/* * Copyright (c) 2004 Roman Shaposhnik * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com) * * Many thanks to Steven M. Schultz for providing clever ideas and * to Michael Niedermayer <michaelni@gmx.at> for writing initial * implementation. * * 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 * @see doc/multithreading.txt */ #include "avcodec.h" #include "internal.h" #include "pthread_internal.h" #include "thread.h" /** * Set the threading algorithms used. * * Threading requires more than one thread. * Frame threading requires entire frames to be passed to the codec, * and introduces extra decoding delay, so is incompatible with low_delay. * * @param avctx The context. */ static void validate_thread_parameters(AVCodecContext *avctx) { int frame_threading_supported = (avctx->codec->capabilities & AV_CODEC_CAP_FRAME_THREADS) && !(avctx->flags & AV_CODEC_FLAG_TRUNCATED) && !(avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && !(avctx->flags2 & AV_CODEC_FLAG2_CHUNKS); if (avctx->thread_count == 1) { avctx->active_thread_type = 0; } else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) { avctx->active_thread_type = FF_THREAD_FRAME; } else if (avctx->codec->capabilities & AV_CODEC_CAP_SLICE_THREADS && avctx->thread_type & FF_THREAD_SLICE) { avctx->active_thread_type = FF_THREAD_SLICE; } else if (!(avctx->codec->capabilities & AV_CODEC_CAP_AUTO_THREADS)) { avctx->thread_count = 1; avctx->active_thread_type = 0; } if (avctx->thread_count > MAX_AUTO_THREADS) av_log(avctx, AV_LOG_WARNING, "Application has requested %d threads. Using a thread count greater than %d is not recommended.\n", avctx->thread_count, MAX_AUTO_THREADS); } int ff_thread_init(AVCodecContext *avctx) { validate_thread_parameters(avctx); if (avctx->active_thread_type&FF_THREAD_SLICE) return ff_slice_thread_init(avctx); else if (avctx->active_thread_type&FF_THREAD_FRAME) return ff_frame_thread_init(avctx); return 0; } void ff_thread_free(AVCodecContext *avctx) { if (avctx->active_thread_type&FF_THREAD_FRAME) ff_frame_thread_free(avctx, avctx->thread_count); else ff_slice_thread_free(avctx); }