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libavformat/mmst.c

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00001 /*
00002  * MMS protocol over TCP
00003  * Copyright (c) 2006,2007 Ryan Martell
00004  * Copyright (c) 2007 Björn Axelsson
00005  * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com>
00006  *
00007  * This file is part of FFmpeg.
00008  *
00009  * FFmpeg is free software; you can redistribute it and/or
00010  * modify it under the terms of the GNU Lesser General Public
00011  * License as published by the Free Software Foundation; either
00012  * version 2.1 of the License, or (at your option) any later version.
00013  *
00014  * FFmpeg is distributed in the hope that it will be useful,
00015  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00016  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00017  * Lesser General Public License for more details.
00018  *
00019  * You should have received a copy of the GNU Lesser General Public
00020  * License along with FFmpeg; if not, write to the Free Software
00021  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00022  */
00023 
00024 /* References
00025  * MMS protocol specification:
00026  *  [1]http://msdn.microsoft.com/en-us/library/cc234711(PROT.10).aspx
00027  * ASF specification. Revision 01.20.03.
00028  *  [2]http://msdn.microsoft.com/en-us/library/bb643323.aspx
00029  */
00030 
00031 #include "avformat.h"
00032 #include "mms.h"
00033 #include "internal.h"
00034 #include "avio_internal.h"
00035 #include "libavutil/intreadwrite.h"
00036 #include "libavcodec/bytestream.h"
00037 #include "network.h"
00038 #include "url.h"
00039 
00040 #define LOCAL_ADDRESS 0xc0a80081    // FIXME get and use correct local ip address.
00041 #define LOCAL_PORT    1037          // as above.
00042 
00043 typedef enum {
00044     CS_PKT_INITIAL                  = 0x01,
00045     CS_PKT_PROTOCOL_SELECT          = 0x02,
00046     CS_PKT_MEDIA_FILE_REQUEST       = 0x05,
00047     CS_PKT_START_FROM_PKT_ID        = 0x07,
00048     CS_PKT_STREAM_PAUSE             = 0x09,
00049     CS_PKT_STREAM_CLOSE             = 0x0d,
00050     CS_PKT_MEDIA_HEADER_REQUEST     = 0x15,
00051     CS_PKT_TIMING_DATA_REQUEST      = 0x18,
00052     CS_PKT_USER_PASSWORD            = 0x1a,
00053     CS_PKT_KEEPALIVE                = 0x1b,
00054     CS_PKT_STREAM_ID_REQUEST        = 0x33,
00055 } MMSCSPacketType;
00056 
00058 typedef enum {
00061     SC_PKT_CLIENT_ACCEPTED          = 0x01,
00062     SC_PKT_PROTOCOL_ACCEPTED        = 0x02,
00063     SC_PKT_PROTOCOL_FAILED          = 0x03,
00064     SC_PKT_MEDIA_PKT_FOLLOWS        = 0x05,
00065     SC_PKT_MEDIA_FILE_DETAILS       = 0x06,
00066     SC_PKT_HEADER_REQUEST_ACCEPTED  = 0x11,
00067     SC_PKT_TIMING_TEST_REPLY        = 0x15,
00068     SC_PKT_PASSWORD_REQUIRED        = 0x1a,
00069     SC_PKT_KEEPALIVE                = 0x1b,
00070     SC_PKT_STREAM_STOPPED           = 0x1e,
00071     SC_PKT_STREAM_CHANGING          = 0x20,
00072     SC_PKT_STREAM_ID_ACCEPTED       = 0x21,
00077     SC_PKT_CANCEL                   = -1,
00078     SC_PKT_NO_DATA                  = -2,
00083     SC_PKT_ASF_HEADER               = 0x010000,// make it bigger than 0xFF in case of
00084     SC_PKT_ASF_MEDIA                = 0x010001,// receiving false data packets.
00086 } MMSSCPacketType;
00087 
00088 typedef struct {
00089     MMSContext  mms;
00090     int outgoing_packet_seq;             
00091     char path[256];                      
00092     char host[128];                      
00093     int incoming_packet_seq;             
00094     int incoming_flags;                  
00095     int packet_id;                       
00096     unsigned int header_packet_id;       
00097 } MMSTContext;
00098 
00100 static void start_command_packet(MMSTContext *mmst, MMSCSPacketType packet_type)
00101 {
00102     MMSContext *mms    = &mmst->mms;
00103     mms->write_out_ptr = mms->out_buffer;
00104 
00105     bytestream_put_le32(&mms->write_out_ptr, 1); // start sequence
00106     bytestream_put_le32(&mms->write_out_ptr, 0xb00bface);
00107     bytestream_put_le32(&mms->write_out_ptr, 0); // Length starts from after the protocol type bytes
00108     bytestream_put_le32(&mms->write_out_ptr, MKTAG('M','M','S',' '));
00109     bytestream_put_le32(&mms->write_out_ptr, 0);
00110     bytestream_put_le32(&mms->write_out_ptr, mmst->outgoing_packet_seq++);
00111     bytestream_put_le64(&mms->write_out_ptr, 0); // timestamp
00112     bytestream_put_le32(&mms->write_out_ptr, 0);
00113     bytestream_put_le16(&mms->write_out_ptr, packet_type);
00114     bytestream_put_le16(&mms->write_out_ptr, 3); // direction to server
00115 }
00116 
00118 static void insert_command_prefixes(MMSContext *mms,
00119         uint32_t prefix1, uint32_t prefix2)
00120 {
00121     bytestream_put_le32(&mms->write_out_ptr, prefix1); // first prefix
00122     bytestream_put_le32(&mms->write_out_ptr, prefix2); // second prefix
00123 }
00124 
00126 static int send_command_packet(MMSTContext *mmst)
00127 {
00128     MMSContext *mms  = &mmst->mms;
00129     int len= mms->write_out_ptr - mms->out_buffer;
00130     int exact_length = FFALIGN(len, 8);
00131     int first_length= exact_length - 16;
00132     int len8= first_length/8;
00133     int write_result;
00134 
00135     // update packet length fields.
00136     AV_WL32(mms->out_buffer + 8, first_length);
00137     AV_WL32(mms->out_buffer + 16, len8);
00138     AV_WL32(mms->out_buffer + 32, len8-2);
00139     memset(mms->write_out_ptr, 0, exact_length - len);
00140 
00141     // write it out.
00142     write_result= ffurl_write(mms->mms_hd, mms->out_buffer, exact_length);
00143     if(write_result != exact_length) {
00144         av_log(NULL, AV_LOG_ERROR,
00145                "Failed to write data of length %d: %d (%s)\n",
00146                exact_length, write_result,
00147                write_result < 0 ? strerror(write_result) :
00148                    "The server closed the connection");
00149         return AVERROR(EIO);
00150     }
00151 
00152     return 0;
00153 }
00154 
00155 static void mms_put_utf16(MMSContext *mms, const uint8_t *src)
00156 {
00157     AVIOContext bic;
00158     int size = mms->write_out_ptr - mms->out_buffer;
00159     int len;
00160     ffio_init_context(&bic, mms->write_out_ptr,
00161             sizeof(mms->out_buffer) - size, 1, NULL, NULL, NULL, NULL);
00162 
00163     len = avio_put_str16le(&bic, src);
00164     mms->write_out_ptr += len;
00165 }
00166 
00167 static int send_time_test_data(MMSTContext *mmst)
00168 {
00169     start_command_packet(mmst, CS_PKT_TIMING_DATA_REQUEST);
00170     insert_command_prefixes(&mmst->mms, 0x00f0f0f0, 0x0004000b);
00171     return send_command_packet(mmst);
00172 }
00173 
00174 static int send_protocol_select(MMSTContext *mmst)
00175 {
00176     char data_string[256];
00177     MMSContext *mms = &mmst->mms;
00178 
00179     start_command_packet(mmst, CS_PKT_PROTOCOL_SELECT);
00180     insert_command_prefixes(mms, 0, 0xffffffff);
00181     bytestream_put_le32(&mms->write_out_ptr, 0);          // maxFunnelBytes
00182     bytestream_put_le32(&mms->write_out_ptr, 0x00989680); // maxbitRate
00183     bytestream_put_le32(&mms->write_out_ptr, 2);          // funnelMode
00184     snprintf(data_string, sizeof(data_string), "\\\\%d.%d.%d.%d\\%s\\%d",
00185             (LOCAL_ADDRESS>>24)&0xff,
00186             (LOCAL_ADDRESS>>16)&0xff,
00187             (LOCAL_ADDRESS>>8)&0xff,
00188             LOCAL_ADDRESS&0xff,
00189             "TCP",                                        // or UDP
00190             LOCAL_PORT);
00191 
00192     mms_put_utf16(mms, data_string);
00193     return send_command_packet(mmst);
00194 }
00195 
00196 static int send_media_file_request(MMSTContext *mmst)
00197 {
00198     MMSContext *mms = &mmst->mms;
00199     start_command_packet(mmst, CS_PKT_MEDIA_FILE_REQUEST);
00200     insert_command_prefixes(mms, 1, 0xffffffff);
00201     bytestream_put_le32(&mms->write_out_ptr, 0);
00202     bytestream_put_le32(&mms->write_out_ptr, 0);
00203     mms_put_utf16(mms, mmst->path + 1); // +1 for skip "/"
00204 
00205     return send_command_packet(mmst);
00206 }
00207 
00208 static void handle_packet_stream_changing_type(MMSTContext *mmst)
00209 {
00210     MMSContext *mms = &mmst->mms;
00211     av_dlog(NULL, "Stream changing!\n");
00212 
00213     // 40 is the packet header size, 7 is the prefix size.
00214     mmst->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7);
00215     av_dlog(NULL, "Changed header prefix to 0x%x", mmst->header_packet_id);
00216 }
00217 
00218 static int send_keepalive_packet(MMSTContext *mmst)
00219 {
00220     // respond to a keepalive with a keepalive...
00221     start_command_packet(mmst, CS_PKT_KEEPALIVE);
00222     insert_command_prefixes(&mmst->mms, 1, 0x100FFFF);
00223     return send_command_packet(mmst);
00224 }
00225 
00228 static void pad_media_packet(MMSContext *mms)
00229 {
00230     if(mms->remaining_in_len<mms->asf_packet_len) {
00231         int padding_size = mms->asf_packet_len - mms->remaining_in_len;
00232         memset(mms->in_buffer + mms->remaining_in_len, 0, padding_size);
00233         mms->remaining_in_len += padding_size;
00234     }
00235 }
00236 
00238 static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
00239 {
00240     int read_result;
00241     MMSSCPacketType packet_type= -1;
00242     MMSContext *mms = &mmst->mms;
00243     for(;;) {
00244         read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer, 8);
00245         if (read_result != 8) {
00246             if(read_result < 0) {
00247                 av_log(NULL, AV_LOG_ERROR,
00248                        "Error reading packet header: %d (%s)\n",
00249                        read_result, strerror(read_result));
00250                 packet_type = SC_PKT_CANCEL;
00251             } else {
00252                 av_log(NULL, AV_LOG_ERROR,
00253                        "The server closed the connection\n");
00254                 packet_type = SC_PKT_NO_DATA;
00255             }
00256             return packet_type;
00257         }
00258 
00259         // handle command packet.
00260         if(AV_RL32(mms->in_buffer + 4)==0xb00bface) {
00261             int length_remaining, hr;
00262 
00263             mmst->incoming_flags= mms->in_buffer[3];
00264             read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer+8, 4);
00265             if(read_result != 4) {
00266                 av_log(NULL, AV_LOG_ERROR,
00267                        "Reading command packet length failed: %d (%s)\n",
00268                        read_result,
00269                        read_result < 0 ? strerror(read_result) :
00270                            "The server closed the connection");
00271                 return read_result < 0 ? read_result : AVERROR(EIO);
00272             }
00273 
00274             length_remaining= AV_RL32(mms->in_buffer+8) + 4;
00275             av_dlog(NULL, "Length remaining is %d\n", length_remaining);
00276             // read the rest of the packet.
00277             if (length_remaining < 0
00278                 || length_remaining > sizeof(mms->in_buffer) - 12) {
00279                 av_log(NULL, AV_LOG_ERROR,
00280                        "Incoming packet length %d exceeds bufsize %zu\n",
00281                        length_remaining, sizeof(mms->in_buffer) - 12);
00282                 return AVERROR_INVALIDDATA;
00283             }
00284             read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer + 12,
00285                                             length_remaining) ;
00286             if (read_result != length_remaining) {
00287                 av_log(NULL, AV_LOG_ERROR,
00288                        "Reading pkt data (length=%d) failed: %d (%s)\n",
00289                        length_remaining, read_result,
00290                        read_result < 0 ? strerror(read_result) :
00291                            "The server closed the connection");
00292                 return read_result < 0 ? read_result : AVERROR(EIO);
00293             }
00294             packet_type= AV_RL16(mms->in_buffer+36);
00295             if (read_result >= 44 && (hr = AV_RL32(mms->in_buffer + 40))) {
00296                 av_log(NULL, AV_LOG_ERROR,
00297                        "Server sent a message with packet type 0x%x and error status code 0x%08x\n", packet_type, hr);
00298                 return AVERROR(EINVAL);
00299             }
00300         } else {
00301             int length_remaining;
00302             int packet_id_type;
00303             int tmp;
00304 
00305             // note we cache the first 8 bytes,
00306             // then fill up the buffer with the others
00307             tmp                       = AV_RL16(mms->in_buffer + 6);
00308             length_remaining          = (tmp - 8) & 0xffff;
00309             mmst->incoming_packet_seq = AV_RL32(mms->in_buffer);
00310             packet_id_type            = mms->in_buffer[4];
00311             mmst->incoming_flags      = mms->in_buffer[5];
00312 
00313             if (length_remaining < 0
00314                 || length_remaining > sizeof(mms->in_buffer) - 8) {
00315                 av_log(NULL, AV_LOG_ERROR,
00316                        "Data length %d is invalid or too large (max=%zu)\n",
00317                        length_remaining, sizeof(mms->in_buffer));
00318                 return AVERROR_INVALIDDATA;
00319             }
00320             mms->remaining_in_len    = length_remaining;
00321             mms->read_in_ptr         = mms->in_buffer;
00322             read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer, length_remaining);
00323             if(read_result != length_remaining) {
00324                 av_log(NULL, AV_LOG_ERROR,
00325                        "Failed to read packet data of size %d: %d (%s)\n",
00326                        length_remaining, read_result,
00327                        read_result < 0 ? strerror(read_result) :
00328                            "The server closed the connection");
00329                 return read_result < 0 ? read_result : AVERROR(EIO);
00330             }
00331 
00332             // if we successfully read everything.
00333             if(packet_id_type == mmst->header_packet_id) {
00334                 packet_type = SC_PKT_ASF_HEADER;
00335                 // Store the asf header
00336                 if(!mms->header_parsed) {
00337                     void *p = av_realloc(mms->asf_header,
00338                                   mms->asf_header_size + mms->remaining_in_len);
00339                     if (!p) {
00340                         av_freep(&mms->asf_header);
00341                         return AVERROR(ENOMEM);
00342                     }
00343                     mms->asf_header = p;
00344                     memcpy(mms->asf_header + mms->asf_header_size,
00345                            mms->read_in_ptr, mms->remaining_in_len);
00346                     mms->asf_header_size += mms->remaining_in_len;
00347                 }
00348                 // 0x04 means asf header is sent in multiple packets.
00349                 if (mmst->incoming_flags == 0x04)
00350                     continue;
00351             } else if(packet_id_type == mmst->packet_id) {
00352                 packet_type = SC_PKT_ASF_MEDIA;
00353             } else {
00354                 av_dlog(NULL, "packet id type %d is old.", packet_id_type);
00355                 continue;
00356             }
00357         }
00358 
00359         // preprocess some packet type
00360         if(packet_type == SC_PKT_KEEPALIVE) {
00361             send_keepalive_packet(mmst);
00362             continue;
00363         } else if(packet_type == SC_PKT_STREAM_CHANGING) {
00364             handle_packet_stream_changing_type(mmst);
00365         } else if(packet_type == SC_PKT_ASF_MEDIA) {
00366             pad_media_packet(mms);
00367         }
00368         return packet_type;
00369     }
00370 }
00371 
00372 static int mms_safe_send_recv(MMSTContext *mmst,
00373                               int (*send_fun)(MMSTContext *mmst),
00374                               const MMSSCPacketType expect_type)
00375 {
00376     MMSSCPacketType type;
00377     if(send_fun) {
00378         int ret = send_fun(mmst);
00379         if (ret < 0) {
00380             av_dlog(NULL, "Send Packet error before expecting recv packet %d\n", expect_type);
00381             return ret;
00382         }
00383     }
00384 
00385     if ((type = get_tcp_server_response(mmst)) != expect_type) {
00386         av_log(NULL, AV_LOG_ERROR,
00387                "Corrupt stream (unexpected packet type 0x%x, expected 0x%x)\n",
00388                type, expect_type);
00389         return AVERROR_INVALIDDATA;
00390     } else {
00391         return 0;
00392     }
00393 }
00394 
00395 static int send_media_header_request(MMSTContext *mmst)
00396 {
00397     MMSContext *mms = &mmst->mms;
00398     start_command_packet(mmst, CS_PKT_MEDIA_HEADER_REQUEST);
00399     insert_command_prefixes(mms, 1, 0);
00400     bytestream_put_le32(&mms->write_out_ptr, 0);
00401     bytestream_put_le32(&mms->write_out_ptr, 0x00800000);
00402     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff);
00403     bytestream_put_le32(&mms->write_out_ptr, 0);
00404     bytestream_put_le32(&mms->write_out_ptr, 0);
00405     bytestream_put_le32(&mms->write_out_ptr, 0);
00406 
00407     // the media preroll value in milliseconds?
00408     bytestream_put_le32(&mms->write_out_ptr, 0);
00409     bytestream_put_le32(&mms->write_out_ptr, 0x40AC2000);
00410     bytestream_put_le32(&mms->write_out_ptr, 2);
00411     bytestream_put_le32(&mms->write_out_ptr, 0);
00412 
00413     return send_command_packet(mmst);
00414 }
00415 
00417 static int send_startup_packet(MMSTContext *mmst)
00418 {
00419     char data_string[256];
00420     MMSContext *mms = &mmst->mms;
00421     // SubscriberName is defined in MS specification linked below.
00422     // The guid value can be any valid value.
00423     // http://download.microsoft.com/
00424     // download/9/5/E/95EF66AF-9026-4BB0-A41D-A4F81802D92C/%5BMS-WMSP%5D.pdf
00425     snprintf(data_string, sizeof(data_string),
00426             "NSPlayer/7.0.0.1956; {%s}; Host: %s",
00427             "7E667F5D-A661-495E-A512-F55686DDA178", mmst->host);
00428 
00429     start_command_packet(mmst, CS_PKT_INITIAL);
00430     insert_command_prefixes(mms, 0, 0x0004000b);
00431     bytestream_put_le32(&mms->write_out_ptr, 0x0003001c);
00432     mms_put_utf16(mms, data_string);
00433     return send_command_packet(mmst);
00434 }
00435 
00437 static int send_stream_selection_request(MMSTContext *mmst)
00438 {
00439     int i;
00440     MMSContext *mms = &mmst->mms;
00441     //  send the streams we want back...
00442     start_command_packet(mmst, CS_PKT_STREAM_ID_REQUEST);
00443     bytestream_put_le32(&mms->write_out_ptr, mms->stream_num);         // stream nums
00444     for(i= 0; i<mms->stream_num; i++) {
00445         bytestream_put_le16(&mms->write_out_ptr, 0xffff);              // flags
00446         bytestream_put_le16(&mms->write_out_ptr, mms->streams[i].id);  // stream id
00447         bytestream_put_le16(&mms->write_out_ptr, 0);                   // selection
00448     }
00449     return send_command_packet(mmst);
00450 }
00451 
00452 static int send_close_packet(MMSTContext *mmst)
00453 {
00454     start_command_packet(mmst, CS_PKT_STREAM_CLOSE);
00455     insert_command_prefixes(&mmst->mms, 1, 1);
00456 
00457     return send_command_packet(mmst);
00458 }
00459 
00461 static int mms_close(URLContext *h)
00462 {
00463     MMSTContext *mmst = (MMSTContext *)h->priv_data;
00464     MMSContext *mms   = &mmst->mms;
00465     if(mms->mms_hd) {
00466         send_close_packet(mmst);
00467         ffurl_close(mms->mms_hd);
00468     }
00469 
00470     /* free all separately allocated pointers in mms */
00471     av_free(mms->streams);
00472     av_free(mms->asf_header);
00473     av_freep(&h->priv_data);
00474 
00475     return 0;
00476 }
00477 
00478 static int send_media_packet_request(MMSTContext *mmst)
00479 {
00480     MMSContext *mms = &mmst->mms;
00481     start_command_packet(mmst, CS_PKT_START_FROM_PKT_ID);
00482     insert_command_prefixes(mms, 1, 0x0001FFFF);
00483     bytestream_put_le64(&mms->write_out_ptr, 0);          // seek timestamp
00484     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // unknown
00485     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // packet offset
00486     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
00487     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
00488     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
00489     bytestream_put_byte(&mms->write_out_ptr, 0x00);       // stream time limit flag
00490 
00491     mmst->packet_id++;                                     // new packet_id
00492     bytestream_put_le32(&mms->write_out_ptr, mmst->packet_id);
00493     return send_command_packet(mmst);
00494 }
00495 
00496 
00497 static void clear_stream_buffers(MMSContext *mms)
00498 {
00499     mms->remaining_in_len = 0;
00500     mms->read_in_ptr      = mms->in_buffer;
00501 }
00502 
00503 static int mms_open(URLContext *h, const char *uri, int flags)
00504 {
00505     MMSTContext *mmst;
00506     MMSContext *mms;
00507     int port, err;
00508     char tcpname[256];
00509 
00510     h->is_streamed = 1;
00511     mmst = h->priv_data = av_mallocz(sizeof(MMSTContext));
00512     if (!h->priv_data)
00513         return AVERROR(ENOMEM);
00514     mms = &mmst->mms;
00515 
00516     // only for MMS over TCP, so set proto = NULL
00517     av_url_split(NULL, 0, NULL, 0,
00518             mmst->host, sizeof(mmst->host), &port, mmst->path,
00519             sizeof(mmst->path), uri);
00520 
00521     if(port<0)
00522         port = 1755; // defaut mms protocol port
00523 
00524     // establish tcp connection.
00525     ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, mmst->host, port, NULL);
00526     err = ffurl_open(&mms->mms_hd, tcpname, AVIO_RDWR);
00527     if (err)
00528         goto fail;
00529 
00530     mmst->packet_id        = 3;          // default, initial value.
00531     mmst->header_packet_id = 2;          // default, initial value.
00532     err = mms_safe_send_recv(mmst, send_startup_packet, SC_PKT_CLIENT_ACCEPTED);
00533     if (err)
00534         goto fail;
00535     err = mms_safe_send_recv(mmst, send_time_test_data, SC_PKT_TIMING_TEST_REPLY);
00536     if (err)
00537         goto fail;
00538     err = mms_safe_send_recv(mmst, send_protocol_select, SC_PKT_PROTOCOL_ACCEPTED);
00539     if (err)
00540         goto fail;
00541     err = mms_safe_send_recv(mmst, send_media_file_request, SC_PKT_MEDIA_FILE_DETAILS);
00542     if (err)
00543         goto fail;
00544     err = mms_safe_send_recv(mmst, send_media_header_request, SC_PKT_HEADER_REQUEST_ACCEPTED);
00545     if (err)
00546         goto fail;
00547     err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_HEADER);
00548     if (err)
00549         goto fail;
00550     if((mmst->incoming_flags != 0X08) && (mmst->incoming_flags != 0X0C)) {
00551         av_log(NULL, AV_LOG_ERROR,
00552                "The server does not support MMST (try MMSH or RTSP)\n");
00553         err = AVERROR(EINVAL);
00554         goto fail;
00555     }
00556     err = ff_mms_asf_header_parser(mms);
00557     if (err) {
00558         av_dlog(NULL, "asf header parsed failed!\n");
00559         goto fail;
00560     }
00561     mms->header_parsed = 1;
00562 
00563     if (!mms->asf_packet_len || !mms->stream_num)
00564         goto fail;
00565 
00566     clear_stream_buffers(mms);
00567     err = mms_safe_send_recv(mmst, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED);
00568     if (err)
00569         goto fail;
00570     // send media packet request
00571     err = mms_safe_send_recv(mmst, send_media_packet_request, SC_PKT_MEDIA_PKT_FOLLOWS);
00572     if (err) {
00573         goto fail;
00574     }
00575     av_dlog(NULL, "Leaving open (success)\n");
00576     return 0;
00577 fail:
00578     mms_close(h);
00579     av_dlog(NULL, "Leaving open (failure: %d)\n", err);
00580     return err;
00581 }
00582 
00584 static int mms_read(URLContext *h, uint8_t *buf, int size)
00585 {
00586     /* TODO: see tcp.c:tcp_read() about a possible timeout scheme */
00587     MMSTContext *mmst = h->priv_data;
00588     MMSContext *mms   = &mmst->mms;
00589     int result = 0;
00590 
00591     do {
00592         if(mms->asf_header_read_size < mms->asf_header_size) {
00593             /* Read from ASF header buffer */
00594             result = ff_mms_read_header(mms, buf, size);
00595         } else if(mms->remaining_in_len) {
00596             /* Read remaining packet data to buffer.
00597              * the result can not be zero because remaining_in_len is positive.*/
00598             result = ff_mms_read_data(mms, buf, size);
00599         } else {
00600             /* Read from network */
00601             int err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_MEDIA);
00602             if (err == 0) {
00603                 if(mms->remaining_in_len>mms->asf_packet_len) {
00604                     av_log(NULL, AV_LOG_ERROR,
00605                            "Incoming pktlen %d is larger than ASF pktsize %d\n",
00606                            mms->remaining_in_len, mms->asf_packet_len);
00607                     result= AVERROR(EIO);
00608                 } else {
00609                     // copy the data to the packet buffer.
00610                     result = ff_mms_read_data(mms, buf, size);
00611                     if (result == 0) {
00612                         av_dlog(NULL, "read asf media paket size is zero!\n");
00613                         break;
00614                     }
00615                 }
00616             } else {
00617                 av_dlog(NULL, "read packet error!\n");
00618                 break;
00619             }
00620         }
00621     } while(!result); // only return one packet.
00622     return result;
00623 }
00624 
00625 URLProtocol ff_mmst_protocol = {
00626     .name      = "mmst",
00627     .url_open  = mms_open,
00628     .url_read  = mms_read,
00629     .url_close = mms_close,
00630 };

Generated on Fri Feb 22 2013 07:24:31 for FFmpeg by  doxygen 1.7.1