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 static int pva_get_payload(demuxer_t *d, pva_payload_t *payload)
 198 {
 199         uint8_t flags,pes_head_len;
 200         uint16_t pack_size;
 201         off_t pva_payload_start;
 202         unsigned char buffer[256];
 203 #ifndef PVA_NEW_PREBYTES_CODE
 204         demux_packet_t * dp;    //hack to deliver the preBytes (see PVA doc)
 205 #endif
 206         pva_priv_t * priv;
 207
 208
 209         if(d==NULL)
 210         {
 211                 mp_msg(MSGT_DEMUX,MSGL_ERR,"demux_pva: pva_get_payload got passed a NULL pointer!\n");
 212                 return 0;
 213         }
 214
 215         priv = (pva_priv_t *)d->priv;
 216         d->filepos=stream_tell(d->stream);
 217
 218
 219
 220
 221         if(d->stream->eof)
 222         {
 223                 mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: pva_get_payload() detected stream->eof!!!\n");
 224                 return 0;
 225         }
 226
 227         //printf("priv->just_synced %s\n",priv->just_synced?"SET":"UNSET");
 228
 229 #ifdef PVA_NEW_PREBYTES_CODE
 230         if(priv->prebytes_delivered)
 231                 /* The previous call to this fn has delivered the preBytes. Then we are already inside
 232                  * the payload. Let's just deliver the video along with its right PTS, the one we stored
 233                  * in the priv structure and was in the PVA header before the PreBytes.
 234                  */
 235         {
 236                 //printf("prebytes_delivered=1. Resetting.\n");
 237                 payload->size = priv->video_size_after_prebytes;
 238                 payload->pts = priv->video_pts_after_prebytes;
 239                 payload->is_packet_start = 1;
 240                 payload->offset = stream_tell(d->stream);
 241                 payload->type = VIDEOSTREAM;
 242                 priv->prebytes_delivered = 0;
 243                 return 1;
 244         }
 245 #endif
 246         if(!priv->just_synced)
 247         {
 248                 if(stream_read_word(d->stream) != (('A'<<8)|'V'))
 249                 {
 250                         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));
 251                         if(!pva_sync(d))
 252                         {
 253                                 if (!d->stream->eof)
 254                                 {
 255                                         mp_msg(MSGT_DEMUX,MSGL_ERR,"demux_pva: couldn't sync! (broken file?)");
 256                                 }
 257                                 return 0;
 258                         }
 259                 }
 260         }
 261         if(priv->just_synced)
 262         {
 263                 payload->type=priv->synced_stream_id;
 264                 priv->just_synced=0;
 265         }
 266         else
 267         {
 268                 payload->type=stream_read_char(d->stream);
 269                 stream_skip(d->stream,2); //counter and reserved
 270         }
 271         flags=stream_read_char(d->stream);
 272         payload->is_packet_start=flags & 0x10;
 273         pack_size=stream_read_word(d->stream);
 274         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);
 275         pva_payload_start=stream_tell(d->stream);
 276
 277
 278         /*
 279          * The code in the #ifdef directive below is a hack needed to get badly formatted PVA files
 280          * such as the ones written by MultiDec played back correctly.
 281          * Basically, it works like this: if the PVA packet does not signal a PES header, but the
 282          * payload looks like one, let's assume it IS one. It has worked for me up to now.
 283          * It can be disabled since it's quite an ugly hack and could potentially break things up
 284          * if the PVA audio payload happens to start with 0x000001 even without being a non signalled
 285          * PES header start.
 286          * Though it's quite unlikely, it potentially could (AFAIK).
 287          */
 288 #ifdef DEMUX_PVA_MULTIDEC_HACK
 289         if(payload->type==MAINAUDIOSTREAM)
 290         {
 291                 stream_read(d->stream,buffer,3);
 292                 if(buffer[0]==0x00 && buffer[1]==0x00 && buffer[2]==0x01 && !payload->is_packet_start)
 293                 {
 294                         mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: suspecting non signaled audio PES packet start. Maybe file by MultiDec?\n");
 295                         payload->is_packet_start=1;
 296                 }
 297                 stream_seek(d->stream,stream_tell(d->stream)-3);
 298         }
 299 #endif
 300
 301
 302         if(!payload->is_packet_start)
 303         {
 304                 payload->offset=stream_tell(d->stream);
 305                 payload->size=pack_size;
 306         }
 307         else
 308         {       //here comes the good part...
 309                 switch(payload->type)
 310                 {
 311                         case VIDEOSTREAM:
 312                                 payload->pts=(float)(stream_read_dword(d->stream))/90000;
 313                                 //printf("Video PTS: %f\n",payload->pts);
 314                                 if((flags&0x03)
 315 #ifdef PVA_NEW_PREBYTES_CODE
 316                                                 && !priv->prebytes_delivered
 317 #endif
 318                                                 )
 319                                 {
 320 #ifndef PVA_NEW_PREBYTES_CODE
 321                                         dp=new_demux_packet(flags&0x03);
 322                                         stream_read(d->stream,dp->buffer,flags & 0x03); //read PreBytes
 323                                         ds_add_packet(d->video,dp);
 324 #else
 325                                         //printf("Delivering prebytes. Setting prebytes_delivered.");
 326                                         payload->offset=stream_tell(d->stream);
 327                                         payload->size = flags & 0x03;
 328                                         priv->video_pts_after_prebytes = payload->pts;
 329                                         priv->video_size_after_prebytes = pack_size - 4 - (flags & 0x03);
 330                                         payload->pts=priv->last_video_pts;
 331                                         payload->is_packet_start=0;
 332                                         priv->prebytes_delivered=1;
 333                                         return 1;
 334 #endif
 335                                 }
 336
 337
 338                                 //now we are at real beginning of payload.
 339                                 payload->offset=stream_tell(d->stream);
 340                                 //size is pack_size minus PTS size minus PreBytes size.
 341                                 payload->size=pack_size - 4 - (flags & 0x03);
 342                                 break;
 343                         case MAINAUDIOSTREAM:
 344                                 stream_skip(d->stream,3); //FIXME properly parse PES header.
 345                                 //printf("StreamID in audio PES header: 0x%2X\n",stream_read_char(d->stream));
 346                                 stream_skip(d->stream,4);
 347
 348                                 buffer[255]=stream_read_char(d->stream);
 349                                 pes_head_len=stream_read_char(d->stream);
 350                                 stream_read(d->stream,buffer,pes_head_len);
 351                                 if(!(buffer[255]&0x80)) //PES header does not contain PTS.
 352                                 {
 353                                         mp_msg(MSGT_DEMUX,MSGL_V,"Audio PES packet does not contain PTS. (pes_head_len=%d)\n",pes_head_len);
 354                                         payload->pts=priv->last_audio_pts;
 355                                         break;
 356                                 }
 357                                 else            //PES header DOES contain PTS
 358                                 {
 359                                         if((buffer[0] & 0xf0)!=0x20) // PTS badly formatted
 360                                         {
 361                                                 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]);
 362                                                 payload->pts=priv->last_audio_pts;
 363                                         //      return 0;
 364                                         }
 365                                         else
 366                                         {
 367                                                 uint64_t temp_pts;
 368
 369                                                 temp_pts=0LL;
 370                                                 temp_pts|=((uint64_t)(buffer[0] & 0x0e) << 29);
 371                                                 temp_pts|=buffer[1]<<22;
 372                                                 temp_pts|=(buffer[2] & 0xfe) << 14;
 373                                                 temp_pts|=buffer[3]<<7;
 374                                                 temp_pts|=(buffer[4] & 0xfe) >> 1;
 375                                                 /*
 376                                                 * PTS parsing is hopefully finished.
 377                                                 */
 378                                                 payload->pts=(float)temp_pts/90000;
 379                                         }
 380                                 }
 381                                 payload->offset=stream_tell(d->stream);
 382                                 payload->size=pack_size-stream_tell(d->stream)+pva_payload_start;
 383                                 break;
 384                 }
 385         }
 386         return 1;
 387 }
 388
 389 // 0 = EOF or no stream found
 390 // 1 = successfully read a packet
 391 static int demux_pva_fill_buffer (demuxer_t * demux, demux_stream_t *ds)
 392 {
 393         uint8_t done=0;
 394         demux_packet_t * dp;
 395         pva_priv_t * priv=demux->priv;
 396         pva_payload_t current_payload;
 397
 398         while(!done)
 399         {
 400                 if(!pva_get_payload(demux,&current_payload)) return 0;
 401                 switch(current_payload.type)
 402                 {
 403                         case VIDEOSTREAM:
 404                                 if(demux->video->id==-1) demux->video->id=0;
 405                                 if(!current_payload.is_packet_start && priv->last_video_pts==-1)
 406                                 {
 407                                         /* We should only be here at the beginning of a stream, when we have
 408                                          * not yet encountered a valid Video PTS, or after a seek.
 409                                          * So, skip these starting packets in order not to deliver the
 410                                          * player a bogus PTS.
 411                                          */
 412                                         done=0;
 413                                 }
 414                                 else
 415                                 {
 416                                         /*
 417                                          * In every other condition, we are delivering the payload. Set this
 418                                          * so that the following code knows whether to skip it or read it.
 419                                          */
 420                                         done=1;
 421                                 }
 422                                 if(demux->video->id!=0) done=0;
 423                                 if(current_payload.is_packet_start)
 424                                 {
 425                                         priv->last_video_pts=current_payload.pts;
 426                                         //mp_msg(MSGT_DEMUXER,MSGL_DBG2,"demux_pva: Video PTS=%llu , delivered %f\n",current_payload.pts,priv->last_video_pts);
 427                                 }
 428                                 if(done)
 429                                 {
 430                                         dp=new_demux_packet(current_payload.size);
 431                                         dp->pts=priv->last_video_pts;
 432                                         stream_read(demux->stream,dp->buffer,current_payload.size);
 433                                         ds_add_packet(demux->video,dp);
 434                                 }
 435                                 else
 436                                 {
 437                                         //printf("Skipping %u video bytes\n",current_payload.size);
 438                                         stream_skip(demux->stream,current_payload.size);
 439                                 }
 440                                 break;
 441                         case MAINAUDIOSTREAM:
 442                                 if(demux->audio->id==-1) demux->audio->id=0;
 443                                 if(!current_payload.is_packet_start && priv->last_audio_pts==-1)
 444                                 {
 445                                         /* Same as above for invalid video PTS, just for audio. */
 446                                         done=0;
 447                                 }
 448                                 else
 449                                 {
 450                                         done=1;
 451                                 }
 452                                 if(current_payload.is_packet_start)
 453                                 {
 454                                         priv->last_audio_pts=current_payload.pts;
 455                                 }
 456                                 if(demux->audio->id!=0) done=0;
 457                                 if(done)
 458                                 {
 459                                         dp=new_demux_packet(current_payload.size);
 460                                         dp->pts=priv->last_audio_pts;
 461                                         if(current_payload.offset != stream_tell(demux->stream))
 462                                                 stream_seek(demux->stream,current_payload.offset);
 463                                         stream_read(demux->stream,dp->buffer,current_payload.size);
 464                                         ds_add_packet(demux->audio,dp);
 465                                 }
 466                                 else
 467                                 {
 468                                         stream_skip(demux->stream,current_payload.size);
 469                                 }
 470                                 break;
 471                 }
 472         }
 473         return 1;
 474 }
 475
 476 static void demux_seek_pva(demuxer_t * demuxer,float rel_seek_secs,float audio_delay,int flags)
 477 {
 478         int total_bitrate=0;
 479         off_t dest_offset;
 480         pva_priv_t * priv=demuxer->priv;
 481
 482         total_bitrate=((sh_audio_t *)demuxer->audio->sh)->i_bps + ((sh_video_t *)demuxer->video->sh)->i_bps;
 483
 484         /*
 485          * Compute absolute offset inside the stream. Approximate total bitrate with sum of bitrates
 486          * reported by the audio and video codecs. The seek is not accurate because, just like
 487          * with MPEG streams, the bitrate is not constant. Moreover, we do not take into account
 488          * the overhead caused by PVA and PES headers.
 489          * If the calculated absolute offset is negative, seek to the beginning of the file.
 490          */
 491
 492         dest_offset=stream_tell(demuxer->stream)+rel_seek_secs*total_bitrate;
 493         if(dest_offset<0) dest_offset=0;
 494
 495         stream_seek(demuxer->stream,dest_offset);
 496
 497         if(!pva_sync(demuxer))
 498         {
 499                 mp_msg(MSGT_DEMUX,MSGL_V,"demux_pva: Couldn't seek!\n");
 500                 return;
 501         }
 502
 503         /*
 504          * Reset the PTS info inside the pva_priv_t structure. This way we don't deliver
 505          * data with the wrong PTSs (the ones we had before seeking).
 506          *
 507          */
 508
 509         priv->last_video_pts=-1;
 510         priv->last_audio_pts=-1;
 511 }
 512
 513
 514
 515 static void demux_close_pva(demuxer_t * demuxer)
 516 {
 517         free(demuxer->priv);
 518         demuxer->priv = NULL;
 519 }
 520
 521
 522 const demuxer_desc_t demuxer_desc_pva = {
 523   "PVA demuxer",
 524   "pva",
 525   "PVA",
 526   "Matteo Giani",
 527   "streams from DVB cards",
 528   DEMUXER_TYPE_PVA,
 529   0, // unsafe autodetect
 530   pva_check_file,
 531   demux_pva_fill_buffer,
 532   demux_open_pva,
 533   demux_close_pva,
 534   demux_seek_pva,
 535   NULL
 536 };