Make hex_to_data a lavf internal function
[libav.git] / libavformat / rtpdec_mpeg4.c
1 /**
2 * Common code for the RTP depacketization of MPEG-4 formats.
3 * Copyright (c) 2010 Fabrice Bellard
4 * Romain Degez
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23 /**
24 * @file
25 * @brief MPEG4 / RTP Code
26 * @author Fabrice Bellard
27 * @author Romain Degez
28 */
29
30 #include "rtpdec_formats.h"
31 #include "internal.h"
32 #include "libavutil/avstring.h"
33 #include "libavcodec/get_bits.h"
34 #include <strings.h>
35
36 /** Structure listing useful vars to parse RTP packet payload*/
37 struct PayloadContext
38 {
39 int sizelength;
40 int indexlength;
41 int indexdeltalength;
42 int profile_level_id;
43 int streamtype;
44 int objecttype;
45 char *mode;
46
47 /** mpeg 4 AU headers */
48 struct AUHeaders {
49 int size;
50 int index;
51 int cts_flag;
52 int cts;
53 int dts_flag;
54 int dts;
55 int rap_flag;
56 int streamstate;
57 } *au_headers;
58 int au_headers_allocated;
59 int nb_au_headers;
60 int au_headers_length_bytes;
61 int cur_au_index;
62 };
63
64 typedef struct {
65 const char *str;
66 uint16_t type;
67 uint32_t offset;
68 } AttrNameMap;
69
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[]=
74 {
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) },
87 { NULL, -1, -1 },
88 };
89
90 static PayloadContext *new_context(void)
91 {
92 return av_mallocz(sizeof(PayloadContext));
93 }
94
95 static void free_context(PayloadContext * data)
96 {
97 int i;
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)
103 */
104 av_free(&data->au_headers[i]);
105 }
106 av_free(data->mode);
107 av_free(data);
108 }
109
110 static int parse_fmtp_config(AVCodecContext * codec, char *value)
111 {
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);
121 return 0;
122 }
123
124 static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf)
125 {
126 int au_headers_length, au_header_size, i;
127 GetBitContext getbitcontext;
128
129 /* decode the first 2 bytes where the AUHeader sections are stored
130 length in bits */
131 au_headers_length = AV_RB16(buf);
132
133 if (au_headers_length > RTP_MAX_PACKET_LENGTH)
134 return -1;
135
136 data->au_headers_length_bytes = (au_headers_length + 7) / 8;
137
138 /* skip AU headers length section (2 bytes) */
139 buf += 2;
140
141 init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8);
142
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))
146 return -1;
147
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;
153 }
154
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);
163 }
164
165 data->nb_au_headers = 1;
166
167 return 0;
168 }
169
170
171 /* Follows RFC 3640 */
172 static int aac_parse_packet(AVFormatContext *ctx,
173 PayloadContext *data,
174 AVStream *st,
175 AVPacket *pkt,
176 uint32_t *timestamp,
177 const uint8_t *buf, int len, int flags)
178 {
179 if (rtp_parse_mp4_au(data, buf))
180 return -1;
181
182 buf += data->au_headers_length_bytes + 2;
183 len -= data->au_headers_length_bytes + 2;
184
185 /* XXX: Fixme we only handle the case where rtp_parse_mp4_au define
186 one au_header */
187 av_new_packet(pkt, data->au_headers[0].size);
188 memcpy(pkt->data, buf, data->au_headers[0].size);
189
190 pkt->stream_index = st->index;
191 return 0;
192 }
193
194 static int parse_fmtp(AVStream *stream, PayloadContext *data,
195 char *attr, char *value)
196 {
197 AVCodecContext *codec = stream->codec;
198 int res, i;
199
200 if (!strcmp(attr, "config")) {
201 res = parse_fmtp_config(codec, value);
202
203 if (res < 0)
204 return res;
205 }
206
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);
217 }
218 }
219 }
220 return 0;
221 }
222
223 static int parse_sdp_line(AVFormatContext *s, int st_index,
224 PayloadContext *data, const char *line)
225 {
226 const char *p;
227
228 if (av_strstart(line, "fmtp:", &p))
229 return ff_parse_fmtp(s->streams[st_index], data, p, parse_fmtp);
230
231 return 0;
232 }
233
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,
239 .open = NULL,
240 .close = NULL,
241 .parse_packet = NULL
242 };
243
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,
249 .open = new_context,
250 .close = free_context,
251 .parse_packet = aac_parse_packet
252 };