2 * Common code for the RTP depacketization of MPEG-4 formats.
3 * Copyright (c) 2010 Fabrice Bellard
6 * This file is part of Libav.
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.
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.
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
25 * @brief MPEG4 / RTP Code
26 * @author Fabrice Bellard
27 * @author Romain Degez
30 #include "rtpdec_formats.h"
32 #include "libavutil/attributes.h"
33 #include "libavutil/avstring.h"
34 #include "libavcodec/get_bits.h"
36 #define MAX_AAC_HBR_FRAME_SIZE 8191
38 /** Structure listing useful vars to parse RTP packet payload */
39 struct PayloadContext {
48 /** mpeg 4 AU headers */
59 int au_headers_allocated;
61 int au_headers_length_bytes;
64 uint8_t buf[FFMAX(RTP_MAX_PACKET_LENGTH, MAX_AAC_HBR_FRAME_SIZE)];
65 int buf_pos, buf_size;
69 typedef struct AttrNameMap {
75 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
76 #define ATTR_NAME_TYPE_INT 0
77 #define ATTR_NAME_TYPE_STR 1
78 static 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) },
94 static void free_context(PayloadContext *data)
96 av_free(data->au_headers);
101 static int parse_fmtp_config(AVCodecContext *codec, const char *value)
103 /* decode the hexa encoded parameter */
104 int len = ff_hex_to_data(NULL, value);
105 av_free(codec->extradata);
106 codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
107 if (!codec->extradata)
108 return AVERROR(ENOMEM);
109 codec->extradata_size = len;
110 ff_hex_to_data(codec->extradata, value);
114 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
116 int au_headers_length, au_header_size, i;
117 GetBitContext getbitcontext;
120 return AVERROR_INVALIDDATA;
122 /* decode the first 2 bytes where the AUHeader sections are stored
124 au_headers_length = AV_RB16(buf);
126 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
129 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
131 /* skip AU headers length section (2 bytes) */
135 if (len < data->au_headers_length_bytes)
136 return AVERROR_INVALIDDATA;
138 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
140 /* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
141 au_header_size = data->sizelength + data->indexlength;
142 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
145 data->nb_au_headers = au_headers_length / au_header_size;
146 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
147 av_free(data->au_headers);
148 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
149 if (!data->au_headers)
150 return AVERROR(ENOMEM);
151 data->au_headers_allocated = data->nb_au_headers;
154 for (i = 0; i < data->nb_au_headers; ++i) {
155 data->au_headers[i].size = get_bits_long(&getbitcontext, data->sizelength);
156 data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength);
163 /* Follows RFC 3640 */
164 static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
165 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
166 const uint8_t *buf, int len, uint16_t seq,
172 if (data->cur_au_index > data->nb_au_headers) {
173 av_log(ctx, AV_LOG_ERROR, "Invalid parser state\n");
174 return AVERROR_INVALIDDATA;
176 if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size) {
177 av_log(ctx, AV_LOG_ERROR, "Invalid AU size\n");
178 return AVERROR_INVALIDDATA;
180 if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0) {
181 av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
184 memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size);
185 data->buf_pos += data->au_headers[data->cur_au_index].size;
186 pkt->stream_index = st->index;
187 data->cur_au_index++;
189 if (data->cur_au_index == data->nb_au_headers) {
197 if (rtp_parse_mp4_au(data, buf, len)) {
198 av_log(ctx, AV_LOG_ERROR, "Error parsing AU headers\n");
202 buf += data->au_headers_length_bytes + 2;
203 len -= data->au_headers_length_bytes + 2;
204 if (data->nb_au_headers == 1 && len < data->au_headers[0].size) {
205 /* Packet is fragmented */
207 if (!data->buf_pos) {
208 if (data->au_headers[0].size > MAX_AAC_HBR_FRAME_SIZE) {
209 av_log(ctx, AV_LOG_ERROR, "Invalid AU size\n");
210 return AVERROR_INVALIDDATA;
213 data->buf_size = data->au_headers[0].size;
214 data->timestamp = *timestamp;
217 if (data->timestamp != *timestamp ||
218 data->au_headers[0].size != data->buf_size ||
219 data->buf_pos + len > MAX_AAC_HBR_FRAME_SIZE) {
222 av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
223 return AVERROR_INVALIDDATA;
226 memcpy(&data->buf[data->buf_pos], buf, len);
227 data->buf_pos += len;
229 if (!(flags & RTP_FLAG_MARKER))
230 return AVERROR(EAGAIN);
232 if (data->buf_pos != data->buf_size) {
234 av_log(ctx, AV_LOG_ERROR, "Missed some packets, discarding frame\n");
235 return AVERROR_INVALIDDATA;
239 ret = av_new_packet(pkt, data->buf_size);
241 av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
244 pkt->stream_index = st->index;
246 memcpy(pkt->data, data->buf, data->buf_size);
251 if (len < data->au_headers[0].size) {
252 av_log(ctx, AV_LOG_ERROR, "First AU larger than packet size\n");
253 return AVERROR_INVALIDDATA;
255 if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0) {
256 av_log(ctx, AV_LOG_ERROR, "Out of memory\n");
259 memcpy(pkt->data, buf, data->au_headers[0].size);
260 len -= data->au_headers[0].size;
261 buf += data->au_headers[0].size;
262 pkt->stream_index = st->index;
264 if (len > 0 && data->nb_au_headers > 1) {
265 data->buf_size = FFMIN(len, sizeof(data->buf));
266 memcpy(data->buf, buf, data->buf_size);
267 data->cur_au_index = 1;
275 static int parse_fmtp(AVFormatContext *s,
276 AVStream *stream, PayloadContext *data,
277 char *attr, char *value)
279 AVCodecContext *codec = stream->codec;
282 if (!strcmp(attr, "config")) {
283 res = parse_fmtp_config(codec, value);
289 if (codec->codec_id == AV_CODEC_ID_AAC) {
290 /* Looking for a known attribute */
291 for (i = 0; attr_names[i].str; ++i) {
292 if (!av_strcasecmp(attr, attr_names[i].str)) {
293 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
294 *(int *)((char *)data+
295 attr_names[i].offset) = atoi(value);
296 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
297 *(char **)((char *)data+
298 attr_names[i].offset) = av_strdup(value);
305 static int parse_sdp_line(AVFormatContext *s, int st_index,
306 PayloadContext *data, const char *line)
313 if (av_strstart(line, "fmtp:", &p))
314 return ff_parse_fmtp(s, s->streams[st_index], data, p, parse_fmtp);
319 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
320 .enc_name = "MP4V-ES",
321 .codec_type = AVMEDIA_TYPE_VIDEO,
322 .codec_id = AV_CODEC_ID_MPEG4,
323 .need_parsing = AVSTREAM_PARSE_FULL,
324 .priv_data_size = sizeof(PayloadContext),
325 .parse_sdp_a_line = parse_sdp_line,
328 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
329 .enc_name = "mpeg4-generic",
330 .codec_type = AVMEDIA_TYPE_AUDIO,
331 .codec_id = AV_CODEC_ID_AAC,
332 .priv_data_size = sizeof(PayloadContext),
333 .parse_sdp_a_line = parse_sdp_line,
334 .free = free_context,
335 .parse_packet = aac_parse_packet,