dvdnav.c

linux下的MPEG1

/* 
 * Copyright (C) 2000 Rich Wareham <[e-mail]>
 * 
 * This file is part of libdvdnav, a DVD navigation library.
 * 
 * libdvdnav is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * libdvdnav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
 *
 * $Id: dvdnav.c,v 1.34 2005/10/15 14:04:05 jcdutton Exp $
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

/*
#define LOG_DEBUG
*/

#include "dvdnav_internal.h"
#include "read_cache.h"
#include "nav_read.h"

#include <stdlib.h>
#include <stdio.h>
#include <sys/time.h>

#include "remap.h"

static dvdnav_status_t dvdnav_clear(dvdnav_t * this) {
  /* clear everything except file, vm, mutex, readahead */

  if (this->file) DVDCloseFile(this->file);
  this->file = NULL;

  memset(&this->pci,0,sizeof(this->pci));
  memset(&this->dsi,0,sizeof(this->dsi));
  this->last_cmd_nav_lbn = SRI_END_OF_CELL;

  /* Set initial values of flags */
  this->position_current.still = 0;
  this->skip_still = 0;
  this->sync_wait = 0;
  this->sync_wait_skip = 0;
  this->spu_clut_changed = 0;
  this->started = 0;

  dvdnav_read_cache_clear(this->cache);
  
  return DVDNAV_STATUS_OK;
}

dvdnav_status_t dvdnav_open(dvdnav_t** dest, const char *path) {
  dvdnav_t *this;
  struct timeval time;
  
  /* Create a new structure */
  fprintf(MSG_OUT, "libdvdnav: Using dvdnav version %s from http://xine.sf.net\n", VERSION);

  (*dest) = NULL;
  this = (dvdnav_t*)malloc(sizeof(dvdnav_t));
  if(!this)
    return DVDNAV_STATUS_ERR;
  memset(this, 0, (sizeof(dvdnav_t) ) ); /* Make sure this structure is clean */
 
  pthread_mutex_init(&this->vm_lock, NULL);
  /* Initialise the error string */
  printerr("");

  /* Initialise the VM */
  this->vm = vm_new_vm();
  if(!this->vm) {
    printerr("Error initialising the DVD VM.");
    pthread_mutex_destroy(&this->vm_lock);
    free(this);
    return DVDNAV_STATUS_ERR;
  }
  if(!vm_reset(this->vm, path)) {
    printerr("Error starting the VM / opening the DVD device.");
    pthread_mutex_destroy(&this->vm_lock);
    vm_free_vm(this->vm);
    free(this);
    return DVDNAV_STATUS_ERR;
  }

  /* Set the path. FIXME: Is a deep copy 'right' */
  strncpy(this->path, path, MAX_PATH_LEN);

  /* Pre-open and close a file so that the CSS-keys are cached. */
  this->file = DVDOpenFile(vm_get_dvd_reader(this->vm), 0, DVD_READ_MENU_VOBS);
    
  /* Start the read-ahead cache. */
  this->cache = dvdnav_read_cache_new(this);

  /* Seed the random numbers. So that the DVD VM Command rand()
   * gives a different start value each time a DVD is played. */
  gettimeofday(&time, NULL);
  srand(time.tv_usec);
 
  dvdnav_clear(this);
 
  (*dest) = this;
  return DVDNAV_STATUS_OK;
}

dvdnav_status_t dvdnav_close(dvdnav_t *this) {

#ifdef LOG_DEBUG
  fprintf(MSG_OUT, "libdvdnav: close:called\n");
#endif

  if(!this) {
    printerr("Passed a NULL pointer.");
    return DVDNAV_STATUS_ERR;
  }

  if (this->file) {
    DVDCloseFile(this->file);
#ifdef LOG_DEBUG
    fprintf(MSG_OUT, "libdvdnav: close:file closing\n");
#endif
    this->file = NULL;
  }

  /* Free the VM */
  if(this->vm)
    vm_free_vm(this->vm);

  pthread_mutex_destroy(&this->vm_lock);

  /* We leave the final freeing of the entire structure to the cache,
   * because we don't know, if there are still buffers out in the wild,
   * that must return first. */
  if(this->cache)
    dvdnav_read_cache_free(this->cache);
  else
    free(this);
  
  return DVDNAV_STATUS_OK;
}

dvdnav_status_t dvdnav_reset(dvdnav_t *this) {
  dvdnav_status_t result;

#ifdef LOG_DEBUG
  fprintf(MSG_OUT, "libdvdnav: reset:called\n");
#endif

  if(!this) {
    printerr("Passed a NULL pointer.");
    return DVDNAV_STATUS_ERR;
  }

  pthread_mutex_lock(&this->vm_lock); 

#ifdef LOG_DEBUG
  fprintf(MSG_OUT, "libdvdnav: reseting vm\n");
#endif
  if(!vm_reset(this->vm, NULL)) {
    printerr("Error restarting the VM.");
    pthread_mutex_unlock(&this->vm_lock); 
    return DVDNAV_STATUS_ERR;
  }
#ifdef LOG_DEBUG
  fprintf(MSG_OUT, "libdvdnav: clearing dvdnav\n");
#endif
  result = dvdnav_clear(this);

  pthread_mutex_unlock(&this->vm_lock); 
  return result;
}

dvdnav_status_t dvdnav_path(dvdnav_t *this, const char** path) {

  if(!this || !path) {
    printerr("Passed a NULL pointer.");
    return DVDNAV_STATUS_ERR;
  }

  (*path) = this->path;

  return DVDNAV_STATUS_OK;
}

const char* dvdnav_err_to_string(dvdnav_t *this) {
  
  if(!this)
    return "Hey! You gave me a NULL pointer you naughty person!";
  
  return this->err_str;
}

/* converts a dvd_time_t to PTS ticks */
int64_t dvdnav_convert_time(dvd_time_t *time) {
  int64_t result;
  int64_t frames;
  
  result  = (time->hour    >> 4  ) * 10 * 60 * 60 * 90000;
  result += (time->hour    & 0x0f)      * 60 * 60 * 90000;
  result += (time->minute  >> 4  )      * 10 * 60 * 90000;
  result += (time->minute  & 0x0f)           * 60 * 90000;
  result += (time->second  >> 4  )           * 10 * 90000;
  result += (time->second  & 0x0f)                * 90000;
  
  frames  = ((time->frame_u & 0x30) >> 4) * 10;
  frames += ((time->frame_u & 0x0f)     )     ;
  
  if (time->frame_u & 0x80)
    result += frames * 3000;
  else
    result += frames * 3600;
  
  return result;
}

/*
 * Returns 1 if block contains NAV packet, 0 otherwise.
 * Processes said NAV packet if present.
 *
 * Most of the code in here is copied from xine's MPEG demuxer
 * so any bugs which are found in that should be corrected here also.
 */
static int32_t dvdnav_decode_packet(dvdnav_t *this, uint8_t *p, dsi_t *nav_dsi, pci_t *nav_pci) {
  int32_t        bMpeg1 = 0;
  uint32_t       nHeaderLen;
  uint32_t       nPacketLen;
  uint32_t       nStreamID;

  if (p[3] == 0xBA) { /* program stream pack header */
    int32_t nStuffingBytes;

    bMpeg1 = (p[4] & 0x40) == 0;

    if (bMpeg1) {
      p += 12;
    } else { /* mpeg2 */
      nStuffingBytes = p[0xD] & 0x07;
      p += 14 + nStuffingBytes;
    }
  }

  if (p[3] == 0xbb) { /* program stream system header */
    nHeaderLen = (p[4] << 8) | p[5];
    p += 6 + nHeaderLen;
  }

  /* we should now have a PES packet here */
  if (p[0] || p[1] || (p[2] != 1)) {
    fprintf(MSG_OUT, "libdvdnav: demux error! %02x %02x %02x (should be 0x000001) \n",p[0],p[1],p[2]);
    return 0;
  }

  nPacketLen = p[4] << 8 | p[5];
  nStreamID  = p[3];

  nHeaderLen = 6;
  p += nHeaderLen;

  if (nStreamID == 0xbf) { /* Private stream 2 */
#if 0
    int32_t i;
    fprintf(MSG_OUT, "libdvdnav: nav packet=%u\n",p-p_start-6);
    for(i=0;i<80;i++)
      fprintf(MSG_OUT, "%02x ",p[i-6]);
    fprintf(MSG_OUT, "\n");
#endif

    if(p[0] == 0x00) {
      navRead_PCI(nav_pci, p+1);
    }

    p += nPacketLen;

    /* We should now have a DSI packet. */
    if(p[6] == 0x01) {
      nPacketLen = p[4] << 8 | p[5];
      p += 6;
      navRead_DSI(nav_dsi, p+1);
    } 
    return 1;
  }
  return 0;
}

/* DSI is used for most angle stuff. 
 * PCI is used for only non-seemless angle stuff
 */ 
static int32_t dvdnav_get_vobu(dvdnav_t *this, dsi_t *nav_dsi, pci_t *nav_pci, dvdnav_vobu_t *vobu) {
  uint32_t next;
  int32_t angle, num_angle;

  vobu->vobu_start = nav_dsi->dsi_gi.nv_pck_lbn; /* Absolute offset from start of disk */
  vobu->vobu_length = nav_dsi->dsi_gi.vobu_ea; /* Relative offset from vobu_start */
     
  /*
   * If we're not at the end of this cell, we can determine the next
   * VOBU to display using the VOBU_SRI information section of the
   * DSI.  Using this value correctly follows the current angle,
   * avoiding the doubled scenes in The Matrix, and makes our life
   * really happy.
   *
   * vobu_next is an offset value, 0x3fffffff = SRI_END_OF_CELL
   * DVDs are about 6 Gigs, which is only up to 0x300000 blocks
   * Should really assert if bit 31 != 1
   */
  
#if 0
  /* Old code -- may still be useful one day */
  if(nav_dsi->vobu_sri.next_vobu != SRI_END_OF_CELL ) {
    vobu->vobu_next = ( nav_dsi->vobu_sri.next_vobu & 0x3fffffff );
  } else {
    vobu->vobu_next = vobu->vobu_length;
  }
#else
  /* Relative offset from vobu_start */
  vobu->vobu_next = ( nav_dsi->vobu_sri.next_vobu & 0x3fffffff );
#endif
  
  vm_get_angle_info(this->vm, &angle, &num_angle);

  /* FIMXE: The angle reset doesn't work for some reason for the moment */
#if 0
  if((num_angle < angle) && (angle != 1)) {
    fprintf(MSG_OUT, "libdvdnav: angle ends!\n");
    
    /* This is to switch back to angle one when we
     * finish with angles. */
    dvdnav_angle_change(this, 1);
  } 
#endif

  if(num_angle != 0) {
    
    if((next = nav_pci->nsml_agli.nsml_agl_dsta[angle-1]) != 0) {
      if((next & 0x3fffffff) != 0) {
	if(next & 0x80000000)
	  vobu->vobu_next = - (int32_t)(next & 0x3fffffff);
	else
	  vobu->vobu_next = + (int32_t)(next & 0x3fffffff);
      }
    } else if((next = nav_dsi->sml_agli.data[angle-1].address) != 0) {
      vobu->vobu_length = nav_dsi->sml_pbi.ilvu_ea;
      
      if((next & 0x80000000) && (next != 0x7fffffff))
	vobu->vobu_next =  - (int32_t)(next & 0x3fffffff);
      else
	vobu->vobu_next =  + (int32_t)(next & 0x3fffffff);
    }
  }

  return 1;