2 * Copyright (c) 2004 Roman Shaposhnik
3 * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
5 * Many thanks to Steven M. Schultz for providing clever ideas and
6 * to Michael Niedermayer <michaelni@gmx.at> for writing initial
9 * This file is part of FFmpeg.
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.
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.
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
28 * Multithreading support functions
29 * @see doc/multithreading.txt
34 #include "pthread_internal.h"
38 * Set the threading algorithms used.
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.
44 * @param avctx The context.
46 static void validate_thread_parameters(AVCodecContext
*avctx
)
48 int frame_threading_supported
= (avctx
->codec
->capabilities
& CODEC_CAP_FRAME_THREADS
)
49 && !(avctx
->flags
& CODEC_FLAG_TRUNCATED
)
50 && !(avctx
->flags
& CODEC_FLAG_LOW_DELAY
)
51 && !(avctx
->flags2
& 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
& CODEC_CAP_SLICE_THREADS
&&
57 avctx
->thread_type
& FF_THREAD_SLICE
) {
58 avctx
->active_thread_type
= FF_THREAD_SLICE
;
59 } else if (!(avctx
->codec
->capabilities
& CODEC_CAP_AUTO_THREADS
)) {
60 avctx
->thread_count
= 1;
61 avctx
->active_thread_type
= 0;
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
);
70 int ff_thread_init(AVCodecContext
*avctx
)
72 validate_thread_parameters(avctx
);
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
);
82 void ff_thread_free(AVCodecContext
*avctx
)
84 if (avctx
->active_thread_type
&FF_THREAD_FRAME
)
85 ff_frame_thread_free(avctx
, avctx
->thread_count
);
87 ff_slice_thread_free(avctx
);