| 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/attributes.h" |
| 33 | #include "libavutil/avstring.h" |
| 34 | #include "libavcodec/get_bits.h" |
| 35 | |
| 36 | /** Structure listing useful vars to parse RTP packet payload */ |
| 37 | struct PayloadContext { |
| 38 | int sizelength; |
| 39 | int indexlength; |
| 40 | int indexdeltalength; |
| 41 | int profile_level_id; |
| 42 | int streamtype; |
| 43 | int objecttype; |
| 44 | char *mode; |
| 45 | |
| 46 | /** mpeg 4 AU headers */ |
| 47 | struct AUHeaders { |
| 48 | int size; |
| 49 | int index; |
| 50 | int cts_flag; |
| 51 | int cts; |
| 52 | int dts_flag; |
| 53 | int dts; |
| 54 | int rap_flag; |
| 55 | int streamstate; |
| 56 | } *au_headers; |
| 57 | int au_headers_allocated; |
| 58 | int nb_au_headers; |
| 59 | int au_headers_length_bytes; |
| 60 | int cur_au_index; |
| 61 | |
| 62 | uint8_t buf[RTP_MAX_PACKET_LENGTH]; |
| 63 | int buf_pos, buf_size; |
| 64 | }; |
| 65 | |
| 66 | typedef struct { |
| 67 | const char *str; |
| 68 | uint16_t type; |
| 69 | uint32_t offset; |
| 70 | } AttrNameMap; |
| 71 | |
| 72 | /* All known fmtp parameters and the corresponding RTPAttrTypeEnum */ |
| 73 | #define ATTR_NAME_TYPE_INT 0 |
| 74 | #define ATTR_NAME_TYPE_STR 1 |
| 75 | static const AttrNameMap attr_names[] = { |
| 76 | { "SizeLength", ATTR_NAME_TYPE_INT, |
| 77 | offsetof(PayloadContext, sizelength) }, |
| 78 | { "IndexLength", ATTR_NAME_TYPE_INT, |
| 79 | offsetof(PayloadContext, indexlength) }, |
| 80 | { "IndexDeltaLength", ATTR_NAME_TYPE_INT, |
| 81 | offsetof(PayloadContext, indexdeltalength) }, |
| 82 | { "profile-level-id", ATTR_NAME_TYPE_INT, |
| 83 | offsetof(PayloadContext, profile_level_id) }, |
| 84 | { "StreamType", ATTR_NAME_TYPE_INT, |
| 85 | offsetof(PayloadContext, streamtype) }, |
| 86 | { "mode", ATTR_NAME_TYPE_STR, |
| 87 | offsetof(PayloadContext, mode) }, |
| 88 | { NULL, -1, -1 }, |
| 89 | }; |
| 90 | |
| 91 | static PayloadContext *new_context(void) |
| 92 | { |
| 93 | return av_mallocz(sizeof(PayloadContext)); |
| 94 | } |
| 95 | |
| 96 | static void free_context(PayloadContext *data) |
| 97 | { |
| 98 | av_free(data->au_headers); |
| 99 | av_free(data->mode); |
| 100 | av_free(data); |
| 101 | } |
| 102 | |
| 103 | static int parse_fmtp_config(AVCodecContext *codec, char *value) |
| 104 | { |
| 105 | /* decode the hexa encoded parameter */ |
| 106 | int len = ff_hex_to_data(NULL, value); |
| 107 | av_free(codec->extradata); |
| 108 | if (ff_alloc_extradata(codec, len)) |
| 109 | return AVERROR(ENOMEM); |
| 110 | ff_hex_to_data(codec->extradata, value); |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | static int rtp_parse_mp4_au(PayloadContext *data, const uint8_t *buf, int len) |
| 115 | { |
| 116 | int au_headers_length, au_header_size, i; |
| 117 | GetBitContext getbitcontext; |
| 118 | |
| 119 | if (len < 2) |
| 120 | return AVERROR_INVALIDDATA; |
| 121 | |
| 122 | /* decode the first 2 bytes where the AUHeader sections are stored |
| 123 | length in bits */ |
| 124 | au_headers_length = AV_RB16(buf); |
| 125 | |
| 126 | if (au_headers_length > RTP_MAX_PACKET_LENGTH) |
| 127 | return -1; |
| 128 | |
| 129 | data->au_headers_length_bytes = (au_headers_length + 7) / 8; |
| 130 | |
| 131 | /* skip AU headers length section (2 bytes) */ |
| 132 | buf += 2; |
| 133 | len -= 2; |
| 134 | |
| 135 | if (len < data->au_headers_length_bytes) |
| 136 | return AVERROR_INVALIDDATA; |
| 137 | |
| 138 | init_get_bits(&getbitcontext, buf, data->au_headers_length_bytes * 8); |
| 139 | |
| 140 | /* XXX: Wrong if optional additional sections are present (cts, dts etc...) */ |
| 141 | au_header_size = data->sizelength + data->indexlength; |
| 142 | if (au_header_size <= 0 || (au_headers_length % au_header_size != 0)) |
| 143 | return -1; |
| 144 | |
| 145 | data->nb_au_headers = au_headers_length / au_header_size; |
| 146 | if (!data->au_headers || data->au_headers_allocated < data->nb_au_headers) { |
| 147 | av_free(data->au_headers); |
| 148 | data->au_headers = av_malloc(sizeof(struct AUHeaders) * data->nb_au_headers); |
| 149 | if (!data->au_headers) |
| 150 | return AVERROR(ENOMEM); |
| 151 | data->au_headers_allocated = data->nb_au_headers; |
| 152 | } |
| 153 | |
| 154 | for (i = 0; i < data->nb_au_headers; ++i) { |
| 155 | data->au_headers[i].size = get_bits_long(&getbitcontext, data->sizelength); |
| 156 | data->au_headers[i].index = get_bits_long(&getbitcontext, data->indexlength); |
| 157 | } |
| 158 | |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | |
| 163 | /* Follows RFC 3640 */ |
| 164 | static int aac_parse_packet(AVFormatContext *ctx, PayloadContext *data, |
| 165 | AVStream *st, AVPacket *pkt, uint32_t *timestamp, |
| 166 | const uint8_t *buf, int len, uint16_t seq, |
| 167 | int flags) |
| 168 | { |
| 169 | int ret; |
| 170 | |
| 171 | if (!buf) { |
| 172 | if (data->cur_au_index > data->nb_au_headers) |
| 173 | return AVERROR_INVALIDDATA; |
| 174 | if (data->buf_size - data->buf_pos < data->au_headers[data->cur_au_index].size) |
| 175 | return AVERROR_INVALIDDATA; |
| 176 | if ((ret = av_new_packet(pkt, data->au_headers[data->cur_au_index].size)) < 0) |
| 177 | return ret; |
| 178 | memcpy(pkt->data, &data->buf[data->buf_pos], data->au_headers[data->cur_au_index].size); |
| 179 | data->buf_pos += data->au_headers[data->cur_au_index].size; |
| 180 | pkt->stream_index = st->index; |
| 181 | data->cur_au_index++; |
| 182 | return data->cur_au_index < data->nb_au_headers; |
| 183 | } |
| 184 | |
| 185 | if (rtp_parse_mp4_au(data, buf, len)) |
| 186 | return -1; |
| 187 | |
| 188 | buf += data->au_headers_length_bytes + 2; |
| 189 | len -= data->au_headers_length_bytes + 2; |
| 190 | |
| 191 | if (len < data->au_headers[0].size) |
| 192 | return AVERROR_INVALIDDATA; |
| 193 | if ((ret = av_new_packet(pkt, data->au_headers[0].size)) < 0) |
| 194 | return ret; |
| 195 | memcpy(pkt->data, buf, data->au_headers[0].size); |
| 196 | len -= data->au_headers[0].size; |
| 197 | buf += data->au_headers[0].size; |
| 198 | pkt->stream_index = st->index; |
| 199 | |
| 200 | if (len > 0 && data->nb_au_headers > 1) { |
| 201 | data->buf_size = FFMIN(len, sizeof(data->buf)); |
| 202 | memcpy(data->buf, buf, data->buf_size); |
| 203 | data->cur_au_index = 1; |
| 204 | data->buf_pos = 0; |
| 205 | return 1; |
| 206 | } |
| 207 | |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | static int parse_fmtp(AVFormatContext *s, |
| 212 | AVStream *stream, PayloadContext *data, |
| 213 | char *attr, char *value) |
| 214 | { |
| 215 | AVCodecContext *codec = stream->codec; |
| 216 | int res, i; |
| 217 | |
| 218 | if (!strcmp(attr, "config")) { |
| 219 | res = parse_fmtp_config(codec, value); |
| 220 | |
| 221 | if (res < 0) |
| 222 | return res; |
| 223 | } |
| 224 | |
| 225 | if (codec->codec_id == AV_CODEC_ID_AAC) { |
| 226 | /* Looking for a known attribute */ |
| 227 | for (i = 0; attr_names[i].str; ++i) { |
| 228 | if (!av_strcasecmp(attr, attr_names[i].str)) { |
| 229 | if (attr_names[i].type == ATTR_NAME_TYPE_INT) { |
| 230 | *(int *)((char *)data+ |
| 231 | attr_names[i].offset) = atoi(value); |
| 232 | } else if (attr_names[i].type == ATTR_NAME_TYPE_STR) |
| 233 | *(char **)((char *)data+ |
| 234 | attr_names[i].offset) = av_strdup(value); |
| 235 | } |
| 236 | } |
| 237 | } |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static int parse_sdp_line(AVFormatContext *s, int st_index, |
| 242 | PayloadContext *data, const char *line) |
| 243 | { |
| 244 | const char *p; |
| 245 | |
| 246 | if (st_index < 0) |
| 247 | return 0; |
| 248 | |
| 249 | if (av_strstart(line, "fmtp:", &p)) |
| 250 | return ff_parse_fmtp(s, s->streams[st_index], data, p, parse_fmtp); |
| 251 | |
| 252 | return 0; |
| 253 | } |
| 254 | |
| 255 | static av_cold int init_video(AVFormatContext *s, int st_index, |
| 256 | PayloadContext *data) |
| 257 | { |
| 258 | if (st_index < 0) |
| 259 | return 0; |
| 260 | s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL; |
| 261 | return 0; |
| 262 | } |
| 263 | |
| 264 | RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler = { |
| 265 | .enc_name = "MP4V-ES", |
| 266 | .codec_type = AVMEDIA_TYPE_VIDEO, |
| 267 | .codec_id = AV_CODEC_ID_MPEG4, |
| 268 | .init = init_video, |
| 269 | .parse_sdp_a_line = parse_sdp_line, |
| 270 | }; |
| 271 | |
| 272 | RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler = { |
| 273 | .enc_name = "mpeg4-generic", |
| 274 | .codec_type = AVMEDIA_TYPE_AUDIO, |
| 275 | .codec_id = AV_CODEC_ID_AAC, |
| 276 | .parse_sdp_a_line = parse_sdp_line, |
| 277 | .alloc = new_context, |
| 278 | .free = free_context, |
| 279 | .parse_packet = aac_parse_packet |
| 280 | }; |