libmpdemux/demux_pva.c

   1 /*
   2  * demuxer for PVA files, such as the ones produced by software to manage
   3  * DVB boards like the Hauppauge WinTV DVBs
   4  * copyright (c) 2002 Matteo Giani
   5  *
   6  * Uses info from the PVA file specifications found at
   7  * http://www.technotrend.de/download/av_format_v1.pdf
   8  *
   9  * This file is part of MPlayer.
  10  *
  11  * MPlayer is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * MPlayer is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 /* WARNING: Quite a hack was required in order to get files by MultiDec
  27  * played back correctly. If it breaks anything else, just comment out
  28  * the #define below and it will not be compiled in. */
  29 #define DEMUX_PVA_MULTIDEC_HACK
  30 #define PVA_NEW_PREBYTES_CODE
  31
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <string.h>
  35
  36 #include "config.h"
  37 #include "mp_msg.h"
  38 #include "help_mp.h"
  39
  40 #include "stream/stream.h"
  41 #include "demuxer.h"
  42 #include "stheader.h"
  43
  44 /*
  45  * #defines below taken from PVA spec (see URL above)
  46  */
  47
  48 #define PVA_MAX_VIDEO_PACK_LEN 6*1024
  49
  50 #define VIDEOSTREAM 0x01
  51 #define MAINAUDIOSTREAM 0x02
  52
  53 typedef struct {
  54         off_t offset;
  55         long size;
  56         uint8_t type;
  57         uint8_t is_packet_start;
  58         float pts;
  59 } pva_payload_t;
  60
  61
  62 typedef struct {
  63         float last_audio_pts;
  64         float last_video_pts;
  65 #ifdef PVA_NEW_PREBYTES_CODE
  66         float video_pts_after_prebytes;
  67         long video_size_after_prebytes;
  68         uint8_t prebytes_delivered;
  69 #endif
  70         uint8_t just_synced;
  71         uint8_t synced_stream_id;
  72 } pva_priv_t;
  73
  74
  75
  76 int pva_sync(demuxer_t * demuxer)
  77 {
  78         uint8_t buffer[5]={0,0,0,0,0};
  79         int count;
  80         pva_priv_t * priv = (pva_priv_t *) demuxer->priv;
  81
  82
  83          /* This function is used to find the next nearest PVA packet start after a seek, since a PVA file
  84           * is not indexed.
  85           * The just_synced field is in the priv structure so that pva_get_payload knows pva_sync
  86           * has already read (part of) the PVA header. This way we can avoid to seek back and (hopefully)
  87           * be able to read from pipes and such.
  88           */
  89
  90
  91         for(count=0 ; count<PVA_MAX_VIDEO_PACK_LEN && !demuxer->stream->eof && !priv->just_synced ; count++)
  92         {
  93                 buffer[0]=buffer[1];
  94                 buffer[1]=buffer[2];
  95                 buffer[2]=buffer[3];
  96                 buffer[3]=buffer[4];
  97                 buffer[4]=stream_read_char(demuxer->stream);
  98                 /*
  99                  * Check for a PVA packet beginning sequence: we check both the "AV" word at the
 100                  * very beginning and the "0x55" reserved byte (which is unused and set to 0x55 by spec)
 101                  */
 102                 if(buffer[0]=='A' && buffer[1] == 'V' && buffer[4] == 0x55) priv->just_synced=1;
 103                 //printf("demux_pva: pva_sync(): current offset= %ld\n",stream_tell(demuxer->stream));
 104         }
 105         if(priv->just_synced)
 106         {
 107                 priv->synced_stream_id=buffer[2];
 108                 return 1;
 109         }
 110         else
 111         {
 112                 return 0;
 113         }
 114 }
 115
 116 static int pva_check_file(demuxer_t * demuxer)
 117 {
 118         uint8_t buffer[5]={0,0,0,0,0};
 119         mp_msg(MSGT_DEMUX, MSGL_V, "Checking for PVA\n");
 120         stream_read(demuxer->stream,buffer,5);
 121         if(buffer[0]=='A' && buffer[1] == 'V' && buffer[4] == 0x55)
 122         {
 123                 mp_msg(MSGT_DEMUX,MSGL_DBG2, "Success: PVA\n");
 124                 return DEMUXER_TYPE_PVA;
 125         }
 126         else
 127         {
 128                 mp_msg(MSGT_DEMUX,MSGL_DBG2, "Failed: PVA\n");
 129                 return 0;
 130         }
 131 }
 132
 133 static demuxer_t * demux_open_pva (demuxer_t * demuxer)
 134 {
 135         sh_video_t *sh_video = new_sh_video(demuxer,0);
 136         sh_audio_t *sh_audio = new_sh_audio(demuxer,0);
 137
 138
 139         pva_priv_t * priv;
 140
 141         stream_reset(demuxer->stream);
 142         stream_seek(demuxer->stream,0);
 143
 144
 145
 146         priv=malloc(sizeof(pva_priv_t));
 147
 148         if(demuxer->stream->type!=STREAMTYPE_FILE) demuxer->seekable=0;
 149         else demuxer->seekable=1;
 150
 151         demuxer->priv=priv;
 152         memset(demuxer->priv,0,sizeof(pva_priv_t));
 153
 154         if(!pva_sync(demuxer))
 155         {
 156                 mp_msg(MSGT_DEMUX,MSGL_ERR,"Not a PVA file.\n");
 157                 return NULL;
 158         }
 159
 160         //printf("priv->just_synced %s after initial sync!\n",priv->just_synced?"set":"UNSET");
 161
 162         demuxer->video->sh=sh_video;
 163
 164         //printf("demuxer->stream->end_pos= %d\n",demuxer->stream->end_pos);
 165
 166
 167         mp_msg(MSGT_DEMUXER,MSGL_INFO,"Opened PVA demuxer...\n");
 168
 169         /*
 170          * Audio and Video codecs:
 171          * the PVA spec only allows MPEG2 video and MPEG layer II audio. No need to check the formats then.
 172          * Moreover, there would be no way to do that since the PVA stream format has no fields to describe
 173          * the used codecs.
 174          */
 175
 176         sh_video->format=0x10000002;
 177         sh_video->ds=demuxer->video;
 178
 179         /*
 180         printf("demuxer->video->id==%d\n",demuxer->video->id);
 181         printf("demuxer->audio->id==%d\n",demuxer->audio->id);
 182         */
 183
 184         demuxer->audio->id = 0;
 185         demuxer->audio->sh=sh_audio;
 186         sh_audio->format=0x50;
 187         sh_audio->ds=demuxer->audio;
 188
 189         demuxer->movi_start=0;
 190         demuxer->movi_end=demuxer->stream->end_pos;
 191
 192         priv->last_video_pts=-1;
 193         priv->last_audio_pts=-1;
 194
 195         return demuxer;
 196 }
 197
 198 int pva_get_payload(demuxer_t * d,pva_payload_t * payload);
 199
 200 // 0 = EOF or no stream found
 201 // 1 = successfully read a packet
 202 static int demux_pva_fill_buffer (demuxer_t * demux, demux_stream_t *ds)
 203 {
 204         uint8_t done=0;
 205         demux_packet_t * dp;
 206         pva_priv_t * priv=demux->priv;
 207         pva_payload_t current_payload;
 208
 209         while(!done)
 210         {
 211                 if(!pva_get_payload(demux,&current_payload)) return 0;
 212                 switch(current_payload.type)
 213                 {
 214                         case VIDEOSTREAM:
 215                                 if(demux->video->id==-1) demux->video->id=0;
 216                                 if(!current_payload.is_packet_start && priv->last_video_pts==-1)
 217                                 {
 218                                         /* We should only be here at the beginning of a stream, when we have
 219                                          * not yet encountered a valid Video PTS, or after a seek.
 220                                          * So, skip these starting packets in order not to deliver the
 221                                          * player a bogus PTS.
 222                                          */
 223                                         done=0;
 224                                 }
 225                                 else
 226                                 {
 227                                         /*
 228                                          * In every other condition, we are delivering the payload. Set this
 229                                          * so that the following code knows whether to skip it or read it.
 230                                          */
 231                                         done=1;
 232                                 }
 233                                 if(demux->video->id!=0) done=0;
 234                                 if(current_payload.is_packet_start)
 235                                 {
 236                                         priv->last_video_pts=current_payload.pts;
 237                                         //mp_msg(MSGT_DEMUXER,MSGL_DBG2,"demux_pva: Video PTS=%llu , delivered %f\n",current_payload.pts,priv->last_video_pts);
 238                                 }
 239                                 if(done)
 240                                 {
 241                                         dp=new_demux_packet(current_payload.size);
 242                                         dp->pts=priv->last_video_pts;
 243                                         stream_read(demux->stream,dp->buffer,current_payload.size);
 244                                         ds_add_packet(demux->video,dp);
 245                                 }
 246                                 else
 247                                 {
 248                                         //printf("Skipping %u video bytes\n",current_payload.size);
 249                                         stream_skip(demux->stream,current_payload.size);
 250                                 }
 251                                 break;
 252                         case MAINAUDIOSTREAM:
 253                                 if(demux->audio->id==-1) demux->audio->id=0;
 254                                 if(!current_payload.is_packet_start && priv->last_audio_pts==-1)
 255                                 {
 256                                         /* Same as above for invalid video PTS, just for audio. */
 257                                         done=0;
 258                                 }
 259                                 else
 260                                 {
 261                                         done=1;
 262                                 }
 263                                 if(current_payload.is_packet_start)
 264                                 {
 265                                         priv->last_audio_pts=current_payload.pts;
 266                                 }
 267                                 if(demux->audio->id!=0) done=0;
 268                                 if(done)
 269                                 {
 270                                         dp=new_demux_packet(current_payload.size);
 271                                         dp->pts=priv->last_audio_pts;
 272                                         if(current_payload.offset != stream_tell(demux->stream))
 273                                                 stream_seek(demux->stream,current_payload.offset);
 274                                         stream_read(demux->stream,dp->buffer,current_payload.size);
 275                                         ds_add_packet(demux->audio,dp);
 276                                 }
 277                                 else
 278                                 {
 279                                         stream_skip(demux->stream,current_payload.size);
 280                                 }
 281                                 break;
 282                 }
 283         }
 284         return 1;
 285 }
 286
 287 int pva_get_payload(demuxer_t * d,pva_payload_t * payload)
 288 {
 289         uint8_t flags,pes_head_len;
 290         uint16_t pack_size;
 291         off_t next_offset,pva_payload_start;
 292         unsigned char buffer[256];
 293 #ifndef PVA_NEW_PREBYTES_CODE
 294         demux_packet_t * dp;    //hack to deliver the preBytes (see PVA doc)
 295 #endif
 296         pva_priv_t * priv;
 297
 298
 299         if(d==NULL)
 300         {
 301                 mp_msg(MSGT_DEMUX,MSGL_ERR,"demux_pva: pva_get_payload got passed a NULL pointer!\n");
 302                 return 0;
 303         }
 304
 305         priv = (pva_priv_t *)d->priv;
 306         d->filepos=stream_tell(d->stream);
 307
 308
 309
 310
 311         if(d->stream->eof)
 312         {
 313                 mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: pva_get_payload() detected stream->eof!!!\n");
 314                 return 0;
 315         }
 316
 317         //printf("priv->just_synced %s\n",priv->just_synced?"SET":"UNSET");
 318
 319 #ifdef PVA_NEW_PREBYTES_CODE
 320         if(priv->prebytes_delivered)
 321                 /* The previous call to this fn has delivered the preBytes. Then we are already inside
 322                  * the payload. Let's just deliver the video along with its right PTS, the one we stored
 323                  * in the priv structure and was in the PVA header before the PreBytes.
 324                  */
 325         {
 326                 //printf("prebytes_delivered=1. Resetting.\n");
 327                 payload->size = priv->video_size_after_prebytes;
 328                 payload->pts = priv->video_pts_after_prebytes;
 329                 payload->is_packet_start = 1;
 330                 payload->offset = stream_tell(d->stream);
 331                 payload->type = VIDEOSTREAM;
 332                 priv->prebytes_delivered = 0;
 333                 return 1;
 334         }
 335 #endif
 336         if(!priv->just_synced)
 337         {
 338                 if(stream_read_word(d->stream) != (('A'<<8)|'V'))
 339                 {
 340                         mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: pva_get_payload() missed a SyncWord at %"PRId64"!! Trying to sync...\n",(int64_t)stream_tell(d->stream));
 341                         if(!pva_sync(d))
 342                         {
 343                                 if (!d->stream->eof)
 344                                 {
 345                                         mp_msg(MSGT_DEMUX,MSGL_ERR,"demux_pva: couldn't sync! (broken file?)");
 346                                 }
 347                                 return 0;
 348                         }
 349                 }
 350         }
 351         if(priv->just_synced)
 352         {
 353                 payload->type=priv->synced_stream_id;
 354                 priv->just_synced=0;
 355         }
 356         else
 357         {
 358                 payload->type=stream_read_char(d->stream);
 359                 stream_skip(d->stream,2); //counter and reserved
 360         }
 361         flags=stream_read_char(d->stream);
 362         payload->is_packet_start=flags & 0x10;
 363         pack_size=le2me_16(stream_read_word(d->stream));
 364         mp_msg(MSGT_DEMUX,MSGL_DBG2,"demux_pva::pva_get_payload(): pack_size=%u field read at offset %"PRIu64"\n",pack_size,(int64_t)stream_tell(d->stream)-2);
 365         pva_payload_start=stream_tell(d->stream);
 366         next_offset=pva_payload_start+pack_size;
 367
 368
 369         /*
 370          * The code in the #ifdef directive below is a hack needed to get badly formatted PVA files
 371          * such as the ones written by MultiDec played back correctly.
 372          * Basically, it works like this: if the PVA packet does not signal a PES header, but the
 373          * payload looks like one, let's assume it IS one. It has worked for me up to now.
 374          * It can be disabled since it's quite an ugly hack and could potentially break things up
 375          * if the PVA audio payload happens to start with 0x000001 even without being a non signalled
 376          * PES header start.
 377          * Though it's quite unlikely, it potentially could (AFAIK).
 378          */
 379 #ifdef DEMUX_PVA_MULTIDEC_HACK
 380         if(payload->type==MAINAUDIOSTREAM)
 381         {
 382                 stream_read(d->stream,buffer,3);
 383                 if(buffer[0]==0x00 && buffer[1]==0x00 && buffer[2]==0x01 && !payload->is_packet_start)
 384                 {
 385                         mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: suspecting non signaled audio PES packet start. Maybe file by MultiDec?\n");
 386                         payload->is_packet_start=1;
 387                 }
 388                 stream_seek(d->stream,stream_tell(d->stream)-3);
 389         }
 390 #endif
 391
 392
 393         if(!payload->is_packet_start)
 394         {
 395                 payload->offset=stream_tell(d->stream);
 396                 payload->size=pack_size;
 397         }
 398         else
 399         {       //here comes the good part...
 400                 switch(payload->type)
 401                 {
 402                         case VIDEOSTREAM:
 403                                 payload->pts=(float)(le2me_32(stream_read_dword(d->stream)))/90000;
 404                                 //printf("Video PTS: %f\n",payload->pts);
 405                                 if((flags&0x03)
 406 #ifdef PVA_NEW_PREBYTES_CODE
 407                                                 && !priv->prebytes_delivered
 408 #endif
 409                                                 )
 410                                 {
 411 #ifndef PVA_NEW_PREBYTES_CODE
 412                                         dp=new_demux_packet(flags&0x03);
 413                                         stream_read(d->stream,dp->buffer,flags & 0x03); //read PreBytes
 414                                         ds_add_packet(d->video,dp);
 415 #else
 416                                         //printf("Delivering prebytes. Setting prebytes_delivered.");
 417                                         payload->offset=stream_tell(d->stream);
 418                                         payload->size = flags & 0x03;
 419                                         priv->video_pts_after_prebytes = payload->pts;
 420                                         priv->video_size_after_prebytes = pack_size - 4 - (flags & 0x03);
 421                                         payload->pts=priv->last_video_pts;
 422                                         payload->is_packet_start=0;
 423                                         priv->prebytes_delivered=1;
 424                                         return 1;
 425 #endif
 426                                 }
 427
 428
 429                                 //now we are at real beginning of payload.
 430                                 payload->offset=stream_tell(d->stream);
 431                                 //size is pack_size minus PTS size minus PreBytes size.
 432                                 payload->size=pack_size - 4 - (flags & 0x03);
 433                                 break;
 434                         case MAINAUDIOSTREAM:
 435                                 stream_skip(d->stream,3); //FIXME properly parse PES header.
 436                                 //printf("StreamID in audio PES header: 0x%2X\n",stream_read_char(d->stream));
 437                                 stream_skip(d->stream,4);
 438
 439                                 buffer[255]=stream_read_char(d->stream);
 440                                 pes_head_len=stream_read_char(d->stream);
 441                                 stream_read(d->stream,buffer,pes_head_len);
 442                                 if(!buffer[255]&0x80) //PES header does not contain PTS.
 443                                 {
 444                                         mp_msg(MSGT_DEMUX,MSGL_V,"Audio PES packet does not contain PTS. (pes_head_len=%d)\n",pes_head_len);
 445                                         payload->pts=priv->last_audio_pts;
 446                                         break;
 447                                 }
 448                                 else            //PES header DOES contain PTS
 449                                 {
 450                                         if((buffer[0] & 0xf0)!=0x20) // PTS badly formatted
 451                                         {
 452                                                 mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: expected audio PTS but badly formatted... (read 0x%02X). Falling back to previous PTS (hack).\n",buffer[0]);
 453                                                 payload->pts=priv->last_audio_pts;
 454                                         //      return 0;
 455                                         }
 456                                         else
 457                                         {
 458                                                 uint64_t temp_pts;
 459
 460                                                 temp_pts=0LL;
 461                                                 temp_pts|=((uint64_t)(buffer[0] & 0x0e) << 29);
 462                                                 temp_pts|=buffer[1]<<22;
 463                                                 temp_pts|=(buffer[2] & 0xfe) << 14;
 464                                                 temp_pts|=buffer[3]<<7;
 465                                                 temp_pts|=(buffer[4] & 0xfe) >> 1;
 466                                                 /*
 467                                                 * PTS parsing is hopefully finished.
 468                                                 */
 469                                                 payload->pts=(float)le2me_64(temp_pts)/90000;
 470                                         }
 471                                 }
 472                                 payload->offset=stream_tell(d->stream);
 473                                 payload->size=pack_size-stream_tell(d->stream)+pva_payload_start;
 474                                 break;
 475                 }
 476         }
 477         return 1;
 478 }
 479
 480 static void demux_seek_pva(demuxer_t * demuxer,float rel_seek_secs,float audio_delay,int flags)
 481 {
 482         int total_bitrate=0;
 483         off_t dest_offset;
 484         pva_priv_t * priv=demuxer->priv;
 485
 486         total_bitrate=((sh_audio_t *)demuxer->audio->sh)->i_bps + ((sh_video_t *)demuxer->video->sh)->i_bps;
 487
 488         /*
 489          * Compute absolute offset inside the stream. Approximate total bitrate with sum of bitrates
 490          * reported by the audio and video codecs. The seek is not accurate because, just like
 491          * with MPEG streams, the bitrate is not constant. Moreover, we do not take into account
 492          * the overhead caused by PVA and PES headers.
 493          * If the calculated absolute offset is negative, seek to the beginning of the file.
 494          */
 495
 496         dest_offset=stream_tell(demuxer->stream)+rel_seek_secs*total_bitrate;
 497         if(dest_offset<0) dest_offset=0;
 498
 499         stream_seek(demuxer->stream,dest_offset);
 500
 501         if(!pva_sync(demuxer))
 502         {
 503                 mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: Couldn't seek!\n");
 504                 return;
 505         }
 506
 507         /*
 508          * Reset the PTS info inside the pva_priv_t structure. This way we don't deliver
 509          * data with the wrong PTSs (the ones we had before seeking).
 510          *
 511          */
 512
 513         priv->last_video_pts=-1;
 514         priv->last_audio_pts=-1;
 515 }
 516
 517
 518
 519 static void demux_close_pva(demuxer_t * demuxer)
 520 {
 521         if(demuxer->priv)
 522         {
 523                 free(demuxer->priv);
 524                 demuxer->priv=NULL;
 525         }
 526 }
 527
 528
 529 const demuxer_desc_t demuxer_desc_pva = {
 530   "PVA demuxer",
 531   "pva",
 532   "PVA",
 533   "Matteo Giani",
 534   "streams from DVB cards",
 535   DEMUXER_TYPE_PVA,
 536   0, // unsafe autodetect
 537   pva_check_file,
 538   demux_pva_fill_buffer,
 539   demux_open_pva,
 540   demux_close_pva,
 541   demux_seek_pva,
 542   NULL
 543 };