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/*
* Copyright (c) 2007 Bobby Bingham
*
* 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
* FIFO buffering filter
*/
#include "libavutil/avassert.h"
#include "libavutil/audioconvert.h"
#include "libavutil/mathematics.h"
#include "libavutil/samplefmt.h"
#include "audio.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"
typedef struct Buf {
AVFilterBufferRef *buf;
struct Buf *next;
} Buf;
typedef struct {
Buf root;
Buf *last; ///< last buffered frame
/**
* When a specific number of output samples is requested, the partial
* buffer is stored here
*/
AVFilterBufferRef *buf_out;
int allocated_samples; ///< number of samples buf_out was allocated for
} FifoContext;
static av_cold int init(AVFilterContext *ctx, const char *args)
{
FifoContext *fifo = ctx->priv;
fifo->last = &fifo->root;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
FifoContext *fifo = ctx->priv;
Buf *buf, *tmp;
for (buf = fifo->root.next; buf; buf = tmp) {
tmp = buf->next;
avfilter_unref_bufferp(&buf->buf);
av_free(buf);
}
avfilter_unref_bufferp(&fifo->buf_out);
}
static int add_to_queue(AVFilterLink *inlink, AVFilterBufferRef *buf)
{
FifoContext *fifo = inlink->dst->priv;
inlink->cur_buf = NULL;
fifo->last->next = av_mallocz(sizeof(Buf));
if (!fifo->last->next) {
avfilter_unref_buffer(buf);
return AVERROR(ENOMEM);
}
fifo->last = fifo->last->next;
fifo->last->buf = buf;
return 0;
}
static void queue_pop(FifoContext *s)
{
Buf *tmp = s->root.next->next;
if (s->last == s->root.next)
s->last = &s->root;
av_freep(&s->root.next);
s->root.next = tmp;
}
static int end_frame(AVFilterLink *inlink)
{
return 0;
}
static int draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
{
return 0;
}
/**
* Move data pointers and pts offset samples forward.
*/
static void buffer_offset(AVFilterLink *link, AVFilterBufferRef *buf,
int offset)
{
int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
int planar = av_sample_fmt_is_planar(link->format);
int planes = planar ? nb_channels : 1;
int block_align = av_get_bytes_per_sample(link->format) * (planar ? 1 : nb_channels);
int i;
av_assert0(buf->audio->nb_samples > offset);
for (i = 0; i < planes; i++)
buf->extended_data[i] += block_align*offset;
if (buf->data != buf->extended_data)
memcpy(buf->data, buf->extended_data,
FFMIN(planes, FF_ARRAY_ELEMS(buf->data)) * sizeof(*buf->data));
buf->linesize[0] -= block_align*offset;
buf->audio->nb_samples -= offset;
if (buf->pts != AV_NOPTS_VALUE) {
buf->pts += av_rescale_q(offset, (AVRational){1, link->sample_rate},
link->time_base);
}
}
static int calc_ptr_alignment(AVFilterBufferRef *buf)
{
int planes = av_sample_fmt_is_planar(buf->format) ?
av_get_channel_layout_nb_channels(buf->audio->channel_layout) : 1;
int min_align = 128;
int p;
for (p = 0; p < planes; p++) {
int cur_align = 128;
while ((intptr_t)buf->extended_data[p] % cur_align)
cur_align >>= 1;
if (cur_align < min_align)
min_align = cur_align;
}
return min_align;
}
static int return_audio_frame(AVFilterContext *ctx)
{
AVFilterLink *link = ctx->outputs[0];
FifoContext *s = ctx->priv;
AVFilterBufferRef *head = s->root.next->buf;
AVFilterBufferRef *buf_out;
int ret;
if (!s->buf_out &&
head->audio->nb_samples >= link->request_samples &&
calc_ptr_alignment(head) >= 32) {
if (head->audio->nb_samples == link->request_samples) {
buf_out = head;
queue_pop(s);
} else {
buf_out = avfilter_ref_buffer(head, AV_PERM_READ);
if (!buf_out)
return AVERROR(ENOMEM);
buf_out->audio->nb_samples = link->request_samples;
buffer_offset(link, head, link->request_samples);
}
} else {
int nb_channels = av_get_channel_layout_nb_channels(link->channel_layout);
if (!s->buf_out) {
s->buf_out = ff_get_audio_buffer(link, AV_PERM_WRITE,
link->request_samples);
if (!s->buf_out)
return AVERROR(ENOMEM);
s->buf_out->audio->nb_samples = 0;
s->buf_out->pts = head->pts;
s->allocated_samples = link->request_samples;
} else if (link->request_samples != s->allocated_samples) {
av_log(ctx, AV_LOG_ERROR, "request_samples changed before the "
"buffer was returned.\n");
return AVERROR(EINVAL);
}
while (s->buf_out->audio->nb_samples < s->allocated_samples) {
int len = FFMIN(s->allocated_samples - s->buf_out->audio->nb_samples,
head->audio->nb_samples);
av_samples_copy(s->buf_out->extended_data, head->extended_data,
s->buf_out->audio->nb_samples, 0, len, nb_channels,
link->format);
s->buf_out->audio->nb_samples += len;
if (len == head->audio->nb_samples) {
avfilter_unref_buffer(head);
queue_pop(s);
if (!s->root.next &&
(ret = ff_request_frame(ctx->inputs[0])) < 0) {
if (ret == AVERROR_EOF) {
av_samples_set_silence(s->buf_out->extended_data,
s->buf_out->audio->nb_samples,
s->allocated_samples -
s->buf_out->audio->nb_samples,
nb_channels, link->format);
s->buf_out->audio->nb_samples = s->allocated_samples;
break;
}
return ret;
}
head = s->root.next->buf;
} else {
buffer_offset(link, head, len);
}
}
buf_out = s->buf_out;
s->buf_out = NULL;
}
return ff_filter_samples(link, buf_out);
}
static int request_frame(AVFilterLink *outlink)
{
FifoContext *fifo = outlink->src->priv;
int ret = 0;
if (!fifo->root.next) {
if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0)
return ret;
}
/* by doing this, we give ownership of the reference to the next filter,
* so we don't have to worry about dereferencing it ourselves. */
switch (outlink->type) {
case AVMEDIA_TYPE_VIDEO:
if ((ret = ff_start_frame(outlink, fifo->root.next->buf)) < 0 ||
(ret = ff_draw_slice(outlink, 0, outlink->h, 1)) < 0 ||
(ret = ff_end_frame(outlink)) < 0)
return ret;
queue_pop(fifo);
break;
case AVMEDIA_TYPE_AUDIO:
if (outlink->request_samples) {
return return_audio_frame(outlink->src);
} else {
ret = ff_filter_samples(outlink, fifo->root.next->buf);
queue_pop(fifo);
}
break;
default:
return AVERROR(EINVAL);
}
return ret;
}
AVFilter avfilter_vf_fifo = {
.name = "fifo",
.description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(FifoContext),
.inputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.get_video_buffer= ff_null_get_video_buffer,
.start_frame = add_to_queue,
.draw_slice = draw_slice,
.end_frame = end_frame,
.rej_perms = AV_PERM_REUSE2, },
{ .name = NULL}},
.outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.request_frame = request_frame, },
{ .name = NULL}},
};
AVFilter avfilter_af_afifo = {
.name = "afifo",
.description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(FifoContext),
.inputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.get_audio_buffer = ff_null_get_audio_buffer,
.filter_samples = add_to_queue,
.rej_perms = AV_PERM_REUSE2, },
{ .name = NULL}},
.outputs = (const AVFilterPad[]) {{ .name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.request_frame = request_frame, },
{ .name = NULL}},
};
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