buffersink.c
/*
* Copyright (c) 2011 Stefano Sabatini
*
* 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
*/
/**
* @file
* buffer sink
*/
#include "libavutil/audio_fifo.h"
#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/common.h"
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "audio.h"
#include "avfilter.h"
#include "buffersink.h"
#include "internal.h"
typedef struct BufferSinkContext {
AVFrame *cur_frame; ///< last frame 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, AVFrame *frame)
{
BufferSinkContext *s = link->dst->priv;
av_assert0(!s->cur_frame);
s->cur_frame = frame;
return 0;
}
int attribute_align_arg av_buffersink_get_frame(AVFilterContext *ctx,
AVFrame *frame)
{
BufferSinkContext *s = ctx->priv;
AVFilterLink *link = ctx->inputs[0];
int ret;
if ((ret = ff_request_frame(link)) < 0)
return ret;
if (!s->cur_frame)
return AVERROR(EINVAL);
av_frame_move_ref(frame, s->cur_frame);
av_frame_free(&s->cur_frame);
return 0;
}
static int read_from_fifo(AVFilterContext *ctx, AVFrame *frame,
int nb_samples)
{
BufferSinkContext *s = ctx->priv;
AVFilterLink *link = ctx->inputs[0];
AVFrame *tmp;
if (!(tmp = ff_get_audio_buffer(link, nb_samples)))
return AVERROR(ENOMEM);
av_audio_fifo_read(s->audio_fifo, (void**)tmp->extended_data, nb_samples);
tmp->pts = s->next_pts;
s->next_pts += av_rescale_q(nb_samples, (AVRational){1, link->sample_rate},
link->time_base);
av_frame_move_ref(frame, tmp);
av_frame_free(&tmp);
return 0;
}
int attribute_align_arg av_buffersink_get_samples(AVFilterContext *ctx,
AVFrame *frame, 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) {
if (av_audio_fifo_size(s->audio_fifo) >= nb_samples)
return read_from_fifo(ctx, frame, nb_samples);
ret = ff_request_frame(link);
if (ret == AVERROR_EOF && av_audio_fifo_size(s->audio_fifo))
return read_from_fifo(ctx, frame, av_audio_fifo_size(s->audio_fifo));
else if (ret < 0)
return ret;
if (s->cur_frame->pts != AV_NOPTS_VALUE) {
s->next_pts = s->cur_frame->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**)s->cur_frame->extended_data,
s->cur_frame->nb_samples);
av_frame_free(&s->cur_frame);
}
return ret;
}
static const AVFilterPad avfilter_vsink_buffer_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.needs_fifo = 1
},
{ NULL }
};
AVFilter ff_vsink_buffer = {
.name = "buffersink",
.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,
.needs_fifo = 1
},
{ NULL }
};
AVFilter ff_asink_abuffer = {
.name = "abuffersink",
.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,
};