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path: root/libavformat/rtpdec_mpeg4.c (plain)
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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 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 MPEG-4 / RTP Code
26 * @author Fabrice Bellard
27 * @author Romain Degez
28 */
29
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
36#define MAX_AAC_HBR_FRAME_SIZE 8191
37
38/** Structure listing useful vars to parse RTP packet payload */
39struct PayloadContext {
40 int sizelength;
41 int indexlength;
42 int indexdeltalength;
43 int profile_level_id;
44 int streamtype;
45 int objecttype;
46 char *mode;
47
48 /** mpeg 4 AU headers */
49 struct AUHeaders {
50 int size;
51 int index;
52 int cts_flag;
53 int cts;
54 int dts_flag;
55 int dts;
56 int rap_flag;
57 int streamstate;
58 } *au_headers;
59 int au_headers_allocated;
60 int nb_au_headers;
61 int au_headers_length_bytes;
62 int cur_au_index;
63
64 uint8_t buf[FFMAX(RTP_MAX_PACKET_LENGTH, MAX_AAC_HBR_FRAME_SIZE)];
65 int buf_pos, buf_size;
66 uint32_t timestamp;
67};
68
69typedef struct AttrNameMap {
70 const char *str;
71 uint16_t type;
72 uint32_t offset;
73} AttrNameMap;
74
75/* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
76#define ATTR_NAME_TYPE_INT 0
77#define ATTR_NAME_TYPE_STR 1
78static const AttrNameMap attr_names[] = {
79 { "SizeLength", ATTR_NAME_TYPE_INT,
80 offsetof(PayloadContext, sizelength) },
81 { "IndexLength", ATTR_NAME_TYPE_INT,
82 offsetof(PayloadContext, indexlength) },
83 { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
84 offsetof(PayloadContext, indexdeltalength) },
85 { "profile-level-id", ATTR_NAME_TYPE_INT,
86 offsetof(PayloadContext, profile_level_id) },
87 { "StreamType", ATTR_NAME_TYPE_INT,
88 offsetof(PayloadContext, streamtype) },
89 { "mode", ATTR_NAME_TYPE_STR,
90 offsetof(PayloadContext, mode) },
91 { NULL, -1, -1 },
92};
93
94static void close_context(PayloadContext *data)
95{
96 av_freep(&data->au_headers);
97 av_freep(&data->mode);
98}
99
100static int parse_fmtp_config(AVCodecParameters *par, const char *value)
101{
102 /* decode the hexa encoded parameter */
103 int len = ff_hex_to_data(NULL, value);
104 av_freep(&par->extradata);
105 if (ff_alloc_extradata(par, len))
106 return AVERROR(ENOMEM);
107 ff_hex_to_data(par->extradata, value);
108 return 0;
109}
110
111static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
112{
113 int au_headers_length, au_header_size, i;
114 GetBitContext getbitcontext;
115
116 if (len < 2)
117 return AVERROR_INVALIDDATA;
118
119 /* decode the first 2 bytes where the AUHeader sections are stored
120 length in bits */
121 au_headers_length = AV_RB16(buf);
122
123 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
124 return -1;
125
126 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
127
128 /* skip AU headers length section (2 bytes) */
129 buf += 2;
130 len -= 2;
131
132 if (len < data->au_headers_length_bytes)
133 return AVERROR_INVALIDDATA;
134
135 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
136
137 /* XXX: Wrong if optional additional sections are present (cts, dts etc...) */
138 au_header_size = data->sizelength + data->indexlength;
139 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
140 return -1;
141
142 data->nb_au_headers = au_headers_length / au_header_size;
143 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
144 av_free(data->au_headers);
145 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
146 if (!data->au_headers)
147 return AVERROR(ENOMEM);
148 data->au_headers_allocated = data->nb_au_headers;
149 }
150
151 for (i = 0; i < data->nb_au_headers; ++i) {
152 data->au_headers[i].size = get_bits_long(&getbitcontext, data->sizelength);
153 data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength);
154 }
155
156 return 0;
157}
158
159
160/* Follows RFC 3640 */
161static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
162 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
163 const uint8_t *buf, int len, uint16_t seq,
164 int flags)
165{
166 int ret;
167
168
169 if (!buf) {
170 if (data->cur_au_index > data->nb_au_headers) {
171 av_log(ctx, AV_LOG_ERROR, "Invalid parser state\n");
172 return AVERROR_INVALIDDATA;
173 }
174 if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size) {
175 av_log(ctx, AV_LOG_ERROR, "Invalid AU size\n");
176 return AVERROR_INVALIDDATA;
177 }
178 if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0) {
179 av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
180 return ret;
181 }
182 memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size);
183 data->buf_pos += data->au_headers[data->cur_au_index].size;
184 pkt->stream_index = st->index;
185 data->cur_au_index++;
186
187 if (data->cur_au_index == data->nb_au_headers) {
188 data->buf_pos = 0;
189 return 0;
190 }
191
192 return 1;
193 }
194
195 if (rtp_parse_mp4_au(data, buf, len)) {
196 av_log(ctx, AV_LOG_ERROR, "Error parsing AU headers\n");
197 return -1;
198 }
199
200 buf += data->au_headers_length_bytes + 2;
201 len -= data->au_headers_length_bytes + 2;
202 if (data->nb_au_headers == 1 && len < data->au_headers[0].size) {
203 /* Packet is fragmented */
204
205 if (!data->buf_pos) {
206 if (data->au_headers[0].size > MAX_AAC_HBR_FRAME_SIZE) {
207 av_log(ctx, AV_LOG_ERROR, "Invalid AU size\n");
208 return AVERROR_INVALIDDATA;
209 }
210
211 data->buf_size = data->au_headers[0].size;
212 data->timestamp = *timestamp;
213 }
214
215 if (data->timestamp != *timestamp ||
216 data->au_headers[0].size != data->buf_size ||
217 data->buf_pos + len > MAX_AAC_HBR_FRAME_SIZE) {
218 data->buf_pos = 0;
219 data->buf_size = 0;
220 av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
221 return AVERROR_INVALIDDATA;
222 }
223
224 memcpy(&data->buf[data->buf_pos], buf, len);
225 data->buf_pos += len;
226
227 if (!(flags & RTP_FLAG_MARKER))
228 return AVERROR(EAGAIN);
229
230 if (data->buf_pos != data->buf_size) {
231 data->buf_pos = 0;
232 av_log(ctx, AV_LOG_ERROR, "Missed some packets, discarding frame\n");
233 return AVERROR_INVALIDDATA;
234 }
235
236 data->buf_pos = 0;
237 ret = av_new_packet(pkt, data->buf_size);
238 if (ret < 0) {
239 av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
240 return ret;
241 }
242 pkt->stream_index = st->index;
243
244 memcpy(pkt->data, data->buf, data->buf_size);
245
246 return 0;
247 }
248
249 if (len < data->au_headers[0].size) {
250 av_log(ctx, AV_LOG_ERROR, "First AU larger than packet size\n");
251 return AVERROR_INVALIDDATA;
252 }
253 if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0) {
254 av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
255 return ret;
256 }
257 memcpy(pkt->data, buf, data->au_headers[0].size);
258 len -= data->au_headers[0].size;
259 buf += data->au_headers[0].size;
260 pkt->stream_index = st->index;
261
262 if (len > 0 && data->nb_au_headers > 1) {
263 data->buf_size = FFMIN(len, sizeof(data->buf));
264 memcpy(data->buf, buf, data->buf_size);
265 data->cur_au_index = 1;
266 data->buf_pos = 0;
267 return 1;
268 }
269
270 return 0;
271}
272
273static int parse_fmtp(AVFormatContext *s,
274 AVStream *stream, PayloadContext *data,
275 const char *attr, const char *value)
276{
277 AVCodecParameters *par = stream->codecpar;
278 int res, i;
279
280 if (!strcmp(attr, "config")) {
281 res = parse_fmtp_config(par, value);
282
283 if (res < 0)
284 return res;
285 }
286
287 if (par->codec_id == AV_CODEC_ID_AAC) {
288 /* Looking for a known attribute */
289 for (i = 0; attr_names[i].str; ++i) {
290 if (!av_strcasecmp(attr, attr_names[i].str)) {
291 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
292 int val = atoi(value);
293 if (val > 32) {
294 av_log(s, AV_LOG_ERROR,
295 "The %s field size is invalid (%d)\n",
296 attr, val);
297 return AVERROR_INVALIDDATA;
298 }
299 *(int *)((char *)data+
300 attr_names[i].offset) = val;
301 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR) {
302 char *val = av_strdup(value);
303 if (!val)
304 return AVERROR(ENOMEM);
305 *(char **)((char *)data+
306 attr_names[i].offset) = val;
307 }
308 }
309 }
310 }
311 return 0;
312}
313
314static int parse_sdp_line(AVFormatContext *s, int st_index,
315 PayloadContext *data, const char *line)
316{
317 const char *p;
318
319 if (st_index < 0)
320 return 0;
321
322 if (av_strstart(line, "fmtp:", &p))
323 return ff_parse_fmtp(s, s->streams[st_index], data, p, parse_fmtp);
324
325 return 0;
326}
327
328RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
329 .enc_name = "MP4V-ES",
330 .codec_type = AVMEDIA_TYPE_VIDEO,
331 .codec_id = AV_CODEC_ID_MPEG4,
332 .need_parsing = AVSTREAM_PARSE_FULL,
333 .priv_data_size = sizeof(PayloadContext),
334 .parse_sdp_a_line = parse_sdp_line,
335};
336
337RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
338 .enc_name = "mpeg4-generic",
339 .codec_type = AVMEDIA_TYPE_AUDIO,
340 .codec_id = AV_CODEC_ID_AAC,
341 .priv_data_size = sizeof(PayloadContext),
342 .parse_sdp_a_line = parse_sdp_line,
343 .close = close_context,
344 .parse_packet = aac_parse_packet,
345};
346
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