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