1/* 2 * Xiph RTP Protocols 3 * Copyright (c) 2009 Colin McQuillian 4 * Copyright (c) 2010 Josh Allmann 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 Xiph / RTP Code 26 * @author Colin McQuillan <m.niloc@gmail.com> 27 * @author Josh Allmann <joshua.allmann@gmail.com> 28 */ 29 30#include "libavutil/attributes.h" 31#include "libavutil/avassert.h" 32#include "libavutil/avstring.h" 33#include "libavutil/base64.h" 34#include "libavcodec/bytestream.h" 35 36#include "internal.h" 37#include "rtpdec.h" 38#include "rtpdec_formats.h" 39 40/** 41 * RTP/Xiph specific private data. 42 */ 43struct PayloadContext { 44 unsigned ident; ///< 24-bit stream configuration identifier 45 uint32_t timestamp; 46 AVIOContext* fragment; ///< buffer for split payloads 47 uint8_t *split_buf; 48 int split_pos, split_buf_len, split_buf_size; 49 int split_pkts; 50}; 51 52static PayloadContext *xiph_new_context(void) 53{ 54 return av_mallocz(sizeof(PayloadContext)); 55} 56 57static inline void free_fragment_if_needed(PayloadContext * data) 58{ 59 if (data->fragment) { 60 uint8_t* p; 61 avio_close_dyn_buf(data->fragment, &p); 62 av_free(p); 63 data->fragment = NULL; 64 } 65} 66 67static void xiph_free_context(PayloadContext * data) 68{ 69 free_fragment_if_needed(data); 70 av_free(data->split_buf); 71 av_free(data); 72} 73 74static av_cold int xiph_vorbis_init(AVFormatContext *ctx, int st_index, 75 PayloadContext *data) 76{ 77 if (st_index < 0) 78 return 0; 79 ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_HEADERS; 80 return 0; 81} 82 83 84static int xiph_handle_packet(AVFormatContext *ctx, PayloadContext *data, 85 AVStream *st, AVPacket *pkt, uint32_t *timestamp, 86 const uint8_t *buf, int len, uint16_t seq, 87 int flags) 88{ 89 90 int ident, fragmented, tdt, num_pkts, pkt_len; 91 92 if (!buf) { 93 if (!data->split_buf || data->split_pos + 2 > data->split_buf_len || 94 data->split_pkts <= 0) { 95 av_log(ctx, AV_LOG_ERROR, "No more data to return\n"); 96 return AVERROR_INVALIDDATA; 97 } 98 pkt_len = AV_RB16(data->split_buf + data->split_pos); 99 data->split_pos += 2; 100 if (data->split_pos + pkt_len > data->split_buf_len) { 101 av_log(ctx, AV_LOG_ERROR, "Not enough data to return\n"); 102 return AVERROR_INVALIDDATA; 103 } 104 if (av_new_packet(pkt, pkt_len)) { 105 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); 106 return AVERROR(ENOMEM); 107 } 108 pkt->stream_index = st->index; 109 memcpy(pkt->data, data->split_buf + data->split_pos, pkt_len); 110 data->split_pos += pkt_len; 111 data->split_pkts--; 112 return data->split_pkts > 0; 113 } 114 115 if (len < 6) { 116 av_log(ctx, AV_LOG_ERROR, "Invalid %d byte packet\n", len); 117 return AVERROR_INVALIDDATA; 118 } 119 120 // read xiph rtp headers 121 ident = AV_RB24(buf); 122 fragmented = buf[3] >> 6; 123 tdt = (buf[3] >> 4) & 3; 124 num_pkts = buf[3] & 0xf; 125 pkt_len = AV_RB16(buf + 4); 126 127 if (pkt_len > len - 6) { 128 av_log(ctx, AV_LOG_ERROR, 129 "Invalid packet length %d in %d byte packet\n", pkt_len, 130 len); 131 return AVERROR_INVALIDDATA; 132 } 133 134 if (ident != data->ident) { 135 av_log(ctx, AV_LOG_ERROR, 136 "Unimplemented Xiph SDP configuration change detected\n"); 137 return AVERROR_PATCHWELCOME; 138 } 139 140 if (tdt) { 141 av_log(ctx, AV_LOG_ERROR, 142 "Unimplemented RTP Xiph packet settings (%d,%d,%d)\n", 143 fragmented, tdt, num_pkts); 144 return AVERROR_PATCHWELCOME; 145 } 146 147 buf += 6; // move past header bits 148 len -= 6; 149 150 if (fragmented == 0) { 151 if (av_new_packet(pkt, pkt_len)) { 152 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); 153 return AVERROR(ENOMEM); 154 } 155 pkt->stream_index = st->index; 156 memcpy(pkt->data, buf, pkt_len); 157 buf += pkt_len; 158 len -= pkt_len; 159 num_pkts--; 160 161 if (num_pkts > 0) { 162 if (len > data->split_buf_size || !data->split_buf) { 163 av_freep(&data->split_buf); 164 data->split_buf_size = 2 * len; 165 data->split_buf = av_malloc(data->split_buf_size); 166 if (!data->split_buf) { 167 av_log(ctx, AV_LOG_ERROR, "Out of memory.\n"); 168 av_free_packet(pkt); 169 return AVERROR(ENOMEM); 170 } 171 } 172 memcpy(data->split_buf, buf, len); 173 data->split_buf_len = len; 174 data->split_pos = 0; 175 data->split_pkts = num_pkts; 176 return 1; 177 } 178 179 return 0; 180 181 } else if (fragmented == 1) { 182 // start of xiph data fragment 183 int res; 184 185 // end packet has been lost somewhere, so drop buffered data 186 free_fragment_if_needed(data); 187 188 if((res = avio_open_dyn_buf(&data->fragment)) < 0) 189 return res; 190 191 avio_write(data->fragment, buf, pkt_len); 192 data->timestamp = *timestamp; 193 194 } else { 195 av_assert1(fragmented < 4); 196 if (data->timestamp != *timestamp) { 197 // skip if fragmented timestamp is incorrect; 198 // a start packet has been lost somewhere 199 free_fragment_if_needed(data); 200 av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match!\n"); 201 return AVERROR_INVALIDDATA; 202 } 203 if (!data->fragment) { 204 av_log(ctx, AV_LOG_WARNING, 205 "Received packet without a start fragment; dropping.\n"); 206 return AVERROR(EAGAIN); 207 } 208 209 // copy data to fragment buffer 210 avio_write(data->fragment, buf, pkt_len); 211 212 if (fragmented == 3) { 213 // end of xiph data packet 214 int ret = ff_rtp_finalize_packet(pkt, &data->fragment, st->index); 215 if (ret < 0) { 216 av_log(ctx, AV_LOG_ERROR, 217 "Error occurred when getting fragment buffer."); 218 return ret; 219 } 220 221 return 0; 222 } 223 } 224 225 return AVERROR(EAGAIN); 226} 227 228/** 229 * Length encoding described in RFC5215 section 3.1.1. 230 */ 231static int get_base128(const uint8_t ** buf, const uint8_t * buf_end) 232{ 233 int n = 0; 234 for (; *buf < buf_end; ++*buf) { 235 n <<= 7; 236 n += **buf & 0x7f; 237 if (!(**buf & 0x80)) { 238 ++*buf; 239 return n; 240 } 241 } 242 return 0; 243} 244 245/** 246 * Based off parse_packed_headers in Vorbis RTP 247 */ 248static int 249parse_packed_headers(const uint8_t * packed_headers, 250 const uint8_t * packed_headers_end, 251 AVCodecContext * codec, PayloadContext * xiph_data) 252{ 253 254 unsigned num_packed, num_headers, length, length1, length2, extradata_alloc; 255 uint8_t *ptr; 256 257 if (packed_headers_end - packed_headers < 9) { 258 av_log(codec, AV_LOG_ERROR, 259 "Invalid %"PTRDIFF_SPECIFIER" byte packed header.", 260 packed_headers_end - packed_headers); 261 return AVERROR_INVALIDDATA; 262 } 263 264 num_packed = bytestream_get_be32(&packed_headers); 265 xiph_data->ident = bytestream_get_be24(&packed_headers); 266 length = bytestream_get_be16(&packed_headers); 267 num_headers = get_base128(&packed_headers, packed_headers_end); 268 length1 = get_base128(&packed_headers, packed_headers_end); 269 length2 = get_base128(&packed_headers, packed_headers_end); 270 271 if (num_packed != 1 || num_headers > 3) { 272 av_log(codec, AV_LOG_ERROR, 273 "Unimplemented number of headers: %d packed headers, %d headers\n", 274 num_packed, num_headers); 275 return AVERROR_PATCHWELCOME; 276 } 277 278 if (packed_headers_end - packed_headers != length || 279 length1 > length || length2 > length - length1) { 280 av_log(codec, AV_LOG_ERROR, 281 "Bad packed header lengths (%d,%d,%"PTRDIFF_SPECIFIER",%d)\n", length1, 282 length2, packed_headers_end - packed_headers, length); 283 return AVERROR_INVALIDDATA; 284 } 285 286 /* allocate extra space: 287 * -- length/255 +2 for xiphlacing 288 * -- one for the '2' marker 289 * -- FF_INPUT_BUFFER_PADDING_SIZE required */ 290 extradata_alloc = length + length/255 + 3 + FF_INPUT_BUFFER_PADDING_SIZE; 291 292 if (ff_alloc_extradata(codec, extradata_alloc)) { 293 av_log(codec, AV_LOG_ERROR, "Out of memory\n"); 294 return AVERROR(ENOMEM); 295 } 296 ptr = codec->extradata; 297 *ptr++ = 2; 298 ptr += av_xiphlacing(ptr, length1); 299 ptr += av_xiphlacing(ptr, length2); 300 memcpy(ptr, packed_headers, length); 301 ptr += length; 302 codec->extradata_size = ptr - codec->extradata; 303 // clear out remaining parts of the buffer 304 memset(ptr, 0, extradata_alloc - codec->extradata_size); 305 306 return 0; 307} 308 309static int xiph_parse_fmtp_pair(AVFormatContext *s, 310 AVStream* stream, 311 PayloadContext *xiph_data, 312 char *attr, char *value) 313{ 314 AVCodecContext *codec = stream->codec; 315 int result = 0; 316 317 if (!strcmp(attr, "sampling")) { 318 if (!strcmp(value, "YCbCr-4:2:0")) { 319 codec->pix_fmt = AV_PIX_FMT_YUV420P; 320 } else if (!strcmp(value, "YCbCr-4:4:2")) { 321 codec->pix_fmt = AV_PIX_FMT_YUV422P; 322 } else if (!strcmp(value, "YCbCr-4:4:4")) { 323 codec->pix_fmt = AV_PIX_FMT_YUV444P; 324 } else { 325 av_log(s, AV_LOG_ERROR, 326 "Unsupported pixel format %s\n", attr); 327 return AVERROR_INVALIDDATA; 328 } 329 } else if (!strcmp(attr, "width")) { 330 /* This is an integer between 1 and 1048561 331 * and MUST be in multiples of 16. */ 332 codec->width = atoi(value); 333 return 0; 334 } else if (!strcmp(attr, "height")) { 335 /* This is an integer between 1 and 1048561 336 * and MUST be in multiples of 16. */ 337 codec->height = atoi(value); 338 return 0; 339 } else if (!strcmp(attr, "delivery-method")) { 340 /* Possible values are: inline, in_band, out_band/specific_name. */ 341 return AVERROR_PATCHWELCOME; 342 } else if (!strcmp(attr, "configuration-uri")) { 343 /* NOTE: configuration-uri is supported only under 2 conditions: 344 *--after the delivery-method tag 345 * --with a delivery-method value of out_band */ 346 return AVERROR_PATCHWELCOME; 347 } else if (!strcmp(attr, "configuration")) { 348 /* NOTE: configuration is supported only AFTER the delivery-method tag 349 * The configuration value is a base64 encoded packed header */ 350 uint8_t *decoded_packet = NULL; 351 int packet_size; 352 size_t decoded_alloc = strlen(value) / 4 * 3 + 4; 353 354 if (decoded_alloc <= INT_MAX) { 355 decoded_packet = av_malloc(decoded_alloc); 356 if (decoded_packet) { 357 packet_size = 358 av_base64_decode(decoded_packet, value, decoded_alloc); 359 360 result = parse_packed_headers 361 (decoded_packet, decoded_packet + packet_size, codec, 362 xiph_data); 363 } else { 364 av_log(s, AV_LOG_ERROR, 365 "Out of memory while decoding SDP configuration.\n"); 366 result = AVERROR(ENOMEM); 367 } 368 } else { 369 av_log(s, AV_LOG_ERROR, "Packet too large\n"); 370 result = AVERROR_INVALIDDATA; 371 } 372 av_free(decoded_packet); 373 } 374 return result; 375} 376 377static int xiph_parse_sdp_line(AVFormatContext *s, int st_index, 378 PayloadContext *data, const char *line) 379{ 380 const char *p; 381 382 if (st_index < 0) 383 return 0; 384 385 if (av_strstart(line, "fmtp:", &p)) { 386 return ff_parse_fmtp(s, s->streams[st_index], data, p, 387 xiph_parse_fmtp_pair); 388 } 389 390 return 0; 391} 392 393RTPDynamicProtocolHandler ff_theora_dynamic_handler = { 394 .enc_name = "theora", 395 .codec_type = AVMEDIA_TYPE_VIDEO, 396 .codec_id = AV_CODEC_ID_THEORA, 397 .parse_sdp_a_line = xiph_parse_sdp_line, 398 .alloc = xiph_new_context, 399 .free = xiph_free_context, 400 .parse_packet = xiph_handle_packet 401}; 402 403RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = { 404 .enc_name = "vorbis", 405 .codec_type = AVMEDIA_TYPE_AUDIO, 406 .codec_id = AV_CODEC_ID_VORBIS, 407 .init = xiph_vorbis_init, 408 .parse_sdp_a_line = xiph_parse_sdp_line, 409 .alloc = xiph_new_context, 410 .free = xiph_free_context, 411 .parse_packet = xiph_handle_packet 412}; 413