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lavfi: add select filter

Address trac issue #92.

Stefano Sabatini committed 15 years ago

Commit 07586b61 parent 3c2c52b6 files · +471 −1Browse files

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6 files
  1. Changelog +1 −0
  2. doc/filters.texi +116 −0
  3. libavfilter/Makefile +1 −0
  4. libavfilter/allfilters.c +1 −0
  5. libavfilter/avfilter.h +1 −1
  6. libavfilter/vf_select.c +351 −0
Changelog+1−0
@@ -18,6 +18,7 @@ version <next>: · 17 unmodified lines
18- 9bit and 10bit H.264 decoding18- 9bit and 10bit H.264 decoding
19- 9bit and 10bit FFV1 encoding / decoding19- 9bit and 10bit FFV1 encoding / decoding
20- split filter added20- split filter added
21- select filter added
21 22
22 23
23version 0.7_beta1:24version 0.7_beta1:
doc/filters.texi+116−0
@@ -1163,6 +1163,122 @@ scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub" · 1162 unmodified lines
1163scale='min(500\, iw*3/2):-1'1163scale='min(500\, iw*3/2):-1'
1164@end example1164@end example
1165 1165
1166@section select
1167Select frames to pass in output.
1168
1169It accepts in input an expression, which is evaluated for each input
1170frame. If the expression is evaluated to a non-zero value, the frame
1171is selected and passed to the output, otherwise it is discarded.
1172
1173The expression can contain the following constants:
1174
1175@table @option
1176@item PI
1177Greek PI
1178
1179@item PHI
1180golden ratio
1181
1182@item E
1183Euler number
1184
1185@item n
1186the sequential number of the filtered frame, starting from 0
1187
1188@item selected_n
1189the sequential number of the selected frame, starting from 0
1190
1191@item prev_selected_n
1192the sequential number of the last selected frame, NAN if undefined
1193
1194@item TB
1195timebase of the input timestamps
1196
1197@item pts
1198the PTS (Presentation TimeStamp) of the filtered video frame,
1199expressed in @var{TB} units, NAN if undefined
1200
1201@item t
1202the PTS (Presentation TimeStamp) of the filtered video frame,
1203expressed in seconds, NAN if undefined
1204
1205@item prev_pts
1206the PTS of the previously filtered video frame, NAN if undefined
1207
1208@item prev_selected_pts
1209the PTS of the last previously filtered video frame, NAN if undefined
1210
1211@item prev_selected_t
1212the PTS of the last previously selected video frame, NAN if undefined
1213
1214@item start_pts
1215the PTS of the first video frame in the video, NAN if undefined
1216
1217@item start_t
1218the time of the first video frame in the video, NAN if undefined
1219
1220@item pict_type
1221the picture type of the filtered frame, can assume one of the following
1222values:
1223@table @option
1224@item PICT_TYPE_I
1225@item PICT_TYPE_P
1226@item PICT_TYPE_B
1227@item PICT_TYPE_S
1228@item PICT_TYPE_SI
1229@item PICT_TYPE_SP
1230@item PICT_TYPE_BI
1231@end table
1232
1233@item interlace_type
1234the frame interlace type, can assume one of the following values:
1235@table @option
1236@item INTERLACE_TYPE_P
1237the frame is progressive (not interlaced)
1238@item INTERLACE_TYPE_T
1239the frame is top-field-first
1240@item INTERLACE_TYPE_B
1241the frame is bottom-field-first
1242@end table
1243
1244@item key
12451 if the filtered frame is a key-frame, 0 otherwise
1246
1247@item pos
1248the position in the file of the filtered frame, -1 if the information
1249is not available (e.g. for synthetic video)
1250@end table
1251
1252The default value of the select expression is "1".
1253
1254Some examples follow:
1255
1256@example
1257# select all frames in input
1258select
1259
1260# the above is the same as:
1261select=1
1262
1263# skip all frames:
1264select=0
1265
1266# select only I-frames
1267select='eq(pict_type\,PICT_TYPE_I)'
1268
1269# select one frame every 100
1270select='not(mod(n\,100))'
1271
1272# select only frames contained in the 10-20 time interval
1273select='gte(t\,10)*lte(t\,20)'
1274
1275# select only I frames contained in the 10-20 time interval
1276select='gte(t\,10)*lte(t\,20)*eq(pict_type\,PICT_TYPE_I)'
1277
1278# select frames with a minimum distance of 10 seconds
1279select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
1280@end example
1281
1166@anchor{setdar}1282@anchor{setdar}
1167@section setdar1283@section setdar
1168 1284
libavfilter/Makefile+1−0
@@ -46,6 +46,7 @@ OBJS-$(CONFIG_OVERLAY_FILTER) += vf_overlay.o · 45 unmodified lines
46OBJS-$(CONFIG_PAD_FILTER) += vf_pad.o46OBJS-$(CONFIG_PAD_FILTER) += vf_pad.o
47OBJS-$(CONFIG_PIXDESCTEST_FILTER) += vf_pixdesctest.o47OBJS-$(CONFIG_PIXDESCTEST_FILTER) += vf_pixdesctest.o
48OBJS-$(CONFIG_SCALE_FILTER) += vf_scale.o48OBJS-$(CONFIG_SCALE_FILTER) += vf_scale.o
49OBJS-$(CONFIG_SELECT_FILTER) += vf_select.o
49OBJS-$(CONFIG_SETDAR_FILTER) += vf_aspect.o50OBJS-$(CONFIG_SETDAR_FILTER) += vf_aspect.o
50OBJS-$(CONFIG_SETPTS_FILTER) += vf_setpts.o51OBJS-$(CONFIG_SETPTS_FILTER) += vf_setpts.o
51OBJS-$(CONFIG_SETSAR_FILTER) += vf_aspect.o52OBJS-$(CONFIG_SETSAR_FILTER) += vf_aspect.o
libavfilter/allfilters.c+1−0
@@ -62,6 +62,7 @@ void avfilter_register_all(void) · 61 unmodified lines
62 REGISTER_FILTER (PAD, pad, vf);62 REGISTER_FILTER (PAD, pad, vf);
63 REGISTER_FILTER (PIXDESCTEST, pixdesctest, vf);63 REGISTER_FILTER (PIXDESCTEST, pixdesctest, vf);
64 REGISTER_FILTER (SCALE, scale, vf);64 REGISTER_FILTER (SCALE, scale, vf);
65 REGISTER_FILTER (SELECT, select, vf);
65 REGISTER_FILTER (SETDAR, setdar, vf);66 REGISTER_FILTER (SETDAR, setdar, vf);
66 REGISTER_FILTER (SETPTS, setpts, vf);67 REGISTER_FILTER (SETPTS, setpts, vf);
67 REGISTER_FILTER (SETSAR, setsar, vf);68 REGISTER_FILTER (SETSAR, setsar, vf);
libavfilter/avfilter.h+1−1
@@ -26,7 +26,7 @@ · 25 unmodified lines
26#include "libavutil/samplefmt.h"26#include "libavutil/samplefmt.h"
27 27
28#define LIBAVFILTER_VERSION_MAJOR 228#define LIBAVFILTER_VERSION_MAJOR 2
29#define LIBAVFILTER_VERSION_MINOR 1029#define LIBAVFILTER_VERSION_MINOR 11
30#define LIBAVFILTER_VERSION_MICRO 030#define LIBAVFILTER_VERSION_MICRO 0
31 31
32#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \32#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
libavfilter/vf_select.c+351−0
@@ -0,0 +1,351 @@
1/*
2 * Copyright (c) 2011 Stefano Sabatini
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
22 * @file
23 * filter for selecting which frame passes in the filterchain
24 */
25
26#include "libavutil/eval.h"
27#include "libavutil/fifo.h"
28#include "avfilter.h"
29
30static const char *var_names[] = {
31 "E", ///< Euler number
32 "PHI", ///< golden ratio
33 "PI", ///< greek pi
34
35 "TB", ///< timebase
36
37 "pts", ///< original pts in the file of the frame
38 "start_pts", ///< first PTS in the stream, expressed in TB units
39 "prev_pts", ///< previous frame PTS
40 "prev_selected_pts", ///< previous selected frame PTS
41
42 "t", ///< first PTS in seconds
43 "start_t", ///< first PTS in the stream, expressed in seconds
44 "prev_t", ///< previous frame time
45 "prev_selected_t", ///< previously selected time
46
47 "pict_type", ///< the type of picture in the movie
48 "PICT_TYPE_I",
49 "PICT_TYPE_P",
50 "PICT_TYPE_B",
51 "PICT_TYPE_S",
52 "PICT_TYPE_SI",
53 "PICT_TYPE_SP",
54 "PICT_TYPE_BI",
55
56 "interlace_type", ///< the frame interlace type
57 "INTERLACE_TYPE_P",
58 "INTERLACE_TYPE_T",
59 "INTERLACE_TYPE_B",
60
61 "n", ///< frame number (starting from zero)
62 "selected_n", ///< selected frame number (starting from zero)
63 "prev_selected_n", ///< number of the last selected frame
64
65 "key", ///< tell if the frame is a key frame
66 "pos", ///< original position in the file of the frame
67
68 NULL
69};
70
71enum var_name {
72 VAR_E,
73 VAR_PHI,
74 VAR_PI,
75
76 VAR_TB,
77
78 VAR_PTS,
79 VAR_START_PTS,
80 VAR_PREV_PTS,
81 VAR_PREV_SELECTED_PTS,
82
83 VAR_T,
84 VAR_START_T,
85 VAR_PREV_T,
86 VAR_PREV_SELECTED_T,
87
88 VAR_PICT_TYPE,
89 VAR_PICT_TYPE_I,
90 VAR_PICT_TYPE_P,
91 VAR_PICT_TYPE_B,
92 VAR_PICT_TYPE_S,
93 VAR_PICT_TYPE_SI,
94 VAR_PICT_TYPE_SP,
95 VAR_PICT_TYPE_BI,
96
97 VAR_INTERLACE_TYPE,
98 VAR_INTERLACE_TYPE_P,
99 VAR_INTERLACE_TYPE_T,
100 VAR_INTERLACE_TYPE_B,
101
102 VAR_N,
103 VAR_SELECTED_N,
104 VAR_PREV_SELECTED_N,
105
106 VAR_KEY,
107 VAR_POS,
108
109 VAR_VARS_NB
110};
111
112#define FIFO_SIZE 8
113
114typedef struct {
115 AVExpr *expr;
116 double var_values[VAR_VARS_NB];
117 double select;
118 int cache_frames;
119 AVFifoBuffer *pending_frames; ///< FIFO buffer of video frames
120} SelectContext;
121
122static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
123{
124 SelectContext *select = ctx->priv;
125 int ret;
126
127 if ((ret = av_expr_parse(&select->expr, args ? args : "1",
128 var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
129 av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", args);
130 return ret;
131 }
132
133 select->pending_frames = av_fifo_alloc(FIFO_SIZE*sizeof(AVFilterBufferRef*));
134 if (!select->pending_frames) {
135 av_log(ctx, AV_LOG_ERROR, "Failed to allocate pending frames buffer.\n");
136 return AVERROR(ENOMEM);
137 }
138 return 0;
139}
140
141#define INTERLACE_TYPE_P 0
142#define INTERLACE_TYPE_T 1
143#define INTERLACE_TYPE_B 2
144
145static int config_input(AVFilterLink *inlink)
146{
147 SelectContext *select = inlink->dst->priv;
148
149 select->var_values[VAR_E] = M_E;
150 select->var_values[VAR_PHI] = M_PHI;
151 select->var_values[VAR_PI] = M_PI;
152
153 select->var_values[VAR_N] = 0.0;
154 select->var_values[VAR_SELECTED_N] = 0.0;
155
156 select->var_values[VAR_TB] = av_q2d(inlink->time_base);
157
158 select->var_values[VAR_PREV_PTS] = NAN;
159 select->var_values[VAR_PREV_SELECTED_PTS] = NAN;
160 select->var_values[VAR_PREV_SELECTED_T] = NAN;
161 select->var_values[VAR_START_PTS] = NAN;
162 select->var_values[VAR_START_T] = NAN;
163
164 select->var_values[VAR_PICT_TYPE_I] = AV_PICTURE_TYPE_I;
165 select->var_values[VAR_PICT_TYPE_P] = AV_PICTURE_TYPE_P;
166 select->var_values[VAR_PICT_TYPE_B] = AV_PICTURE_TYPE_B;
167 select->var_values[VAR_PICT_TYPE_SI] = AV_PICTURE_TYPE_SI;
168 select->var_values[VAR_PICT_TYPE_SP] = AV_PICTURE_TYPE_SP;
169
170 select->var_values[VAR_INTERLACE_TYPE_P] = INTERLACE_TYPE_P;
171 select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T;
172 select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B;;
173
174 return 0;
175}
176
177#define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
178#define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
179
180static int select_frame(AVFilterContext *ctx, AVFilterBufferRef *picref)
181{
182 SelectContext *select = ctx->priv;
183 AVFilterLink *inlink = ctx->inputs[0];
184 double res;
185
186 if (isnan(select->var_values[VAR_START_PTS]))
187 select->var_values[VAR_START_PTS] = TS2D(picref->pts);
188
189 select->var_values[VAR_PTS] = TS2D(picref->pts);
190 select->var_values[VAR_T ] = picref->pts * av_q2d(inlink->time_base);
191 select->var_values[VAR_POS] = picref->pos == -1 ? NAN : picref->pos;
192 select->var_values[VAR_PREV_PTS] = TS2D(picref ->pts);
193
194 select->var_values[VAR_INTERLACE_TYPE] =
195 !picref->video->interlaced ? INTERLACE_TYPE_P :
196 picref->video->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B;
197 select->var_values[VAR_PICT_TYPE] = picref->video->pict_type;
198
199 res = av_expr_eval(select->expr, select->var_values, NULL);
200 av_log(inlink->dst, AV_LOG_DEBUG,
201 "n:%d pts:%d t:%f pos:%d interlace_type:%c key:%d pict_type:%c "
202 "-> select:%f\n",
203 (int)select->var_values[VAR_N],
204 (int)select->var_values[VAR_PTS],
205 select->var_values[VAR_T],
206 (int)select->var_values[VAR_POS],
207 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' :
208 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' :
209 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?',
210 (int)select->var_values[VAR_KEY],
211 av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]),
212 res);
213
214 select->var_values[VAR_N] += 1.0;
215
216 if (res) {
217 select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N];
218 select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS];
219 select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T];
220 select->var_values[VAR_SELECTED_N] += 1.0;
221 }
222 return res;
223}
224
225static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
226{
227 SelectContext *select = inlink->dst->priv;
228
229 select->select = select_frame(inlink->dst, picref);
230 if (select->select) {
231 /* frame was requested through poll_frame */
232 if (select->cache_frames) {
233 if (!av_fifo_space(select->pending_frames))
234 av_log(inlink->dst, AV_LOG_ERROR,
235 "Buffering limit reached, cannot cache more frames\n");
236 else
237 av_fifo_generic_write(select->pending_frames, &picref,
238 sizeof(picref), NULL);
239 return;
240 }
241 avfilter_start_frame(inlink->dst->outputs[0], avfilter_ref_buffer(picref, ~0));
242 }
243}
244
245static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
246{
247 SelectContext *select = inlink->dst->priv;
248
249 if (select->select && !select->cache_frames)
250 avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
251}
252
253static void end_frame(AVFilterLink *inlink)
254{
255 SelectContext *select = inlink->dst->priv;
256 AVFilterBufferRef *picref = inlink->cur_buf;
257
258 if (select->select) {
259 if (select->cache_frames)
260 return;
261 avfilter_end_frame(inlink->dst->outputs[0]);
262 }
263 avfilter_unref_buffer(picref);
264}
265
266static int request_frame(AVFilterLink *outlink)
267{
268 AVFilterContext *ctx = outlink->src;
269 SelectContext *select = ctx->priv;
270 AVFilterLink *inlink = outlink->src->inputs[0];
271 select->select = 0;
272
273 if (av_fifo_size(select->pending_frames)) {
274 AVFilterBufferRef *picref;
275 av_fifo_generic_read(select->pending_frames, &picref, sizeof(picref), NULL);
276 avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
277 avfilter_draw_slice(outlink, 0, outlink->h, 1);
278 avfilter_end_frame(outlink);
279 avfilter_unref_buffer(picref);
280 return 0;
281 }
282
283 while (!select->select) {
284 int ret = avfilter_request_frame(inlink);
285 if (ret < 0)
286 return ret;
287 }
288
289 return 0;
290}
291
292static int poll_frame(AVFilterLink *outlink)
293{
294 SelectContext *select = outlink->src->priv;
295 AVFilterLink *inlink = outlink->src->inputs[0];
296 int count, ret;
297
298 if (!av_fifo_size(select->pending_frames)) {
299 if ((count = avfilter_poll_frame(inlink)) <= 0)
300 return count;
301 /* request frame from input, and apply select condition to it */
302 select->cache_frames = 1;
303 while (count-- && av_fifo_space(select->pending_frames)) {
304 ret = avfilter_request_frame(inlink);
305 if (ret < 0)
306 break;
307 }
308 select->cache_frames = 0;
309 }
310
311 return av_fifo_size(select->pending_frames)/sizeof(AVFilterBufferRef *);
312}
313
314static av_cold void uninit(AVFilterContext *ctx)
315{
316 SelectContext *select = ctx->priv;
317 AVFilterBufferRef *picref;
318 int i;
319
320 av_expr_free(select->expr);
321 select->expr = NULL;
322
323 for (i = 0; i < av_fifo_size(select->pending_frames)/sizeof(picref); i++) {
324 av_fifo_generic_read(select->pending_frames, &picref, sizeof(picref), NULL);
325 avfilter_unref_buffer(picref);
326 }
327 av_fifo_free(select->pending_frames);
328}
329
330AVFilter avfilter_vf_select = {
331 .name = "select",
332 .description = NULL_IF_CONFIG_SMALL("Select frames to pass in output."),
333 .init = init,
334 .uninit = uninit,
335
336 .priv_size = sizeof(SelectContext),
337
338 .inputs = (AVFilterPad[]) {{ .name = "default",
339 .type = AVMEDIA_TYPE_VIDEO,
340 .get_video_buffer = avfilter_null_get_video_buffer,
341 .config_props = config_input,
342 .start_frame = start_frame,
343 .draw_slice = draw_slice,
344 .end_frame = end_frame },
345 { .name = NULL }},
346 .outputs = (AVFilterPad[]) {{ .name = "default",
347 .type = AVMEDIA_TYPE_VIDEO,
348 .poll_frame = poll_frame,
349 .request_frame = request_frame, },
350 { .name = NULL}},
351};

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