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thread.h
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1 /*
2  * Copyright (c) 2008 Alexander Strange <astrange@ithinksw.com>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * Multithreading support functions
24  * @author Alexander Strange <astrange@ithinksw.com>
25  */
26 
27 #ifndef AVCODEC_THREAD_H
28 #define AVCODEC_THREAD_H
29 
30 #include "config.h"
31 #include "avcodec.h"
32 
33 /**
34  * Wait for decoding threads to finish and reset internal state.
35  * Called by avcodec_flush_buffers().
36  *
37  * @param avctx The context.
38  */
39 void ff_thread_flush(AVCodecContext *avctx);
40 
41 /**
42  * Submit a new frame to a decoding thread.
43  * Returns the next available frame in picture. *got_picture_ptr
44  * will be 0 if none is available.
45  * The return value on success is the size of the consumed packet for
46  * compatibility with avcodec_decode_video2(). This means the decoder
47  * has to consume the full packet.
48  *
49  * Parameters are the same as avcodec_decode_video2().
50  */
51 int ff_thread_decode_frame(AVCodecContext *avctx, AVFrame *picture,
52  int *got_picture_ptr, AVPacket *avpkt);
53 
54 /**
55  * If the codec defines update_thread_context(), call this
56  * when they are ready for the next thread to start decoding
57  * the next frame. After calling it, do not change any variables
58  * read by the update_thread_context() method, or call ff_thread_get_buffer().
59  *
60  * @param avctx The context.
61  */
63 
64 /**
65  * Notify later decoding threads when part of their reference picture is ready.
66  * Call this when some part of the picture is finished decoding.
67  * Later calls with lower values of progress have no effect.
68  *
69  * @param f The picture being decoded.
70  * @param progress Value, in arbitrary units, of how much of the picture has decoded.
71  * @param field The field being decoded, for field-picture codecs.
72  * 0 for top field or frame pictures, 1 for bottom field.
73  */
74 void ff_thread_report_progress(AVFrame *f, int progress, int field);
75 
76 /**
77  * Wait for earlier decoding threads to finish reference pictures.
78  * Call this before accessing some part of a picture, with a given
79  * value for progress, and it will return after the responsible decoding
80  * thread calls ff_thread_report_progress() with the same or
81  * higher value for progress.
82  *
83  * @param f The picture being referenced.
84  * @param progress Value, in arbitrary units, to wait for.
85  * @param field The field being referenced, for field-picture codecs.
86  * 0 for top field or frame pictures, 1 for bottom field.
87  */
88 void ff_thread_await_progress(AVFrame *f, int progress, int field);
89 
90 /**
91  * Wrapper around get_buffer() for frame-multithreaded codecs.
92  * Call this function instead of ff_get_buffer(f).
93  * Cannot be called after the codec has called ff_thread_finish_setup().
94  *
95  * @param avctx The current context.
96  * @param f The frame to write into.
97  */
99 
100 /**
101  * Wrapper around release_buffer() frame-for multithreaded codecs.
102  * Call this function instead of avctx->release_buffer(f).
103  * The AVFrame will be copied and the actual release_buffer() call
104  * will be performed later. The contents of data pointed to by the
105  * AVFrame should not be changed until ff_thread_get_buffer() is called
106  * on it.
107  *
108  * @param avctx The current context.
109  * @param f The picture being released.
110  */
112 
115 
116 #endif /* AVCODEC_THREAD_H */