/*

 * 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/mem.h"

#include "audio_frame_queue.h"

#include "encode.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);

}