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 if (codec->extradata)
115 av_free(codec->extradata);
116 codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
117 if (!codec->extradata)
118 return AVERROR(ENOMEM);
119 codec->extradata_size = len;
120 ff_hex_to_data(codec->extradata, value);
124 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
126 int au_headers_length, au_header_size, i;
127 GetBitContext getbitcontext;
129 /* decode the first 2 bytes where the AUHeader sections are stored
131 au_headers_length = AV_RB16(buf);
133 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
136 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
138 /* skip AU headers length section (2 bytes) */
141 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
143 /* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
144 au_header_size = data->sizelength + data->indexlength;
145 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
148 data->nb_au_headers = au_headers_length / au_header_size;
149 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
150 av_free(data->au_headers);
151 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
152 data->au_headers_allocated = data->nb_au_headers;
155 /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
156 In my test, the FAAD decoder does not behave correctly when sending each AU one by one
157 but does when sending the whole as one big packet... */
158 data->au_headers[0].size = 0;
159 data->au_headers[0].index = 0;
160 for (i = 0; i < data->nb_au_headers; ++i) {
161 data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
162 data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
165 data->nb_au_headers = 1;
171 /* Follows RFC 3640 */
172 static int aac_parse_packet(AVFormatContext *ctx,
173 PayloadContext *data,
177 const uint8_t *buf, int len, int flags)
179 if (rtp_parse_mp4_au(data, buf))
182 buf += data->au_headers_length_bytes + 2;
183 len -= data->au_headers_length_bytes + 2;
185 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
187 av_new_packet(pkt, data->au_headers[0].size);
188 memcpy(pkt->data, buf, data->au_headers[0].size);
190 pkt->stream_index = st->index;
194 static int parse_fmtp(AVStream *stream, PayloadContext *data,
195 char *attr, char *value)
197 AVCodecContext *codec = stream->codec;
200 if (!strcmp(attr, "config")) {
201 res = parse_fmtp_config(codec, value);
207 if (codec->codec_id == CODEC_ID_AAC) {
208 /* Looking for a known attribute */
209 for (i = 0; attr_names[i].str; ++i) {
210 if (!strcasecmp(attr, attr_names[i].str)) {
211 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
212 *(int *)((char *)data+
213 attr_names[i].offset) = atoi(value);
214 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
215 *(char **)((char *)data+
216 attr_names[i].offset) = av_strdup(value);
223 static int parse_sdp_line(AVFormatContext *s, int st_index,
224 PayloadContext *data, const char *line)
228 if (av_strstart(line, "fmtp:", &p))
229 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
234 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
235 .enc_name = "MP4V-ES",
236 .codec_type = AVMEDIA_TYPE_VIDEO,
237 .codec_id = CODEC_ID_MPEG4,
238 .parse_sdp_a_line = parse_sdp_line,
244 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
245 .enc_name = "mpeg4-generic",
246 .codec_type = AVMEDIA_TYPE_AUDIO,
247 .codec_id = CODEC_ID_AAC,
248 .parse_sdp_a_line = parse_sdp_line,
250 .close = free_context,
251 .parse_packet = aac_parse_packet