126 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
		
			4.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2004 Roman Shaposhnik
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|  * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
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|  *
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|  * Many thanks to Steven M. Schultz for providing clever ideas and
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|  * to Michael Niedermayer <michaelni@gmx.at> for writing initial
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|  * implementation.
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| /**
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|  * @file
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|  * Multithreading support functions
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|  * @see doc/multithreading.txt
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|  */
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| 
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| #include "libavutil/thread.h"
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| 
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| #include "avcodec.h"
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| #include "codec_internal.h"
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| #include "pthread_internal.h"
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| #include "thread.h"
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| 
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| /**
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|  * Set the threading algorithms used.
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|  *
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|  * Threading requires more than one thread.
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|  * Frame threading requires entire frames to be passed to the codec,
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|  * and introduces extra decoding delay, so is incompatible with low_delay.
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|  *
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|  * @param avctx The context.
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|  */
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| static void validate_thread_parameters(AVCodecContext *avctx)
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| {
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|     int frame_threading_supported = (avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS)
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|                                 && !(avctx->flags  & AV_CODEC_FLAG_LOW_DELAY)
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|                                 && !(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS);
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|     if (avctx->thread_count == 1) {
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|         avctx->active_thread_type = 0;
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|     } else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {
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|         avctx->active_thread_type = FF_THREAD_FRAME;
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|     } else if (avctx->codec->capabilities & AV_CODEC_CAP_SLICE_THREADS &&
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|                avctx->thread_type & FF_THREAD_SLICE) {
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|         avctx->active_thread_type = FF_THREAD_SLICE;
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|     } else if (!(ffcodec(avctx->codec)->caps_internal & FF_CODEC_CAP_AUTO_THREADS)) {
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|         avctx->thread_count       = 1;
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|         avctx->active_thread_type = 0;
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|     }
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| 
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|     if (avctx->thread_count > MAX_AUTO_THREADS)
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|         av_log(avctx, AV_LOG_WARNING,
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|                "Application has requested %d threads. Using a thread count greater than %d is not recommended.\n",
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|                avctx->thread_count, MAX_AUTO_THREADS);
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| }
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| 
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| int ff_thread_init(AVCodecContext *avctx)
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| {
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|     validate_thread_parameters(avctx);
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| 
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|     if (avctx->active_thread_type&FF_THREAD_SLICE)
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|         return ff_slice_thread_init(avctx);
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|     else if (avctx->active_thread_type&FF_THREAD_FRAME)
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|         return ff_frame_thread_init(avctx);
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| 
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|     return 0;
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| }
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| 
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| void ff_thread_free(AVCodecContext *avctx)
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| {
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|     if (avctx->active_thread_type&FF_THREAD_FRAME)
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|         ff_frame_thread_free(avctx, avctx->thread_count);
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|     else
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|         ff_slice_thread_free(avctx);
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| }
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| 
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| av_cold void ff_pthread_free(void *obj, const unsigned offsets[])
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| {
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|     unsigned cnt = *(unsigned*)((char*)obj + offsets[0]);
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|     const unsigned *cur_offset = offsets;
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| 
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|     *(unsigned*)((char*)obj + offsets[0]) = 0;
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| 
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|     for (; *(++cur_offset) != THREAD_SENTINEL && cnt; cnt--)
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|         pthread_mutex_destroy((pthread_mutex_t*)((char*)obj + *cur_offset));
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|     for (; *(++cur_offset) != THREAD_SENTINEL && cnt; cnt--)
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|         pthread_cond_destroy ((pthread_cond_t *)((char*)obj + *cur_offset));
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| }
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| 
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| av_cold int ff_pthread_init(void *obj, const unsigned offsets[])
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| {
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|     const unsigned *cur_offset = offsets;
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|     unsigned cnt = 0;
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|     int err;
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| 
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| #define PTHREAD_INIT_LOOP(type)                                               \
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|     for (; *(++cur_offset) != THREAD_SENTINEL; cnt++) {                       \
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|         pthread_ ## type ## _t *dst = (void*)((char*)obj + *cur_offset);      \
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|         err = pthread_ ## type ## _init(dst, NULL);                           \
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|         if (err) {                                                            \
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|             err = AVERROR(err);                                               \
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|             goto fail;                                                        \
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|         }                                                                     \
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|     }
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|     PTHREAD_INIT_LOOP(mutex)
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|     PTHREAD_INIT_LOOP(cond)
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| 
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| fail:
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|     *(unsigned*)((char*)obj + offsets[0]) = cnt;
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|     return err;
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| }
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