/*
  * Copyright (c) 2011 Stefano Sabatini
  *

  * 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
  * buffer sink
  */
 

 #include "libavutil/audio_fifo.h"

 #include "libavutil/avassert.h"

 #include "libavutil/channel_layout.h"

 #include "libavutil/common.h"

 #include "libavutil/mathematics.h"

 #include "audio.h"

 #include "avfilter.h"
 #include "buffersink.h"

 #include "internal.h"

 
 typedef struct {

     AVFilterBufferRef *cur_buf;  ///< last buffer delivered on the sink

     AVAudioFifo  *audio_fifo;    ///< FIFO for audio samples
     int64_t next_pts;            ///< interpolating audio pts

 } BufferSinkContext;
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     BufferSinkContext *sink = ctx->priv;
 

     if (sink->audio_fifo)
         av_audio_fifo_free(sink->audio_fifo);

 }
 

 static int filter_frame(AVFilterLink *link, AVFilterBufferRef *buf)

 {

     BufferSinkContext *s = link->dst->priv;

 //     av_assert0(!s->cur_buf);

     s->cur_buf    = buf;

     return 0;

 }

 int ff_buffersink_read_compat(AVFilterContext *ctx, AVFilterBufferRef **buf)

 {

     BufferSinkContext *s    = ctx->priv;

     AVFilterLink      *link = ctx->inputs[0];
     int ret;
 

     if (!buf)
         return ff_poll_frame(ctx->inputs[0]);

     if ((ret = ff_request_frame(link)) < 0)

         return ret;
 

     if (!s->cur_buf)

         return AVERROR(EINVAL);
 

     *buf       = s->cur_buf;
     s->cur_buf = NULL;

 
     return 0;
 }
 

 static int read_from_fifo(AVFilterContext *ctx, AVFilterBufferRef **pbuf,
                           int nb_samples)
 {
     BufferSinkContext *s = ctx->priv;
     AVFilterLink   *link = ctx->inputs[0];
     AVFilterBufferRef *buf;
 
     if (!(buf = ff_get_audio_buffer(link, AV_PERM_WRITE, nb_samples)))
         return AVERROR(ENOMEM);
     av_audio_fifo_read(s->audio_fifo, (void**)buf->extended_data, nb_samples);
 
     buf->pts = s->next_pts;
     s->next_pts += av_rescale_q(nb_samples, (AVRational){1, link->sample_rate},
                                 link->time_base);
 
     *pbuf = buf;
     return 0;
 
 }
 

 int ff_buffersink_read_samples_compat(AVFilterContext *ctx, AVFilterBufferRef **pbuf,
                                       int nb_samples)

 {
     BufferSinkContext *s = ctx->priv;
     AVFilterLink   *link = ctx->inputs[0];
     int ret = 0;
 
     if (!s->audio_fifo) {
         int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
         if (!(s->audio_fifo = av_audio_fifo_alloc(link->format, nb_channels, nb_samples)))
             return AVERROR(ENOMEM);
     }
 
     while (ret >= 0) {
         AVFilterBufferRef *buf;
 
         if (av_audio_fifo_size(s->audio_fifo) >= nb_samples)
             return read_from_fifo(ctx, pbuf, nb_samples);
 
         ret = av_buffersink_read(ctx, &buf);
         if (ret == AVERROR_EOF && av_audio_fifo_size(s->audio_fifo))
             return read_from_fifo(ctx, pbuf, av_audio_fifo_size(s->audio_fifo));
         else if (ret < 0)
             return ret;
 
         if (buf->pts != AV_NOPTS_VALUE) {
             s->next_pts = buf->pts -
                           av_rescale_q(av_audio_fifo_size(s->audio_fifo),
                                        (AVRational){ 1, link->sample_rate },
                                        link->time_base);
         }
 
         ret = av_audio_fifo_write(s->audio_fifo, (void**)buf->extended_data,
                                   buf->audio->nb_samples);
         avfilter_unref_buffer(buf);
     }
 
     return ret;
 }
 

 static const AVFilterPad avfilter_vsink_buffer_inputs[] = {
     {
         .name        = "default",
         .type        = AVMEDIA_TYPE_VIDEO,

         .filter_frame = filter_frame,

         .min_perms   = AV_PERM_READ,
         .needs_fifo  = 1
     },
     { NULL }
 };
 

 AVFilter avfilter_vsink_buffer = {

 #if AV_HAVE_INCOMPATIBLE_FORK_ABI
     .name      = "buffersink",
 #else

     .name      = "buffersink_old",

 #endif

     .description = NULL_IF_CONFIG_SMALL("Buffer video frames, and make them available to the end of the filter graph."),
     .priv_size = sizeof(BufferSinkContext),
     .uninit    = uninit,
 

     .inputs    = avfilter_vsink_buffer_inputs,

     .outputs   = NULL,

 };

 static const AVFilterPad avfilter_asink_abuffer_inputs[] = {
     {
         .name           = "default",
         .type           = AVMEDIA_TYPE_AUDIO,

         .filter_frame   = filter_frame,

         .min_perms      = AV_PERM_READ,
         .needs_fifo     = 1
     },
     { NULL }
 };
 

 AVFilter avfilter_asink_abuffer = {

 #if AV_HAVE_INCOMPATIBLE_FORK_ABI
     .name      = "abuffersink",
 #else

     .name      = "abuffersink_old",

 #endif

     .description = NULL_IF_CONFIG_SMALL("Buffer audio frames, and make them available to the end of the filter graph."),
     .priv_size = sizeof(BufferSinkContext),
     .uninit    = uninit,
 

     .inputs    = avfilter_asink_abuffer_inputs,

     .outputs   = NULL,

 };