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path: root/libavfilter/framesync.c (plain)
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1/*
2 * Copyright (c) 2013 Nicolas George
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 License
8 * 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
14 * GNU Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public License
17 * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#define FF_INTERNAL_FIELDS 1
22#include "framequeue.h"
23
24#include "libavutil/avassert.h"
25#include "avfilter.h"
26#include "bufferqueue.h"
27#include "framesync.h"
28#include "internal.h"
29
30#define OFFSET(member) offsetof(FFFrameSync, member)
31
32static const char *framesync_name(void *ptr)
33{
34 return "framesync";
35}
36
37static const AVClass framesync_class = {
38 .version = LIBAVUTIL_VERSION_INT,
39 .class_name = "framesync",
40 .item_name = framesync_name,
41 .category = AV_CLASS_CATEGORY_FILTER,
42 .option = NULL,
43 .parent_log_context_offset = OFFSET(parent),
44};
45
46enum {
47 STATE_BOF,
48 STATE_RUN,
49 STATE_EOF,
50};
51
52int ff_framesync_init(FFFrameSync *fs, void *parent, unsigned nb_in)
53{
54 fs->class = &framesync_class;
55 fs->parent = parent;
56 fs->nb_in = nb_in;
57
58 fs->in = av_calloc(nb_in, sizeof(*fs->in));
59 if (!fs->in)
60 return AVERROR(ENOMEM);
61 return 0;
62}
63
64static void framesync_sync_level_update(FFFrameSync *fs)
65{
66 unsigned i, level = 0;
67
68 for (i = 0; i < fs->nb_in; i++)
69 if (fs->in[i].state != STATE_EOF)
70 level = FFMAX(level, fs->in[i].sync);
71 av_assert0(level <= fs->sync_level);
72 if (level < fs->sync_level)
73 av_log(fs, AV_LOG_VERBOSE, "Sync level %u\n", level);
74 if (level)
75 fs->sync_level = level;
76 else
77 fs->eof = 1;
78}
79
80int ff_framesync_configure(FFFrameSync *fs)
81{
82 unsigned i;
83 int64_t gcd, lcm;
84
85 if (!fs->time_base.num) {
86 for (i = 0; i < fs->nb_in; i++) {
87 if (fs->in[i].sync) {
88 if (fs->time_base.num) {
89 gcd = av_gcd(fs->time_base.den, fs->in[i].time_base.den);
90 lcm = (fs->time_base.den / gcd) * fs->in[i].time_base.den;
91 if (lcm < AV_TIME_BASE / 2) {
92 fs->time_base.den = lcm;
93 fs->time_base.num = av_gcd(fs->time_base.num,
94 fs->in[i].time_base.num);
95 } else {
96 fs->time_base.num = 1;
97 fs->time_base.den = AV_TIME_BASE;
98 break;
99 }
100 } else {
101 fs->time_base = fs->in[i].time_base;
102 }
103 }
104 }
105 if (!fs->time_base.num) {
106 av_log(fs, AV_LOG_ERROR, "Impossible to set time base\n");
107 return AVERROR(EINVAL);
108 }
109 av_log(fs, AV_LOG_VERBOSE, "Selected %d/%d time base\n",
110 fs->time_base.num, fs->time_base.den);
111 }
112
113 for (i = 0; i < fs->nb_in; i++)
114 fs->in[i].pts = fs->in[i].pts_next = AV_NOPTS_VALUE;
115 fs->sync_level = UINT_MAX;
116 framesync_sync_level_update(fs);
117
118 return 0;
119}
120
121static void framesync_advance(FFFrameSync *fs)
122{
123 int latest;
124 unsigned i;
125 int64_t pts;
126
127 if (fs->eof)
128 return;
129 while (!fs->frame_ready) {
130 latest = -1;
131 for (i = 0; i < fs->nb_in; i++) {
132 if (!fs->in[i].have_next) {
133 if (latest < 0 || fs->in[i].pts < fs->in[latest].pts)
134 latest = i;
135 }
136 }
137 if (latest >= 0) {
138 fs->in_request = latest;
139 break;
140 }
141
142 pts = fs->in[0].pts_next;
143 for (i = 1; i < fs->nb_in; i++)
144 if (fs->in[i].pts_next < pts)
145 pts = fs->in[i].pts_next;
146 if (pts == INT64_MAX) {
147 fs->eof = 1;
148 break;
149 }
150 for (i = 0; i < fs->nb_in; i++) {
151 if (fs->in[i].pts_next == pts ||
152 (fs->in[i].before == EXT_INFINITY &&
153 fs->in[i].state == STATE_BOF)) {
154 av_frame_free(&fs->in[i].frame);
155 fs->in[i].frame = fs->in[i].frame_next;
156 fs->in[i].pts = fs->in[i].pts_next;
157 fs->in[i].frame_next = NULL;
158 fs->in[i].pts_next = AV_NOPTS_VALUE;
159 fs->in[i].have_next = 0;
160 fs->in[i].state = fs->in[i].frame ? STATE_RUN : STATE_EOF;
161 if (fs->in[i].sync == fs->sync_level && fs->in[i].frame)
162 fs->frame_ready = 1;
163 if (fs->in[i].state == STATE_EOF &&
164 fs->in[i].after == EXT_STOP)
165 fs->eof = 1;
166 }
167 }
168 if (fs->eof)
169 fs->frame_ready = 0;
170 if (fs->frame_ready)
171 for (i = 0; i < fs->nb_in; i++)
172 if ((fs->in[i].state == STATE_BOF &&
173 fs->in[i].before == EXT_STOP))
174 fs->frame_ready = 0;
175 fs->pts = pts;
176 }
177}
178
179static int64_t framesync_pts_extrapolate(FFFrameSync *fs, unsigned in,
180 int64_t pts)
181{
182 /* Possible enhancement: use the link's frame rate */
183 return pts + 1;
184}
185
186static void framesync_inject_frame(FFFrameSync *fs, unsigned in, AVFrame *frame)
187{
188 int64_t pts;
189
190 av_assert0(!fs->in[in].have_next);
191 if (frame) {
192 pts = av_rescale_q(frame->pts, fs->in[in].time_base, fs->time_base);
193 frame->pts = pts;
194 } else {
195 pts = fs->in[in].state != STATE_RUN || fs->in[in].after == EXT_INFINITY
196 ? INT64_MAX : framesync_pts_extrapolate(fs, in, fs->in[in].pts);
197 fs->in[in].sync = 0;
198 framesync_sync_level_update(fs);
199 }
200 fs->in[in].frame_next = frame;
201 fs->in[in].pts_next = pts;
202 fs->in[in].have_next = 1;
203}
204
205int ff_framesync_add_frame(FFFrameSync *fs, unsigned in, AVFrame *frame)
206{
207 av_assert1(in < fs->nb_in);
208 if (!fs->in[in].have_next)
209 framesync_inject_frame(fs, in, frame);
210 else
211 ff_bufqueue_add(fs, &fs->in[in].queue, frame);
212 return 0;
213}
214
215void ff_framesync_next(FFFrameSync *fs)
216{
217 unsigned i;
218
219 av_assert0(!fs->frame_ready);
220 for (i = 0; i < fs->nb_in; i++)
221 if (!fs->in[i].have_next && fs->in[i].queue.available)
222 framesync_inject_frame(fs, i, ff_bufqueue_get(&fs->in[i].queue));
223 fs->frame_ready = 0;
224 framesync_advance(fs);
225}
226
227void ff_framesync_drop(FFFrameSync *fs)
228{
229 fs->frame_ready = 0;
230}
231
232int ff_framesync_get_frame(FFFrameSync *fs, unsigned in, AVFrame **rframe,
233 unsigned get)
234{
235 AVFrame *frame;
236 unsigned need_copy = 0, i;
237 int64_t pts_next;
238 int ret;
239
240 if (!fs->in[in].frame) {
241 *rframe = NULL;
242 return 0;
243 }
244 frame = fs->in[in].frame;
245 if (get) {
246 /* Find out if we need to copy the frame: is there another sync
247 stream, and do we know if its current frame will outlast this one? */
248 pts_next = fs->in[in].have_next ? fs->in[in].pts_next : INT64_MAX;
249 for (i = 0; i < fs->nb_in && !need_copy; i++)
250 if (i != in && fs->in[i].sync &&
251 (!fs->in[i].have_next || fs->in[i].pts_next < pts_next))
252 need_copy = 1;
253 if (need_copy) {
254 if (!(frame = av_frame_clone(frame)))
255 return AVERROR(ENOMEM);
256 if ((ret = av_frame_make_writable(frame)) < 0) {
257 av_frame_free(&frame);
258 return ret;
259 }
260 } else {
261 fs->in[in].frame = NULL;
262 }
263 fs->frame_ready = 0;
264 }
265 *rframe = frame;
266 return 0;
267}
268
269void ff_framesync_uninit(FFFrameSync *fs)
270{
271 unsigned i;
272
273 for (i = 0; i < fs->nb_in; i++) {
274 av_frame_free(&fs->in[i].frame);
275 av_frame_free(&fs->in[i].frame_next);
276 ff_bufqueue_discard_all(&fs->in[i].queue);
277 }
278
279 av_freep(&fs->in);
280}
281
282int ff_framesync_process_frame(FFFrameSync *fs, unsigned all)
283{
284 int ret, count = 0;
285
286 av_assert0(fs->on_event);
287 while (1) {
288 ff_framesync_next(fs);
289 if (fs->eof || !fs->frame_ready)
290 break;
291 if ((ret = fs->on_event(fs)) < 0)
292 return ret;
293 ff_framesync_drop(fs);
294 count++;
295 if (!all)
296 break;
297 }
298 if (!count && fs->eof)
299 return AVERROR_EOF;
300 return count;
301}
302
303int ff_framesync_filter_frame(FFFrameSync *fs, AVFilterLink *inlink,
304 AVFrame *in)
305{
306 int ret;
307
308 if ((ret = ff_framesync_process_frame(fs, 1)) < 0)
309 return ret;
310 if ((ret = ff_framesync_add_frame(fs, FF_INLINK_IDX(inlink), in)) < 0)
311 return ret;
312 if ((ret = ff_framesync_process_frame(fs, 0)) < 0)
313 return ret;
314 return 0;
315}
316
317int ff_framesync_request_frame(FFFrameSync *fs, AVFilterLink *outlink)
318{
319 AVFilterContext *ctx = outlink->src;
320 int input, ret, i;
321
322 if ((ret = ff_framesync_process_frame(fs, 0)) < 0)
323 return ret;
324 if (ret > 0)
325 return 0;
326 if (fs->eof)
327 return AVERROR_EOF;
328 input = fs->in_request;
329 /* Detect status change early */
330 for (i = 0; i < fs->nb_in; i++)
331 if (!ff_framequeue_queued_frames(&ctx->inputs[i]->fifo) &&
332 ctx->inputs[i]->status_in && !ctx->inputs[i]->status_out)
333 input = i;
334 ret = ff_request_frame(ctx->inputs[input]);
335 if (ret == AVERROR_EOF) {
336 if ((ret = ff_framesync_add_frame(fs, input, NULL)) < 0)
337 return ret;
338 if ((ret = ff_framesync_process_frame(fs, 0)) < 0)
339 return ret;
340 ret = 0;
341 }
342 return ret;
343}
344
generated by cgit at 2024-05-17 18:52:52 (GMT)