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/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;
68 /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */
69 #define ATTR_NAME_TYPE_INT 0
70 #define ATTR_NAME_TYPE_STR 1
71 static const AttrNameMap attr_names[] = {
72 { "SizeLength", ATTR_NAME_TYPE_INT,
73 offsetof(PayloadContext, sizelength) },
74 { "IndexLength", ATTR_NAME_TYPE_INT,
75 offsetof(PayloadContext, indexlength) },
76 { "IndexDeltaLength", ATTR_NAME_TYPE_INT,
77 offsetof(PayloadContext, indexdeltalength) },
78 { "profile-level-id", ATTR_NAME_TYPE_INT,
79 offsetof(PayloadContext, profile_level_id) },
80 { "StreamType", ATTR_NAME_TYPE_INT,
81 offsetof(PayloadContext, streamtype) },
82 { "mode", ATTR_NAME_TYPE_STR,
83 offsetof(PayloadContext, mode) },
87 static PayloadContext *new_context(void)
89 return av_mallocz(sizeof(PayloadContext));
92 static void free_context(PayloadContext *data)
94 av_free(data->au_headers);
99 static int parse_fmtp_config(AVCodecContext *codec, char *value)
101 /* decode the hexa encoded parameter */
102 int len = ff_hex_to_data(NULL, value);
103 av_free(codec->extradata);
104 codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
105 if (!codec->extradata)
106 return AVERROR(ENOMEM);
107 codec->extradata_size = len;
108 ff_hex_to_data(codec->extradata, value);
112 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
114 int au_headers_length, au_header_size, i;
115 GetBitContext getbitcontext;
117 /* decode the first 2 bytes where the AUHeader sections are stored
119 au_headers_length = AV_RB16(buf);
121 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
124 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
126 /* skip AU headers length section (2 bytes) */
129 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
131 /* XXX: Wrong if optionnal additional sections are present (cts, dts etc...) */
132 au_header_size = data->sizelength + data->indexlength;
133 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
136 data->nb_au_headers = au_headers_length / au_header_size;
137 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
138 av_free(data->au_headers);
139 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
140 data->au_headers_allocated = data->nb_au_headers;
143 /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
144 In my test, the FAAD decoder does not behave correctly when sending each AU one by one
145 but does when sending the whole as one big packet... */
146 data->au_headers[0].size = 0;
147 data->au_headers[0].index = 0;
148 for (i = 0; i < data->nb_au_headers; ++i) {
149 data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
150 data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
153 data->nb_au_headers = 1;
159 /* Follows RFC 3640 */
160 static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
161 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
162 const uint8_t *buf, int len, int flags)
164 if (rtp_parse_mp4_au(data, buf))
167 buf += data->au_headers_length_bytes + 2;
168 len -= data->au_headers_length_bytes + 2;
170 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
172 av_new_packet(pkt, data->au_headers[0].size);
173 memcpy(pkt->data, buf, data->au_headers[0].size);
175 pkt->stream_index = st->index;
179 static int parse_fmtp(AVStream *stream, PayloadContext *data,
180 char *attr, char *value)
182 AVCodecContext *codec = stream->codec;
185 if (!strcmp(attr, "config")) {
186 res = parse_fmtp_config(codec, value);
192 if (codec->codec_id == AV_CODEC_ID_AAC) {
193 /* Looking for a known attribute */
194 for (i = 0; attr_names[i].str; ++i) {
195 if (!av_strcasecmp(attr, attr_names[i].str)) {
196 if (attr_names[i].type == ATTR_NAME_TYPE_INT) {
197 *(int *)((char *)data+
198 attr_names[i].offset) = atoi(value);
199 } else if (attr_names[i].type == ATTR_NAME_TYPE_STR)
200 *(char **)((char *)data+
201 attr_names[i].offset) = av_strdup(value);
208 static int parse_sdp_line(AVFormatContext *s, int st_index,
209 PayloadContext *data, const char *line)
216 if (av_strstart(line, "fmtp:", &p))
217 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
222 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
223 .enc_name = "MP4V-ES",
224 .codec_type = AVMEDIA_TYPE_VIDEO,
225 .codec_id = AV_CODEC_ID_MPEG4,
226 .parse_sdp_a_line = parse_sdp_line,
229 RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = {
230 .enc_name = "mpeg4-generic",
231 .codec_type = AVMEDIA_TYPE_AUDIO,
232 .codec_id = AV_CODEC_ID_AAC,
233 .parse_sdp_a_line = parse_sdp_line,
234 .alloc = new_context,
235 .free = free_context,
236 .parse_packet = aac_parse_packet