libhb/decmpeg2.c

   1 /* $Id: decmpeg2.c,v 1.12 2005/03/03 16:30:42 titer Exp $
   2
   3    This file is part of the HandBrake source code.
   4    Homepage: <http://handbrake.m0k.org/>.
   5    It may be used under the terms of the GNU General Public License. */
   6
   7 #include "hb.h"
   8
   9 #include "mpeg2dec/mpeg2.h"
  10
  11 /**********************************************************************
  12  * hb_libmpeg2_t
  13  **********************************************************************
  14  * A convenient libmpeg wrapper, used both here and in scan.c
  15  *********************************************************************/
  16 struct hb_libmpeg2_s
  17 {
  18     mpeg2dec_t         * libmpeg2;
  19     const mpeg2_info_t * info;
  20     int                  width;
  21     int                  height;
  22     int                  rate;
  23     int                  aspect_ratio;
  24     int                  got_iframe;
  25     int                  look_for_break;
  26     int64_t              last_pts;
  27 };
  28
  29 /**********************************************************************
  30  * hb_libmpeg2_init
  31  **********************************************************************
  32  *
  33  *********************************************************************/
  34 hb_libmpeg2_t * hb_libmpeg2_init()
  35 {
  36     hb_libmpeg2_t * m = calloc( sizeof( hb_libmpeg2_t ), 1 );
  37
  38     m->libmpeg2 = mpeg2_init();
  39     m->info     = mpeg2_info( m->libmpeg2 );
  40     m->last_pts = -1;
  41     m->look_for_break = 0;
  42
  43     return m;
  44 }
  45
  46 /**********************************************************************
  47  * hb_libmpeg2_decode
  48  **********************************************************************
  49  *
  50  *********************************************************************/
  51 int hb_libmpeg2_decode( hb_libmpeg2_t * m, hb_buffer_t * buf_es,
  52                         hb_list_t * list_raw )
  53 {
  54     mpeg2_state_t   state;
  55     hb_buffer_t   * buf;
  56     uint8_t       * data;
  57     int             chap_break = 0;
  58
  59     /* Feed libmpeg2 */
  60     if( buf_es->start > -1 )
  61     {
  62         mpeg2_tag_picture( m->libmpeg2, buf_es->start >> 32,
  63                            buf_es->start & 0xFFFFFFFF );
  64     }
  65     mpeg2_buffer( m->libmpeg2, buf_es->data,
  66                   buf_es->data + buf_es->size );
  67
  68     for( ;; )
  69     {
  70         state = mpeg2_parse( m->libmpeg2 );
  71         if( state == STATE_BUFFER )
  72         {
  73             /* Require some more data */
  74             break;
  75         }
  76         else if( state == STATE_SEQUENCE )
  77         {
  78             if( !( m->width && m->height && m->rate ) )
  79             {
  80                 m->width  = m->info->sequence->width;
  81                 m->height = m->info->sequence->height;
  82                 m->rate   = m->info->sequence->frame_period;
  83
  84                 if( m->rate == 900900 )
  85                 {
  86                     /* 29.97 fps. 3:2 pulldown might, or might not be
  87                        used. I can't find a way to know, so we always
  88                        output 23.976 */
  89                     m->rate = 1126125;
  90                 }
  91             }
  92             if ( m->aspect_ratio <= 0 )
  93             {
  94               // We can parse out the aspect ratio from the Sequence Start Header data in buf_es->data
  95
  96               // Make sure we have the correct data in the buffer
  97               if ((buf_es->data[0] == 0x00) && (buf_es->data[1] == 0x00) && (buf_es->data[2] == 0x01) && (buf_es->data[3] == 0xb3))
  98               {
  99                 unsigned char ar_fr = buf_es->data[7];    // Top 4 bits == aspect ratio flag  - bottom 4 bits == rate flags
 100                 switch ((ar_fr & 0xf0) >> 4)
 101                 {
 102                   case 2:
 103                     m->aspect_ratio = HB_ASPECT_BASE * 4 / 3;   // 4:3
 104                     break;
 105                   case 3:
 106                     m->aspect_ratio = HB_ASPECT_BASE * 16 / 9;  // 16:9
 107                     break;
 108                   default:
 109                     hb_log("hb_libmpeg2_decode - STATE_SEQUENCE unexpected aspect ratio/frame rate 0x%x\n", ar_fr);
 110                     break;
 111                 }
 112               }
 113             }
 114         }
 115         else if( state == STATE_GOP && m->look_for_break == 2)
 116         {
 117             printf("MPEG2: Group of pictures found, searching for I-Frame\n");
 118             m->look_for_break = 1;
 119         }
 120         else if( ( state == STATE_SLICE || state == STATE_END ) &&
 121                  m->info->display_fbuf )
 122         {
 123             if( ( m->info->display_picture->flags &
 124                   PIC_MASK_CODING_TYPE ) == PIC_FLAG_CODING_TYPE_I )
 125             {
 126                 m->got_iframe = 1;
 127
 128                 // If we are looking for a break, insert the chapter break on an I-Frame
 129                 if( m->look_for_break == 1 )
 130                 {
 131                     printf("MPEG2: I-Frame Found\n");
 132                     m->look_for_break = 0;
 133                     chap_break = 1;
 134                 }
 135             }
 136
 137             if( m->got_iframe )
 138             {
 139                 buf  = hb_buffer_init( m->width * m->height * 3 / 2 );
 140                 data = buf->data;
 141
 142                 // Was a good break point found?
 143                 if( chap_break )
 144                 {
 145                     printf("MPEG2: Chapter Break Inserted\n");
 146                     chap_break = 0;
 147                     buf->new_chap = 1;
 148                 }
 149
 150                 memcpy( data, m->info->display_fbuf->buf[0],
 151                         m->width * m->height );
 152                 data += m->width * m->height;
 153                 memcpy( data, m->info->display_fbuf->buf[1],
 154                         m->width * m->height / 4 );
 155                 data += m->width * m->height / 4;
 156                 memcpy( data, m->info->display_fbuf->buf[2],
 157                         m->width * m->height / 4 );
 158
 159                 if( m->info->display_picture->flags & PIC_FLAG_TAGS )
 160                 {
 161                     buf->start =
 162                         ( (uint64_t) m->info->display_picture->tag << 32 ) |
 163                         ( (uint64_t) m->info->display_picture->tag2 );
 164                 }
 165                 else if( m->last_pts > -1 )
 166                 {
 167                     /* For some reason nb_fields is sometimes 1 while it
 168                        should be 2 */
 169                     buf->start = m->last_pts +
 170                         MAX( 2, m->info->display_picture->nb_fields ) *
 171                         m->info->sequence->frame_period / 600;
 172                 }
 173                 else
 174                 {
 175                     buf->start = -1;
 176                 }
 177                 m->last_pts = buf->start;
 178
 179                 hb_list_add( list_raw, buf );
 180             }
 181         }
 182         else if( state == STATE_INVALID )
 183         {
 184             mpeg2_reset( m->libmpeg2, 0 );
 185         }
 186     }
 187     return 1;
 188 }
 189
 190 /**********************************************************************
 191  * hb_libmpeg2_info
 192  **********************************************************************
 193  *
 194  *********************************************************************/
 195 void hb_libmpeg2_info( hb_libmpeg2_t * m, int * width, int * height,
 196                         int * rate, int *aspect_ratio )
 197 {
 198     *width  = m->width;
 199     *height = m->height;
 200     *rate   = m->rate;
 201     *aspect_ratio = m->aspect_ratio;
 202 }
 203
 204 /**********************************************************************
 205  * hb_libmpeg2_close
 206  **********************************************************************
 207  *
 208  *********************************************************************/
 209 void hb_libmpeg2_close( hb_libmpeg2_t ** _m )
 210 {
 211     hb_libmpeg2_t * m = *_m;
 212
 213     mpeg2_close( m->libmpeg2 );
 214
 215     free( m );
 216     *_m = NULL;
 217 }
 218
 219 /**********************************************************************
 220  * The decmpeg2 work object
 221  **********************************************************************
 222  *
 223  *********************************************************************/
 224 struct hb_work_private_s
 225 {
 226     hb_libmpeg2_t * libmpeg2;
 227     hb_list_t     * list;
 228 };
 229
 230 /**********************************************************************
 231  * hb_work_decmpeg2_init
 232  **********************************************************************
 233  *
 234  *********************************************************************/
 235 int decmpeg2Init( hb_work_object_t * w, hb_job_t * job )
 236 {
 237     hb_work_private_t * pv;
 238
 239     pv              = calloc( 1, sizeof( hb_work_private_t ) );
 240     w->private_data = pv;
 241
 242     pv->libmpeg2 = hb_libmpeg2_init();
 243     pv->list     = hb_list_init();
 244
 245     return 0;
 246 }
 247
 248 /**********************************************************************
 249  * Work
 250  **********************************************************************
 251  *
 252  *********************************************************************/
 253 int decmpeg2Work( hb_work_object_t * w, hb_buffer_t ** buf_in,
 254                    hb_buffer_t ** buf_out )
 255 {
 256     hb_work_private_t * pv = w->private_data;
 257     hb_buffer_t * buf, * last = NULL;
 258
 259     // The reader found a chapter break, consume it completely, and remove it from the
 260     // stream. We need to shift it.
 261     if( (*buf_in)->new_chap )
 262     {
 263         printf("MPEG2: Chapter Break Cell Found, searching for GOP\n");
 264         pv->libmpeg2->look_for_break = 2;
 265         (*buf_in)->new_chap = 0;
 266     }
 267
 268     hb_libmpeg2_decode( pv->libmpeg2, *buf_in, pv->list );
 269
 270     *buf_out = NULL;
 271     while( ( buf = hb_list_item( pv->list, 0 ) ) )
 272     {
 273         hb_list_rem( pv->list, buf );
 274         if( last )
 275         {
 276             last->next = buf;
 277             last       = buf;
 278         }
 279         else
 280         {
 281             *buf_out = buf;
 282             last     = buf;
 283         }
 284     }
 285
 286     return HB_WORK_OK;
 287 }
 288
 289 /**********************************************************************
 290  * Close
 291  **********************************************************************
 292  *
 293  *********************************************************************/
 294 void decmpeg2Close( hb_work_object_t * w )
 295 {
 296     hb_work_private_t * pv = w->private_data;
 297     hb_list_close( &pv->list );
 298     hb_libmpeg2_close( &pv->libmpeg2 );
 299     free( pv );
 300 }
 301
 302 hb_work_object_t hb_decmpeg2 =
 303 {
 304     WORK_DECMPEG2,
 305     "MPEG-2 decoder (libmpeg2)",
 306     decmpeg2Init,
 307     decmpeg2Work,
 308     decmpeg2Close
 309 };
 310