cf309cd3b30e58c8c4f1d63f7189b7744e51201c
[libav.git] / libavformat / rtpdec_mpeg4.c
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 FFmpeg.
7 *
8 * FFmpeg 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 * FFmpeg 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 FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file
25 * @brief MPEG4 / RTP Code
26 * @author Fabrice Bellard
27 * @author Romain Degez
28 */
29
30 #include "rtpdec_formats.h"
31 #include "internal.h"
32 #include "libavutil/avstring.h"
33 #include "libavcodec/get_bits.h"
34 #include <strings.h>
35
36 /** Structure listing useful vars to parse RTP packet payload*/
37 struct PayloadContext
38 {
39 int sizelength;
40 int indexlength;
41 int indexdeltalength;
42 int profile_level_id;
43 int streamtype;
44 int objecttype;
45 char *mode;
46
47 /** mpeg 4 AU headers */
48 struct AUHeaders {
49 int size;
50 int index;
51 int cts_flag;
52 int cts;
53 int dts_flag;
54 int dts;
55 int rap_flag;
56 int streamstate;
57 } *au_headers;
58 int au_headers_allocated;
59 int nb_au_headers;
60 int au_headers_length_bytes;
61 int cur_au_index;
62 };
63
64 /* return the length and optionally the data */
65 static int hex_to_data(uint8_t *data, const char *p)
66 {
67 int c, len, v;
68
69 len = 0;
70 v = 1;
71 for (;;) {
72 p += strspn(p, SPACE_CHARS);
73 if (*p == '\0')
74 break;
75 c = toupper((unsigned char) *p++);
76 if (c >= '0' && c <= '9')
77 c = c - '0';
78 else if (c >= 'A' && c <= 'F')
79 c = c - 'A' + 10;
80 else
81 break;
82 v = (v << 4) | c;
83 if (v & 0x100) {
84 if (data)
85 data[len] = v;
86 len++;
87 v = 1;
88 }
89 }
90 return len;
91 }
92
93 typedef struct {
94 const char *str;
95 uint16_t type;
96 uint32_t offset;
97 } AttrNameMap;
98
99 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
100 #define ATTR_NAME_TYPE_INT 0
101 #define ATTR_NAME_TYPE_STR 1
102 static const AttrNameMap attr_names[]=
103 {
104 { "SizeLength", ATTR_NAME_TYPE_INT,
105 offsetof(PayloadContext, sizelength) },
106 { "IndexLength", ATTR_NAME_TYPE_INT,
107 offsetof(PayloadContext, indexlength) },
108 { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
109 offsetof(PayloadContext, indexdeltalength) },
110 { "profile-level-id", ATTR_NAME_TYPE_INT,
111 offsetof(PayloadContext, profile_level_id) },
112 { "StreamType", ATTR_NAME_TYPE_INT,
113 offsetof(PayloadContext, streamtype) },
114 { "mode", ATTR_NAME_TYPE_STR,
115 offsetof(PayloadContext, mode) },
116 { NULL, -1, -1 },
117 };
118
119 static PayloadContext *new_context(void)
120 {
121 return av_mallocz(sizeof(PayloadContext));
122 }
123
124 static void free_context(PayloadContext * data)
125 {
126 int i;
127 for (i = 0; i < data->nb_au_headers; i++) {
128 /* according to rtp_parse_mp4_au, we treat multiple
129 * au headers as one, so nb_au_headers is always 1.
130 * loop anyway in case this changes.
131 * (note: changes done carelessly might lead to a double free)
132 */
133 av_free(&data->au_headers[i]);
134 }
135 av_free(data->mode);
136 av_free(data);
137 }
138
139 static int parse_fmtp_config(AVCodecContext * codec, char *value)
140 {
141 /* decode the hexa encoded parameter */
142 int len = hex_to_data(NULL, value);
143 if (codec->extradata)
144 av_free(codec->extradata);
145 codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
146 if (!codec->extradata)
147 return AVERROR(ENOMEM);
148 codec->extradata_size = len;
149 hex_to_data(codec->extradata, value);
150 return 0;
151 }
152
153 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
154 {
155 int au_headers_length, au_header_size, i;
156 GetBitContext getbitcontext;
157
158 /* decode the first 2 bytes where the AUHeader sections are stored
159 length in bits */
160 au_headers_length = AV_RB16(buf);
161
162 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
163 return -1;
164
165 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
166
167 /* skip AU headers length section (2 bytes) */
168 buf += 2;
169
170 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
171
172 /* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
173 au_header_size = data->sizelength + data->indexlength;
174 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
175 return -1;
176
177 data->nb_au_headers = au_headers_length / au_header_size;
178 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
179 av_free(data->au_headers);
180 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
181 data->au_headers_allocated = data->nb_au_headers;
182 }
183
184 /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
185 In my test, the FAAD decoder does not behave correctly when sending each AU one by one
186 but does when sending the whole as one big packet... */
187 data->au_headers[0].size = 0;
188 data->au_headers[0].index = 0;
189 for (i = 0; i < data->nb_au_headers; ++i) {
190 data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
191 data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
192 }
193
194 data->nb_au_headers = 1;
195
196 return 0;
197 }
198
199
200 /* Follows RFC 3640 */
201 static int aac_parse_packet(AVFormatContext *ctx,
202 PayloadContext *data,
203 AVStream *st,
204 AVPacket *pkt,
205 uint32_t *timestamp,
206 const uint8_t *buf, int len, int flags)
207 {
208 if (rtp_parse_mp4_au(data, buf))
209 return -1;
210
211 buf += data->au_headers_length_bytes + 2;
212 len -= data->au_headers_length_bytes + 2;
213
214 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
215 one au_header */
216 av_new_packet(pkt, data->au_headers[0].size);
217 memcpy(pkt->data, buf, data->au_headers[0].size);
218
219 pkt->stream_index = st->index;
220 return 0;
221 }
222
223 static int parse_fmtp(AVStream *stream, PayloadContext *data,
224 char *attr, char *value)
225 {
226 AVCodecContext *codec = stream->codec;
227 int res, i;
228
229 if (!strcmp(attr, "config")) {
230 res = parse_fmtp_config(codec, value);
231
232 if (res < 0)
233 return res;
234 }
235
236 if (codec->codec_id == CODEC_ID_AAC) {
237 /* Looking for a known attribute */
238 for (i = 0; attr_names[i].str; ++i) {
239 if (!strcasecmp(attr, attr_names[i].str)) {
240 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
241 *(int *)((char *)data+
242 attr_names[i].offset) = atoi(value);
243 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
244 *(char **)((char *)data+
245 attr_names[i].offset) = av_strdup(value);
246 }
247 }
248 }
249 return 0;
250 }
251
252 static int parse_sdp_line(AVFormatContext *s, int st_index,
253 PayloadContext *data, const char *line)
254 {
255 const char *p;
256
257 if (av_strstart(line, "fmtp:", &p))
258 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
259
260 return 0;
261 }
262
263 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
264 .enc_name = "MP4V-ES",
265 .codec_type = AVMEDIA_TYPE_VIDEO,
266 .codec_id = CODEC_ID_MPEG4,
267 .parse_sdp_a_line = parse_sdp_line,
268 .open = NULL,
269 .close = NULL,
270 .parse_packet = NULL
271 };
272
273 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
274 .enc_name = "mpeg4-generic",
275 .codec_type = AVMEDIA_TYPE_AUDIO,
276 .codec_id = CODEC_ID_AAC,
277 .parse_sdp_a_line = parse_sdp_line,
278 .open = new_context,
279 .close = free_context,
280 .parse_packet = aac_parse_packet
281 };