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*/
46 /** mpeg 4 AU headers */
57 int au_headers_allocated;
59 int au_headers_length_bytes;
69 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
70 #define ATTR_NAME_TYPE_INT 0
71 #define ATTR_NAME_TYPE_STR 1
72 static const AttrNameMap attr_names[]=
74 { "SizeLength", ATTR_NAME_TYPE_INT,
75 offsetof(PayloadContext, sizelength) },
76 { "IndexLength", ATTR_NAME_TYPE_INT,
77 offsetof(PayloadContext, indexlength) },
78 { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
79 offsetof(PayloadContext, indexdeltalength) },
80 { "profile-level-id", ATTR_NAME_TYPE_INT,
81 offsetof(PayloadContext, profile_level_id) },
82 { "StreamType", ATTR_NAME_TYPE_INT,
83 offsetof(PayloadContext, streamtype) },
84 { "mode", ATTR_NAME_TYPE_STR,
85 offsetof(PayloadContext, mode) },
89 static PayloadContext *new_context(void)
91 return av_mallocz(sizeof(PayloadContext));
94 static void free_context(PayloadContext * data)
96 av_free(data->au_headers);
101 static int parse_fmtp_config(AVCodecContext * codec, 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)
116 int au_headers_length, au_header_size, i;
117 GetBitContext getbitcontext;
119 /* decode the first 2 bytes where the AUHeader sections are stored
121 au_headers_length = AV_RB16(buf);
123 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
126 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
128 /* skip AU headers length section (2 bytes) */
131 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
133 /* XXX: Wrong if optional additional sections are present (cts, dts etc...) */
134 au_header_size = data->sizelength + data->indexlength;
135 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
138 data->nb_au_headers = au_headers_length / au_header_size;
139 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
140 av_free(data->au_headers);
141 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
142 data->au_headers_allocated = data->nb_au_headers;
145 /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
146 In my test, the FAAD decoder does not behave correctly when sending each AU one by one
147 but does when sending the whole as one big packet... */
148 data->au_headers[0].size = 0;
149 data->au_headers[0].index = 0;
150 for (i = 0; i < data->nb_au_headers; ++i) {
151 data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
152 data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
155 data->nb_au_headers = 1;
161 /* Follows RFC 3640 */
162 static int aac_parse_packet(AVFormatContext *ctx,
163 PayloadContext *data,
167 const uint8_t *buf, int len, int flags)
169 if (rtp_parse_mp4_au(data, buf))
172 buf += data->au_headers_length_bytes + 2;
173 len -= data->au_headers_length_bytes + 2;
175 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
177 av_new_packet(pkt, data->au_headers[0].size);
178 memcpy(pkt->data, buf, data->au_headers[0].size);
180 pkt->stream_index = st->index;
184 static int parse_fmtp(AVStream *stream, PayloadContext *data,
185 char *attr, char *value)
187 AVCodecContext *codec = stream->codec;
190 if (!strcmp(attr, "config")) {
191 res = parse_fmtp_config(codec, value);
197 if (codec->codec_id == AV_CODEC_ID_AAC) {
198 /* Looking for a known attribute */
199 for (i = 0; attr_names[i].str; ++i) {
200 if (!av_strcasecmp(attr, attr_names[i].str)) {
201 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
202 *(int *)((char *)data+
203 attr_names[i].offset) = atoi(value);
204 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
205 *(char **)((char *)data+
206 attr_names[i].offset) = av_strdup(value);
213 static int parse_sdp_line(AVFormatContext *s, int st_index,
214 PayloadContext *data, const char *line)
221 if (av_strstart(line, "fmtp:", &p))
222 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
227 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
228 .enc_name = "MP4V-ES",
229 .codec_type = AVMEDIA_TYPE_VIDEO,
230 .codec_id = AV_CODEC_ID_MPEG4,
231 .parse_sdp_a_line = parse_sdp_line,
234 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
235 .enc_name = "mpeg4-generic",
236 .codec_type = AVMEDIA_TYPE_AUDIO,
237 .codec_id = AV_CODEC_ID_AAC,
238 .parse_sdp_a_line = parse_sdp_line,
239 .alloc = new_context,
240 .free = free_context,
241 .parse_packet = aac_parse_packet