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New cropping algorithm - determine cropping rectangle from a median filter run across...
[handbrake-jp/handbrake-jp-git.git] / libhb / scan.c
index cda52e3..f7ded05 100644 (file)
@@ -1,7 +1,7 @@
 /* $Id: scan.c,v 1.52 2005/11/25 15:05:25 titer Exp $
 
    This file is part of the HandBrake source code.
-   Homepage: <http://handbrake.m0k.org/>.
+   Homepage: <http://handbrake.fr/>.
    It may be used under the terms of the GNU General Public License. */
 
 #include "hb.h"
 typedef struct
 {
     hb_handle_t * h;
-    
+
     char        * path;
     int           title_index;
     hb_list_t   * list_title;
-    
+
     hb_dvd_t    * dvd;
        hb_stream_t * stream;
-       
+
 } hb_scan_t;
 
 static void ScanFunc( void * );
 static int  DecodePreviews( hb_scan_t *, hb_title_t * title );
-static void LookForAC3AndDCA( hb_title_t * title, hb_buffer_t * b );
-static int  AllAC3AndDCAOK( hb_title_t * title );
+static void LookForAudio( hb_title_t * title, hb_buffer_t * b );
+static int  AllAudioOK( hb_title_t * title );
+
+static const char *aspect_to_string( int aspect )
+{
+    switch ( aspect )
+    {
+        case HB_ASPECT_BASE * 1 / 1:    return "1:1";
+        case HB_ASPECT_BASE * 4 / 3:    return "4:3";
+        case HB_ASPECT_BASE * 16 / 9:   return "16:9";
+        case HB_ASPECT_BASE * 221 / 100:   return "2.21:1";
+    }
+    static char arstr[32];
+    double a = (double)aspect / HB_ASPECT_BASE;
+    sprintf( arstr, aspect >= 1.? "%.2f:1" : "1:%.2f", a );
+    return arstr;
+}
 
 hb_thread_t * hb_scan_init( hb_handle_t * handle, const char * path,
                             int title_index, hb_list_t * list_title )
@@ -47,7 +62,7 @@ static void ScanFunc( void * _data )
 
        data->dvd = NULL;
        data->stream = NULL;
-       
+
     /* Try to open the path as a DVD. If it fails, try as a file */
     hb_log( "scan: trying to open with libdvdread" );
     if( ( data->dvd = hb_dvd_init( data->path ) ) )
@@ -70,19 +85,14 @@ static void ScanFunc( void * _data )
             }
         }
     }
+    else if ( (data->stream = hb_stream_open( data->path, 0 ) ) != NULL )
+    {
+        hb_list_add( data->list_title, hb_stream_title_scan( data->stream ) );
+    }
     else
     {
-        if ( hb_stream_is_stream_type(data->path) )
-        {
-          hb_log( "scan: trying to open as MPEG-2 Stream");
-                 data->stream = hb_stream_open (data->path);
-          hb_list_add( data->list_title, hb_stream_title_scan( data->stream ) );
-        }
-        else
-        {
-            hb_log( "scan: unrecognized file type" );
-            return;
-        }
+        hb_log( "scan: unrecognized file type" );
+        return;
     }
 
     for( i = 0; i < hb_list_count( data->list_title ); )
@@ -136,42 +146,15 @@ static void ScanFunc( void * _data )
             hb_list_rem( data->list_title, title );
             continue;
         }
-        
-               if (data->stream)
-               {
-                       // Stream based processing uses PID's to handle the different audio options for a given title
-                       for( j = 0; j < hb_list_count( title->list_audio ); j++ )
-                       {
-                               audio = hb_list_item( title->list_audio, j );
-                               hb_stream_update_audio(data->stream, audio);
-                       }
-               }
-               else if (data->dvd)
-               {
-                       /* Make sure we found AC3 rates and bitrates */
-                       for( j = 0; j < hb_list_count( title->list_audio ); )
-                       {
-                               audio = hb_list_item( title->list_audio, j );
-                               if( audio->codec == HB_ACODEC_AC3 &&
-                                       !audio->bitrate )
-                               {
-                                       hb_list_rem( title->list_audio, audio );
-                                       free( audio );
-                                       continue;
-                               }
-                               j++;
-                       }
-               }
-               
-        /* Make sure we found AC3 / DCA rates and bitrates */
+
+        /* Make sure we found audio rates and bitrates */
         for( j = 0; j < hb_list_count( title->list_audio ); )
         {
             audio = hb_list_item( title->list_audio, j );
-            if( ( audio->codec == HB_ACODEC_AC3 || audio->codec == HB_ACODEC_DCA ) &&
-                !audio->bitrate )
+            if( !audio->config.in.bitrate )
             {
-                hb_log( "scan: removing audio with codec of 0x%x because of no bitrate",
-                    audio->codec );
+                hb_log( "scan: removing audio 0x%x because no bitrate found",
+                        audio->id );
                 hb_list_rem( title->list_audio, audio );
                 free( audio );
                 continue;
@@ -179,7 +162,7 @@ static void ScanFunc( void * _data )
             j++;
         }
 
-        /* Do we still have audio */
+        /* If we don't have any audio streams left, remove the title */
         if( !hb_list_count( title->list_audio ) )
         {
             hb_list_rem( data->list_title, title );
@@ -187,18 +170,6 @@ static void ScanFunc( void * _data )
             continue;
         }
 
-        /* set a default input channel layout of stereo for LPCM or MPEG2 audio */
-        /* AC3 and DCA will already have had their layout set via DecodePreviews above, */
-        /* which calls LookForAC3AndDCA */
-        for( j = 0; j < hb_list_count( title->list_audio ); j++ )
-        {
-            audio = hb_list_item( title->list_audio, j );
-            if( audio->codec == HB_ACODEC_LPCM || audio->codec == HB_ACODEC_MPGA )
-            {
-                audio->input_channel_layout = HB_INPUT_CH_LAYOUT_STEREO;
-            }
-        }
-        
         i++;
     }
 
@@ -220,19 +191,25 @@ static void ScanFunc( void * _data )
         /* Autocrop by default. Gnark gnark */
         memcpy( job->crop, title->crop, 4 * sizeof( int ) );
 
-        if( title->aspect == 16 )
+        /* Preserve a source's pixel aspect, if it's available. */
+        if( title->pixel_aspect_width && title->pixel_aspect_height )
+        {
+            job->pixel_aspect_width  = title->pixel_aspect_width;
+            job->pixel_aspect_height = title->pixel_aspect_height;
+        }
+
+        if( title->aspect == 16 && !job->pixel_aspect_width && !job->pixel_aspect_height)
         {
             hb_reduce( &job->pixel_aspect_width, &job->pixel_aspect_height,
                        16 * title->height, 9 * title->width );
         }
-        else
+        else if( !job->pixel_aspect_width && !job->pixel_aspect_height )
         {
             hb_reduce( &job->pixel_aspect_width, &job->pixel_aspect_height,
                        4 * title->height, 3 * title->width );
         }
 
         job->width = title->width - job->crop[2] - job->crop[3];
-//        job->height = title->height - job->crop[0] - job->crop[1];
         hb_fix_aspect( job, HB_KEEP_WIDTH );
         if( job->height > title->height - job->crop[0] - job->crop[1] )
         {
@@ -240,8 +217,8 @@ static void ScanFunc( void * _data )
             hb_fix_aspect( job, HB_KEEP_HEIGHT );
         }
 
-    hb_log( "scan: title (%d) job->width:%d, job->height:%d",
-            i,job->width, job->height );
+        hb_log( "scan: title (%d) job->width:%d, job->height:%d",
+                i, job->width, job->height );
 
         job->keep_ratio = 1;
 
@@ -252,12 +229,7 @@ static void ScanFunc( void * _data )
         job->vrate      = title->rate;
         job->vrate_base = title->rate_base;
 
-        job->audios[0] = 0;
-        job->audios[1] = -1;
-
-        job->acodec   = HB_ACODEC_FAAC;
-        job->abitrate = 128;
-        job->arate    = 44100;
+        job->list_audio = hb_list_init();
 
         job->subtitle = -1;
 
@@ -277,6 +249,106 @@ static void ScanFunc( void * _data )
     _data = NULL;
 }
 
+// -----------------------------------------------
+// stuff related to cropping
+
+#define DARK 64
+
+static int row_all_dark( hb_title_t *title, uint8_t* luma, int row )
+{
+    int i = title->width;
+    luma += i * row;
+    while ( --i >= 0 )
+    {
+        if ( *luma++ > DARK )
+            return 0;
+    }
+    return 1;
+}
+
+static int column_all_dark( hb_title_t *title, uint8_t* luma, int top, int col )
+{
+    int i = title->height - top;
+    int stride = title->width;
+    luma += stride * top + col;
+    for ( ; --i >= 0; luma += stride )
+    {
+        if ( *luma > DARK )
+            return 0;
+    }
+    return 1;
+}
+#undef DARK
+
+typedef struct {
+    int n;
+    int t[10];
+    int b[10];
+    int l[10];
+    int r[10];
+} crop_record_t;
+
+static void record_crop( crop_record_t *crops, int t, int b, int l, int r )
+{
+    crops->t[crops->n] = t;
+    crops->b[crops->n] = b;
+    crops->l[crops->n] = l;
+    crops->r[crops->n] = r;
+    ++crops->n;
+}
+
+static int compare_int( const void *a, const void *b )
+{
+    return *(const int *)a - *(const int *)b;
+}
+
+static void sort_crops( crop_record_t *crops )
+{
+    qsort( crops->t, crops->n, sizeof(crops->t[0]), compare_int );
+    qsort( crops->b, crops->n, sizeof(crops->t[0]), compare_int );
+    qsort( crops->l, crops->n, sizeof(crops->t[0]), compare_int );
+    qsort( crops->r, crops->n, sizeof(crops->t[0]), compare_int );
+}
+
+// -----------------------------------------------
+// stuff related to title width/height/aspect info
+
+typedef struct {
+    int count;              /* number of times we've seen this info entry */
+    hb_work_info_t info;    /* copy of info entry */
+} info_list_t;
+
+static void remember_info( info_list_t *info_list, hb_work_info_t *info )
+{
+    for ( ; info_list->count; ++info_list )
+    {
+        if ( memcmp( &info_list->info, info, sizeof(*info) ) == 0 )
+        {
+            // we found a match - bump its count
+            ++info_list->count;
+            return;
+        }
+    }
+    // no match found - add new entry to list (info_list points to
+    // the first free slot). NB - we assume that info_list was allocated
+    // so that it's big enough even if there are no dups. I.e., 10 slots
+    // allocated if there are 10 previews.
+    info_list->count = 1;
+    info_list->info = *info;
+}
+
+static void most_common_info( info_list_t *info_list, hb_work_info_t *info )
+{
+    int i, biggest = 0;
+    for ( i = 1; info_list[i].count; ++i )
+    {
+        if ( info_list[i].count > info_list[biggest].count )
+            biggest = i;
+    }
+    *info = info_list[biggest].info;
+    free( info_list );
+}
+
 /***********************************************************************
  * DecodePreviews
  ***********************************************************************
@@ -286,47 +358,53 @@ static void ScanFunc( void * _data )
  **********************************************************************/
 static int DecodePreviews( hb_scan_t * data, hb_title_t * title )
 {
-    int             i, ret;
-    hb_buffer_t   * buf_ps, * buf_es, * buf_raw;
-    hb_list_t     * list_es, * list_raw;
-    hb_libmpeg2_t * mpeg2;
+    int             i, npreviews = 0;
+    hb_buffer_t   * buf_ps, * buf_es;
+    hb_list_t     * list_es;
     int progressive_count = 0;
-    
+    int interlaced_preview_count = 0;
+    info_list_t * info_list = calloc( 10+1, sizeof(*info_list) );
+    crop_record_t *crops = calloc( 1, sizeof(*crops) );
+
     buf_ps   = hb_buffer_init( HB_DVD_READ_BUFFER_SIZE );
     list_es  = hb_list_init();
-    list_raw = hb_list_init();
 
     hb_log( "scan: decoding previews for title %d", title->index );
 
     if (data->dvd)
       hb_dvd_start( data->dvd, title->index, 1 );
-      
+
     for( i = 0; i < 10; i++ )
     {
-        int j, k;
+        int j;
         FILE * file_preview;
         char   filename[1024];
 
-        //hb_log("Seeking to: %f", (float) ( i + 1 ) / 11.0 );
-       
         if (data->dvd)
         {
           if( !hb_dvd_seek( data->dvd, (float) ( i + 1 ) / 11.0 ) )
           {
-              goto error;
+              continue;
           }
         }
         else if (data->stream)
         {
-          if (!hb_stream_seek(data->stream, (float) ( i + 1 ) / 11.0 ) )
+          /* we start reading streams at zero rather than 1/11 because
+           * short streams may have only one sequence header in the entire
+           * file and we need it to decode any previews. */
+          if (!hb_stream_seek(data->stream, (float) i / 11.0 ) )
           {
-            goto error;
+              continue;
           }
         }
-        
+
         hb_log( "scan: preview %d", i + 1 );
 
-        mpeg2 = hb_libmpeg2_init();
+        int vcodec = title->video_codec? title->video_codec : WORK_DECMPEG2;
+        hb_work_object_t *vid_decoder = hb_get_work( vcodec );
+        vid_decoder->codec_param = title->video_codec_param;
+        vid_decoder->init( vid_decoder, NULL );
+        hb_buffer_t * vid_buf = NULL;
 
         for( j = 0; j < 10240 ; j++ )
         {
@@ -334,59 +412,67 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title )
             {
               if( !hb_dvd_read( data->dvd, buf_ps ) )
               {
-                  goto error;
+                  hb_log( "Warning: Could not read data for preview %d, skipped", i + 1 );
+                  goto skip_preview;
               }
             }
             else if (data->stream)
             {
               if ( !hb_stream_read(data->stream,buf_ps) )
               {
-                goto error;
+                  hb_log( "Warning: Could not read data for preview %d, skipped", i + 1 );
+                  goto skip_preview;
               }
             }
-            hb_demux_ps( buf_ps, list_es );
+            if ( title->demuxer == HB_NULL_DEMUXER )
+            {
+                hb_demux_null( buf_ps, list_es, 0 );
+            }
+            else
+            {
+                hb_demux_ps( buf_ps, list_es, 0 );
+            }
 
             while( ( buf_es = hb_list_item( list_es, 0 ) ) )
             {
                 hb_list_rem( list_es, buf_es );
-                if( buf_es->id == 0xE0 && !hb_list_count( list_raw ) )
+                if( buf_es->id == title->video_id && vid_buf == NULL )
                 {
-                    hb_libmpeg2_decode( mpeg2, buf_es, list_raw );
+                    vid_decoder->work( vid_decoder, &buf_es, &vid_buf );
                 }
-                else if( !i )
-                {
-                    LookForAC3AndDCA( title, buf_es );
-                }
-                hb_buffer_close( &buf_es );
-
-                if( hb_list_count( list_raw ) &&
-                    ( i || AllAC3AndDCAOK( title ) ) )
+                else if( ! AllAudioOK( title ) )
                 {
-                    /* We got a picture */
-                    break;
+                    LookForAudio( title, buf_es );
                 }
+                if ( buf_es )
+                    hb_buffer_close( &buf_es );
             }
 
-            if( hb_list_count( list_raw ) &&
-                ( i || AllAC3AndDCAOK( title ) ) )
-            {
+            if( vid_buf && AllAudioOK( title ) )
                 break;
-            }
         }
 
-        if( !hb_list_count( list_raw ) )
+        if( ! vid_buf )
         {
             hb_log( "scan: could not get a decoded picture" );
-            goto error;
+            continue;
         }
 
         /* Get size and rate infos */
-        title->rate = 27000000;
-        int ar;
-        hb_libmpeg2_info( mpeg2, &title->width, &title->height,
-                          &title->rate_base, &ar );
-       
-        if (title->rate_base == 1126125)
+
+        hb_work_info_t vid_info;
+        vid_decoder->info( vid_decoder, &vid_info );
+        vid_decoder->close( vid_decoder );
+        free( vid_decoder );
+
+        remember_info( info_list, &vid_info );
+
+        title->width = vid_info.width;
+        title->height = vid_info.height;
+        title->rate = vid_info.rate;
+        title->rate_base = vid_info.rate_base;
+
+        if( title->rate_base == 1126125 )
         {
             /* Frame FPS is 23.976 (meaning it's progressive), so
                start keeping track of how many are reporting at
@@ -395,42 +481,47 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title )
             */
             progressive_count++;
 
-            if (progressive_count < 6)
+            if( progressive_count < 6 )
+            {
                 /* Not enough frames are reporting as progressive,
                    which means we should be conservative and use
                    29.97 as the title's FPS for now.
                 */
-                title->rate_base = 900900;           
+                title->rate_base = 900900;
+            }
             else
             {
                 /* A majority of the scan frames are progressive. Make that
                     the title's FPS, and announce it once to the log.
                 */
-                if (progressive_count == 6)
-                    hb_log("Title's mostly progressive NTSC, setting fps to 23.976");
-                title->rate_base = 1126125;               
+                if( progressive_count == 6 )
+                {
+                    hb_log("Title's mostly NTSC Film, setting fps to 23.976");
+                }
+                title->rate_base = 1126125;
             }
         }
-               
-        if( i == 2) // Use the third frame's info, so as to skip opening logos
+        else if( title->rate_base == 900900 && progressive_count >= 6 )
         {
-            // The aspect ratio may have already been set by parsing the VOB/IFO details on a DVD, however
-            // if we're working with program/transport streams that data needs to come from within the stream.
-            if (title->aspect <= 0)
-              title->aspect = ar;
-            title->crop[0] = title->crop[1] = title->height / 2;
-            title->crop[2] = title->crop[3] = title->width / 2;
+            /*
+             * We've already deduced that the frame rate is 23.976, so set it
+             * back again.
+             */
+            title->rate_base = 1126125;
         }
 
-        hb_libmpeg2_close( &mpeg2 );
-
         while( ( buf_es = hb_list_item( list_es, 0 ) ) )
         {
             hb_list_rem( list_es, buf_es );
             hb_buffer_close( &buf_es );
         }
 
-        buf_raw = hb_list_item( list_raw, 0 );
+        /* Check preview for interlacing artifacts */
+        if( hb_detect_comb( vid_buf, title->width, title->height, 10, 30, 9, 10, 30, 9 ) )
+        {
+            hb_log("Interlacing detected in preview frame %i", i+1);
+            interlaced_preview_count++;
+        }
 
         hb_get_tempory_filename( data->h, filename, "%x%d",
                                  (intptr_t)title, i );
@@ -438,7 +529,7 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title )
         file_preview = fopen( filename, "w" );
         if( file_preview )
         {
-            fwrite( buf_raw->data, title->width * title->height * 3 / 2,
+            fwrite( vid_buf->data, title->width * title->height * 3 / 2,
                     1, file_preview );
             fclose( file_preview );
         }
@@ -447,68 +538,121 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title )
             hb_log( "scan: fopen failed (%s)", filename );
         }
 
-#define Y    buf_raw->data
-#define DARK 64
-        
         /* Detect black borders */
-        
-        for( j = 0; j < title->width; j++ )
+
+#define Y    vid_buf->data
+        int top, bottom, left, right;
+        int h4 = title->height / 4, w4 = title->width / 4;
+        for ( top = 2; top < h4; ++top )
         {
-            for( k = 0; k < title->crop[0]; k++ )
-                if( Y[ k * title->width + j ] > DARK )
-                {
-                    title->crop[0] = k;
-                    break;
-                }
-            for( k = 0; k < title->crop[1]; k++ )
-                if( Y[ ( title->height - k - 1 ) *
-                       title->width + j ] > DARK )
-                {
-                    title->crop[1] = k;
-                    break;
-                }
+            if ( ! row_all_dark( title, Y, top ) )
+                break;
         }
-        for( j = 0; j < title->height; j++ )
+        if ( top < 4 )
         {
-            for( k = 0; k < title->crop[2]; k++ ) 
-                if( Y[ j * title->width + k ] > DARK )
-                {
-                    title->crop[2] = k;
-                    break;
-                }
-            for( k = 0; k < title->crop[3]; k++ )
-                if( Y[ j * title->width +
-                        title->width - k - 1 ] > DARK )
-                {
-                    title->crop[3] = k;
-                    break;
-                }
+            // we started at row two to avoid the "line 19" noise that shows
+            // up on row 0 & 1 of some TV shows. Since we stopped before row 4
+            // check if row 0 & 1 are dark or if we shouldn't crop the top at all.
+            if ( row_all_dark( title, Y, 0 ) )
+            {
+                top = row_all_dark( title, Y, 1 )? top : 1;
+            }
+            else
+            {
+                top = 0;
+            }
+        }
+        for ( bottom = 0; bottom < h4; ++bottom )
+        {
+            if ( ! row_all_dark( title, Y, title->height - 1 - bottom ) )
+                break;
+        }
+        for ( left = 0; left < w4; ++left )
+        {
+            if ( ! column_all_dark( title, Y, top, left ) )
+                break;
+        }
+        for ( right = 0; right < w4; ++right )
+        {
+            if ( ! column_all_dark( title, Y, top, title->width - 1 - right ) )
+                break;
         }
 
-        while( ( buf_raw = hb_list_item( list_raw, 0 ) ) )
+        // only record the result if all the crops are less than a quarter of
+        // the frame otherwise we can get fooled by frames with a lot of black
+        // like titles, credits & fade-thru-black transitions.
+        if ( top < h4 && bottom < h4 && left < w4 && right < w4 )
         {
-            hb_list_rem( list_raw, buf_raw );
-            hb_buffer_close( &buf_raw );
+            record_crop( crops, top, bottom, left, right );
         }
+        ++npreviews;
+
+skip_preview:
+        if ( vid_buf )
+            hb_buffer_close( &vid_buf );
     }
 
-    title->crop[0] = EVEN( title->crop[0] );
-    title->crop[1] = EVEN( title->crop[1] );
-    title->crop[2] = EVEN( title->crop[2] );
-    title->crop[3] = EVEN( title->crop[3] );
+    if ( npreviews )
+    {
+        // use the most common frame info for our final title dimensions
+        hb_work_info_t vid_info;
+        most_common_info( info_list, &vid_info );
+
+        title->width = vid_info.width;
+        title->height = vid_info.height;
+        title->pixel_aspect_width = vid_info.pixel_aspect_width;
+        title->pixel_aspect_height = vid_info.pixel_aspect_height;
+
+        // compute the aspect ratio based on the storage dimensions and the
+        // pixel aspect ratio (if supplied) or just storage dimensions if no PAR.
+        title->aspect = ( (double)title->width / (double)title->height + 0.05 ) *
+                        HB_ASPECT_BASE;
+
+        double aspect = (double)title->width / (double)title->height;
+        if( title->pixel_aspect_width && title->pixel_aspect_height )
+        {
+            aspect *= (double)title->pixel_aspect_width /
+                      (double)title->pixel_aspect_height;
+        }
+        title->aspect = ( aspect + 0.05 ) * HB_ASPECT_BASE;
 
-    hb_log( "scan: %dx%d, %.3f fps, autocrop = %d/%d/%d/%d",
-            title->width, title->height, (float) title->rate /
-            (float) title->rate_base, title->crop[0], title->crop[1],
-            title->crop[2], title->crop[3] );
+        if ( crops->n )
+        {
+            sort_crops( crops );
+            // The next line selects median cropping - at least
+            // 50% of the frames will have their borders removed.
+            // Other possible choices are loose cropping (i = 0) where 
+            // no non-black pixels will be cropped from any frame and a
+            // tight cropping (i = crops->n - (crops->n >> 2)) where at
+            // least 75% of the frames will have their borders removed.
+            i = crops->n >> 1;
+            title->crop[0] = EVEN( crops->t[i] );
+            title->crop[1] = EVEN( crops->b[i] );
+            title->crop[2] = EVEN( crops->l[i] );
+            title->crop[3] = EVEN( crops->r[i] );
+        }
+        free( crops );
 
-    ret = 1;
-    goto cleanup;
+        hb_log( "scan: %d previews, %dx%d, %.3f fps, autocrop = %d/%d/%d/%d, "
+                "aspect %s, PAR %d:%d",
+                npreviews, title->width, title->height, (float) title->rate /
+                (float) title->rate_base,
+                title->crop[0], title->crop[1], title->crop[2], title->crop[3],
+                aspect_to_string( title->aspect ), title->pixel_aspect_width,
+                title->pixel_aspect_height );
 
-error:
-    ret = 0;
+        if( interlaced_preview_count >= ( npreviews / 2 ) )
+        {
+            hb_log("Title is likely interlaced or telecined (%i out of %i previews). You should do something about that.",
+                   interlaced_preview_count, npreviews);
+            title->detected_interlacing = 1;
+        }
+        else
+        {
+            title->detected_interlacing = 0;
+        }
+    }
 
-cleanup:
     hb_buffer_close( &buf_ps );
     while( ( buf_es = hb_list_item( list_es, 0 ) ) )
     {
@@ -516,35 +660,36 @@ cleanup:
         hb_buffer_close( &buf_es );
     }
     hb_list_close( &list_es );
-    while( ( buf_raw = hb_list_item( list_raw, 0 ) ) )
-    {
-        hb_list_rem( list_raw, buf_raw );
-        hb_buffer_close( &buf_raw );
-    }
-    hb_list_close( &list_raw );
     if (data->dvd)
       hb_dvd_stop( data->dvd );
 
-    return ret;
+    return npreviews;
 }
 
-static void LookForAC3AndDCA( hb_title_t * title, hb_buffer_t * b ) 
+/*
+ * This routine is called for every frame from a non-video elementary stream.
+ * These are a mix of audio & subtitle streams, some of which we want & some
+ * we're ignoring. This routine checks the frame against all our audio streams
+ * to see if it's one we want and haven't identified yet. If yes, it passes the
+ * frame to a codec-specific id routine which is responsible for filling in
+ * the sample rate, bit rate, channels & other audio parameters.
+ *
+ * Since a sample rate is essential for further audio processing, any audio
+ * stream which isn't successfully id'd by is deleted at the end of the scan.
+ * This is necessary to avoid ambiguities where things that might be audio
+ * aren't (e.g., some European DVD Teletext streams use the same IDs as US ATSC
+ * AC-3 audio).
+ */
+static void LookForAudio( hb_title_t * title, hb_buffer_t * b )
 {
     int i;
-    int flags;
-    int rate;
-    int bitrate;
-    int frame_length;
-    dca_state_t * state;
 
-    /* Figure out if this is a AC3 or DCA buffer for a known track */
     hb_audio_t * audio = NULL;
     for( i = 0; i < hb_list_count( title->list_audio ); i++ )
     {
         audio = hb_list_item( title->list_audio, i );
-        /* check if we have an AC3 or DCA which we recognise */
-        if( ( audio->codec == HB_ACODEC_AC3 || audio->codec == HB_ACODEC_DCA ) &&
-            audio->id    == b->id )
+        /* check if this elementary stream is one we want */
+        if ( audio->id == b->id )
         {
             break;
         }
@@ -553,183 +698,83 @@ static void LookForAC3AndDCA( hb_title_t * title, hb_buffer_t * b )
             audio = NULL;
         }
     }
-    if( !audio )
+    if( !audio || audio->config.in.bitrate != 0 )
     {
+        /* not found or already done */
         return;
     }
 
-    if( audio->bitrate )
+    hb_work_object_t *w = hb_codec_decoder( audio->config.in.codec );
+
+    if ( w == NULL || w->bsinfo == NULL )
     {
-        /* Already done for this track */
-        return;
+        hb_log( "Internal error in scan: unhandled audio type %d for id 0x%x",
+                audio->config.in.codec, audio->id );
+        goto drop_audio;
     }
 
-    for( i = 0; i < b->size - 7; i++ )
+    hb_work_info_t info;
+    w->audio = audio;
+    w->codec_param = audio->config.in.codec_param;
+    int ret = w->bsinfo( w, b, &info );
+    if ( ret < 0 )
     {
+        hb_log( "no info on audio type %d/0x%x for id 0x%x",
+                audio->config.in.codec, audio->config.in.codec_param,
+                audio->id );
+        goto drop_audio;
+    }
+    if ( !info.bitrate )
+    {
+        /* didn't find any info */
+        return;
+    }
+    audio->config.in.samplerate = info.rate;
+    audio->config.in.bitrate = info.bitrate;
+    audio->config.in.channel_layout = info.channel_layout;
+    audio->config.flags.ac3 = info.flags;
 
-        if ( audio->codec == HB_ACODEC_AC3 )
-        {
-
-            /* check for a52 */
-            if( a52_syncinfo( &b->data[i], &flags, &rate, &bitrate ) )
-            {
-                hb_log( "scan: AC3, rate=%dHz, bitrate=%d", rate, bitrate );
-                audio->rate    = rate;
-                audio->bitrate = bitrate;
-                switch( flags & A52_CHANNEL_MASK )
-                {
-                    /* mono sources */
-                    case A52_MONO:
-                    case A52_CHANNEL1:
-                    case A52_CHANNEL2:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_MONO;
-                        break;
-                    /* stereo input */
-                    case A52_CHANNEL:
-                    case A52_STEREO:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_STEREO;
-                        break;
-                    /* dolby (DPL1 aka Dolby Surround = 4.0 matrix-encoded) input */
-                    case A52_DOLBY:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_DOLBY;
-                        break;
-                    /* 3F/2R input */
-                    case A52_3F2R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_3F2R;
-                        break;
-                    /* 3F/1R input */
-                    case A52_3F1R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_3F1R;
-                        break;
-                    /* other inputs */
-                    case A52_3F:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_3F;
-                        break;
-                    case A52_2F1R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_2F1R;
-                        break;
-                    case A52_2F2R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_2F2R;
-                        break;
-                    /* unknown */
-                    default:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_STEREO;
-                }
-                
-                /* add in our own LFE flag if the source has LFE */
-                if (flags & A52_LFE)
-                {
-                    audio->input_channel_layout = audio->input_channel_layout | HB_INPUT_CH_LAYOUT_HAS_LFE;
-                }
-
-                /* store the AC3 flags for future reference
-                This enables us to find out if we had a stereo or Dolby source later on */
-                audio->config.a52.ac3flags = flags;
-
-                /* store the ac3 flags in the public ac3flags property too, so we can access it from the GUI */
-                audio->ac3flags = audio->config.a52.ac3flags;
-
-                /* XXX */
-                if ( (flags & A52_CHANNEL_MASK) == A52_DOLBY ) {
-                    sprintf( audio->lang + strlen( audio->lang ),
-                         " (Dolby Surround)" );
-                } else {
-                    sprintf( audio->lang + strlen( audio->lang ),
-                         " (%d.%d ch)",
-                        HB_INPUT_CH_LAYOUT_GET_DISCRETE_FRONT_COUNT(audio->input_channel_layout) +
-                        HB_INPUT_CH_LAYOUT_GET_DISCRETE_REAR_COUNT(audio->input_channel_layout),
-                        HB_INPUT_CH_LAYOUT_GET_DISCRETE_LFE_COUNT(audio->input_channel_layout));
-                }
-
-                break;
-            
-            }
-
-        }
-        else if ( audio->codec == HB_ACODEC_DCA )
-        {
-
-            hb_log( "scan: checking for DCA syncinfo" );
-
-            /* check for dca */
-            state = dca_init( 0 );
-            if( dca_syncinfo( state, &b->data[i], &flags, &rate, &bitrate, &frame_length ) )
-            {
-                hb_log( "scan: DCA, rate=%dHz, bitrate=%d", rate, bitrate );
-                audio->rate    = rate;
-                audio->bitrate = bitrate;
-                switch( flags & DCA_CHANNEL_MASK )
-                {
-                    /* mono sources */
-                    case DCA_MONO:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_MONO;
-                        break;
-                    /* stereo input */
-                    case DCA_CHANNEL:
-                    case DCA_STEREO:
-                    case DCA_STEREO_SUMDIFF:
-                    case DCA_STEREO_TOTAL:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_STEREO;
-                        break;
-                    /* 3F/2R input */
-                    case DCA_3F2R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_3F2R;
-                        break;
-                    /* 3F/1R input */
-                    case DCA_3F1R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_3F1R;
-                        break;
-                    /* other inputs */
-                    case DCA_3F:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_3F;
-                        break;
-                    case DCA_2F1R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_2F1R;
-                        break;
-                    case DCA_2F2R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_2F2R;
-                        break;
-                    case DCA_4F2R:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_4F2R;
-                        break;
-                    /* unknown */
-                    default:
-                        audio->input_channel_layout = HB_INPUT_CH_LAYOUT_STEREO;
-                }
-
-                /* add in our own LFE flag if the source has LFE */
-                if (flags & DCA_LFE)
-                {
-                    audio->input_channel_layout = audio->input_channel_layout | HB_INPUT_CH_LAYOUT_HAS_LFE;
-                }
-
-                /* store the DCA flags for future reference
-                This enables us to find out if we had a stereo or Dolby source later on */
-                audio->config.dca.dcaflags = flags;
-
-                /* store the dca flags in the public dcaflags property too, so we can access it from the GUI */
-                audio->dcaflags = audio->config.dca.dcaflags;
-
-                /* XXX */
-                if ( (flags & DCA_CHANNEL_MASK) == DCA_DOLBY ) {
-                    sprintf( audio->lang + strlen( audio->lang ),
-                         " (Dolby Surround)" );
-                } else {
-                    sprintf( audio->lang + strlen( audio->lang ),
-                         " (%d.%d ch)",
-                        HB_INPUT_CH_LAYOUT_GET_DISCRETE_FRONT_COUNT(audio->input_channel_layout) +
-                        HB_INPUT_CH_LAYOUT_GET_DISCRETE_REAR_COUNT(audio->input_channel_layout),
-                        HB_INPUT_CH_LAYOUT_GET_DISCRETE_LFE_COUNT(audio->input_channel_layout));
-                }
-
-                break;
-            }
-        }
+    // update the audio description string based on the info we found
+    if ( audio->config.flags.ac3 & AUDIO_F_DOLBY )
+    {
+        strcat( audio->config.lang.description, " (Dolby Surround)" );
+    }
+    else
+    {
+        int layout = audio->config.in.channel_layout;
+        char *desc = audio->config.lang.description +
+                        strlen( audio->config.lang.description );
+        sprintf( desc, " (%d.%d ch)",
+                 HB_INPUT_CH_LAYOUT_GET_DISCRETE_FRONT_COUNT(layout) +
+                     HB_INPUT_CH_LAYOUT_GET_DISCRETE_REAR_COUNT(layout),
+                 HB_INPUT_CH_LAYOUT_GET_DISCRETE_LFE_COUNT(layout) );
     }
 
+    hb_log( "scan: audio 0x%x: %s, rate=%dHz, bitrate=%d %s", audio->id,
+            info.name, audio->config.in.samplerate, audio->config.in.bitrate,
+            audio->config.lang.description );
+    free( w );
+    return;
+
+    // We get here if there's no hope of finding info on an audio bitstream,
+    // either because we don't have a decoder (or a decoder with a bitstream
+    // info proc) or because the decoder's info proc said that the stream
+    // wasn't something it could handle. Delete the item from the title's
+    // audio list so we won't keep reading packets while trying to get its
+    // bitstream info.
+ drop_audio:
+    if ( w )
+        free( w );
+
+    hb_list_rem( title->list_audio, audio );
 }
 
-static int  AllAC3AndDCAOK( hb_title_t * title )
+/*
+ * This routine checks to see if we've ID'd all the audio streams associated
+ * with a title. It returns 0 if there are more to ID & 1 if all are done.
+ */
+static int  AllAudioOK( hb_title_t * title )
 {
     int i;
     hb_audio_t * audio;
@@ -737,12 +782,10 @@ static int  AllAC3AndDCAOK( hb_title_t * title )
     for( i = 0; i < hb_list_count( title->list_audio ); i++ )
     {
         audio = hb_list_item( title->list_audio, i );
-        if( ( audio->codec == HB_ACODEC_AC3 || audio->codec == HB_ACODEC_DCA ) &&
-            !audio->bitrate )
+        if( audio->config.in.bitrate == 0 )
         {
             return 0;
         }
     }
-
     return 1;
 }