2 * Common code for the RTP depacketization of MPEG-4 formats.
3 * Copyright (c) 2010 Fabrice Bellard
6 * This file is part of FFmpeg.
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.
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.
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
25 * @brief MPEG4 / RTP Code
26 * @author Fabrice Bellard
27 * @author Romain Degez
30 #include "rtpdec_formats.h"
32 #include "libavutil/avstring.h"
33 #include "libavcodec/get_bits.h"
35 /** Structure listing useful vars to parse RTP packet payload */
36 struct PayloadContext {
45 /** mpeg 4 AU headers */
56 int au_headers_allocated;
58 int au_headers_length_bytes;
61 uint8_t buf[RTP_MAX_PACKET_LENGTH];
62 int buf_pos, buf_size;
71 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
72 #define ATTR_NAME_TYPE_INT 0
73 #define ATTR_NAME_TYPE_STR 1
74 static const AttrNameMap attr_names[] = {
75 { "SizeLength", ATTR_NAME_TYPE_INT,
76 offsetof(PayloadContext, sizelength) },
77 { "IndexLength", ATTR_NAME_TYPE_INT,
78 offsetof(PayloadContext, indexlength) },
79 { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
80 offsetof(PayloadContext, indexdeltalength) },
81 { "profile-level-id", ATTR_NAME_TYPE_INT,
82 offsetof(PayloadContext, profile_level_id) },
83 { "StreamType", ATTR_NAME_TYPE_INT,
84 offsetof(PayloadContext, streamtype) },
85 { "mode", ATTR_NAME_TYPE_STR,
86 offsetof(PayloadContext, mode) },
90 static PayloadContext *new_context(void)
92 return av_mallocz(sizeof(PayloadContext));
95 static void free_context(PayloadContext *data)
97 av_free(data->au_headers);
102 static int parse_fmtp_config(AVCodecContext *codec, char *value)
104 /* decode the hexa encoded parameter */
105 int len = ff_hex_to_data(NULL, value);
106 av_free(codec->extradata);
107 codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
108 if (!codec->extradata)
109 return AVERROR(ENOMEM);
110 codec->extradata_size = len;
111 ff_hex_to_data(codec->extradata, value);
115 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len)
117 int au_headers_length, au_header_size, i;
118 GetBitContext getbitcontext;
121 return AVERROR_INVALIDDATA;
123 /* decode the first 2 bytes where the AUHeader sections are stored
125 au_headers_length = AV_RB16(buf);
127 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
130 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
132 /* skip AU headers length section (2 bytes) */
136 if (len < data->au_headers_length_bytes)
137 return AVERROR_INVALIDDATA;
139 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
141 /* XXX: Wrong if optional additional sections are present (cts, dts etc...) */
142 au_header_size = data->sizelength + data->indexlength;
143 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
146 data->nb_au_headers = au_headers_length / au_header_size;
147 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
148 av_free(data->au_headers);
149 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
150 if (!data->au_headers)
151 return AVERROR(ENOMEM);
152 data->au_headers_allocated = data->nb_au_headers;
155 for (i = 0; i < data->nb_au_headers; ++i) {
156 data->au_headers[i].size = get_bits_long(&getbitcontext, data->sizelength);
157 data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength);
164 /* Follows RFC 3640 */
165 static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
166 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
167 const uint8_t *buf, int len, uint16_t seq,
173 if (data->cur_au_index > data->nb_au_headers)
174 return AVERROR_INVALIDDATA;
175 if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size)
176 return AVERROR_INVALIDDATA;
177 if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0)
179 memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size);
180 data->buf_pos += data->au_headers[data->cur_au_index].size;
181 pkt->stream_index = st->index;
182 data->cur_au_index++;
183 return data->cur_au_index < data->nb_au_headers;
186 if (rtp_parse_mp4_au(data, buf, len))
189 buf += data->au_headers_length_bytes + 2;
190 len -= data->au_headers_length_bytes + 2;
192 if (len < data->au_headers[0].size)
193 return AVERROR_INVALIDDATA;
194 if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0)
196 memcpy(pkt->data, buf, data->au_headers[0].size);
197 len -= data->au_headers[0].size;
198 buf += data->au_headers[0].size;
199 pkt->stream_index = st->index;
201 if (len > 0 && data->nb_au_headers > 1) {
202 data->buf_size = FFMIN(len, sizeof(data->buf));
203 memcpy(data->buf, buf, data->buf_size);
204 data->cur_au_index = 1;
212 static int parse_fmtp(AVStream *stream, PayloadContext *data,
213 char *attr, char *value)
215 AVCodecContext *codec = stream->codec;
218 if (!strcmp(attr, "config")) {
219 res = parse_fmtp_config(codec, value);
225 if (codec->codec_id == AV_CODEC_ID_AAC) {
226 /* Looking for a known attribute */
227 for (i = 0; attr_names[i].str; ++i) {
228 if (!av_strcasecmp(attr, attr_names[i].str)) {
229 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
230 *(int *)((char *)data+
231 attr_names[i].offset) = atoi(value);
232 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
233 *(char **)((char *)data+
234 attr_names[i].offset) = av_strdup(value);
241 static int parse_sdp_line(AVFormatContext *s, int st_index,
242 PayloadContext *data, const char *line)
249 if (av_strstart(line, "fmtp:", &p))
250 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
255 static int init_video(AVFormatContext *s, int st_index, PayloadContext *data)
259 s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
263 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
264 .enc_name = "MP4V-ES",
265 .codec_type = AVMEDIA_TYPE_VIDEO,
266 .codec_id = AV_CODEC_ID_MPEG4,
268 .parse_sdp_a_line = parse_sdp_line,
271 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
272 .enc_name = "mpeg4-generic",
273 .codec_type = AVMEDIA_TYPE_AUDIO,
274 .codec_id = AV_CODEC_ID_AAC,
275 .parse_sdp_a_line = parse_sdp_line,
276 .alloc = new_context,
277 .free = free_context,
278 .parse_packet = aac_parse_packet