* Implementation of a frame-dropping algorithm for the libmpeg2 plug-in
[vlc.git] / 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 1.9 2003/04/14 22:22:32 massiot 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 #include "vout_synchro.h"
38
39 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
40 #define AR_SQUARE_PICTURE       1                           /* square pixels */
41 #define AR_3_4_PICTURE          2                        /* 3:4 picture (TV) */
42 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
43 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
44
45 /*****************************************************************************
46  * dec_thread_t : libmpeg2 decoder thread descriptor
47  *****************************************************************************/
48 typedef struct dec_thread_t
49 {
50     /*
51      * libmpeg2 properties
52      */
53     mpeg2dec_t          *p_mpeg2dec;
54     const mpeg2_info_t  *p_info;
55
56     /*
57      * Input properties
58      */
59     decoder_fifo_t   *p_fifo;                  /* stores the PES stream data */
60     pes_packet_t     *p_pes;                  /* current PES we are decoding */
61     mtime_t          i_pts;
62     mtime_t          i_previous_pts;
63     mtime_t          i_current_pts;
64     mtime_t          i_period_remainder;
65     int              i_current_rate;
66     picture_t *      p_picture_to_destroy;
67
68     /*
69      * Output properties
70      */
71     vout_thread_t *p_vout;
72     vout_synchro_t *p_synchro;
73
74 } dec_thread_t;
75
76 /*****************************************************************************
77  * Local prototypes
78  *****************************************************************************/
79 static int  OpenDecoder  ( vlc_object_t * );
80 static int  RunDecoder   ( decoder_fifo_t * );
81 static void CloseDecoder ( dec_thread_t * );
82
83 static picture_t *GetNewPicture( dec_thread_t *, uint8_t ** );
84
85 /*****************************************************************************
86  * Module descriptor
87  *****************************************************************************/
88 vlc_module_begin();
89     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
90     set_capability( "decoder", 40 );
91     set_callbacks( OpenDecoder, NULL );
92     add_shortcut( "libmpeg2" );
93 vlc_module_end();
94
95 /*****************************************************************************
96  * OpenDecoder: probe the decoder and return score
97  *****************************************************************************/
98 static int OpenDecoder( vlc_object_t *p_this )
99 {
100     decoder_fifo_t *p_fifo = (decoder_fifo_t*) p_this;
101
102     if( p_fifo->i_fourcc != VLC_FOURCC('m','p','g','v') )
103     {
104         return VLC_EGENERIC;
105     }
106
107     p_fifo->pf_run = RunDecoder;
108     return VLC_SUCCESS;
109 }
110
111 /*****************************************************************************
112  * RunDecoder: the libmpeg2 decoder
113  *****************************************************************************/
114 static int RunDecoder( decoder_fifo_t *p_fifo )
115 {
116     dec_thread_t    *p_dec;
117     data_packet_t   *p_data = NULL;
118     mpeg2_state_t   state;
119     picture_t       *p_pic;
120     int             i_aspect, i_chroma;
121
122     /* Allocate the memory needed to store the thread's structure */
123     if( (p_dec = (dec_thread_t *)malloc (sizeof(dec_thread_t)) )
124         == NULL)
125     {
126         msg_Err( p_fifo, "out of memory" );
127         goto error;
128     }
129
130     /* Initialize the thread properties */
131     memset( p_dec, 0, sizeof(dec_thread_t) );
132     p_dec->p_fifo     = p_fifo;
133     p_dec->p_pes      = NULL;
134     p_dec->p_vout     = NULL;
135     p_dec->p_mpeg2dec = NULL;
136     p_dec->p_info     = NULL;
137     p_dec->i_pts      = mdate() + DEFAULT_PTS_DELAY;
138     p_dec->i_current_pts  = 0;
139     p_dec->i_previous_pts = 0;
140     p_dec->i_period_remainder = 0;
141     p_dec->p_picture_to_destroy = NULL;
142
143     /* Initialize decoder */
144     p_dec->p_mpeg2dec = mpeg2_init();
145     if( p_dec->p_mpeg2dec == NULL)
146         goto error;
147
148     p_dec->p_info = mpeg2_info( p_dec->p_mpeg2dec );
149
150     /* libmpeg2 decoder thread's main loop */
151     while( (!p_dec->p_fifo->b_die) && (!p_dec->p_fifo->b_error) )
152     {
153         state = mpeg2_parse( p_dec->p_mpeg2dec );
154
155         switch( state )
156         {
157         case STATE_BUFFER:
158             /* Feed libmpeg2 a data packet at a time */
159             if( p_data == NULL )
160             {
161                 /* Get the next PES */
162                 if( p_dec->p_pes )
163                     input_DeletePES( p_dec->p_fifo->p_packets_mgt,
164                                      p_dec->p_pes );
165
166                 input_ExtractPES( p_dec->p_fifo, &p_dec->p_pes );
167                 if( !p_dec->p_pes )
168                 {
169                     p_dec->p_fifo->b_error = 1;
170                     break;
171                 }
172
173                 if( p_dec->p_pes->b_discontinuity )
174                 {
175                     vout_SynchroReset( p_dec->p_synchro );
176                     if ( p_dec->p_info->current_fbuf != NULL )
177                         p_dec->p_picture_to_destroy
178                             = p_dec->p_info->current_fbuf->id;
179                 }
180
181                 if( p_dec->p_pes->i_pts )
182                 {
183                     mpeg2_pts( p_dec->p_mpeg2dec,
184                                (uint32_t)p_dec->p_pes->i_pts );
185                     p_dec->i_previous_pts = p_dec->i_current_pts;
186                     p_dec->i_current_pts = p_dec->p_pes->i_pts;
187                 }
188
189                 p_dec->i_current_rate = p_dec->p_pes->i_rate;
190                 p_data = p_dec->p_pes->p_first;
191             }
192
193             if( p_data != NULL )
194             {
195                 mpeg2_buffer( p_dec->p_mpeg2dec,
196                               p_data->p_payload_start,
197                               p_data->p_payload_end );
198
199                 p_data = p_data->p_next;
200             }
201             break;
202
203         case STATE_SEQUENCE:
204         {
205             /* Initialize video output */
206             uint8_t *buf[3];
207             buf[0] = buf[1] = buf[2] = NULL;
208
209             /* Check whether the input gives a particular aspect ratio */
210             if( p_dec->p_fifo->p_demux_data
211                 && ( *(int*)(p_dec->p_fifo->p_demux_data) & 0x7 ) )
212             {
213                 i_aspect = *(int*)(p_dec->p_fifo->p_demux_data);
214                 switch( i_aspect )
215                 {
216                 case AR_3_4_PICTURE:
217                     i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
218                     break;
219                 case AR_16_9_PICTURE:
220                     i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
221                     break;
222                 case AR_221_1_PICTURE:
223                     i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
224                     break;
225                 case AR_SQUARE_PICTURE:
226                 default:
227                     i_aspect = VOUT_ASPECT_FACTOR *
228                                    p_dec->p_info->sequence->width /
229                                    p_dec->p_info->sequence->height;
230                     break;
231                 }
232             }
233             else
234             {
235                 /* Use the value provided in the MPEG sequence header */
236                 i_aspect = ((uint64_t)p_dec->p_info->sequence->width) *
237                     p_dec->p_info->sequence->pixel_width * VOUT_ASPECT_FACTOR /
238                     p_dec->p_info->sequence->height /
239                     p_dec->p_info->sequence->pixel_height;
240             }
241
242             i_chroma = VLC_FOURCC('Y','V','1','2');
243
244             p_dec->p_vout = vout_Request( p_dec->p_fifo, p_dec->p_vout,
245                                           p_dec->p_info->sequence->width,
246                                           p_dec->p_info->sequence->height,
247                                           i_chroma, i_aspect );
248
249             mpeg2_custom_fbuf( p_dec->p_mpeg2dec, 1 );
250
251             /* Set the first 2 reference frames */
252             mpeg2_set_buf( p_dec->p_mpeg2dec, buf, NULL );
253             mpeg2_set_buf( p_dec->p_mpeg2dec, buf, NULL );
254
255             p_dec->p_synchro = vout_SynchroInit( p_dec->p_fifo, p_dec->p_vout,
256                 1000000 * 27 / p_dec->p_info->sequence->frame_period * 1001 );
257         }
258         break;
259
260         case STATE_PICTURE:
261         {
262             uint8_t *buf[3];
263             buf[0] = buf[1] = buf[2] = NULL;
264
265             vout_SynchroNewPicture( p_dec->p_synchro,
266                 p_dec->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
267                 p_dec->p_info->current_picture->nb_fields,
268                 (p_dec->p_info->current_picture->flags & PIC_FLAG_PTS) ?
269                     ( (p_dec->p_info->current_picture->pts ==
270                                 (uint32_t)p_dec->i_current_pts) ?
271                               p_dec->i_current_pts : p_dec->i_previous_pts ) : 0,
272                 0,
273                 p_dec->i_current_rate );
274
275             if ( !vout_SynchroChoose( p_dec->p_synchro,
276                 p_dec->p_info->current_picture->flags & PIC_MASK_CODING_TYPE ) )
277             {
278                 mpeg2_skip( p_dec->p_mpeg2dec, 1 );
279                 vout_SynchroTrash( p_dec->p_synchro );
280                 mpeg2_set_buf( p_dec->p_mpeg2dec, buf, NULL );
281             }
282             else
283             {
284                 mpeg2_skip( p_dec->p_mpeg2dec, 0 );
285                 vout_SynchroDecode( p_dec->p_synchro );
286                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL ) break;
287                 mpeg2_set_buf( p_dec->p_mpeg2dec, buf, p_pic );
288             }
289         }
290         /* pass-through */
291
292         case STATE_END:
293             if( p_dec->p_info->display_fbuf
294                 && p_dec->p_info->display_fbuf->id )
295             {
296                 p_pic = (picture_t *)p_dec->p_info->display_fbuf->id;
297
298                 if ( p_pic != NULL )
299                 {
300                     if ( p_dec->p_picture_to_destroy != p_pic )
301                     {
302                         vout_SynchroEnd( p_dec->p_synchro,
303                             p_dec->p_info->display_picture->flags
304                              & PIC_MASK_CODING_TYPE,
305                             0 );
306                         vout_DatePicture( p_dec->p_vout, p_pic,
307                             vout_SynchroDate( p_dec->p_synchro ) );
308                         vout_DisplayPicture( p_dec->p_vout, p_pic );
309                     }
310                     else
311                     {
312                         p_dec->p_picture_to_destroy = NULL;
313                         vout_SynchroEnd( p_dec->p_synchro,
314                             p_dec->p_info->display_picture->flags
315                              & PIC_MASK_CODING_TYPE,
316                             1 );
317                         vout_DestroyPicture( p_dec->p_vout, p_pic );
318                     }
319                 }
320                 if( p_dec->p_info->discard_fbuf &&
321                     p_dec->p_info->discard_fbuf->id )
322                 {
323                     vout_UnlinkPicture( p_dec->p_vout, p_pic );
324                 }
325             }
326             break;
327
328         case STATE_INVALID:
329             msg_Warn( p_dec->p_fifo, "Received STATE_INVALID" );
330             break;
331
332         default:
333             break;
334         }
335     }
336
337     /* If b_error is set, the libmpeg2 decoder thread enters the error loop */
338     if( p_dec->p_fifo->b_error )
339     {
340         DecoderError( p_dec->p_fifo );
341     }
342
343     /* End of the libmpeg2 decoder thread */
344     CloseDecoder( p_dec );
345
346     return 0;
347
348  error:
349     DecoderError( p_fifo );
350     if( p_dec )
351     {
352         if( p_dec->p_fifo )
353             p_dec->p_fifo->b_error = 1;
354
355         /* End of the libmpeg2 decoder thread */
356         CloseDecoder( p_dec );
357     }
358
359     return -1;
360 }
361
362 /*****************************************************************************
363  * CloseDecoder: libmpeg2 decoder destruction
364  *****************************************************************************/
365 static void CloseDecoder( dec_thread_t * p_dec )
366 {
367     if( p_dec )
368     {
369         int i_pic;
370
371         if( p_dec->p_pes )
372             input_DeletePES( p_dec->p_fifo->p_packets_mgt, p_dec->p_pes );
373
374         if( p_dec->p_vout )
375         {
376             /* Temporary hack to free the pictures in use by libmpeg2 */
377             for( i_pic = 0; i_pic < p_dec->p_vout->render.i_pictures; i_pic++ )
378             {
379                 if( p_dec->p_vout->render.pp_picture[i_pic]->i_status ==
380                       RESERVED_PICTURE )
381                     vout_DestroyPicture( p_dec->p_vout,
382                                      p_dec->p_vout->render.pp_picture[i_pic] );
383             }
384
385             vout_Request( p_dec->p_fifo, p_dec->p_vout, 0, 0, 0, 0 );
386         }
387
388         if( p_dec->p_synchro )
389             vout_SynchroRelease( p_dec->p_synchro );
390
391         if( p_dec->p_mpeg2dec ) mpeg2_close( p_dec->p_mpeg2dec );
392
393         free( p_dec );
394     }
395 }
396
397 /*****************************************************************************
398  * GetNewPicture: Get a new picture from the vout and set the buf struct
399  *****************************************************************************/
400 static picture_t *GetNewPicture( dec_thread_t *p_dec, uint8_t **pp_buf )
401 {
402     picture_t *p_pic;
403
404     /* Get a new picture */
405     while( !(p_pic = vout_CreatePicture( p_dec->p_vout, 0, 0, 0 ) ) )
406     {
407         if( p_dec->p_fifo->b_die || p_dec->p_fifo->b_error )
408             break;
409
410         msleep( VOUT_OUTMEM_SLEEP );
411     }
412     if( p_pic == NULL )
413         return NULL;
414     vout_LinkPicture( p_dec->p_vout, p_pic );
415
416     pp_buf[0] = p_pic->p[0].p_pixels;
417     pp_buf[1] = p_pic->p[1].p_pixels;
418     pp_buf[2] = p_pic->p[2].p_pixels;
419
420     return p_pic;
421 }