Fix a compile warning when compiling with DEBUG=1. The warning was:
[ffmpeg.git] / libavformat / mmst.c
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 FFmpeg.
8  *
9  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 #include "avformat.h"
24 #include "internal.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavcodec/bytestream.h"
27 #include "network.h"
28 #include "asf.h"
29
30 #define LOCAL_ADDRESS 0xc0a80081    // FIXME get and use correct local ip address.
31 #define LOCAL_PORT    1037          // as above.
32 /** Client to server packet types. */
33 typedef enum {
34     CS_PKT_INITIAL                  = 0x01,
35     CS_PKT_PROTOCOL_SELECT          = 0x02,
36     CS_PKT_MEDIA_FILE_REQUEST       = 0x05,
37     CS_PKT_START_FROM_PKT_ID        = 0x07,
38     CS_PKT_STREAM_PAUSE             = 0x09,
39     CS_PKT_STREAM_CLOSE             = 0x0d,
40     CS_PKT_MEDIA_HEADER_REQUEST     = 0x15,
41     CS_PKT_TIMING_DATA_REQUEST      = 0x18,
42     CS_PKT_USER_PASSWORD            = 0x1a,
43     CS_PKT_KEEPALIVE                = 0x1b,
44     CS_PKT_STREAM_ID_REQUEST        = 0x33,
45 } MMSCSPacketType;
46
47 /** Server to client packet types. */
48 typedef enum {
49     /** Control packets. */
50     /*@{*/
51     SC_PKT_CLIENT_ACCEPTED          = 0x01,
52     SC_PKT_PROTOCOL_ACCEPTED        = 0x02,
53     SC_PKT_PROTOCOL_FAILED          = 0x03,
54     SC_PKT_MEDIA_PKT_FOLLOWS        = 0x05,
55     SC_PKT_MEDIA_FILE_DETAILS       = 0x06,
56     SC_PKT_HEADER_REQUEST_ACCEPTED  = 0x11,
57     SC_PKT_TIMING_TEST_REPLY        = 0x15,
58     SC_PKT_PASSWORD_REQUIRED        = 0x1a,
59     SC_PKT_KEEPALIVE                = 0x1b,
60     SC_PKT_STREAM_STOPPED           = 0x1e,
61     SC_PKT_STREAM_CHANGING          = 0x20,
62     SC_PKT_STREAM_ID_ACCEPTED       = 0x21,
63     /*@}*/
64
65     /** Pseudo packets. */
66     /*@{*/
67     SC_PKT_CANCEL                   = -1,
68     SC_PKT_NO_DATA                  = -2,
69     /*@}*/
70
71     /** Data packets. */
72     /*@{*/
73     SC_PKT_ASF_HEADER               = 0x010000,// make it bigger than 0xFF in case of
74     SC_PKT_ASF_MEDIA                = 0x010001,// receiving false data packets.
75     /*@}*/
76 } MMSSCPacketType;
77
78 typedef struct {
79     int id;
80 }MMSStream;
81
82 typedef struct {
83     int outgoing_packet_seq;             ///< Outgoing packet sequence number.
84     char path[256];                      ///< Path of the resource being asked for.
85     char host[128];                      ///< Host of the resources.
86
87     URLContext *mms_hd;                  ///< TCP connection handle
88     MMSStream streams[MAX_STREAMS];
89
90     /** Buffer for outgoing packets. */
91     /*@{*/
92     uint8_t *write_out_ptr;              ///< Pointer for writting the buffer.
93     uint8_t out_buffer[512];             ///< Buffer for outgoing packet.
94     /*@}*/
95
96     /** Buffer for incoming packets. */
97     /*@{*/
98     uint8_t in_buffer[8192];             ///< Buffer for incoming packets.
99     uint8_t *read_in_ptr;                ///< Pointer for reading from incoming buffer.
100     int remaining_in_len;                ///< Reading length from incoming buffer.
101     /*@}*/
102
103     int incoming_packet_seq;             ///< Incoming packet sequence number.
104     int incoming_flags;                  ///< Incoming packet flags.
105
106     int packet_id;                       ///< Identifier for packets in the current stream.
107     unsigned int header_packet_id;       ///< default is 2.
108
109     /** Internal handling of the ASF header */
110     /*@{*/
111     uint8_t *asf_header;                 ///< Stored ASF header.
112     int asf_header_size;                 ///< Size of stored ASF header.
113     int header_parsed;                   ///< The header has been received and parsed.
114     int asf_packet_len;
115     /*@}*/
116
117     int stream_num;                      ///< stream numbers.
118     int is_playing;
119 } MMSContext;
120
121 /** Create MMST command packet header */
122 static void start_command_packet(MMSContext *mms, MMSCSPacketType packet_type)
123 {
124     mms->write_out_ptr = mms->out_buffer;
125
126     bytestream_put_le32(&mms->write_out_ptr, 1); // start sequence
127     bytestream_put_le32(&mms->write_out_ptr, 0xb00bface);
128     bytestream_put_le32(&mms->write_out_ptr, 0); // Length starts from after the protocol type bytes
129     bytestream_put_le32(&mms->write_out_ptr, MKTAG('M','M','S',' '));
130     bytestream_put_le32(&mms->write_out_ptr, 0);
131     bytestream_put_le32(&mms->write_out_ptr, mms->outgoing_packet_seq++);
132     bytestream_put_le64(&mms->write_out_ptr, 0); // timestamp
133     bytestream_put_le32(&mms->write_out_ptr, 0);
134     bytestream_put_le16(&mms->write_out_ptr, packet_type);
135     bytestream_put_le16(&mms->write_out_ptr, 3); // direction to server
136 }
137
138 /** Add prefixes to MMST command packet. */
139 static void insert_command_prefixes(MMSContext *mms,
140         uint32_t prefix1, uint32_t prefix2)
141 {
142     bytestream_put_le32(&mms->write_out_ptr, prefix1); // first prefix
143     bytestream_put_le32(&mms->write_out_ptr, prefix2); // second prefix
144 }
145
146 /** Send a prepared MMST command packet. */
147 static int send_command_packet(MMSContext *mms)
148 {
149     int exact_length= mms->write_out_ptr - mms->out_buffer;
150     int first_length= exact_length - 16;
151     int len8= first_length/8;
152     int write_result;
153
154     // update packet length fields.
155     AV_WL32(mms->out_buffer + 8, first_length);
156     AV_WL32(mms->out_buffer + 16, len8);
157     AV_WL32(mms->out_buffer + 32, len8-2);
158
159     // write it out.
160     write_result= url_write(mms->mms_hd, mms->out_buffer, exact_length);
161     if(write_result != exact_length) {
162         dprintf(NULL, "url_write returned: %d != %d\n",
163                 write_result, exact_length);
164         return AVERROR_IO;
165     }
166
167     return 0;
168 }
169
170 static void mms_put_utf16(MMSContext *mms, uint8_t *src)
171 {
172     ByteIOContext bic;
173     int size = mms->write_out_ptr - mms->out_buffer;
174     int len;
175     init_put_byte(&bic, mms->write_out_ptr,
176             sizeof(mms->out_buffer) - size, 1, NULL, NULL, NULL, NULL);
177
178     len = ff_put_str16_nolen(&bic, src);
179     mms->write_out_ptr += len;
180 }
181
182 static int send_time_test_data(MMSContext *mms)
183 {
184     start_command_packet(mms, CS_PKT_TIMING_DATA_REQUEST);
185     insert_command_prefixes(mms, 0xf0f0f0f1, 0x0004000b);
186     return send_command_packet(mms);
187 }
188
189 static int send_protocol_select(MMSContext *mms)
190 {
191     char data_string[256];
192
193     start_command_packet(mms, CS_PKT_PROTOCOL_SELECT);
194     insert_command_prefixes(mms, 0, 0xffffffff);
195     bytestream_put_le32(&mms->write_out_ptr, 0);          // maxFunnelBytes
196     bytestream_put_le32(&mms->write_out_ptr, 0x00989680); // maxbitRate
197     bytestream_put_le32(&mms->write_out_ptr, 2);          // funnelMode
198     snprintf(data_string, sizeof(data_string), "\\\\%d.%d.%d.%d\\%s\\%d",
199             (LOCAL_ADDRESS>>24)&0xff,
200             (LOCAL_ADDRESS>>16)&0xff,
201             (LOCAL_ADDRESS>>8)&0xff,
202             LOCAL_ADDRESS&0xff,
203             "TCP",                                        // or UDP
204             LOCAL_PORT);
205
206     mms_put_utf16(mms, data_string);
207     return send_command_packet(mms);
208 }
209
210 static int send_media_file_request(MMSContext *mms)
211 {
212     start_command_packet(mms, CS_PKT_MEDIA_FILE_REQUEST);
213     insert_command_prefixes(mms, 1, 0xffffffff);
214     bytestream_put_le32(&mms->write_out_ptr, 0);
215     bytestream_put_le32(&mms->write_out_ptr, 0);
216     mms_put_utf16(mms, mms->path + 1); // +1 for skip "/"
217
218     return send_command_packet(mms);
219 }
220
221 static void handle_packet_stream_changing_type(MMSContext *mms)
222 {
223     dprintf(NULL, "Stream changing!\n");
224
225     // 40 is the packet header size, 7 is the prefix size.
226     mms->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7);
227     dprintf(NULL, "Changed header prefix to 0x%x", mms->header_packet_id);
228 }
229
230 static int send_keepalive_packet(MMSContext *mms)
231 {
232     // respond to a keepalive with a keepalive...
233     start_command_packet(mms, CS_PKT_KEEPALIVE);
234     insert_command_prefixes(mms, 1, 0x100FFFF);
235     return send_command_packet(mms);
236 }
237
238 /** Pad media packets smaller than max_packet_size and/or adjust read position
239   * after a seek. */
240 static void pad_media_packet(MMSContext *mms)
241 {
242     if(mms->remaining_in_len<mms->asf_packet_len) {
243         int padding_size = mms->asf_packet_len - mms->remaining_in_len;
244         memset(mms->in_buffer + mms->remaining_in_len, 0, padding_size);
245         mms->remaining_in_len += padding_size;
246     }
247 }
248
249 /** Read incoming MMST media, header or command packet. */
250 static MMSSCPacketType get_tcp_server_response(MMSContext *mms)
251 {
252     int read_result;
253     MMSSCPacketType packet_type= -1;
254
255     for(;;) {
256         if((read_result= url_read_complete(mms->mms_hd, mms->in_buffer, 8))==8) {
257             // handle command packet.
258             if(AV_RL32(mms->in_buffer + 4)==0xb00bface) {
259                 mms->incoming_flags= mms->in_buffer[3];
260                 read_result= url_read_complete(mms->mms_hd, mms->in_buffer+8, 4);
261                 if(read_result == 4) {
262                     int length_remaining= AV_RL32(mms->in_buffer+8) + 4;
263                     int hr;
264
265                     dprintf(NULL, "Length remaining is %d\n", length_remaining);
266                     // read the rest of the packet.
267                     if (length_remaining < 0
268                         || length_remaining > sizeof(mms->in_buffer) - 12) {
269                         dprintf(NULL, "Incoming message len %d exceeds buffer len %d\n",
270                             length_remaining, sizeof(mms->in_buffer) - 12);
271                         return -1;
272                     }
273                     read_result = url_read_complete(mms->mms_hd, mms->in_buffer + 12,
274                                                   length_remaining) ;
275                     if (read_result == length_remaining) {
276                         packet_type= AV_RL16(mms->in_buffer+36);
277                     } else {
278                         dprintf(NULL, "read for packet type failed%d!\n", read_result);
279                         return -1;
280                     }
281                     hr = AV_RL32(mms->in_buffer + 40);
282                     if (hr) {
283                         dprintf(NULL, "The server side send back error code:0x%x\n", hr);
284                         return -1;
285                     }
286                 } else {
287                     dprintf(NULL, "read for length remaining failed%d!\n", read_result);
288                     return -1;
289                 }
290             } else {
291                 int length_remaining;
292                 int packet_id_type;
293                 int tmp;
294
295                 assert(mms->remaining_in_len==0);
296
297                 // note we cache the first 8 bytes,
298                 // then fill up the buffer with the others
299                 tmp                       = AV_RL16(mms->in_buffer + 6);
300                 length_remaining          = (tmp - 8) & 0xffff;
301                 mms->incoming_packet_seq  = AV_RL32(mms->in_buffer);
302                 packet_id_type            = mms->in_buffer[4];
303                 mms->incoming_flags       = mms->in_buffer[5];
304
305                 if (length_remaining < 0
306                         || length_remaining > sizeof(mms->in_buffer) - 8) {
307                     dprintf(NULL, "Incoming data len %d exceeds buffer len %d\n",
308                             length_remaining, sizeof(mms->in_buffer));
309                     return -1;
310                 }
311                 mms->remaining_in_len    = length_remaining;
312                 mms->read_in_ptr         = mms->in_buffer;
313                 read_result= url_read_complete(mms->mms_hd, mms->in_buffer, length_remaining);
314                 if(read_result != length_remaining) {
315                     dprintf(NULL, "read_bytes result: %d asking for %d\n",
316                             read_result, length_remaining);
317                     return -1;
318                 } else {
319                     // if we successfully read everything.
320                     if(packet_id_type == mms->header_packet_id) {
321                         packet_type = SC_PKT_ASF_HEADER;
322                         // Store the asf header
323                         if(!mms->header_parsed) {
324                             void *p = av_realloc(mms->asf_header,
325                                               mms->asf_header_size
326                                               + mms->remaining_in_len);
327                             if (!p) {
328                                 av_freep(&mms->asf_header);
329                                 return AVERROR(ENOMEM);
330                             }
331                             mms->asf_header = p;
332                             memcpy(mms->asf_header + mms->asf_header_size,
333                                                  mms->read_in_ptr,
334                                                  mms->remaining_in_len);
335                             mms->asf_header_size += mms->remaining_in_len;
336                         }
337                     } else if(packet_id_type == mms->packet_id) {
338                         packet_type = SC_PKT_ASF_MEDIA;
339                     } else {
340                         dprintf(NULL, "packet id type %d is old.", packet_id_type);
341                         continue;
342                     }
343                 }
344             }
345
346             // preprocess some packet type
347             if(packet_type == SC_PKT_KEEPALIVE) {
348                 send_keepalive_packet(mms);
349                 continue;
350             } else if(packet_type == SC_PKT_STREAM_CHANGING) {
351                 handle_packet_stream_changing_type(mms);
352             } else if(packet_type == SC_PKT_ASF_MEDIA) {
353                 pad_media_packet(mms);
354             }
355             return packet_type;
356         } else {
357             if(read_result<0) {
358                 dprintf(NULL, "Read error (or cancelled) returned %d!\n", read_result);
359                 packet_type = SC_PKT_CANCEL;
360             } else {
361                 dprintf(NULL, "Read result of zero?!\n");
362                 packet_type = SC_PKT_NO_DATA;
363             }
364             return packet_type;
365         }
366     }
367 }
368
369 static int mms_safe_send_recv(MMSContext *mms,
370                               int (*send_fun)(MMSContext *mms),
371                               const MMSSCPacketType expect_type)
372 {
373     MMSSCPacketType type;
374     if(send_fun) {
375         int ret = send_fun(mms);
376         if (ret < 0) {
377             dprintf(NULL, "Send Packet error before expecting recv packet %d\n", expect_type);
378             return ret;
379         }
380     }
381
382     if ((type = get_tcp_server_response(mms)) != expect_type) {
383         dprintf(NULL,"Unexpected packet type %d with type %d\n", type, expect_type);
384         return -1;
385     } else {
386         return 0;
387     }
388 }
389
390 static int send_media_header_request(MMSContext *mms)
391 {
392     start_command_packet(mms, CS_PKT_MEDIA_HEADER_REQUEST);
393     insert_command_prefixes(mms, 1, 0);
394     bytestream_put_le32(&mms->write_out_ptr, 0);
395     bytestream_put_le32(&mms->write_out_ptr, 0x00800000);
396     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff);
397     bytestream_put_le32(&mms->write_out_ptr, 0);
398     bytestream_put_le32(&mms->write_out_ptr, 0);
399     bytestream_put_le32(&mms->write_out_ptr, 0);
400
401     // the media preroll value in milliseconds?
402     bytestream_put_le32(&mms->write_out_ptr, 0);
403     bytestream_put_le32(&mms->write_out_ptr, 0x40AC2000);
404     bytestream_put_le32(&mms->write_out_ptr, 2);
405     bytestream_put_le32(&mms->write_out_ptr, 0);
406
407     return send_command_packet(mms);
408 }
409
410 /** Send the initial handshake. */
411 static int send_startup_packet(MMSContext *mms)
412 {
413     char data_string[256];
414     // SubscriberName is defined in MS specification linked below.
415     // The guid value can be any valid value.
416     // http://download.microsoft.com/
417     // download/9/5/E/95EF66AF-9026-4BB0-A41D-A4F81802D92C/%5BMS-WMSP%5D.pdf
418     snprintf(data_string, sizeof(data_string),
419             "NSPlayer/7.0.0.1956; {%s}; Host: %s",
420             "7E667F5D-A661-495E-A512-F55686DDA178", mms->host);
421
422     start_command_packet(mms, CS_PKT_INITIAL);
423     insert_command_prefixes(mms, 0, 0x0004000b);
424     bytestream_put_le32(&mms->write_out_ptr, 0x0003001c);
425     mms_put_utf16(mms, data_string);
426     return send_command_packet(mms);
427 }
428
429 static int asf_header_parser(MMSContext *mms)
430 {
431     uint8_t *p = mms->asf_header;
432     uint8_t *end;
433     int flags, stream_id, real_header_size;
434     mms->stream_num = 0;
435
436     if (mms->asf_header_size < sizeof(ff_asf_guid) * 2 + 22 ||
437         memcmp(p, ff_asf_header, sizeof(ff_asf_guid)))
438         return -1;
439
440     real_header_size = AV_RL64(p + sizeof(ff_asf_guid));
441     end = mms->asf_header + real_header_size;
442
443     p += sizeof(ff_asf_guid) + 14;
444     while(end - p >= sizeof(ff_asf_guid) + 8) {
445         uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
446         if (!chunksize || chunksize > end - p) {
447             dprintf(NULL, "chunksize is exceptional value:%"PRId64"!\n", chunksize);
448             return -1;
449         }
450         if (!memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
451             /* read packet size */
452             if (end - p > sizeof(ff_asf_guid) * 2 + 68) {
453                 mms->asf_packet_len = AV_RL32(p + sizeof(ff_asf_guid) * 2 + 64);
454                 if (mms->asf_packet_len <= 0 || mms->asf_packet_len > sizeof(mms->in_buffer)) {
455                     dprintf(NULL,"Too large packet len:%d"
456                         " may overwrite in_buffer when padding", mms->asf_packet_len);
457                     return -1;
458                 }
459             }
460         } else if (!memcmp(p, ff_asf_stream_header, sizeof(ff_asf_guid))) {
461             flags     = AV_RL16(p + sizeof(ff_asf_guid)*3 + 24);
462             stream_id = flags & 0x7F;
463             //The second condition is for checking CS_PKT_STREAM_ID_REQUEST packet size,
464             //we can calcuate the packet size by stream_num.
465             //Please see function send_stream_selection_request().
466             if (mms->stream_num < MAX_STREAMS &&
467                     46 + mms->stream_num * 6 < sizeof(mms->out_buffer)) {
468                 mms->streams[mms->stream_num].id = stream_id;
469                 mms->stream_num++;
470             } else {
471                 dprintf(NULL, "Too many streams.\n");
472                 return -1;
473             }
474         }
475         p += chunksize;
476     }
477
478     return 0;
479 }
480
481 /** Send MMST stream selection command based on the AVStream->discard values. */
482 static int send_stream_selection_request(MMSContext *mms)
483 {
484     int i;
485
486     //  send the streams we want back...
487     start_command_packet(mms, CS_PKT_STREAM_ID_REQUEST);
488     bytestream_put_le32(&mms->write_out_ptr, mms->stream_num);         // stream nums
489     for(i= 0; i<mms->stream_num; i++) {
490         bytestream_put_le16(&mms->write_out_ptr, 0xffff);              // flags
491         bytestream_put_le16(&mms->write_out_ptr, mms->streams[i].id);  // stream id
492         bytestream_put_le16(&mms->write_out_ptr, 0);                   // selection
493     }
494
495     bytestream_put_le16(&mms->write_out_ptr, 0);
496
497     return send_command_packet(mms);
498 }
499
500 static int read_data(MMSContext *mms, uint8_t *buf, const int buf_size)
501 {
502     int read_size;
503     read_size = FFMIN(buf_size, mms->remaining_in_len);
504     memcpy(buf, mms->read_in_ptr, read_size);
505     mms->remaining_in_len -= read_size;
506     mms->read_in_ptr      += read_size;
507     return read_size;
508 }
509
510 /** Read at most one media packet (or a whole header). */
511 static int read_mms_packet(MMSContext *mms, uint8_t *buf, int buf_size)
512 {
513     int result = 0, read_header_size = 0;
514     int size_to_copy;
515
516     do {
517         if(read_header_size < mms->asf_header_size && !mms->is_playing) {
518             /* Read from ASF header buffer */
519             size_to_copy= FFMIN(buf_size,
520                                 mms->asf_header_size - read_header_size);
521             memcpy(buf, mms->asf_header + read_header_size, size_to_copy);
522             read_header_size += size_to_copy;
523             result += size_to_copy;
524             dprintf(NULL, "Copied %d bytes from stored header. left: %d\n",
525                    size_to_copy, mms->asf_header_size - read_header_size);
526             if (mms->asf_header_size == read_header_size) {
527                 av_freep(&mms->asf_header);
528                 mms->is_playing = 1;
529             }
530         } else if(mms->remaining_in_len) {
531             /* Read remaining packet data to buffer.
532              * the result can not be zero because remaining_in_len is positive.*/
533             result = read_data(mms, buf, buf_size);
534         } else {
535             /* Read from network */
536             int err = mms_safe_send_recv(mms, NULL, SC_PKT_ASF_MEDIA);
537             if (err == 0) {
538                 if(mms->remaining_in_len>mms->asf_packet_len) {
539                     dprintf(NULL, "Incoming packet"
540                             "larger than the asf packet size stated (%d>%d)\n",
541                             mms->remaining_in_len, mms->asf_packet_len);
542                     result= AVERROR_IO;
543                 } else {
544                     // copy the data to the packet buffer.
545                     result = read_data(mms, buf, buf_size);
546                     if (result == 0) {
547                         dprintf(NULL, "read asf media paket size is zero!\n");
548                         break;
549                     }
550                 }
551             } else {
552                 dprintf(NULL, "read packet error!\n");
553                 break;
554             }
555         }
556     } while(!result); // only return one packet.
557     return result;
558 }
559
560 static int send_close_packet(MMSContext *mms)
561 {
562     start_command_packet(mms, CS_PKT_STREAM_CLOSE);
563     insert_command_prefixes(mms, 1, 1);
564
565     return send_command_packet(mms);
566 }
567
568 /** Close the MMSH/MMST connection */
569 static int mms_close(URLContext *h)
570 {
571     MMSContext *mms = (MMSContext *)h->priv_data;
572
573     if(mms->mms_hd) {
574         send_close_packet(mms);
575         url_close(mms->mms_hd);
576     }
577
578     /* free all separately allocated pointers in mms */
579     av_free(mms->asf_header);
580     av_freep(&h->priv_data);
581
582     return 0;
583 }
584
585 static int mms_open(URLContext *h, const char *uri, int flags)
586 {
587     MMSContext *mms;
588     int port, err;
589     char tcpname[256];
590
591     h->is_streamed = 1;
592     mms = h->priv_data = av_mallocz(sizeof(MMSContext));
593     if (!h->priv_data)
594         return AVERROR(ENOMEM);
595
596     // only for MMS over TCP, so set proto = NULL
597     av_url_split(NULL, 0, NULL, 0,
598             mms->host, sizeof(mms->host), &port, mms->path,
599             sizeof(mms->path), uri);
600
601     if(port<0)
602         port = 1755; // defaut mms protocol port
603
604     // establish tcp connection.
605     ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, mms->host, port, NULL);
606     err = url_open(&mms->mms_hd, tcpname, URL_RDWR);
607     if (err)
608         goto fail;
609
610     mms->packet_id        = 3;          // default, initial value.
611     mms->header_packet_id = 2;          // default, initial value.
612     err = mms_safe_send_recv(mms, send_startup_packet, SC_PKT_CLIENT_ACCEPTED);
613     if (err)
614         goto fail;
615     err = mms_safe_send_recv(mms, send_time_test_data, SC_PKT_TIMING_TEST_REPLY);
616     if (err)
617         goto fail;
618     err = mms_safe_send_recv(mms, send_protocol_select, SC_PKT_PROTOCOL_ACCEPTED);
619     if (err)
620         goto fail;
621     err = mms_safe_send_recv(mms, send_media_file_request, SC_PKT_MEDIA_FILE_DETAILS);
622     if (err)
623         goto fail;
624     err = mms_safe_send_recv(mms, send_media_header_request, SC_PKT_HEADER_REQUEST_ACCEPTED);
625     if (err)
626         goto fail;
627     err = mms_safe_send_recv(mms, NULL, SC_PKT_ASF_HEADER);
628     if (err)
629         goto fail;
630     if((mms->incoming_flags != 0X08) && (mms->incoming_flags != 0X0C))
631         goto fail;
632     err = asf_header_parser(mms);
633     if (err) {
634         dprintf(NULL, "asf header parsed failed!\n");
635         goto fail;
636     }
637     mms->header_parsed = 1;
638
639     if (!mms->asf_packet_len || !mms->stream_num)
640         goto fail;
641
642     dprintf(NULL, "Leaving open (success)\n");
643     return 0;
644 fail:
645     mms_close(h);
646     dprintf(NULL, "Leaving open (failure: %d)\n", err);
647     return err;
648 }
649
650 static int send_media_packet_request(MMSContext *mms)
651 {
652     start_command_packet(mms, CS_PKT_START_FROM_PKT_ID);
653     insert_command_prefixes(mms, 1, 0x0001FFFF);
654     bytestream_put_le64(&mms->write_out_ptr, 0);          // seek timestamp
655     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // unknown
656     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // packet offset
657     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
658     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
659     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
660     bytestream_put_byte(&mms->write_out_ptr, 0x00);       // stream time limit flag
661
662     mms->packet_id++;                                     // new packet_id
663     bytestream_put_le32(&mms->write_out_ptr, mms->packet_id);
664     return send_command_packet(mms);
665 }
666
667
668 static void clear_stream_buffers(MMSContext *mms)
669 {
670     mms->remaining_in_len = 0;
671     mms->read_in_ptr      = mms->in_buffer;
672 }
673
674 /** Read ASF data through the protocol. */
675 static int mms_read(URLContext *h, uint8_t *buf, int size)
676 {
677     /* TODO: see tcp.c:tcp_read() about a possible timeout scheme */
678     MMSContext *mms = h->priv_data;
679     int result = 0;
680
681     /* Since we read the header at open(), this shouldn't be possible */
682     assert(mms->header_parsed);
683
684     if (!mms->is_playing) {
685         dprintf(NULL, "mms_read() before play().\n");
686         clear_stream_buffers(mms);
687         result = mms_safe_send_recv(mms, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED);
688         if (result)
689             return result;
690         // send media packet request
691         result = mms_safe_send_recv(mms, send_media_packet_request, SC_PKT_MEDIA_PKT_FOLLOWS);
692         if (result) {
693             return result;
694         }
695     }
696     return read_mms_packet(mms, buf, size);
697 }
698
699 URLProtocol mmst_protocol = {
700     "mmst",
701     mms_open,
702     mms_read,
703     NULL, // write
704     NULL, // seek
705     mms_close,
706 };