeg4.c
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1 /*
2  * Common code for the RTP depacketization of MPEG-4 formats.
3  * Copyright (c) 2010 Fabrice Bellard
4  * Romain Degez
5  *
6  * This file is part of Libav.
7  *
8  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
30 #include "rtpdec_formats.h"
31 #include "internal.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avstring.h"
34 #include "libavcodec/get_bits.h"
35 
37 struct PayloadContext {
44  char *mode;
45 
47  struct AUHeaders {
48  int size;
49  int index;
50  int cts_flag;
51  int cts;
52  int dts_flag;
53  int dts;
54  int rap_flag;
56  } *au_headers;
61 
64 };
65 
66 typedef struct {
67  const char *str;
68  uint16_t type;
69  uint32_t offset;
70 } AttrNameMap;
71 
72 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
73 #define ATTR_NAME_TYPE_INT 0
74 #define ATTR_NAME_TYPE_STR 1
75 static const AttrNameMap attr_names[] = {
76  { "SizeLength", ATTR_NAME_TYPE_INT,
77  offsetof(PayloadContext, sizelength) },
78  { "IndexLength", ATTR_NAME_TYPE_INT,
79  offsetof(PayloadContext, indexlength) },
80  { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
81  offsetof(PayloadContext, indexdeltalength) },
82  { "profile-level-id", ATTR_NAME_TYPE_INT,
83  offsetof(PayloadContext, profile_level_id) },
84  { "StreamType", ATTR_NAME_TYPE_INT,
85  offsetof(PayloadContext, streamtype) },
86  { "mode", ATTR_NAME_TYPE_STR,
87  offsetof(PayloadContext, mode) },
88  { NULL, -1, -1 },
89 };
90 
92 {
93  return av_mallocz(sizeof(PayloadContext));
94 }
95 
97 {
98  av_free(data->au_headers);
99  av_free(data->mode);
100  av_free(data);
101 }
102 
103 static int parse_fmtp_config(AVCodecContext *codec, char *value)
104 {
105  /* decode the hexa encoded parameter */
106  int len = ff_hex_to_data(NULL, value);
107  av_free(codec->extradata);
109  if (!codec->extradata)
110  return AVERROR(ENOMEM);
111  codec->extradata_size = len;
112  ff_hex_to_data(codec->extradata, value);
113  return 0;
114 }
115 
117 {
118  int au_headers_length, au_header_size, i;
119  GetBitContext getbitcontext;
120 
121  if (len < 2)
122  return AVERROR_INVALIDDATA;
123 
124  /* decode the first 2 bytes where the AUHeader sections are stored
125  length in bits */
126  au_headers_length = AV_RB16(buf);
127 
128  if (au_headers_length > RTP_MAX_PACKET_LENGTH)
129  return -1;
130 
131  data->au_headers_length_bytes = (au_headers_length + 7) / 8;
132 
133  /* skip AU headers length section (2 bytes) */
134  buf += 2;
135  len -= 2;
136 
137  if (len < data->au_headers_length_bytes)
138  return AVERROR_INVALIDDATA;
139 
140  init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
141 
142  /* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
143  au_header_size = data->sizelength + data->indexlength;
144  if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
145  return -1;
146 
147  data->nb_au_headers = au_headers_length / au_header_size;
148  if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
149  av_free(data->au_headers);
150  data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
151  if (!data->au_headers)
152  return AVERROR(ENOMEM);
153  data->au_headers_allocated = data->nb_au_headers;
154  }
155 
156  for (i = 0; i < data->nb_au_headers; ++i) {
157  data->au_headers[i].size = get_bits_long(&getbitcontext, data->sizelength);
158  data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength);
159  }
160 
161  return 0;
162 }
163 
164 
165 /* Follows RFC 3640 */
167  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
168  const uint8_t *buf, int len, uint16_t seq,
169  int flags)
170 {
171  int ret;
172 
173  if (!buf) {
174  if (data->cur_au_index > data->nb_au_headers)
175  return AVERROR_INVALIDDATA;
176  if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size)
177  return AVERROR_INVALIDDATA;
178  if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0)
179  return ret;
180  memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size);
181  data->buf_pos += data->au_headers[data->cur_au_index].size;
182  pkt->stream_index = st->index;
183  data->cur_au_index++;
184  return data->cur_au_index < data->nb_au_headers;
185  }
186 
187  if (rtp_parse_mp4_au(data, buf, len))
188  return -1;
189 
190  buf += data->au_headers_length_bytes + 2;
191  len -= data->au_headers_length_bytes + 2;
192 
193  if (len < data->au_headers[0].size)
194  return AVERROR_INVALIDDATA;
195  if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0)
196  return ret;
197  memcpy(pkt->data, buf, data->au_headers[0].size);
198  len -= data->au_headers[0].size;
199  buf += data->au_headers[0].size;
200  pkt->stream_index = st->index;
201 
202  if (len > 0 && data->nb_au_headers > 1) {
203  data->buf_size = FFMIN(len, sizeof(data->buf));
204  memcpy(data->buf, buf, data->buf_size);
205  data->cur_au_index = 1;
206  data->buf_pos = 0;
207  return 1;
208  }
209 
210  return 0;
211 }
212 
214  AVStream *stream, PayloadContext *data,
215  char *attr, char *value)
216 {
217  AVCodecContext *codec = stream->codec;
218  int res, i;
219 
220  if (!strcmp(attr, "config")) {
221  res = parse_fmtp_config(codec, value);
222 
223  if (res < 0)
224  return res;
225  }
226 
227  if (codec->codec_id == AV_CODEC_ID_AAC) {
228  /* Looking for a known attribute */
229  for (i = 0; attr_names[i].str; ++i) {
230  if (!av_strcasecmp(attr, attr_names[i].str)) {
231  if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
232  *(int *)((char *)data+
233  attr_names[i].offset) = atoi(value);
234  } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
235  *(char **)((char *)data+
236  attr_names[i].offset) = av_strdup(value);
237  }
238  }
239  }
240  return 0;
241 }
242 
243 static int parse_sdp_line(AVFormatContext *s, int st_index,
244  PayloadContext *data, const char *line)
245 {
246  const char *p;
247 
248  if (st_index < 0)
249  return 0;
250 
251  if (av_strstart(line, "fmtp:", &p))
252  return ff_parse_fmtp(s, s->streams[st_index], data, p, parse_fmtp);
253 
254  return 0;
255 }
256 
257 static av_cold int init_video(AVFormatContext *s, int st_index,
259 {
260  if (st_index < 0)
261  return 0;
262  s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
263  return 0;
264 }
265 
267  .enc_name = "MP4V-ES",
268  .codec_type = AVMEDIA_TYPE_VIDEO,
269  .codec_id = AV_CODEC_ID_MPEG4,
270  .init = init_video,
271  .parse_sdp_a_line = parse_sdp_line,
272 };
273 
275  .enc_name = "mpeg4-generic",
276  .codec_type = AVMEDIA_TYPE_AUDIO,
277  .codec_id = AV_CODEC_ID_AAC,
278  .parse_sdp_a_line = parse_sdp_line,
279  .alloc = new_context,
280  .free = free_context,
281  .parse_packet = aac_parse_packet
282 };
AVPacket pkt
Definition: rtpdec_qt.c:37
uint32_t offset
Definition: rtpdec_mpeg4.c:69
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
static int parse_fmtp_config(AVCodecContext *codec, char *value)
Definition: rtpdec_mpeg4.c:103
#define RTP_MAX_PACKET_LENGTH
Definition: rtpdec.h:36
int ff_parse_fmtp(AVFormatContext *s, AVStream *stream, PayloadContext *data, const char *p, int(*parse_fmtp)(AVFormatContext *s, AVStream *stream, PayloadContext *data, char *attr, char *value))
Definition: rtpdec.c:829
RTP/JPEG specific private data.
Definition: rdt.c:83
int index
stream index in AVFormatContext
Definition: avformat.h:700
uint8_t * buf
the temporary storage buffer
Definition: rtpdec_asf.c:170
RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler
Definition: rtpdec_mpeg4.c:274
Macro definitions for various function/variable attributes.
Format I/O context.
Definition: avformat.h:922
uint8_t
#define av_cold
Definition: attributes.h:66
static void free_context(PayloadContext *data)
Definition: rtpdec_mpeg4.c:96
enum AVStreamParseType need_parsing
Definition: avformat.h:867
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1164
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:990
mpeg 4 AU headers
Definition: rtpdec_mpeg4.c:47
uint8_t * data
Definition: avcodec.h:973
static int flags
Definition: log.c:44
bitstream reader API header.
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:81
uint32_t timestamp
current frame timestamp
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:186
#define AV_RB16
Definition: intreadwrite.h:53
#define AVERROR(e)
Definition: error.h:43
Definition: graph2dot.c:49
int au_headers_allocated
Definition: rtpdec_mpeg4.c:57
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:718
uint16_t type
Definition: rtpdec_mpeg4.c:68
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:531
static av_cold int init_video(AVFormatContext *s, int st_index, PayloadContext *data)
Definition: rtpdec_mpeg4.c:257
#define FFMIN(a, b)
Definition: common.h:57
int av_strcasecmp(const char *a, const char *b)
Definition: avstring.c:156
RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler
Definition: rtpdec_mpeg4.c:266
static int aac_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_mpeg4.c:166
#define ATTR_NAME_TYPE_INT
Definition: rtpdec_mpeg4.c:73
const char * str
Definition: rtpdec_mpeg4.c:67
Stream structure.
Definition: avformat.h:699
NULL
Definition: eval.c:55
AVIOContext * data
Definition: rtpdec_vp8.c:35
enum AVCodecID codec_id
Definition: avcodec.h:1067
char * av_strdup(const char *s)
Duplicate the string s.
Definition: mem.c:213
main external API structure.
Definition: avcodec.h:1050
int extradata_size
Definition: avcodec.h:1165
struct PayloadContext::AUHeaders * au_headers
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
#define ATTR_NAME_TYPE_STR
Definition: rtpdec_mpeg4.c:74
const char enc_name[50]
Definition: rtpdec.h:116
static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
Definition: rtpdec_mpeg4.c:116
int ff_hex_to_data(uint8_t *data, const char *p)
Parse a string of hexadecimal strings.
Definition: utils.c:2801
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:304
static int parse_sdp_line(AVFormatContext *s, int st_index, PayloadContext *data, const char *line)
Definition: rtpdec_mpeg4.c:243
static const AttrNameMap attr_names[]
Definition: rtpdec_mpeg4.c:75
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:32
full parsing and repack
Definition: avformat.h:653
int au_headers_length_bytes
Definition: rtpdec_mpeg4.c:59
static int parse_fmtp(AVFormatContext *s, AVStream *stream, PayloadContext *data, char *attr, char *value)
Definition: rtpdec_mpeg4.c:213
int stream_index
Definition: avcodec.h:975
This structure stores compressed data.
Definition: avcodec.h:950
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
static PayloadContext * new_context(void)
Definition: rtpdec_mpeg4.c:91