1/* 2 * MMS protocol over TCP 3 * Copyright (c) 2006,2007 Ryan Martell 4 * Copyright (c) 2007 Bj�rn Axelsson 5 * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com> 6 * 7 * This file is part of Libav. 8 * 9 * Libav is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Lesser General Public 11 * License as published by the Free Software Foundation; either 12 * version 2.1 of the License, or (at your option) any later version. 13 * 14 * Libav is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public 20 * License along with Libav; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 22 */ 23 24/* References 25 * MMS protocol specification: 26 * [1]http://msdn.microsoft.com/en-us/library/cc234711(PROT.10).aspx 27 * ASF specification. Revision 01.20.03. 28 * [2]http://msdn.microsoft.com/en-us/library/bb643323.aspx 29 */ 30 31#include "avformat.h" 32#include "mms.h" 33#include "internal.h" 34#include "avio_internal.h" 35#include "libavutil/intreadwrite.h" 36#include "libavcodec/bytestream.h" 37#include "network.h" 38#include "url.h" 39 40#define LOCAL_ADDRESS 0xc0a80081 // FIXME get and use correct local ip address. 41#define LOCAL_PORT 1037 // as above. 42/** Client to server packet types. */ 43typedef enum { 44 CS_PKT_INITIAL = 0x01, 45 CS_PKT_PROTOCOL_SELECT = 0x02, 46 CS_PKT_MEDIA_FILE_REQUEST = 0x05, 47 CS_PKT_START_FROM_PKT_ID = 0x07, 48 CS_PKT_STREAM_PAUSE = 0x09, 49 CS_PKT_STREAM_CLOSE = 0x0d, 50 CS_PKT_MEDIA_HEADER_REQUEST = 0x15, 51 CS_PKT_TIMING_DATA_REQUEST = 0x18, 52 CS_PKT_USER_PASSWORD = 0x1a, 53 CS_PKT_KEEPALIVE = 0x1b, 54 CS_PKT_STREAM_ID_REQUEST = 0x33, 55} MMSCSPacketType; 56 57/** Server to client packet types. */ 58typedef enum { 59 /** Control packets. */ 60 /*@{*/ 61 SC_PKT_CLIENT_ACCEPTED = 0x01, 62 SC_PKT_PROTOCOL_ACCEPTED = 0x02, 63 SC_PKT_PROTOCOL_FAILED = 0x03, 64 SC_PKT_MEDIA_PKT_FOLLOWS = 0x05, 65 SC_PKT_MEDIA_FILE_DETAILS = 0x06, 66 SC_PKT_HEADER_REQUEST_ACCEPTED = 0x11, 67 SC_PKT_TIMING_TEST_REPLY = 0x15, 68 SC_PKT_PASSWORD_REQUIRED = 0x1a, 69 SC_PKT_KEEPALIVE = 0x1b, 70 SC_PKT_STREAM_STOPPED = 0x1e, 71 SC_PKT_STREAM_CHANGING = 0x20, 72 SC_PKT_STREAM_ID_ACCEPTED = 0x21, 73 /*@}*/ 74 75 /** Pseudo packets. */ 76 /*@{*/ 77 SC_PKT_CANCEL = -1, 78 SC_PKT_NO_DATA = -2, 79 /*@}*/ 80 81 /** Data packets. */ 82 /*@{*/ 83 SC_PKT_ASF_HEADER = 0x010000,// make it bigger than 0xFF in case of 84 SC_PKT_ASF_MEDIA = 0x010001,// receiving false data packets. 85 /*@}*/ 86} MMSSCPacketType; 87 88typedef struct { 89 MMSContext mms; 90 int outgoing_packet_seq; ///< Outgoing packet sequence number. 91 char path[256]; ///< Path of the resource being asked for. 92 char host[128]; ///< Host of the resources. 93 int incoming_packet_seq; ///< Incoming packet sequence number. 94 int incoming_flags; ///< Incoming packet flags. 95 int packet_id; ///< Identifier for packets in the current stream. 96 unsigned int header_packet_id; ///< default is 2. 97} MMSTContext; 98 99/** Create MMST command packet header */ 100static void start_command_packet(MMSTContext *mmst, MMSCSPacketType packet_type) 101{ 102 MMSContext *mms = &mmst->mms; 103 mms->write_out_ptr = mms->out_buffer; 104 105 bytestream_put_le32(&mms->write_out_ptr, 1); // start sequence 106 bytestream_put_le32(&mms->write_out_ptr, 0xb00bface); 107 bytestream_put_le32(&mms->write_out_ptr, 0); // Length starts from after the protocol type bytes 108 bytestream_put_le32(&mms->write_out_ptr, MKTAG('M','M','S',' ')); 109 bytestream_put_le32(&mms->write_out_ptr, 0); 110 bytestream_put_le32(&mms->write_out_ptr, mmst->outgoing_packet_seq++); 111 bytestream_put_le64(&mms->write_out_ptr, 0); // timestamp 112 bytestream_put_le32(&mms->write_out_ptr, 0); 113 bytestream_put_le16(&mms->write_out_ptr, packet_type); 114 bytestream_put_le16(&mms->write_out_ptr, 3); // direction to server 115} 116 117/** Add prefixes to MMST command packet. */ 118static void insert_command_prefixes(MMSContext *mms, 119 uint32_t prefix1, uint32_t prefix2) 120{ 121 bytestream_put_le32(&mms->write_out_ptr, prefix1); // first prefix 122 bytestream_put_le32(&mms->write_out_ptr, prefix2); // second prefix 123} 124 125/** Send a prepared MMST command packet. */ 126static int send_command_packet(MMSTContext *mmst) 127{ 128 MMSContext *mms = &mmst->mms; 129 int len= mms->write_out_ptr - mms->out_buffer; 130 int exact_length = FFALIGN(len, 8); 131 int first_length= exact_length - 16; 132 int len8= first_length/8; 133 int write_result; 134 135 // update packet length fields. 136 AV_WL32(mms->out_buffer + 8, first_length); 137 AV_WL32(mms->out_buffer + 16, len8); 138 AV_WL32(mms->out_buffer + 32, len8-2); 139 memset(mms->write_out_ptr, 0, exact_length - len); 140 141 // write it out. 142 write_result= ffurl_write(mms->mms_hd, mms->out_buffer, exact_length); 143 if(write_result != exact_length) { 144 av_log(NULL, AV_LOG_ERROR, 145 "Failed to write data of length %d: %d (%s)\n", 146 exact_length, write_result, 147 write_result < 0 ? strerror(write_result) : 148 "The server closed the connection"); 149 return AVERROR(EIO); 150 } 151 152 return 0; 153} 154 155static void mms_put_utf16(MMSContext *mms, uint8_t *src) 156{ 157 AVIOContext bic; 158 int size = mms->write_out_ptr - mms->out_buffer; 159 int len; 160 ffio_init_context(&bic, mms->write_out_ptr, 161 sizeof(mms->out_buffer) - size, 1, NULL, NULL, NULL, NULL); 162 163 len = avio_put_str16le(&bic, src); 164 mms->write_out_ptr += len; 165} 166 167static int send_time_test_data(MMSTContext *mmst) 168{ 169 start_command_packet(mmst, CS_PKT_TIMING_DATA_REQUEST); 170 insert_command_prefixes(&mmst->mms, 0x00f0f0f0, 0x0004000b); 171 return send_command_packet(mmst); 172} 173 174static int send_protocol_select(MMSTContext *mmst) 175{ 176 char data_string[256]; 177 MMSContext *mms = &mmst->mms; 178 179 start_command_packet(mmst, CS_PKT_PROTOCOL_SELECT); 180 insert_command_prefixes(mms, 0, 0xffffffff); 181 bytestream_put_le32(&mms->write_out_ptr, 0); // maxFunnelBytes 182 bytestream_put_le32(&mms->write_out_ptr, 0x00989680); // maxbitRate 183 bytestream_put_le32(&mms->write_out_ptr, 2); // funnelMode 184 snprintf(data_string, sizeof(data_string), "\\\\%d.%d.%d.%d\\%s\\%d", 185 (LOCAL_ADDRESS>>24)&0xff, 186 (LOCAL_ADDRESS>>16)&0xff, 187 (LOCAL_ADDRESS>>8)&0xff, 188 LOCAL_ADDRESS&0xff, 189 "TCP", // or UDP 190 LOCAL_PORT); 191 192 mms_put_utf16(mms, data_string); 193 return send_command_packet(mmst); 194} 195 196static int send_media_file_request(MMSTContext *mmst) 197{ 198 MMSContext *mms = &mmst->mms; 199 start_command_packet(mmst, CS_PKT_MEDIA_FILE_REQUEST); 200 insert_command_prefixes(mms, 1, 0xffffffff); 201 bytestream_put_le32(&mms->write_out_ptr, 0); 202 bytestream_put_le32(&mms->write_out_ptr, 0); 203 mms_put_utf16(mms, mmst->path + 1); // +1 for skip "/" 204 205 return send_command_packet(mmst); 206} 207 208static void handle_packet_stream_changing_type(MMSTContext *mmst) 209{ 210 MMSContext *mms = &mmst->mms; 211 av_dlog(NULL, "Stream changing!\n"); 212 213 // 40 is the packet header size, 7 is the prefix size. 214 mmst->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7); 215 av_dlog(NULL, "Changed header prefix to 0x%x", mmst->header_packet_id); 216} 217 218static int send_keepalive_packet(MMSTContext *mmst) 219{ 220 // respond to a keepalive with a keepalive... 221 start_command_packet(mmst, CS_PKT_KEEPALIVE); 222 insert_command_prefixes(&mmst->mms, 1, 0x100FFFF); 223 return send_command_packet(mmst); 224} 225 226/** Pad media packets smaller than max_packet_size and/or adjust read position 227 * after a seek. */ 228static void pad_media_packet(MMSContext *mms) 229{ 230 if(mms->remaining_in_len<mms->asf_packet_len) { 231 int padding_size = mms->asf_packet_len - mms->remaining_in_len; 232 memset(mms->in_buffer + mms->remaining_in_len, 0, padding_size); 233 mms->remaining_in_len += padding_size; 234 } 235} 236 237/** Read incoming MMST media, header or command packet. */ 238static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst) 239{ 240 int read_result; 241 MMSSCPacketType packet_type= -1; 242 MMSContext *mms = &mmst->mms; 243 for(;;) { 244 read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer, 8); 245 if (read_result != 8) { 246 if(read_result < 0) { 247 av_log(NULL, AV_LOG_ERROR, 248 "Error reading packet header: %d (%s)\n", 249 read_result, strerror(read_result)); 250 packet_type = SC_PKT_CANCEL; 251 } else { 252 av_log(NULL, AV_LOG_ERROR, 253 "The server closed the connection\n"); 254 packet_type = SC_PKT_NO_DATA; 255 } 256 return packet_type; 257 } 258 259 // handle command packet. 260 if(AV_RL32(mms->in_buffer + 4)==0xb00bface) { 261 int length_remaining, hr; 262 263 mmst->incoming_flags= mms->in_buffer[3]; 264 read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer+8, 4); 265 if(read_result != 4) { 266 av_log(NULL, AV_LOG_ERROR, 267 "Reading command packet length failed: %d (%s)\n", 268 read_result, 269 read_result < 0 ? strerror(read_result) : 270 "The server closed the connection"); 271 return read_result < 0 ? read_result : AVERROR(EIO); 272 } 273 274 length_remaining= AV_RL32(mms->in_buffer+8) + 4; 275 av_dlog(NULL, "Length remaining is %d\n", length_remaining); 276 // read the rest of the packet. 277 if (length_remaining < 0 278 || length_remaining > sizeof(mms->in_buffer) - 12) { 279 av_log(NULL, AV_LOG_ERROR, 280 "Incoming packet length %d exceeds bufsize %zu\n", 281 length_remaining, sizeof(mms->in_buffer) - 12); 282 return AVERROR_INVALIDDATA; 283 } 284 read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer + 12, 285 length_remaining) ; 286 if (read_result != length_remaining) { 287 av_log(NULL, AV_LOG_ERROR, 288 "Reading pkt data (length=%d) failed: %d (%s)\n", 289 length_remaining, read_result, 290 read_result < 0 ? strerror(read_result) : 291 "The server closed the connection"); 292 return read_result < 0 ? read_result : AVERROR(EIO); 293 } 294 packet_type= AV_RL16(mms->in_buffer+36); 295 if (read_result >= 44 && (hr = AV_RL32(mms->in_buffer + 40))) { 296 av_log(NULL, AV_LOG_ERROR, 297 "Server sent a message with packet type 0x%x and error status code 0x%08x\n", packet_type, hr); 298 return AVERROR(EINVAL); 299 } 300 } else { 301 int length_remaining; 302 int packet_id_type; 303 int tmp; 304 305 // note we cache the first 8 bytes, 306 // then fill up the buffer with the others 307 tmp = AV_RL16(mms->in_buffer + 6); 308 length_remaining = (tmp - 8) & 0xffff; 309 mmst->incoming_packet_seq = AV_RL32(mms->in_buffer); 310 packet_id_type = mms->in_buffer[4]; 311 mmst->incoming_flags = mms->in_buffer[5]; 312 313 if (length_remaining < 0 314 || length_remaining > sizeof(mms->in_buffer) - 8) { 315 av_log(NULL, AV_LOG_ERROR, 316 "Data length %d is invalid or too large (max=%zu)\n", 317 length_remaining, sizeof(mms->in_buffer)); 318 return AVERROR_INVALIDDATA; 319 } 320 mms->remaining_in_len = length_remaining; 321 mms->read_in_ptr = mms->in_buffer; 322 read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer, length_remaining); 323 if(read_result != length_remaining) { 324 av_log(NULL, AV_LOG_ERROR, 325 "Failed to read packet data of size %d: %d (%s)\n", 326 length_remaining, read_result, 327 read_result < 0 ? strerror(read_result) : 328 "The server closed the connection"); 329 return read_result < 0 ? read_result : AVERROR(EIO); 330 } 331 332 // if we successfully read everything. 333 if(packet_id_type == mmst->header_packet_id) { 334 packet_type = SC_PKT_ASF_HEADER; 335 // Store the asf header 336 if(!mms->header_parsed) { 337 void *p = av_realloc(mms->asf_header, 338 mms->asf_header_size + mms->remaining_in_len); 339 if (!p) { 340 av_freep(&mms->asf_header); 341 return AVERROR(ENOMEM); 342 } 343 mms->asf_header = p; 344 memcpy(mms->asf_header + mms->asf_header_size, 345 mms->read_in_ptr, mms->remaining_in_len); 346 mms->asf_header_size += mms->remaining_in_len; 347 } 348 // 0x04 means asf header is sent in multiple packets. 349 if (mmst->incoming_flags == 0x04) 350 continue; 351 } else if(packet_id_type == mmst->packet_id) { 352 packet_type = SC_PKT_ASF_MEDIA; 353 } else { 354 av_dlog(NULL, "packet id type %d is old.", packet_id_type); 355 continue; 356 } 357 } 358 359 // preprocess some packet type 360 if(packet_type == SC_PKT_KEEPALIVE) { 361 send_keepalive_packet(mmst); 362 continue; 363 } else if(packet_type == SC_PKT_STREAM_CHANGING) { 364 handle_packet_stream_changing_type(mmst); 365 } else if(packet_type == SC_PKT_ASF_MEDIA) { 366 pad_media_packet(mms); 367 } 368 return packet_type; 369 } 370} 371 372static int mms_safe_send_recv(MMSTContext *mmst, 373 int (*send_fun)(MMSTContext *mmst), 374 const MMSSCPacketType expect_type) 375{ 376 MMSSCPacketType type; 377 if(send_fun) { 378 int ret = send_fun(mmst); 379 if (ret < 0) { 380 av_dlog(NULL, "Send Packet error before expecting recv packet %d\n", expect_type); 381 return ret; 382 } 383 } 384 385 if ((type = get_tcp_server_response(mmst)) != expect_type) { 386 av_log(NULL, AV_LOG_ERROR, 387 "Corrupt stream (unexpected packet type 0x%x, expected 0x%x)\n", 388 type, expect_type); 389 return AVERROR_INVALIDDATA; 390 } else { 391 return 0; 392 } 393} 394 395static int send_media_header_request(MMSTContext *mmst) 396{ 397 MMSContext *mms = &mmst->mms; 398 start_command_packet(mmst, CS_PKT_MEDIA_HEADER_REQUEST); 399 insert_command_prefixes(mms, 1, 0); 400 bytestream_put_le32(&mms->write_out_ptr, 0); 401 bytestream_put_le32(&mms->write_out_ptr, 0x00800000); 402 bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); 403 bytestream_put_le32(&mms->write_out_ptr, 0); 404 bytestream_put_le32(&mms->write_out_ptr, 0); 405 bytestream_put_le32(&mms->write_out_ptr, 0); 406 407 // the media preroll value in milliseconds? 408 bytestream_put_le32(&mms->write_out_ptr, 0); 409 bytestream_put_le32(&mms->write_out_ptr, 0x40AC2000); 410 bytestream_put_le32(&mms->write_out_ptr, 2); 411 bytestream_put_le32(&mms->write_out_ptr, 0); 412 413 return send_command_packet(mmst); 414} 415 416/** Send the initial handshake. */ 417static int send_startup_packet(MMSTContext *mmst) 418{ 419 char data_string[256]; 420 MMSContext *mms = &mmst->mms; 421 // SubscriberName is defined in MS specification linked below. 422 // The guid value can be any valid value. 423 // http://download.microsoft.com/ 424 // download/9/5/E/95EF66AF-9026-4BB0-A41D-A4F81802D92C/%5BMS-WMSP%5D.pdf 425 snprintf(data_string, sizeof(data_string), 426 "NSPlayer/7.0.0.1956; {%s}; Host: %s", 427 "7E667F5D-A661-495E-A512-F55686DDA178", mmst->host); 428 429 start_command_packet(mmst, CS_PKT_INITIAL); 430 insert_command_prefixes(mms, 0, 0x0004000b); 431 bytestream_put_le32(&mms->write_out_ptr, 0x0003001c); 432 mms_put_utf16(mms, data_string); 433 return send_command_packet(mmst); 434} 435 436/** Send MMST stream selection command based on the AVStream->discard values. */ 437static int send_stream_selection_request(MMSTContext *mmst) 438{ 439 int i; 440 MMSContext *mms = &mmst->mms; 441 // send the streams we want back... 442 start_command_packet(mmst, CS_PKT_STREAM_ID_REQUEST); 443 bytestream_put_le32(&mms->write_out_ptr, mms->stream_num); // stream nums 444 for(i= 0; i<mms->stream_num; i++) { 445 bytestream_put_le16(&mms->write_out_ptr, 0xffff); // flags 446 bytestream_put_le16(&mms->write_out_ptr, mms->streams[i].id); // stream id 447 bytestream_put_le16(&mms->write_out_ptr, 0); // selection 448 } 449 return send_command_packet(mmst); 450} 451 452static int send_close_packet(MMSTContext *mmst) 453{ 454 start_command_packet(mmst, CS_PKT_STREAM_CLOSE); 455 insert_command_prefixes(&mmst->mms, 1, 1); 456 457 return send_command_packet(mmst); 458} 459 460/** Close the MMSH/MMST connection */ 461static int mms_close(URLContext *h) 462{ 463 MMSTContext *mmst = (MMSTContext *)h->priv_data; 464 MMSContext *mms = &mmst->mms; 465 if(mms->mms_hd) { 466 send_close_packet(mmst); 467 ffurl_close(mms->mms_hd); 468 } 469 470 /* free all separately allocated pointers in mms */ 471 av_free(mms->streams); 472 av_free(mms->asf_header); 473 474 return 0; 475} 476 477static int send_media_packet_request(MMSTContext *mmst) 478{ 479 MMSContext *mms = &mmst->mms; 480 start_command_packet(mmst, CS_PKT_START_FROM_PKT_ID); 481 insert_command_prefixes(mms, 1, 0x0001FFFF); 482 bytestream_put_le64(&mms->write_out_ptr, 0); // seek timestamp 483 bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // unknown 484 bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // packet offset 485 bytestream_put_byte(&mms->write_out_ptr, 0xff); // max stream time limit 486 bytestream_put_byte(&mms->write_out_ptr, 0xff); // max stream time limit 487 bytestream_put_byte(&mms->write_out_ptr, 0xff); // max stream time limit 488 bytestream_put_byte(&mms->write_out_ptr, 0x00); // stream time limit flag 489 490 mmst->packet_id++; // new packet_id 491 bytestream_put_le32(&mms->write_out_ptr, mmst->packet_id); 492 return send_command_packet(mmst); 493} 494 495 496static void clear_stream_buffers(MMSContext *mms) 497{ 498 mms->remaining_in_len = 0; 499 mms->read_in_ptr = mms->in_buffer; 500} 501 502static int mms_open(URLContext *h, const char *uri, int flags) 503{ 504 MMSTContext *mmst = h->priv_data; 505 MMSContext *mms; 506 int port, err; 507 char tcpname[256]; 508 509 h->is_streamed = 1; 510 mms = &mmst->mms; 511 512 // only for MMS over TCP, so set proto = NULL 513 av_url_split(NULL, 0, NULL, 0, 514 mmst->host, sizeof(mmst->host), &port, mmst->path, 515 sizeof(mmst->path), uri); 516 517 if(port<0) 518 port = 1755; // defaut mms protocol port 519 520 // establish tcp connection. 521 ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, mmst->host, port, NULL); 522 err = ffurl_open(&mms->mms_hd, tcpname, AVIO_FLAG_READ_WRITE, 523 &h->interrupt_callback, NULL); 524 if (err) 525 goto fail; 526 527 mmst->packet_id = 3; // default, initial value. 528 mmst->header_packet_id = 2; // default, initial value. 529 err = mms_safe_send_recv(mmst, send_startup_packet, SC_PKT_CLIENT_ACCEPTED); 530 if (err) 531 goto fail; 532 err = mms_safe_send_recv(mmst, send_time_test_data, SC_PKT_TIMING_TEST_REPLY); 533 if (err) 534 goto fail; 535 err = mms_safe_send_recv(mmst, send_protocol_select, SC_PKT_PROTOCOL_ACCEPTED); 536 if (err) 537 goto fail; 538 err = mms_safe_send_recv(mmst, send_media_file_request, SC_PKT_MEDIA_FILE_DETAILS); 539 if (err) 540 goto fail; 541 err = mms_safe_send_recv(mmst, send_media_header_request, SC_PKT_HEADER_REQUEST_ACCEPTED); 542 if (err) 543 goto fail; 544 err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_HEADER); 545 if (err) 546 goto fail; 547 if((mmst->incoming_flags != 0X08) && (mmst->incoming_flags != 0X0C)) { 548 av_log(NULL, AV_LOG_ERROR, 549 "The server does not support MMST (try MMSH or RTSP)\n"); 550 err = AVERROR(EINVAL); 551 goto fail; 552 } 553 err = ff_mms_asf_header_parser(mms); 554 if (err) { 555 av_dlog(NULL, "asf header parsed failed!\n"); 556 goto fail; 557 } 558 mms->header_parsed = 1; 559 560 if (!mms->asf_packet_len || !mms->stream_num) 561 goto fail; 562 563 clear_stream_buffers(mms); 564 err = mms_safe_send_recv(mmst, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED); 565 if (err) 566 goto fail; 567 // send media packet request 568 err = mms_safe_send_recv(mmst, send_media_packet_request, SC_PKT_MEDIA_PKT_FOLLOWS); 569 if (err) { 570 goto fail; 571 } 572 av_dlog(NULL, "Leaving open (success)\n"); 573 return 0; 574fail: 575 mms_close(h); 576 av_dlog(NULL, "Leaving open (failure: %d)\n", err); 577 return err; 578} 579 580/** Read ASF data through the protocol. */ 581static int mms_read(URLContext *h, uint8_t *buf, int size) 582{ 583 /* TODO: see tcp.c:tcp_read() about a possible timeout scheme */ 584 MMSTContext *mmst = h->priv_data; 585 MMSContext *mms = &mmst->mms; 586 int result = 0; 587 588 do { 589 if(mms->asf_header_read_size < mms->asf_header_size) { 590 /* Read from ASF header buffer */ 591 result = ff_mms_read_header(mms, buf, size); 592 } else if(mms->remaining_in_len) { 593 /* Read remaining packet data to buffer. 594 * the result can not be zero because remaining_in_len is positive.*/ 595 result = ff_mms_read_data(mms, buf, size); 596 } else { 597 /* Read from network */ 598 int err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_MEDIA); 599 if (err == 0) { 600 if(mms->remaining_in_len>mms->asf_packet_len) { 601 av_log(NULL, AV_LOG_ERROR, 602 "Incoming pktlen %d is larger than ASF pktsize %d\n", 603 mms->remaining_in_len, mms->asf_packet_len); 604 result= AVERROR(EIO); 605 } else { 606 // copy the data to the packet buffer. 607 result = ff_mms_read_data(mms, buf, size); 608 if (result == 0) { 609 av_dlog(NULL, "Read ASF media packet size is zero!\n"); 610 break; 611 } 612 } 613 } else { 614 av_dlog(NULL, "read packet error!\n"); 615 break; 616 } 617 } 618 } while(!result); // only return one packet. 619 return result; 620} 621 622URLProtocol ff_mmst_protocol = { 623 .name = "mmst", 624 .url_open = mms_open, 625 .url_read = mms_read, 626 .url_close = mms_close, 627 .priv_data_size = sizeof(MMSTContext), 628 .flags = URL_PROTOCOL_FLAG_NETWORK, 629}; 630