1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
/*
* 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/vsink_buffer.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;
if ((ret = avfilter_graph_create_filter(&sink, buffersink,
inout->name, NULL,
pix_fmts, lavfi->graph)) < 0)
FAIL(ret);
lavfi->sinks[i] = sink;
if ((ret = avfilter_link(inout->filter_ctx, 0, 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;
}
}
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;
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_vsink_buffer_get_video_buffer_ref(lavfi->sinks[i],
&picref, AV_VSINK_BUF_FLAG_PEEK);
if (ret < 0)
return ret;
d = av_rescale_q(picref->pts, tb, AV_TIME_BASE_Q);
if (d < min_pts) {
min_pts = d;
min_pts_sink_idx = i;
}
}
av_vsink_buffer_get_video_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->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,
};
|