FFmpeg/libavcodec/thread.h
Anton Khirnov a83098ab03 avcodec: deprecate thread_safe_callbacks
They add considerable complexity to frame-threading implementation,
which includes an unavoidably leaking error path, while the advantages
of this option to the users are highly dubious.

It should be always possible and desirable for the callers to make their
get_buffer2() implementation thread-safe, so deprecate this option.
2020-11-27 15:46:50 +01:00

149 lines
5.3 KiB
C

/*
* Copyright (c) 2008 Alexander Strange <astrange@ithinksw.com>
*
* 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
*/
/**
* @file
* Multithreading support functions
* @author Alexander Strange <astrange@ithinksw.com>
*/
#ifndef AVCODEC_THREAD_H
#define AVCODEC_THREAD_H
#include "libavutil/buffer.h"
#include "avcodec.h"
typedef struct ThreadFrame {
AVFrame *f;
AVCodecContext *owner[2];
// progress->data is an array of 2 ints holding progress for top/bottom
// fields
AVBufferRef *progress;
} ThreadFrame;
/**
* Wait for decoding threads to finish and reset internal state.
* Called by avcodec_flush_buffers().
*
* @param avctx The context.
*/
void ff_thread_flush(AVCodecContext *avctx);
/**
* Submit a new frame to a decoding thread.
* Returns the next available frame in picture. *got_picture_ptr
* will be 0 if none is available.
* The return value on success is the size of the consumed packet for
* compatibility with avcodec_decode_video2(). This means the decoder
* has to consume the full packet.
*
* Parameters are the same as avcodec_decode_video2().
*/
int ff_thread_decode_frame(AVCodecContext *avctx, AVFrame *picture,
int *got_picture_ptr, AVPacket *avpkt);
/**
* If the codec defines update_thread_context(), call this
* when they are ready for the next thread to start decoding
* the next frame. After calling it, do not change any variables
* read by the update_thread_context() method, or call ff_thread_get_buffer().
*
* @param avctx The context.
*/
void ff_thread_finish_setup(AVCodecContext *avctx);
/**
* Notify later decoding threads when part of their reference picture is ready.
* Call this when some part of the picture is finished decoding.
* Later calls with lower values of progress have no effect.
*
* @param f The picture being decoded.
* @param progress Value, in arbitrary units, of how much of the picture has decoded.
* @param field The field being decoded, for field-picture codecs.
* 0 for top field or frame pictures, 1 for bottom field.
*/
void ff_thread_report_progress(ThreadFrame *f, int progress, int field);
/**
* Wait for earlier decoding threads to finish reference pictures.
* Call this before accessing some part of a picture, with a given
* value for progress, and it will return after the responsible decoding
* thread calls ff_thread_report_progress() with the same or
* higher value for progress.
*
* @param f The picture being referenced.
* @param progress Value, in arbitrary units, to wait for.
* @param field The field being referenced, for field-picture codecs.
* 0 for top field or frame pictures, 1 for bottom field.
*/
void ff_thread_await_progress(ThreadFrame *f, int progress, int field);
#if FF_API_THREAD_SAFE_CALLBACKS
/**
* Wrapper around get_format() for frame-multithreaded codecs.
* Call this function instead of avctx->get_format().
* Cannot be called after the codec has called ff_thread_finish_setup().
*
* @param avctx The current context.
* @param fmt The list of available formats.
*/
enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt);
#else
#define ff_thread_get_format ff_get_format
#endif
/**
* Wrapper around get_buffer() for frame-multithreaded codecs.
* Call this function instead of ff_get_buffer(f).
* Cannot be called after the codec has called ff_thread_finish_setup().
*
* @param avctx The current context.
* @param f The frame to write into.
*/
int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags);
/**
* Wrapper around release_buffer() frame-for multithreaded codecs.
* Call this function instead of avctx->release_buffer(f).
* The AVFrame will be copied and the actual release_buffer() call
* will be performed later. The contents of data pointed to by the
* AVFrame should not be changed until ff_thread_get_buffer() is called
* on it.
*
* @param avctx The current context.
* @param f The picture being released.
*/
void ff_thread_release_buffer(AVCodecContext *avctx, ThreadFrame *f);
int ff_thread_ref_frame(ThreadFrame *dst, const ThreadFrame *src);
int ff_thread_init(AVCodecContext *s);
int ff_slice_thread_execute_with_mainfunc(AVCodecContext *avctx,
int (*action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr),
int (*main_func)(AVCodecContext *c), void *arg, int *ret, int job_count);
void ff_thread_free(AVCodecContext *s);
int ff_alloc_entries(AVCodecContext *avctx, int count);
void ff_reset_entries(AVCodecContext *avctx);
void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n);
void ff_thread_await_progress2(AVCodecContext *avctx, int field, int thread, int shift);
#endif /* AVCODEC_THREAD_H */