/*

  * 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);

 }