libmpdemux/demux_pva.c

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