ffmpeg/libavcodec/pthread_internal.h

67 lines
3.0 KiB
C

/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef AVCODEC_PTHREAD_INTERNAL_H
#define AVCODEC_PTHREAD_INTERNAL_H
#include "avcodec.h"
/* H.264 slice threading seems to be buggy with more than 16 threads,
* limit the number of threads to 16 for automatic detection */
#define MAX_AUTO_THREADS 16
int ff_slice_thread_init(AVCodecContext *avctx);
void ff_slice_thread_free(AVCodecContext *avctx);
int ff_frame_thread_init(AVCodecContext *avctx);
void ff_frame_thread_free(AVCodecContext *avctx, int thread_count);
#define THREAD_SENTINEL 0 // This forbids putting a mutex/condition variable at the front.
/**
* Initialize/destroy a list of mutexes/conditions contained in a structure.
* The positions of these mutexes/conditions in the structure are given by
* their offsets. Because it is undefined behaviour to destroy
* an uninitialized mutex/condition, ff_pthread_init() stores the number
* of successfully initialized mutexes and conditions in the object itself
* and ff_pthread_free() uses this number to destroy exactly the mutexes and
* condition variables that have been successfully initialized.
*
* @param obj The object containing the mutexes/conditions.
* @param[in] offsets An array of offsets. Its first member gives the offset
* of the variable that contains the count of successfully
* initialized mutexes/condition variables; said variable
* must be an unsigned int. Two arrays of offsets, each
* delimited by a THREAD_SENTINEL follow. The first
* contains the offsets of all the mutexes, the second
* contains the offsets of all the condition variables.
*/
int ff_pthread_init(void *obj, const unsigned offsets[]);
void ff_pthread_free(void *obj, const unsigned offsets[]);
/**
* Macros to help creating the above lists. mutexes and conds need
* to be parentheses-enclosed lists of offsets in the containing structure.
*/
#define OFFSET_ARRAY(...) __VA_ARGS__, THREAD_SENTINEL
#define DEFINE_OFFSET_ARRAY(type, name, cnt_variable, mutexes, conds) \
static const unsigned name ## _offsets[] = { offsetof(type, cnt_variable), \
OFFSET_ARRAY mutexes, \
OFFSET_ARRAY conds }
#endif // AVCODEC_PTHREAD_INTERNAL_H