ffmpeg/libavdevice/lavfi.c

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/*
* 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
* libavfilter virtual input device
*/
/* #define DEBUG */
#include "float.h" /* DBL_MIN, DBL_MAX */
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavfilter/avfilter.h"
#include "libavfilter/avfiltergraph.h"
#include "libavfilter/buffersink.h"
#include "avdevice.h"
typedef struct {
AVClass *class; ///< class for private options
char *graph_str;
AVFilterGraph *graph;
AVFilterContext **sinks;
int *sink_stream_map;
int *stream_sink_map;
} LavfiContext;
static int *create_all_formats(int n)
{
int i, j, *fmts, count = 0;
for (i = 0; i < n; i++)
if (!(av_pix_fmt_descriptors[i].flags & PIX_FMT_HWACCEL))
count++;
if (!(fmts = av_malloc((count+1) * sizeof(int))))
return NULL;
for (j = 0, i = 0; i < n; i++) {
if (!(av_pix_fmt_descriptors[i].flags & PIX_FMT_HWACCEL))
fmts[j++] = i;
}
fmts[j] = -1;
return fmts;
}
av_cold static int lavfi_read_close(AVFormatContext *avctx)
{
LavfiContext *lavfi = avctx->priv_data;
av_freep(&lavfi->sink_stream_map);
av_freep(&lavfi->stream_sink_map);
avfilter_graph_free(&lavfi->graph);
return 0;
}
av_cold static int lavfi_read_header(AVFormatContext *avctx,
AVFormatParameters *ap)
{
LavfiContext *lavfi = avctx->priv_data;
AVFilterInOut *input_links = NULL, *output_links = NULL, *inout;
AVFilter *buffersink;
int *pix_fmts = create_all_formats(PIX_FMT_NB);
int ret = 0, i, n;
#define FAIL(ERR) { ret = ERR; goto end; }
avfilter_register_all();
if (!(buffersink = avfilter_get_by_name("buffersink"))) {
av_log(avctx, AV_LOG_ERROR,
"Missing required buffersink filter, aborting.\n");
FAIL(AVERROR_FILTER_NOT_FOUND);
}
if (!lavfi->graph_str)
lavfi->graph_str = av_strdup(avctx->filename);
/* parse the graph, create a stream for each open output */
if (!(lavfi->graph = avfilter_graph_alloc()))
FAIL(AVERROR(ENOMEM));
if ((ret = avfilter_graph_parse(lavfi->graph, lavfi->graph_str,
&input_links, &output_links, avctx)) < 0)
FAIL(ret);
if (input_links) {
av_log(avctx, AV_LOG_ERROR,
"Open inputs in the filtergraph are not acceptable\n");
FAIL(AVERROR(EINVAL));
}
/* count the outputs */
for (n = 0, inout = output_links; inout; n++, inout = inout->next);
if (!(lavfi->sink_stream_map = av_malloc(sizeof(int) * n)))
FAIL(AVERROR(ENOMEM));
if (!(lavfi->stream_sink_map = av_malloc(sizeof(int) * n)))
FAIL(AVERROR(ENOMEM));
for (i = 0; i < n; i++)
lavfi->stream_sink_map[i] = -1;
/* parse the output link names - they need to be of the form out0, out1, ...
* create a mapping between them and the streams */
for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
int stream_idx;
if (!strcmp(inout->name, "out"))
stream_idx = 0;
else if (sscanf(inout->name, "out%d\n", &stream_idx) != 1) {
av_log(avctx, AV_LOG_ERROR,
"Invalid outpad name '%s'\n", inout->name);
FAIL(AVERROR(EINVAL));
}
if ((unsigned)stream_idx >= n) {
av_log(avctx, AV_LOG_ERROR,
"Invalid index was specified in output '%s', "
"must be a non-negative value < %d\n",
inout->name, n);
FAIL(AVERROR(EINVAL));
}
/* is a video output? */
if (inout->filter_ctx->output_pads[inout->pad_idx].type != AVMEDIA_TYPE_VIDEO) {
av_log(avctx, AV_LOG_ERROR,
"Output '%s' is not a video output, not yet supported", inout->name);
FAIL(AVERROR(EINVAL));
}
if (lavfi->stream_sink_map[stream_idx] != -1) {
av_log(avctx, AV_LOG_ERROR,
"An with stream index %d was already specified\n",
stream_idx);
FAIL(AVERROR(EINVAL));
}
lavfi->sink_stream_map[i] = stream_idx;
lavfi->stream_sink_map[stream_idx] = i;
}
/* for each open output create a corresponding stream */
for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
AVStream *st;
if (!(st = av_new_stream(avctx, i)))
FAIL(AVERROR(ENOMEM));
}
/* create a sink for each output and connect them to the graph */
lavfi->sinks = av_malloc(sizeof(AVFilterContext *) * avctx->nb_streams);
if (!lavfi->sinks)
FAIL(AVERROR(ENOMEM));
for (i = 0, inout = output_links; inout; i++, inout = inout->next) {
AVFilterContext *sink;
AVBufferSinkParams *buffersink_params = av_buffersink_params_alloc();
#if FF_API_OLD_VSINK_API
ret = avfilter_graph_create_filter(&sink, buffersink,
inout->name, NULL,
pix_fmts, lavfi->graph);
#else
buffersink_params->pixel_fmts = pix_fmts;
ret = avfilter_graph_create_filter(&sink, buffersink,
inout->name, NULL,
buffersink_params, lavfi->graph);
#endif
av_freep(&buffersink_params);
if (ret < 0)
goto end;
lavfi->sinks[i] = sink;
if ((ret = avfilter_link(inout->filter_ctx, inout->pad_idx, sink, 0)) < 0)
FAIL(ret);
}
/* configure the graph */
if ((ret = avfilter_graph_config(lavfi->graph, avctx)) < 0)
FAIL(ret);
/* fill each stream with the information in the corresponding sink */
for (i = 0; i < avctx->nb_streams; i++) {
AVFilterLink *link = lavfi->sinks[lavfi->stream_sink_map[i]]->inputs[0];
AVStream *st = avctx->streams[i];
st->codec->codec_type = link->type;
av_set_pts_info(st, 64, link->time_base.num, link->time_base.den);
if (link->type == AVMEDIA_TYPE_VIDEO) {
st->codec->codec_id = CODEC_ID_RAWVIDEO;
st->codec->pix_fmt = link->format;
st->codec->time_base = link->time_base;
st->codec->width = link->w;
st->codec->height = link->h;
st ->sample_aspect_ratio =
st->codec->sample_aspect_ratio = link->sample_aspect_ratio;
}
}
end:
avfilter_inout_free(&input_links);
avfilter_inout_free(&output_links);
if (ret < 0)
lavfi_read_close(avctx);
return ret;
}
static int lavfi_read_packet(AVFormatContext *avctx, AVPacket *pkt)
{
LavfiContext *lavfi = avctx->priv_data;
double min_pts = DBL_MAX;
int min_pts_sink_idx = 0;
AVFilterBufferRef *picref;
AVPicture pict;
int ret, i, size;
/* iterate through all the graph sinks. Select the sink with the
* minimum PTS */
for (i = 0; i < avctx->nb_streams; i++) {
AVRational tb = lavfi->sinks[i]->inputs[0]->time_base;
double d;
int ret = av_buffersink_get_buffer_ref(lavfi->sinks[i],
&picref, AV_BUFFERSINK_FLAG_PEEK);
if (ret < 0)
return ret;
d = av_rescale_q(picref->pts, tb, AV_TIME_BASE_Q);
av_dlog(avctx, "sink_idx:%d time:%f\n", i, d);
if (d < min_pts) {
min_pts = d;
min_pts_sink_idx = i;
}
}
av_dlog(avctx, "min_pts_sink_idx:%i\n", min_pts_sink_idx);
av_buffersink_get_buffer_ref(lavfi->sinks[min_pts_sink_idx], &picref, 0);
size = avpicture_get_size(picref->format, picref->video->w, picref->video->h);
if ((ret = av_new_packet(pkt, size)) < 0)
return ret;
memcpy(pict.data, picref->data, 4*sizeof(picref->data[0]));
memcpy(pict.linesize, picref->linesize, 4*sizeof(picref->linesize[0]));
avpicture_layout(&pict, picref->format, picref->video->w,
picref->video->h, pkt->data, size);
pkt->stream_index = lavfi->sink_stream_map[min_pts_sink_idx];
pkt->pts = picref->pts;
pkt->pos = picref->pos;
pkt->size = size;
avfilter_unref_buffer(picref);
return size;
}
#define OFFSET(x) offsetof(LavfiContext, x)
#define DEC AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{ "graph", "Libavfilter graph", OFFSET(graph_str), FF_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
{ NULL },
};
static const AVClass lavfi_class = {
.class_name = "lavfi indev",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_lavfi_demuxer = {
.name = "lavfi",
.long_name = NULL_IF_CONFIG_SMALL("Libavfilter virtual input device"),
.priv_data_size = sizeof(LavfiContext),
.read_header = lavfi_read_header,
.read_packet = lavfi_read_packet,
.read_close = lavfi_read_close,
.flags = AVFMT_NOFILE,
.priv_class = &lavfi_class,
};