h264_metadata: Add option to delete filler data
[libav.git] / libavfilter / vf_fps.c
1 /*
2 * This file is part of Libav.
3 *
4 * Libav is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 /**
20 * @file
21 * a filter enforcing given constant framerate
22 */
23
24 #include <float.h>
25 #include <stdint.h>
26
27 #include "libavutil/common.h"
28 #include "libavutil/fifo.h"
29 #include "libavutil/mathematics.h"
30 #include "libavutil/opt.h"
31 #include "libavutil/parseutils.h"
32
33 #include "avfilter.h"
34 #include "internal.h"
35 #include "video.h"
36
37 typedef struct FPSContext {
38 const AVClass *class;
39
40 AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps
41
42 /* timestamps in input timebase */
43 int64_t first_pts; ///< pts of the first frame that arrived on this filter
44 int64_t pts; ///< pts of the first frame currently in the fifo
45
46 double start_time; ///< pts, in seconds, of the expected first frame
47
48 AVRational framerate; ///< target framerate
49 char *fps; ///< a string describing target framerate
50
51 /* statistics */
52 int frames_in; ///< number of frames on input
53 int frames_out; ///< number of frames on output
54 int dup; ///< number of frames duplicated
55 int drop; ///< number of framed dropped
56 } FPSContext;
57
58 #define OFFSET(x) offsetof(FPSContext, x)
59 #define V AV_OPT_FLAG_VIDEO_PARAM
60 static const AVOption options[] = {
61 { "fps", "A string describing desired output framerate", OFFSET(fps), AV_OPT_TYPE_STRING, { .str = "25" }, .flags = V },
62 { "start_time", "Assume the first PTS should be this value.", OFFSET(start_time), AV_OPT_TYPE_DOUBLE, { .dbl = DBL_MAX}, -DBL_MAX, DBL_MAX, V },
63 { NULL },
64 };
65
66 static const AVClass class = {
67 .class_name = "FPS filter",
68 .item_name = av_default_item_name,
69 .option = options,
70 .version = LIBAVUTIL_VERSION_INT,
71 };
72
73 static av_cold int init(AVFilterContext *ctx)
74 {
75 FPSContext *s = ctx->priv;
76 int ret;
77
78 if ((ret = av_parse_video_rate(&s->framerate, s->fps)) < 0) {
79 av_log(ctx, AV_LOG_ERROR, "Error parsing framerate %s.\n", s->fps);
80 return ret;
81 }
82
83 if (!(s->fifo = av_fifo_alloc(2*sizeof(AVFrame*))))
84 return AVERROR(ENOMEM);
85
86 s->pts = AV_NOPTS_VALUE;
87 s->first_pts = AV_NOPTS_VALUE;
88
89 av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den);
90 return 0;
91 }
92
93 static void flush_fifo(AVFifoBuffer *fifo)
94 {
95 while (av_fifo_size(fifo)) {
96 AVFrame *tmp;
97 av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL);
98 av_frame_free(&tmp);
99 }
100 }
101
102 static av_cold void uninit(AVFilterContext *ctx)
103 {
104 FPSContext *s = ctx->priv;
105 if (s->fifo) {
106 s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*);
107 flush_fifo(s->fifo);
108 av_fifo_free(s->fifo);
109 }
110
111 av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, "
112 "%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup);
113 }
114
115 static int config_props(AVFilterLink* link)
116 {
117 FPSContext *s = link->src->priv;
118
119 link->time_base = (AVRational){ s->framerate.den, s->framerate.num };
120 link->frame_rate = s->framerate;
121 link->w = link->src->inputs[0]->w;
122 link->h = link->src->inputs[0]->h;
123
124 return 0;
125 }
126
127 static int request_frame(AVFilterLink *outlink)
128 {
129 AVFilterContext *ctx = outlink->src;
130 FPSContext *s = ctx->priv;
131 int frames_out = s->frames_out;
132 int ret = 0;
133
134 while (ret >= 0 && s->frames_out == frames_out)
135 ret = ff_request_frame(ctx->inputs[0]);
136
137 /* flush the fifo */
138 if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) {
139 int i;
140 for (i = 0; av_fifo_size(s->fifo); i++) {
141 AVFrame *buf;
142
143 av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL);
144 buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base,
145 outlink->time_base) + s->frames_out;
146
147 if ((ret = ff_filter_frame(outlink, buf)) < 0)
148 return ret;
149
150 s->frames_out++;
151 }
152 return 0;
153 }
154
155 return ret;
156 }
157
158 static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf)
159 {
160 int ret;
161
162 if (!av_fifo_space(fifo) &&
163 (ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) {
164 av_frame_free(&buf);
165 return ret;
166 }
167
168 av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL);
169 return 0;
170 }
171
172 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
173 {
174 AVFilterContext *ctx = inlink->dst;
175 FPSContext *s = ctx->priv;
176 AVFilterLink *outlink = ctx->outputs[0];
177 int64_t delta;
178 int i, ret;
179
180 s->frames_in++;
181 /* discard frames until we get the first timestamp */
182 if (s->pts == AV_NOPTS_VALUE) {
183 if (buf->pts != AV_NOPTS_VALUE) {
184 ret = write_to_fifo(s->fifo, buf);
185 if (ret < 0)
186 return ret;
187
188 if (s->start_time != DBL_MAX) {
189 double first_pts = s->start_time * AV_TIME_BASE;
190 first_pts = FFMIN(FFMAX(first_pts, INT64_MIN), INT64_MAX);
191 s->first_pts = s->pts = av_rescale_q(first_pts, AV_TIME_BASE_Q,
192 inlink->time_base);
193 av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64")\n",
194 s->first_pts, av_rescale_q(first_pts, AV_TIME_BASE_Q,
195 outlink->time_base));
196 } else {
197 s->first_pts = s->pts = buf->pts;
198 }
199 } else {
200 av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no "
201 "timestamp.\n");
202 av_frame_free(&buf);
203 s->drop++;
204 }
205 return 0;
206 }
207
208 /* now wait for the next timestamp */
209 if (buf->pts == AV_NOPTS_VALUE) {
210 return write_to_fifo(s->fifo, buf);
211 }
212
213 /* number of output frames */
214 delta = av_rescale_q(buf->pts - s->pts, inlink->time_base,
215 outlink->time_base);
216
217 if (delta < 1) {
218 /* drop the frame and everything buffered except the first */
219 AVFrame *tmp;
220 int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*);
221
222 av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop);
223 s->drop += drop;
224
225 av_fifo_generic_read(s->fifo, &tmp, sizeof(tmp), NULL);
226 flush_fifo(s->fifo);
227 ret = write_to_fifo(s->fifo, tmp);
228
229 av_frame_free(&buf);
230 return ret;
231 }
232
233 /* can output >= 1 frames */
234 for (i = 0; i < delta; i++) {
235 AVFrame *buf_out;
236 av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL);
237
238 /* duplicate the frame if needed */
239 if (!av_fifo_size(s->fifo) && i < delta - 1) {
240 AVFrame *dup = av_frame_clone(buf_out);
241
242 av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n");
243 if (dup)
244 ret = write_to_fifo(s->fifo, dup);
245 else
246 ret = AVERROR(ENOMEM);
247
248 if (ret < 0) {
249 av_frame_free(&buf_out);
250 av_frame_free(&buf);
251 return ret;
252 }
253
254 s->dup++;
255 }
256
257 buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base,
258 outlink->time_base) + s->frames_out;
259
260 if ((ret = ff_filter_frame(outlink, buf_out)) < 0) {
261 av_frame_free(&buf);
262 return ret;
263 }
264
265 s->frames_out++;
266 }
267 flush_fifo(s->fifo);
268
269 ret = write_to_fifo(s->fifo, buf);
270 s->pts = s->first_pts + av_rescale_q(s->frames_out, outlink->time_base, inlink->time_base);
271
272 return ret;
273 }
274
275 static const AVFilterPad avfilter_vf_fps_inputs[] = {
276 {
277 .name = "default",
278 .type = AVMEDIA_TYPE_VIDEO,
279 .filter_frame = filter_frame,
280 },
281 { NULL }
282 };
283
284 static const AVFilterPad avfilter_vf_fps_outputs[] = {
285 {
286 .name = "default",
287 .type = AVMEDIA_TYPE_VIDEO,
288 .request_frame = request_frame,
289 .config_props = config_props
290 },
291 { NULL }
292 };
293
294 AVFilter ff_vf_fps = {
295 .name = "fps",
296 .description = NULL_IF_CONFIG_SMALL("Force constant framerate"),
297
298 .init = init,
299 .uninit = uninit,
300
301 .priv_size = sizeof(FPSContext),
302 .priv_class = &class,
303
304 .inputs = avfilter_vf_fps_inputs,
305 .outputs = avfilter_vf_fps_outputs,
306 };