git.sesse.net Git - vlc/blob - modules/codec/libmpeg2.c

   1 /*****************************************************************************
   2  * libmpeg2.c: mpeg2 video decoder module making use of libmpeg2.
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 VideoLAN
   5  * $Id: libmpeg2.c,v 1.6 2003/03/30 18:14:36 gbazin Exp $
   6  *
   7  * Authors: Gildas Bazin <gbazin@netcourrier.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include <vlc/vlc.h>
  28 #include <vlc/vout.h>
  29 #include <vlc/input.h>
  30 #include <vlc/decoder.h>
  31
  32 #include <stdlib.h>                                      /* malloc(), free() */
  33 #include <string.h>                                    /* memcpy(), memset() */
  34
  35 #include <mpeg2dec/mpeg2.h>
  36
  37 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
  38 #define AR_SQUARE_PICTURE       1                           /* square pixels */
  39 #define AR_3_4_PICTURE          2                        /* 3:4 picture (TV) */
  40 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
  41 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
  42
  43 /*****************************************************************************
  44  * dec_thread_t : libmpeg2 decoder thread descriptor
  45  *****************************************************************************/
  46 typedef struct dec_thread_t
  47 {
  48     /*
  49      * libmpeg2 properties
  50      */
  51     mpeg2dec_t          *p_mpeg2dec;
  52     const mpeg2_info_t  *p_info;
  53
  54     /*
  55      * Input properties
  56      */
  57     decoder_fifo_t   *p_fifo;                  /* stores the PES stream data */
  58     pes_packet_t     *p_pes;                  /* current PES we are decoding */
  59     mtime_t          i_pts;
  60     mtime_t          i_previous_pts;
  61     mtime_t          i_current_pts;
  62     mtime_t          i_period_remainder;
  63
  64     /*
  65      * Output properties
  66      */
  67     vout_thread_t *p_vout;
  68
  69 } dec_thread_t;
  70
  71 /*****************************************************************************
  72  * Local prototypes
  73  *****************************************************************************/
  74 static int  OpenDecoder  ( vlc_object_t * );
  75 static int  RunDecoder   ( decoder_fifo_t * );
  76 static void CloseDecoder ( dec_thread_t * );
  77
  78 /*****************************************************************************
  79  * Module descriptor
  80  *****************************************************************************/
  81 vlc_module_begin();
  82     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
  83     set_capability( "decoder", 40 );
  84     set_callbacks( OpenDecoder, NULL );
  85     add_shortcut( "libmpeg2" );
  86 vlc_module_end();
  87
  88 /*****************************************************************************
  89  * OpenDecoder: probe the decoder and return score
  90  *****************************************************************************/
  91 static int OpenDecoder( vlc_object_t *p_this )
  92 {
  93     decoder_fifo_t *p_fifo = (decoder_fifo_t*) p_this;
  94
  95     if( p_fifo->i_fourcc != VLC_FOURCC('m','p','g','v') )
  96     {
  97         return VLC_EGENERIC;
  98     }
  99
 100     p_fifo->pf_run = RunDecoder;
 101     return VLC_SUCCESS;
 102 }
 103 /*****************************************************************************
 104  * RunDecoder: the libmpeg2 decoder
 105  *****************************************************************************/
 106 static int RunDecoder( decoder_fifo_t *p_fifo )
 107 {
 108     dec_thread_t    *p_dec;
 109     data_packet_t   *p_data = NULL;
 110     mpeg2_state_t   state;
 111     picture_t       *p_pic;
 112     int             i_aspect, i_chroma;
 113
 114     /* Allocate the memory needed to store the thread's structure */
 115     if( (p_dec = (dec_thread_t *)malloc (sizeof(dec_thread_t)) )
 116         == NULL)
 117     {
 118         msg_Err( p_fifo, "out of memory" );
 119         goto error;
 120     }
 121
 122     /* Initialize the thread properties */
 123     memset( p_dec, 0, sizeof(dec_thread_t) );
 124     p_dec->p_fifo     = p_fifo;
 125     p_dec->p_pes      = NULL;
 126     p_dec->p_vout     = NULL;
 127     p_dec->p_mpeg2dec = NULL;
 128     p_dec->p_info     = NULL;
 129     p_dec->i_pts      = mdate() + DEFAULT_PTS_DELAY;
 130     p_dec->i_current_pts  = 0;
 131     p_dec->i_previous_pts = 0;
 132     p_dec->i_period_remainder = 0;
 133
 134     /* Initialize decoder */
 135     p_dec->p_mpeg2dec = mpeg2_init();
 136     if( p_dec->p_mpeg2dec == NULL)
 137         goto error;
 138
 139     p_dec->p_info = mpeg2_info( p_dec->p_mpeg2dec );
 140
 141     /* libmpeg2 decoder thread's main loop */
 142     while( (!p_dec->p_fifo->b_die) && (!p_dec->p_fifo->b_error) )
 143     {
 144         state = mpeg2_parse( p_dec->p_mpeg2dec );
 145
 146         switch( state )
 147         {
 148         case STATE_BUFFER:
 149             /* Feed libmpeg2 a data packet at a time */
 150             if( p_data == NULL )
 151             {
 152                 /* Get the next PES */
 153                 if( p_dec->p_pes )
 154                     input_DeletePES( p_dec->p_fifo->p_packets_mgt,
 155                                      p_dec->p_pes );
 156
 157                 input_ExtractPES( p_dec->p_fifo, &p_dec->p_pes );
 158                 if( !p_dec->p_pes )
 159                 {
 160                     p_dec->p_fifo->b_error = 1;
 161                     break;
 162                 }
 163
 164                 if( p_dec->p_pes->i_pts )
 165                 {
 166                     mpeg2_pts( p_dec->p_mpeg2dec,
 167                                (uint32_t)p_dec->p_pes->i_pts );
 168                     p_dec->i_previous_pts = p_dec->i_current_pts;
 169                     p_dec->i_current_pts = p_dec->p_pes->i_pts;
 170                 }
 171                 p_data = p_dec->p_pes->p_first;
 172             }
 173
 174             if( p_data != NULL )
 175             {
 176                 mpeg2_buffer( p_dec->p_mpeg2dec,
 177                               p_data->p_payload_start,
 178                               p_data->p_payload_end );
 179
 180                 p_data = p_data->p_next;
 181             }
 182             break;
 183
 184         case STATE_SEQUENCE:
 185             /* Initialize video output */
 186
 187             /* Check whether the input gives a particular aspect ratio */
 188             if( p_dec->p_fifo->p_demux_data
 189                 && ( *(int*)(p_dec->p_fifo->p_demux_data) & 0x7 ) )
 190             {
 191                 i_aspect = *(int*)(p_dec->p_fifo->p_demux_data);
 192                 switch( i_aspect )
 193                 {
 194                 case AR_3_4_PICTURE:
 195                     i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 196                     break;
 197                 case AR_16_9_PICTURE:
 198                     i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 199                     break;
 200                 case AR_221_1_PICTURE:
 201                     i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 202                     break;
 203                 case AR_SQUARE_PICTURE:
 204                 default:
 205                     i_aspect = VOUT_ASPECT_FACTOR *
 206                                    p_dec->p_info->sequence->width /
 207                                    p_dec->p_info->sequence->height;
 208                     break;
 209                 }
 210             }
 211             else
 212             {
 213                 /* Use the value provided in the MPEG sequence header */
 214                 i_aspect = ((uint64_t)p_dec->p_info->sequence->width) *
 215                     p_dec->p_info->sequence->pixel_width * VOUT_ASPECT_FACTOR /
 216                     p_dec->p_info->sequence->height /
 217                     p_dec->p_info->sequence->pixel_height;
 218             }
 219
 220             i_chroma = VLC_FOURCC('Y','V','1','2');
 221
 222             p_dec->p_vout = vout_Request( p_dec->p_fifo, p_dec->p_vout,
 223                                           p_dec->p_info->sequence->width,
 224                                           p_dec->p_info->sequence->height,
 225                                           i_chroma, i_aspect );
 226             break;
 227
 228         case STATE_PICTURE:
 229         {
 230             uint8_t *buf[3];
 231
 232             /* Get a new picture */
 233             while( !(p_pic = vout_CreatePicture( p_dec->p_vout, 0, 0, 0 ) ) )
 234             {
 235                 if( p_dec->p_fifo->b_die || p_dec->p_fifo->b_error )
 236                     break;
 237
 238                 msleep( VOUT_OUTMEM_SLEEP );
 239             }
 240             if( p_pic == NULL )
 241                 break;
 242
 243             buf[0] = p_pic->p[0].p_pixels;
 244             buf[1] = p_pic->p[1].p_pixels;
 245             buf[2] = p_pic->p[2].p_pixels;
 246             mpeg2_set_buf( p_dec->p_mpeg2dec, buf, p_pic );
 247
 248             /* Store the date for the picture */
 249             if( p_dec->p_info->current_picture->flags & PIC_FLAG_PTS )
 250             {
 251                 p_pic->date = ( p_dec->p_info->current_picture->pts ==
 252                                 (uint32_t)p_dec->i_current_pts ) ?
 253                               p_dec->i_current_pts : p_dec->i_previous_pts;
 254             }
 255         }
 256         break;
 257
 258         case STATE_END:
 259         case STATE_SLICE:
 260             if( p_dec->p_info->display_fbuf
 261                 && p_dec->p_info->display_fbuf->id )
 262             {
 263                 p_pic = (picture_t *)p_dec->p_info->display_fbuf->id;
 264
 265                 /* Date the new picture */
 266                 if( p_dec->p_info->display_picture->flags & PIC_FLAG_PTS )
 267                 {
 268                     p_dec->i_pts = p_pic->date;
 269                     p_dec->i_period_remainder = 0;
 270                 }
 271                 else
 272                 {
 273                     p_dec->i_pts += ( (p_dec->p_info->sequence->frame_period +
 274                                        p_dec->i_period_remainder) / 27 );
 275                     p_dec->i_period_remainder =
 276                         p_dec->p_info->sequence->frame_period +
 277                         p_dec->i_period_remainder -
 278                         ( p_dec->p_info->sequence->frame_period +
 279                           p_dec->i_period_remainder ) / 27 * 27;
 280                 }
 281                 vout_DatePicture( p_dec->p_vout, p_pic, p_dec->i_pts );
 282
 283                 vout_DisplayPicture( p_dec->p_vout, p_pic );
 284
 285                 /* Handle pulldown by adding some delay to the pts of the next
 286                  * picture. */
 287                 if( p_dec->p_info->display_picture->nb_fields > 2 )
 288                 {
 289                     int i_repeat_fields =
 290                         p_dec->p_info->display_picture->nb_fields - 2;
 291
 292                     p_dec->i_pts += ( (p_dec->p_info->sequence->frame_period +
 293                                        p_dec->i_period_remainder)
 294                                       / 27 / 2 * i_repeat_fields );
 295                     p_dec->i_period_remainder =
 296                         p_dec->p_info->sequence->frame_period +
 297                         p_dec->i_period_remainder -
 298                         ( p_dec->p_info->sequence->frame_period +
 299                           p_dec->i_period_remainder ) / 27 / 2 * 27 * 2;
 300                 }
 301             }
 302             break;
 303
 304         default:
 305             break;
 306         }
 307     }
 308
 309     /* If b_error is set, the libmpeg2 decoder thread enters the error loop */
 310     if( p_dec->p_fifo->b_error )
 311     {
 312         DecoderError( p_dec->p_fifo );
 313     }
 314
 315     /* End of the libmpeg2 decoder thread */
 316     CloseDecoder( p_dec );
 317
 318     return 0;
 319
 320  error:
 321     DecoderError( p_fifo );
 322     if( p_dec )
 323     {
 324         if( p_dec->p_fifo )
 325             p_dec->p_fifo->b_error = 1;
 326
 327         /* End of the libmpeg2 decoder thread */
 328         CloseDecoder( p_dec );
 329     }
 330
 331     return -1;
 332 }
 333
 334 /*****************************************************************************
 335  * CloseDecoder: libmpeg2 decoder destruction
 336  *****************************************************************************/
 337 static void CloseDecoder( dec_thread_t * p_dec )
 338 {
 339     if( p_dec )
 340     {
 341         if( p_dec->p_pes )
 342             input_DeletePES( p_dec->p_fifo->p_packets_mgt, p_dec->p_pes );
 343
 344         vout_Request( p_dec->p_fifo, p_dec->p_vout, 0, 0, 0, 0 );
 345
 346         if( p_dec->p_mpeg2dec ) mpeg2_close( p_dec->p_mpeg2dec );
 347
 348         free( p_dec );
 349     }
 350 }