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 "analyse.h"
  39
  40 static void x264_lookahead_shift( x264_synch_frame_list_t *dst, x264_synch_frame_list_t *src, int count )
  41 {
  42     int i = count;
  43     while( i-- )
  44     {
  45         assert( dst->i_size < dst->i_max_size );
  46         assert( src->i_size );
  47         dst->list[ dst->i_size++ ] = x264_frame_shift( src->list );
  48         src->i_size--;
  49     }
  50     if( count )
  51     {
  52         x264_pthread_cond_broadcast( &dst->cv_fill );
  53         x264_pthread_cond_broadcast( &src->cv_empty );
  54     }
  55 }
  56
  57 static void x264_lookahead_update_last_nonb( x264_t *h, x264_frame_t *new_nonb )
  58 {
  59     if( h->lookahead->last_nonb )
  60         x264_frame_push_unused( h, h->lookahead->last_nonb );
  61     h->lookahead->last_nonb = new_nonb;
  62     new_nonb->i_reference_count++;
  63 }
  64
  65 #if HAVE_PTHREAD
  66 static void x264_lookahead_slicetype_decide( x264_t *h )
  67 {
  68     x264_stack_align( x264_slicetype_decide, h );
  69
  70     x264_lookahead_update_last_nonb( h, h->lookahead->next.list[0] );
  71
  72     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
  73     while( h->lookahead->ofbuf.i_size == h->lookahead->ofbuf.i_max_size )
  74         x264_pthread_cond_wait( &h->lookahead->ofbuf.cv_empty, &h->lookahead->ofbuf.mutex );
  75
  76     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
  77     x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, h->lookahead->next.list[0]->i_bframes + 1 );
  78     x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
  79
  80     /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
  81     if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
  82         x264_stack_align( x264_slicetype_analyse, h, 1 );
  83
  84     x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
  85 }
  86
  87 static void x264_lookahead_thread( x264_t *h )
  88 {
  89     int shift;
  90 #if HAVE_MMX
  91     if( h->param.cpu&X264_CPU_SSE_MISALIGN )
  92         x264_cpu_mask_misalign_sse();
  93 #endif
  94     while( !h->lookahead->b_exit_thread )
  95     {
  96         x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
  97         x264_pthread_mutex_lock( &h->lookahead->next.mutex );
  98         shift = X264_MIN( h->lookahead->next.i_max_size - h->lookahead->next.i_size, h->lookahead->ifbuf.i_size );
  99         x264_lookahead_shift( &h->lookahead->next, &h->lookahead->ifbuf, shift );
 100         x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
 101         if( h->lookahead->next.i_size <= h->lookahead->i_slicetype_length )
 102         {
 103             while( !h->lookahead->ifbuf.i_size && !h->lookahead->b_exit_thread )
 104                 x264_pthread_cond_wait( &h->lookahead->ifbuf.cv_fill, &h->lookahead->ifbuf.mutex );
 105             x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 106         }
 107         else
 108         {
 109             x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 110             x264_lookahead_slicetype_decide( h );
 111         }
 112     }   /* end of input frames */
 113     x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
 114     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
 115     x264_lookahead_shift( &h->lookahead->next, &h->lookahead->ifbuf, h->lookahead->ifbuf.i_size );
 116     x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
 117     x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 118     while( h->lookahead->next.i_size )
 119         x264_lookahead_slicetype_decide( h );
 120     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
 121     h->lookahead->b_thread_active = 0;
 122     x264_pthread_cond_broadcast( &h->lookahead->ofbuf.cv_fill );
 123     x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
 124 }
 125 #endif
 126
 127 int x264_lookahead_init( x264_t *h, int i_slicetype_length )
 128 {
 129     x264_lookahead_t *look;
 130     CHECKED_MALLOCZERO( look, sizeof(x264_lookahead_t) );
 131     for( int i = 0; i < h->param.i_threads; i++ )
 132         h->thread[i]->lookahead = look;
 133
 134     look->i_last_keyframe = - h->param.i_keyint_max;
 135     look->b_analyse_keyframe = (h->param.rc.b_mb_tree || (h->param.rc.i_vbv_buffer_size && h->param.rc.i_lookahead))
 136                                && !h->param.rc.b_stat_read;
 137     look->i_slicetype_length = i_slicetype_length;
 138
 139     /* init frame lists */
 140     if( x264_synch_frame_list_init( &look->ifbuf, h->param.i_sync_lookahead+3 ) ||
 141         x264_synch_frame_list_init( &look->next, h->frames.i_delay+3 ) ||
 142         x264_synch_frame_list_init( &look->ofbuf, h->frames.i_delay+3 ) )
 143         goto fail;
 144
 145     if( !h->param.i_sync_lookahead )
 146         return 0;
 147
 148     x264_t *look_h = h->thread[h->param.i_threads];
 149     *look_h = *h;
 150     if( x264_macroblock_cache_allocate( look_h ) )
 151         goto fail;
 152
 153     if( x264_macroblock_thread_allocate( look_h, 1 ) < 0 )
 154         goto fail;
 155
 156     if( x264_pthread_create( &look_h->thread_handle, NULL, (void *)x264_lookahead_thread, look_h ) )
 157         goto fail;
 158     look->b_thread_active = 1;
 159
 160     return 0;
 161 fail:
 162     x264_free( look );
 163     return -1;
 164 }
 165
 166 void x264_lookahead_delete( x264_t *h )
 167 {
 168     if( h->param.i_sync_lookahead )
 169     {
 170         x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
 171         h->lookahead->b_exit_thread = 1;
 172         x264_pthread_cond_broadcast( &h->lookahead->ifbuf.cv_fill );
 173         x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
 174         x264_pthread_join( h->thread[h->param.i_threads]->thread_handle, NULL );
 175         x264_macroblock_cache_free( h->thread[h->param.i_threads] );
 176         x264_macroblock_thread_free( h->thread[h->param.i_threads], 1 );
 177         x264_free( h->thread[h->param.i_threads] );
 178     }
 179     x264_synch_frame_list_delete( &h->lookahead->ifbuf );
 180     x264_synch_frame_list_delete( &h->lookahead->next );
 181     if( h->lookahead->last_nonb )
 182         x264_frame_push_unused( h, h->lookahead->last_nonb );
 183     x264_synch_frame_list_delete( &h->lookahead->ofbuf );
 184     x264_free( h->lookahead );
 185 }
 186
 187 void x264_lookahead_put_frame( x264_t *h, x264_frame_t *frame )
 188 {
 189     if( h->param.i_sync_lookahead )
 190         x264_synch_frame_list_push( &h->lookahead->ifbuf, frame );
 191     else
 192         x264_synch_frame_list_push( &h->lookahead->next, frame );
 193 }
 194
 195 int x264_lookahead_is_empty( x264_t *h )
 196 {
 197     x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
 198     x264_pthread_mutex_lock( &h->lookahead->next.mutex );
 199     int 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 }