ffmpeg/libavcodec/thread.h

   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 "libavutil/buffer.h"
  31
  32 #include "config.h"
  33 #include "avcodec.h"
  34
  35 typedef struct ThreadFrame {
  36     AVFrame *f;
  37     AVCodecContext *owner;
  38     // progress->data is an array of 2 ints holding progress for top/bottom
  39     // fields
  40     AVBufferRef *progress;
  41 } ThreadFrame;
  42
  43 /**
  44  * Wait for decoding threads to finish and reset internal state.
  45  * Called by avcodec_flush_buffers().
  46  *
  47  * @param avctx The context.
  48  */
  49 void ff_thread_flush(AVCodecContext *avctx);
  50
  51 /**
  52  * Submit a new frame to a decoding thread.
  53  * Returns the next available frame in picture. *got_picture_ptr
  54  * will be 0 if none is available.
  55  * The return value on success is the size of the consumed packet for
  56  * compatibility with avcodec_decode_video2(). This means the decoder
  57  * has to consume the full packet.
  58  *
  59  * Parameters are the same as avcodec_decode_video2().
  60  */
  61 int ff_thread_decode_frame(AVCodecContext *avctx, AVFrame *picture,
  62                            int *got_picture_ptr, AVPacket *avpkt);
  63
  64 /**
  65  * If the codec defines update_thread_context(), call this
  66  * when they are ready for the next thread to start decoding
  67  * the next frame. After calling it, do not change any variables
  68  * read by the update_thread_context() method, or call ff_thread_get_buffer().
  69  *
  70  * @param avctx The context.
  71  */
  72 void ff_thread_finish_setup(AVCodecContext *avctx);
  73
  74 /**
  75  * Notify later decoding threads when part of their reference picture is ready.
  76  * Call this when some part of the picture is finished decoding.
  77  * Later calls with lower values of progress have no effect.
  78  *
  79  * @param f The picture being decoded.
  80  * @param progress Value, in arbitrary units, of how much of the picture has decoded.
  81  * @param field The field being decoded, for field-picture codecs.
  82  * 0 for top field or frame pictures, 1 for bottom field.
  83  */
  84 void ff_thread_report_progress(ThreadFrame *f, int progress, int field);
  85
  86 /**
  87  * Wait for earlier decoding threads to finish reference pictures.
  88  * Call this before accessing some part of a picture, with a given
  89  * value for progress, and it will return after the responsible decoding
  90  * thread calls ff_thread_report_progress() with the same or
  91  * higher value for progress.
  92  *
  93  * @param f The picture being referenced.
  94  * @param progress Value, in arbitrary units, to wait for.
  95  * @param field The field being referenced, for field-picture codecs.
  96  * 0 for top field or frame pictures, 1 for bottom field.
  97  */
  98 void ff_thread_await_progress(ThreadFrame *f, int progress, int field);
  99
 100 /**
 101  * Wrapper around get_format() for frame-multithreaded codecs.
 102  * Call this function instead of avctx->get_format().
 103  * Cannot be called after the codec has called ff_thread_finish_setup().
 104  *
 105  * @param avctx The current context.
 106  * @param fmt The list of available formats.
 107  */
 108 enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt);
 109
 110 /**
 111  * Wrapper around get_buffer() for frame-multithreaded codecs.
 112  * Call this function instead of ff_get_buffer(f).
 113  * Cannot be called after the codec has called ff_thread_finish_setup().
 114  *
 115  * @param avctx The current context.
 116  * @param f The frame to write into.
 117  */
 118 int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags);
 119
 120 /**
 121  * Wrapper around release_buffer() frame-for multithreaded codecs.
 122  * Call this function instead of avctx->release_buffer(f).
 123  * The AVFrame will be copied and the actual release_buffer() call
 124  * will be performed later. The contents of data pointed to by the
 125  * AVFrame should not be changed until ff_thread_get_buffer() is called
 126  * on it.
 127  *
 128  * @param avctx The current context.
 129  * @param f The picture being released.
 130  */
 131 void ff_thread_release_buffer(AVCodecContext *avctx, ThreadFrame *f);
 132
 133 int ff_thread_ref_frame(ThreadFrame *dst, ThreadFrame *src);
 134
 135 int ff_thread_init(AVCodecContext *s);
 136 void ff_thread_free(AVCodecContext *s);
 137
 138 int ff_alloc_entries(AVCodecContext *avctx, int count);
 139 void ff_reset_entries(AVCodecContext *avctx);
 140 void ff_thread_report_progress2(AVCodecContext *avctx, int field, int thread, int n);
 141 void ff_thread_await_progress2(AVCodecContext *avctx,  int field, int thread, int shift);
 142
 143 #endif /* AVCODEC_THREAD_H */