1 /*****************************************************************************
2 * lookahead.c: Lookahead slicetype decisions for x264
3 *****************************************************************************
4 * Lookahead.c and associated modifications:
5 * Copyright (C) 2008 Avail Media
7 * Authors: Michael Kazmier <mkazmier@availmedia.com>
8 * Alex Giladi <agiladi@availmedia.com>
9 * Steven Walters <kemuri9@gmail.com>
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.
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.
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 *****************************************************************************/
26 /* LOOKAHEAD (threaded and non-threaded mode)
29 * [1] Slice type / scene cut;
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.
37 #include "common/common.h"
38 #include "common/cpu.h"
41 static void x264_lookahead_shift( x264_synch_frame_list_t *dst, x264_synch_frame_list_t *src, int count )
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 );
53 x264_pthread_cond_broadcast( &dst->cv_fill );
54 x264_pthread_cond_broadcast( &src->cv_empty );
58 static void x264_lookahead_update_last_nonb( x264_t *h, x264_frame_t *new_nonb )
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++;
67 static void x264_lookahead_slicetype_decide( x264_t *h )
70 x264_stack_align( x264_slicetype_decide, h );
72 while( IS_X264_TYPE_B( h->lookahead->next.list[bframes]->i_type ) )
74 x264_lookahead_update_last_nonb( h, h->lookahead->next.list[bframes] );
76 x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
77 while( h->lookahead->ofbuf.i_size == h->lookahead->ofbuf.i_max_size )
78 x264_pthread_cond_wait( &h->lookahead->ofbuf.cv_empty, &h->lookahead->ofbuf.mutex );
80 x264_pthread_mutex_lock( &h->lookahead->next.mutex );
81 x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, bframes + 1 );
82 x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
84 /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
85 if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
86 x264_stack_align( x264_slicetype_analyse, h, 1 );
88 x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
91 static void x264_lookahead_thread( x264_t *h )
95 if( h->param.cpu&X264_CPU_SSE_MISALIGN )
96 x264_cpu_mask_misalign_sse();
98 while( !h->lookahead->b_exit_thread )
100 x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
101 x264_pthread_mutex_lock( &h->lookahead->next.mutex );
102 shift = X264_MIN( h->lookahead->next.i_max_size - h->lookahead->next.i_size, h->lookahead->ifbuf.i_size );
103 x264_lookahead_shift( &h->lookahead->next, &h->lookahead->ifbuf, shift );
104 x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
105 if( h->lookahead->next.i_size <= h->lookahead->i_slicetype_length )
107 while( !h->lookahead->ifbuf.i_size && !h->lookahead->b_exit_thread )
108 x264_pthread_cond_wait( &h->lookahead->ifbuf.cv_fill, &h->lookahead->ifbuf.mutex );
109 x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
113 x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
114 x264_lookahead_slicetype_decide( h );
116 } /* end of input frames */
117 x264_pthread_mutex_lock( &h->lookahead->ifbuf.mutex );
118 x264_pthread_mutex_lock( &h->lookahead->next.mutex );
119 x264_lookahead_shift( &h->lookahead->next, &h->lookahead->ifbuf, h->lookahead->ifbuf.i_size );
120 x264_pthread_mutex_unlock( &h->lookahead->next.mutex );
121 x264_pthread_mutex_unlock( &h->lookahead->ifbuf.mutex );
122 while( h->lookahead->next.i_size )
123 x264_lookahead_slicetype_decide( h );
124 x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
125 h->lookahead->b_thread_active = 0;
126 x264_pthread_cond_broadcast( &h->lookahead->ofbuf.cv_fill );
127 x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
131 int x264_lookahead_init( x264_t *h, int i_slicetype_length )
133 x264_lookahead_t *look;
134 CHECKED_MALLOCZERO( look, sizeof(x264_lookahead_t) );
136 for( i = 0; i < h->param.i_threads; i++ )
137 h->thread[i]->lookahead = look;
139 look->i_last_idr = - h->param.i_keyint_max;
140 look->b_analyse_keyframe = (h->param.rc.b_mb_tree || (h->param.rc.i_vbv_buffer_size && h->param.rc.i_lookahead))
141 && !h->param.rc.b_stat_read;
142 look->i_slicetype_length = i_slicetype_length;
144 /* init frame lists */
145 if( x264_synch_frame_list_init( &look->ifbuf, h->param.i_sync_lookahead+3 ) ||
146 x264_synch_frame_list_init( &look->next, h->frames.i_delay+3 ) ||
147 x264_synch_frame_list_init( &look->ofbuf, h->frames.i_delay+3 ) )
150 if( !h->param.i_sync_lookahead )
153 x264_t *look_h = h->thread[h->param.i_threads];
155 if( x264_macroblock_cache_init( look_h ) )
158 if( x264_pthread_create( &look_h->thread_handle, NULL, (void *)x264_lookahead_thread, look_h ) )
160 look->b_thread_active = 1;
168 void x264_lookahead_delete( x264_t *h )
170 if( h->param.i_sync_lookahead )
172 h->lookahead->b_exit_thread = 1;
173 x264_pthread_cond_broadcast( &h->lookahead->ifbuf.cv_fill );
174 x264_pthread_join( h->thread[h->param.i_threads]->thread_handle, NULL );
175 x264_macroblock_cache_end( h->thread[h->param.i_threads] );
176 x264_free( h->thread[h->param.i_threads] );
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 );
186 void x264_lookahead_put_frame( x264_t *h, x264_frame_t *frame )
188 if( h->param.i_sync_lookahead )
189 x264_synch_frame_list_push( &h->lookahead->ifbuf, frame );
191 x264_synch_frame_list_push( &h->lookahead->next, frame );
194 int x264_lookahead_is_empty( x264_t *h )
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 );
205 static void x264_lookahead_encoder_shift( x264_t *h )
210 while( h->lookahead->ofbuf.list[i_frames] )
212 if( IS_X264_TYPE_B( h->lookahead->ofbuf.list[bframes]->i_type ) )
218 if( h->lookahead->ofbuf.list[i_frames] )
220 x264_frame_push( h->frames.current, x264_frame_shift( &h->lookahead->ofbuf.list[bframes] ) );
221 h->lookahead->ofbuf.i_size--;
222 if( h->param.b_bframe_pyramid && bframes > 1 )
224 x264_frame_t *mid = x264_frame_shift( &h->lookahead->ofbuf.list[bframes/2] );
225 h->lookahead->ofbuf.i_size--;
226 mid->i_type = X264_TYPE_BREF;
227 x264_frame_push( h->frames.current, mid );
232 x264_frame_push( h->frames.current, x264_frame_shift( h->lookahead->ofbuf.list ) );
233 h->lookahead->ofbuf.i_size--;
235 x264_pthread_cond_broadcast( &h->lookahead->ofbuf.cv_empty );
239 void x264_lookahead_get_frames( x264_t *h )
241 if( h->param.i_sync_lookahead )
242 { /* We have a lookahead thread, so get frames from there */
243 x264_pthread_mutex_lock( &h->lookahead->ofbuf.mutex );
244 while( !h->lookahead->ofbuf.i_size && h->lookahead->b_thread_active )
245 x264_pthread_cond_wait( &h->lookahead->ofbuf.cv_fill, &h->lookahead->ofbuf.mutex );
246 x264_lookahead_encoder_shift( h );
247 x264_pthread_mutex_unlock( &h->lookahead->ofbuf.mutex );
250 { /* We are not running a lookahead thread, so perform all the slicetype decide on the fly */
252 if( h->frames.current[0] || !h->lookahead->next.i_size )
255 x264_stack_align( x264_slicetype_decide, h );
258 while( IS_X264_TYPE_B( h->lookahead->next.list[bframes]->i_type ) )
261 x264_lookahead_update_last_nonb( h, h->lookahead->next.list[bframes] );
262 x264_lookahead_shift( &h->lookahead->ofbuf, &h->lookahead->next, bframes + 1 );
264 /* For MB-tree and VBV lookahead, we have to perform propagation analysis on I-frames too. */
265 if( h->lookahead->b_analyse_keyframe && IS_X264_TYPE_I( h->lookahead->last_nonb->i_type ) )
266 x264_stack_align( x264_slicetype_analyse, h, 1 );
268 x264_lookahead_encoder_shift( h );