git.sesse.net Git - x264/blob - encoder/lookahead.c

   1 /*****************************************************************************
   2  * lookahead.c: Lookahead slicetype decisions for x264
   3  *****************************************************************************
   4  * Lookahead.c and associated modifications:
   5  *     Copyright (C) 2008 Avail Media
   6  *
   7  * Authors: Michael Kazmier <mkazmier@availmedia.com>
   8  *          Alex Giladi <agiladi@availmedia.com>
   9  *          Steven Walters <kemuri9@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  24  *****************************************************************************/
  25
  26 /* LOOKAHEAD (threaded and non-threaded mode)
  27  *
  28  * Lookahead types:
  29  *     [1] Slice type / scene cut;
  30  *
  31  * In non-threaded mode, we run the existing slicetype decision code as it was.
  32  * In threaded mode, we run in a separate thread, that lives between the calls
  33  * to x264_encoder_open() and x264_encoder_close(), and performs lookahead for
  34  * the number of frames specified in rc_lookahead.  Recommended setting is
  35  * # of bframes + # of threads.
  36  */
  37 #include "common/common.h"
  38 #include "common/cpu.h"
  39 #include "analyse.h"
  40
  41 static void x264_lookahead_shift( x264_synch_frame_list_t *dst, x264_synch_frame_list_t *src, int count )
  42 {
  43     int i = count;
  44     while( i-- )
  45     {
  46         assert( dst->i_size < dst->i_max_size );
  47         assert( src->i_size );
  48         dst->list[ dst->i_size++ ] = x264_frame_shift( src->list );
  49         src->i_size--;
  50     }
  51     if( count )
  52     {
  53         x264_pthread_cond_broadcast( &dst->cv_fill );
  54         x264_pthread_cond_broadcast( &src->cv_empty );
  55     }
  56 }
  57
  58 static void x264_lookahead_update_last_nonb( x264_t *h, x264_frame_t *new_nonb )
  59 {
  60     if( h->lookahead->last_nonb )
  61         x264_frame_push_unused( h, h->lookahead->last_nonb );
  62     h->lookahead->last_nonb = new_nonb;
  63     new_nonb->i_reference_count++;
  64 }
  65
  66 #ifdef HAVE_PTHREAD
  67 static void x264_lookahead_slicetype_decide( x264_t *h )
  68 {
  69     x264_stack_align( x264_slicetype_decide, h );
  70
  71     x264_lookahead_update_last_nonb( h, h->lookahead->next.list[0] );
  72
  73     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
  74     while( h->lookahead->ofbuf.i_size == h->lookahead->ofbuf.i_max_size )
  75         x264_pthread_cond_wait( &h->lookahead->ofbuf.cv_empty, &h->lookahead->ofbuf.mutex );
  76
  77     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
  78     x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, h->lookahead->next.list[0]->i_bframes + 1 );
  79     x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
  80
  81     /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
  82     if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
  83         x264_stack_align( x264_slicetype_analyse, h, 1 );
  84
  85     x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
  86 }
  87
  88 static void x264_lookahead_thread( x264_t *h )
  89 {
  90     int shift;
  91 #ifdef HAVE_MMX
  92     if( h->param.cpu&X264_CPU_SSE_MISALIGN )
  93         x264_cpu_mask_misalign_sse();
  94 #endif
  95     while( !h->lookahead->b_exit_thread )
  96     {
  97         x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
  98         x264_pthread_mutex_lock( &h->lookahead->next.mutex );
  99         shift = X264_MIN( h->lookahead->next.i_max_size - h->lookahead->next.i_size, h->lookahead->ifbuf.i_size );
 100         x264_lookahead_shift( &h->lookahead->next, &h->lookahead->ifbuf, shift );
 101         x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
 102         if( h->lookahead->next.i_size <= h->lookahead->i_slicetype_length )
 103         {
 104             while( !h->lookahead->ifbuf.i_size && !h->lookahead->b_exit_thread )
 105                 x264_pthread_cond_wait( &h->lookahead->ifbuf.cv_fill, &h->lookahead->ifbuf.mutex );
 106             x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 107         }
 108         else
 109         {
 110             x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 111             x264_lookahead_slicetype_decide( h );
 112         }
 113     }   /* end of input frames */
 114     x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
 115     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
 116     x264_lookahead_shift( &h->lookahead->next, &h->lookahead->ifbuf, h->lookahead->ifbuf.i_size );
 117     x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
 118     x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 119     while( h->lookahead->next.i_size )
 120         x264_lookahead_slicetype_decide( h );
 121     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
 122     h->lookahead->b_thread_active = 0;
 123     x264_pthread_cond_broadcast( &h->lookahead->ofbuf.cv_fill );
 124     x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
 125 }
 126 #endif
 127
 128 int x264_lookahead_init( x264_t *h, int i_slicetype_length )
 129 {
 130     x264_lookahead_t *look;
 131     CHECKED_MALLOCZERO( look, sizeof(x264_lookahead_t) );
 132     int i;
 133     for( i = 0; i < h->param.i_threads; i++ )
 134         h->thread[i]->lookahead = look;
 135
 136     look->i_last_idr = - h->param.i_keyint_max;
 137     look->b_analyse_keyframe = (h->param.rc.b_mb_tree || (h->param.rc.i_vbv_buffer_size && h->param.rc.i_lookahead))
 138                                && !h->param.rc.b_stat_read;
 139     look->i_slicetype_length = i_slicetype_length;
 140
 141     /* init frame lists */
 142     if( x264_synch_frame_list_init( &look->ifbuf, h->param.i_sync_lookahead+3 ) ||
 143         x264_synch_frame_list_init( &look->next, h->frames.i_delay+3 ) ||
 144         x264_synch_frame_list_init( &look->ofbuf, h->frames.i_delay+3 ) )
 145         goto fail;
 146
 147     if( !h->param.i_sync_lookahead )
 148         return 0;
 149
 150     x264_t *look_h = h->thread[h->param.i_threads];
 151     *look_h = *h;
 152     if( x264_macroblock_cache_init( look_h ) )
 153         goto fail;
 154
 155     if( x264_pthread_create( &look_h->thread_handle, NULL, (void *)x264_lookahead_thread, look_h ) )
 156         goto fail;
 157     look->b_thread_active = 1;
 158
 159     return 0;
 160 fail:
 161     x264_free( look );
 162     return -1;
 163 }
 164
 165 void x264_lookahead_delete( x264_t *h )
 166 {
 167     if( h->param.i_sync_lookahead )
 168     {
 169         x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
 170         h->lookahead->b_exit_thread = 1;
 171         x264_pthread_cond_broadcast( &h->lookahead->ifbuf.cv_fill );
 172         x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 173         x264_pthread_join( h->thread[h->param.i_threads]->thread_handle, NULL );
 174         x264_macroblock_cache_end( h->thread[h->param.i_threads] );
 175         x264_free( h->thread[h->param.i_threads]->scratch_buffer );
 176         x264_free( h->thread[h->param.i_threads] );
 177     }
 178     x264_synch_frame_list_delete( &h->lookahead->ifbuf );
 179     x264_synch_frame_list_delete( &h->lookahead->next );
 180     if( h->lookahead->last_nonb )
 181         x264_frame_push_unused( h, h->lookahead->last_nonb );
 182     x264_synch_frame_list_delete( &h->lookahead->ofbuf );
 183     x264_free( h->lookahead );
 184 }
 185
 186 void x264_lookahead_put_frame( x264_t *h, x264_frame_t *frame )
 187 {
 188     if( h->param.i_sync_lookahead )
 189         x264_synch_frame_list_push( &h->lookahead->ifbuf, frame );
 190     else
 191         x264_synch_frame_list_push( &h->lookahead->next, frame );
 192 }
 193
 194 int x264_lookahead_is_empty( x264_t *h )
 195 {
 196     int b_empty;
 197     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
 198     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
 199     b_empty = !h->lookahead->next.i_size && !h->lookahead->ofbuf.i_size;
 200     x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
 201     x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
 202     return b_empty;
 203 }
 204
 205 static void x264_lookahead_encoder_shift( x264_t *h )
 206 {
 207     if( !h->lookahead->ofbuf.i_size )
 208         return;
 209     int i_frames = h->lookahead->ofbuf.list[0]->i_bframes + 1;
 210     while( i_frames-- )
 211     {
 212         x264_frame_push( h->frames.current, x264_frame_shift( h->lookahead->ofbuf.list ) );
 213         h->lookahead->ofbuf.i_size--;
 214     }
 215     x264_pthread_cond_broadcast( &h->lookahead->ofbuf.cv_empty );
 216 }
 217
 218 void x264_lookahead_get_frames( x264_t *h )
 219 {
 220     if( h->param.i_sync_lookahead )
 221     {   /* We have a lookahead thread, so get frames from there */
 222         x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
 223         while( !h->lookahead->ofbuf.i_size && h->lookahead->b_thread_active )
 224             x264_pthread_cond_wait( &h->lookahead->ofbuf.cv_fill, &h->lookahead->ofbuf.mutex );
 225         x264_lookahead_encoder_shift( h );
 226         x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
 227     }
 228     else
 229     {   /* We are not running a lookahead thread, so perform all the slicetype decide on the fly */
 230
 231         if( h->frames.current[0] || !h->lookahead->next.i_size )
 232             return;
 233
 234         x264_stack_align( x264_slicetype_decide, h );
 235         x264_lookahead_update_last_nonb( h, h->lookahead->next.list[0] );
 236         x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, h->lookahead->next.list[0]->i_bframes + 1 );
 237
 238         /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
 239         if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
 240             x264_stack_align( x264_slicetype_analyse, h, 1 );
 241
 242         x264_lookahead_encoder_shift( h );
 243     }
 244 }