1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
|
/*
* Common code for the RTP depacketization of MPEG-4 formats.
* Copyright (c) 2010 Fabrice Bellard
* Romain Degez
*
* This file is part of Libav.
*
* Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* @brief MPEG4 / RTP Code
* @author Fabrice Bellard
* @author Romain Degez
*/
#include "rtpdec_formats.h"
#include "internal.h"
#include "libavutil/avstring.h"
#include "libavcodec/get_bits.h"
/** Structure listing useful vars to parse RTP packet payload */
struct PayloadContext {
int sizelength;
int indexlength;
int indexdeltalength;
int profile_level_id;
int streamtype;
int objecttype;
char *mode;
/** mpeg 4 AU headers */
struct AUHeaders {
int size;
int index;
int cts_flag;
int cts;
int dts_flag;
int dts;
int rap_flag;
int streamstate;
} *au_headers;
int au_headers_allocated;
int nb_au_headers;
int au_headers_length_bytes;
int cur_au_index;
};
typedef struct {
const char *str;
uint16_t type;
uint32_t offset;
} AttrNameMap;
/* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
#define ATTR_NAME_TYPE_INT 0
#define ATTR_NAME_TYPE_STR 1
static const AttrNameMap attr_names[] = {
{ "SizeLength", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, sizelength) },
{ "IndexLength", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, indexlength) },
{ "IndexDeltaLength", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, indexdeltalength) },
{ "profile-level-id", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, profile_level_id) },
{ "StreamType", ATTR_NAME_TYPE_INT,
offsetof(PayloadContext, streamtype) },
{ "mode", ATTR_NAME_TYPE_STR,
offsetof(PayloadContext, mode) },
{ NULL, -1, -1 },
};
static PayloadContext *new_context(void)
{
return av_mallocz(sizeof(PayloadContext));
}
static void free_context(PayloadContext *data)
{
av_free(data->au_headers);
av_free(data->mode);
av_free(data);
}
static int parse_fmtp_config(AVCodecContext *codec, char *value)
{
/* decode the hexa encoded parameter */
int len = ff_hex_to_data(NULL, value);
av_free(codec->extradata);
codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
if (!codec->extradata)
return AVERROR(ENOMEM);
codec->extradata_size = len;
ff_hex_to_data(codec->extradata, value);
return 0;
}
static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
{
int au_headers_length, au_header_size, i;
GetBitContext getbitcontext;
/* decode the first 2 bytes where the AUHeader sections are stored
length in bits */
au_headers_length = AV_RB16(buf);
if (au_headers_length > RTP_MAX_PACKET_LENGTH)
return -1;
data->au_headers_length_bytes = (au_headers_length + 7) / 8;
/* skip AU headers length section (2 bytes) */
buf += 2;
init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
/* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
au_header_size = data->sizelength + data->indexlength;
if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
return -1;
data->nb_au_headers = au_headers_length / au_header_size;
if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
av_free(data->au_headers);
data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
data->au_headers_allocated = data->nb_au_headers;
}
/* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
In my test, the FAAD decoder does not behave correctly when sending each AU one by one
but does when sending the whole as one big packet... */
data->au_headers[0].size = 0;
data->au_headers[0].index = 0;
for (i = 0; i < data->nb_au_headers; ++i) {
data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
}
data->nb_au_headers = 1;
return 0;
}
/* Follows RFC 3640 */
static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, int flags)
{
if (rtp_parse_mp4_au(data, buf))
return -1;
buf += data->au_headers_length_bytes + 2;
len -= data->au_headers_length_bytes + 2;
/* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
one au_header */
av_new_packet(pkt, data->au_headers[0].size);
memcpy(pkt->data, buf, data->au_headers[0].size);
pkt->stream_index = st->index;
return 0;
}
static int parse_fmtp(AVStream *stream, PayloadContext *data,
char *attr, char *value)
{
AVCodecContext *codec = stream->codec;
int res, i;
if (!strcmp(attr, "config")) {
res = parse_fmtp_config(codec, value);
if (res < 0)
return res;
}
if (codec->codec_id == AV_CODEC_ID_AAC) {
/* Looking for a known attribute */
for (i = 0; attr_names[i].str; ++i) {
if (!av_strcasecmp(attr, attr_names[i].str)) {
if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
*(int *)((char *)data+
attr_names[i].offset) = atoi(value);
} else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
*(char **)((char *)data+
attr_names[i].offset) = av_strdup(value);
}
}
}
return 0;
}
static int parse_sdp_line(AVFormatContext *s, int st_index,
PayloadContext *data, const char *line)
{
const char *p;
if (st_index < 0)
return 0;
if (av_strstart(line, "fmtp:", &p))
return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
return 0;
}
RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
.enc_name = "MP4V-ES",
.codec_type = AVMEDIA_TYPE_VIDEO,
.codec_id = AV_CODEC_ID_MPEG4,
.parse_sdp_a_line = parse_sdp_line,
};
RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
.enc_name = "mpeg4-generic",
.codec_type = AVMEDIA_TYPE_AUDIO,
.codec_id = AV_CODEC_ID_AAC,
.parse_sdp_a_line = parse_sdp_line,
.alloc = new_context,
.free = free_context,
.parse_packet = aac_parse_packet
};
|
