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;
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, int len)
114 int au_headers_length, au_header_size, i;
115 GetBitContext getbitcontext;
118 return AVERROR_INVALIDDATA;
120 /* decode the first 2 bytes where the AUHeader sections are stored
122 au_headers_length = AV_RB16(buf);
124 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
127 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
129 /* skip AU headers length section (2 bytes) */
133 if (len < data->au_headers_length_bytes)
134 return AVERROR_INVALIDDATA;
136 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
138 /* XXX: Wrong if optional additional sections are present (cts, dts etc...) */
139 au_header_size = data->sizelength + data->indexlength;
140 if (au_header_size <= 0 || (au_headers_length % au_header_size != 0))
143 data->nb_au_headers = au_headers_length / au_header_size;
144 if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) {
145 av_free(data->au_headers);
146 data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers);
147 if (!data->au_headers)
148 return AVERROR(ENOMEM);
149 data->au_headers_allocated = data->nb_au_headers;
152 /* XXX: We handle multiple AU Section as only one (need to fix this for interleaving)
153 In my test, the FAAD decoder does not behave correctly when sending each AU one by one
154 but does when sending the whole as one big packet... */
155 data->au_headers[0].size = 0;
156 data->au_headers[0].index = 0;
157 for (i = 0; i < data->nb_au_headers; ++i) {
158 data->au_headers[0].size += get_bits_long(&getbitcontext, data->sizelength);
159 data->au_headers[0].index = get_bits_long(&getbitcontext, data->indexlength);
162 data->nb_au_headers = 1;
168 /* Follows RFC 3640 */
169 static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data,
170 AVStream *st, AVPacket *pkt, uint32_t *timestamp,
171 const uint8_t *buf, int len, uint16_t seq,
175 if (rtp_parse_mp4_au(data, buf, len))
178 buf += data->au_headers_length_bytes + 2;
179 len -= data->au_headers_length_bytes + 2;
181 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
183 if (len < data->au_headers[0].size)
184 return AVERROR_INVALIDDATA;
185 if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0)
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 == AV_CODEC_ID_AAC) {
207 /* Looking for a known attribute */
208 for (i = 0; attr_names[i].str; ++i) {
209 if (!av_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)
230 if (av_strstart(line, "fmtp:", &p))
231 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
236 RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = {
237 .enc_name = "MP4V-ES",
238 .codec_type = AVMEDIA_TYPE_VIDEO,
239 .codec_id = AV_CODEC_ID_MPEG4,
240 .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 = AV_CODEC_ID_AAC,
247 .parse_sdp_a_line = parse_sdp_line,
248 .alloc = new_context,
249 .free = free_context,
250 .parse_packet = aac_parse_packet