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"
36 /** Structure listing useful vars to parse RTP packet payload*/
47 /** mpeg 4 AU headers */
58 int au_headers_allocated;
60 int au_headers_length_bytes;
70 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
71 #define ATTR_NAME_TYPE_INT 0
72 #define ATTR_NAME_TYPE_STR 1
73 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)
98 for (i = 0; i < data->nb_au_headers; i++) {
99 /* according to rtp_parse_mp4_au, we treat multiple
100 * au headers as one, so nb_au_headers is always 1.
101 * loop anyway in case this changes.
102 * (note: changes done carelessly might lead to a double free)
104 av_free(&data->au_headers[i]);
110 static int parse_fmtp_config(AVCodecContext * codec, char *value)
112 /* decode the hexa encoded parameter */
113 int len = ff_hex_to_data(NULL, value);
114 av_free(codec->extradata);
115 codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
116 if (!codec->extradata)
117 return AVERROR(ENOMEM);
118 codec->extradata_size = len;
119 ff_hex_to_data(codec->extradata, value);
123 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
125 int au_headers_length, au_header_size, i;
126 GetBitContext getbitcontext;
128 /* decode the first 2 bytes where the AUHeader sections are stored
130 au_headers_length = AV_RB16(buf);
132 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
135 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
137 /* skip AU headers length section (2 bytes) */
140 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
142 /* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
143 au_header_size = data->sizelength + data->indexlength;
144 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
147 data->nb_au_headers = au_headers_length / au_header_size;
148 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
149 av_free(data->au_headers);
150 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
151 data->au_headers_allocated = data->nb_au_headers;
154 /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
155 In my test, the FAAD decoder does not behave correctly when sending each AU one by one
156 but does when sending the whole as one big packet... */
157 data->au_headers[0].size = 0;
158 data->au_headers[0].index = 0;
159 for (i = 0; i < data->nb_au_headers; ++i) {
160 data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
161 data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
164 data->nb_au_headers = 1;
170 /* Follows RFC 3640 */
171 static int aac_parse_packet(AVFormatContext *ctx,
172 PayloadContext *data,
176 const uint8_t *buf, int len, int flags)
178 if (rtp_parse_mp4_au(data, buf))
181 buf += data->au_headers_length_bytes + 2;
182 len -= data->au_headers_length_bytes + 2;
184 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
186 av_new_packet(pkt, data->au_headers[0].size);
187 memcpy(pkt->data, buf, data->au_headers[0].size);
189 pkt->stream_index = st->index;
193 static int parse_fmtp(AVStream *stream, PayloadContext *data,
194 char *attr, char *value)
196 AVCodecContext *codec = stream->codec;
199 if (!strcmp(attr, "config")) {
200 res = parse_fmtp_config(codec, value);
206 if (codec->codec_id == CODEC_ID_AAC) {
207 /* Looking for a known attribute */
208 for (i = 0; attr_names[i].str; ++i) {
209 if (!strcasecmp(attr, attr_names[i].str)) {
210 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
211 *(int *)((char *)data+
212 attr_names[i].offset) = atoi(value);
213 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
214 *(char **)((char *)data+
215 attr_names[i].offset) = av_strdup(value);
222 static int parse_sdp_line(AVFormatContext *s, int st_index,
223 PayloadContext *data, const char *line)
227 if (av_strstart(line, "fmtp:", &p))
228 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
233 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
234 .enc_name = "MP4V-ES",
235 .codec_type = AVMEDIA_TYPE_VIDEO,
236 .codec_id = CODEC_ID_MPEG4,
237 .parse_sdp_a_line = parse_sdp_line,
243 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
244 .enc_name = "mpeg4-generic",
245 .codec_type = AVMEDIA_TYPE_AUDIO,
246 .codec_id = CODEC_ID_AAC,
247 .parse_sdp_a_line = parse_sdp_line,
249 .close = free_context,
250 .parse_packet = aac_parse_packet