/* * Audio Frame Queue * Copyright (c) 2012 Justin Ruggles * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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 "libavutil/mathematics.h"#include "internal.h"#include "audio_frame_queue.h" av_cold void ff_af_queue_init(AVCodecContext *avctx, AudioFrameQueue *afq){    afq->avctx             = avctx;    afq->next_pts          = AV_NOPTS_VALUE;    afq->remaining_delay   = avctx->delay;    afq->remaining_samples = avctx->delay;    afq->frame_queue       = NULL;} static void delete_next_frame(AudioFrameQueue *afq){    AudioFrame *f = afq->frame_queue;    if (f) {        afq->frame_queue = f->next;        f->next = NULL;        av_freep(&f);    }} void ff_af_queue_close(AudioFrameQueue *afq){    /* remove/free any remaining frames */    while (afq->frame_queue)        delete_next_frame(afq);    memset(afq, 0, sizeof(*afq));} #ifdef DEBUGstatic void af_queue_log_state(AudioFrameQueue *afq){    AudioFrame *f;    av_dlog(afq->avctx, "remaining delay   = %d\n", afq->remaining_delay);    av_dlog(afq->avctx, "remaining samples = %d\n", afq->remaining_samples);    av_dlog(afq->avctx, "frames:\n");    f = afq->frame_queue;    while (f) {        av_dlog(afq->avctx, "  [ pts=%9"PRId64" duration=%d ]\n",                f->pts, f->duration);        f = f->next;    }}#endif /* DEBUG */ int ff_af_queue_add(AudioFrameQueue *afq, const AVFrame *f){    AudioFrame *new_frame;    AudioFrame *queue_end = afq->frame_queue;     /* find the end of the queue */    while (queue_end && queue_end->next)        queue_end = queue_end->next;     /* allocate new frame queue entry */    if (!(new_frame = av_malloc(sizeof(*new_frame))))        return AVERROR(ENOMEM);     /* get frame parameters */    new_frame->next = NULL;    new_frame->duration = f->nb_samples;    if (f->pts != AV_NOPTS_VALUE) {        new_frame->pts = av_rescale_q(f->pts,                                      afq->avctx->time_base,                                      (AVRational){ 1, afq->avctx->sample_rate });        afq->next_pts = new_frame->pts + new_frame->duration;    } else {        new_frame->pts = AV_NOPTS_VALUE;        afq->next_pts  = AV_NOPTS_VALUE;    }     /* add new frame to the end of the queue */    if (!queue_end)        afq->frame_queue = new_frame;    else        queue_end->next = new_frame;     /* add frame sample count */    afq->remaining_samples += f->nb_samples; #ifdef DEBUG    af_queue_log_state(afq);#endif     return 0;} void ff_af_queue_remove(AudioFrameQueue *afq, int nb_samples, int64_t *pts,                        int *duration){    int64_t out_pts = AV_NOPTS_VALUE;    int removed_samples = 0; #ifdef DEBUG    af_queue_log_state(afq);#endif     /* get output pts from the next frame or generated pts */    if (afq->frame_queue) {        if (afq->frame_queue->pts != AV_NOPTS_VALUE)            out_pts = afq->frame_queue->pts - afq->remaining_delay;    } else {        if (afq->next_pts != AV_NOPTS_VALUE)            out_pts = afq->next_pts - afq->remaining_delay;    }    if (pts) {        if (out_pts != AV_NOPTS_VALUE)            *pts = ff_samples_to_time_base(afq->avctx, out_pts);        else            *pts = AV_NOPTS_VALUE;    }     /* if the delay is larger than the packet duration, we use up delay samples       for the output packet and leave all frames in the queue */    if (afq->remaining_delay >= nb_samples) {        removed_samples      += nb_samples;        afq->remaining_delay -= nb_samples;    }    /* remove frames from the queue until we have enough to cover the       requested number of samples or until the queue is empty */    while (removed_samples < nb_samples && afq->frame_queue) {        removed_samples += afq->frame_queue->duration;        delete_next_frame(afq);    }    afq->remaining_samples -= removed_samples;     /* if there are no frames left and we have room for more samples, use       any remaining delay samples */    if (removed_samples < nb_samples && afq->remaining_samples > 0) {        int add_samples = FFMIN(afq->remaining_samples,                                nb_samples - removed_samples);        removed_samples        += add_samples;        afq->remaining_samples -= add_samples;    }    if (removed_samples > nb_samples)        av_log(afq->avctx, AV_LOG_WARNING, "frame_size is too large\n");    if (duration)        *duration = ff_samples_to_time_base(afq->avctx, removed_samples);}