/*
  * Audio Frame Queue
  * Copyright (c) 2012 Justin Ruggles
  *

  * 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
  */
 

 #include "libavutil/attributes.h"

 #include "libavutil/common.h"

 #include "audio_frame_queue.h"

 #include "internal.h"
 #include "libavutil/avassert.h"

 av_cold void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq)

 {

     afq->avctx = avctx;

     afq->remaining_delay   = avctx->initial_padding;
     afq->remaining_samples = avctx->initial_padding;

     afq->frame_count       = 0;

 }
 
 void ff_af_queue_close(AudioFrameQueue *afq)
 {

     if(afq->frame_count)

         av_log(afq->avctx, AV_LOG_WARNING, "%d frames left in the queue on closing\n", afq->frame_count);

     av_freep(&afq->frames);

     memset(afq, 0, sizeof(*afq));
 }
 
 int ff_af_queue_add(AudioFrameQueue *afq, const AVFrame *f)
 {

     AudioFrame *new = av_fast_realloc(afq->frames, &afq->frame_alloc, sizeof(*afq->frames)*(afq->frame_count+1));
     if(!new)

         return AVERROR(ENOMEM);

     afq->frames = new;
     new += afq->frame_count;

 
     /* get frame parameters */

     new->duration = f->nb_samples;
     new->duration += afq->remaining_delay;

     if (f->pts != AV_NOPTS_VALUE) {

         new->pts = av_rescale_q(f->pts,

                                       afq->avctx->time_base,
                                       (AVRational){ 1, afq->avctx->sample_rate });

         new->pts -= afq->remaining_delay;
         if(afq->frame_count && new[-1].pts >= new->pts)

             av_log(afq->avctx, AV_LOG_WARNING, "Queue input is backward in time\n");

     } else {

         new->pts = AV_NOPTS_VALUE;

     }

     afq->remaining_delay = 0;

 
     /* add frame sample count */
     afq->remaining_samples += f->nb_samples;
 

     afq->frame_count++;

 
     return 0;
 }
 
 void ff_af_queue_remove(AudioFrameQueue *afq, int nb_samples, int64_t *pts,

                         int64_t *duration)

 {
     int64_t out_pts = AV_NOPTS_VALUE;
     int removed_samples = 0;

     int i;

     if (afq->frame_count || afq->frame_alloc) {
         if (afq->frames->pts != AV_NOPTS_VALUE)
             out_pts = afq->frames->pts;

     }

     if(!afq->frame_count)

         av_log(afq->avctx, AV_LOG_WARNING, "Trying to remove %d samples, but the queue is empty\n", nb_samples);

     if (pts)
         *pts = ff_samples_to_time_base(afq->avctx, out_pts);
 
     for(i=0; nb_samples && i<afq->frame_count; i++){
         int n= FFMIN(afq->frames[i].duration, nb_samples);
         afq->frames[i].duration -= n;
         nb_samples              -= n;
         removed_samples         += n;
         if(afq->frames[i].pts != AV_NOPTS_VALUE)
             afq->frames[i].pts      += n;

     }

     afq->remaining_samples -= removed_samples;

     i -= i && afq->frames[i-1].duration;
     memmove(afq->frames, afq->frames + i, sizeof(*afq->frames) * (afq->frame_count - i));
     afq->frame_count -= i;
 
     if(nb_samples){
         av_assert0(!afq->frame_count);

         av_assert0(afq->remaining_samples == afq->remaining_delay);

         if(afq->frames && afq->frames[0].pts != AV_NOPTS_VALUE)

             afq->frames[0].pts += nb_samples;

         av_log(afq->avctx, AV_LOG_DEBUG, "Trying to remove %d more samples than there are in the queue\n", nb_samples);

     }
     if (duration)
         *duration = ff_samples_to_time_base(afq->avctx, removed_samples);
 }