1 /*
2 * Copyright (c) 2004 Roman Shaposhnik
3 * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
4 *
5 * Many thanks to Steven M. Schultz for providing clever ideas and
6 * to Michael Niedermayer <michaelni@gmx.at> for writing initial
7 * implementation.
8 *
9 * This file is part of FFmpeg.
10 *
11 * FFmpeg is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2.1 of the License, or (at your option) any later version.
15 *
16 * FFmpeg is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with FFmpeg; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26 /**
27 * @file
28 * Multithreading support functions
29 * @see doc/multithreading.txt
30 */
31
32 #include "avcodec.h"
33 #include "internal.h"
34 #include "pthread_internal.h"
35 #include "thread.h"
36
37 /**
38 * Set the threading algorithms used.
39 *
40 * Threading requires more than one thread.
41 * Frame threading requires entire frames to be passed to the codec,
42 * and introduces extra decoding delay, so is incompatible with low_delay.
43 *
44 * @param avctx The context.
45 */
validate_thread_parameters(AVCodecContext * avctx)46 static void validate_thread_parameters(AVCodecContext *avctx)
47 {
48 int frame_threading_supported = (avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS)
49 && !(avctx->flags & AV_CODEC_FLAG_TRUNCATED)
50 && !(avctx->flags & AV_CODEC_FLAG_LOW_DELAY)
51 && !(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS);
52 if (avctx->thread_count == 1) {
53 avctx->active_thread_type = 0;
54 } else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {
55 avctx->active_thread_type = FF_THREAD_FRAME;
56 } else if (avctx->codec->capabilities & AV_CODEC_CAP_SLICE_THREADS &&
57 avctx->thread_type & FF_THREAD_SLICE) {
58 avctx->active_thread_type = FF_THREAD_SLICE;
59 } else if (!(avctx->codec->caps_internal & FF_CODEC_CAP_AUTO_THREADS)) {
60 avctx->thread_count = 1;
61 avctx->active_thread_type = 0;
62 }
63
64 if (avctx->thread_count > MAX_AUTO_THREADS)
65 av_log(avctx, AV_LOG_WARNING,
66 "Application has requested %d threads. Using a thread count greater than %d is not recommended.\n",
67 avctx->thread_count, MAX_AUTO_THREADS);
68 }
69
ff_thread_init(AVCodecContext * avctx)70 int ff_thread_init(AVCodecContext *avctx)
71 {
72 validate_thread_parameters(avctx);
73
74 if (avctx->active_thread_type&FF_THREAD_SLICE)
75 return ff_slice_thread_init(avctx);
76 else if (avctx->active_thread_type&FF_THREAD_FRAME)
77 return ff_frame_thread_init(avctx);
78
79 return 0;
80 }
81
ff_thread_free(AVCodecContext * avctx)82 void ff_thread_free(AVCodecContext *avctx)
83 {
84 if (avctx->active_thread_type&FF_THREAD_FRAME)
85 ff_frame_thread_free(avctx, avctx->thread_count);
86 else
87 ff_slice_thread_free(avctx);
88 }
89