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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 #include "libavutil/avassert.h"
22 #include "libavutil/opt.h"
23 #include "avfilter.h"
24 #include "filters.h"
25 #include "framesync.h"
26 #include "internal.h"
27 
28 #define OFFSET(member) offsetof(FFFrameSync, member)
29 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
30 
framesync_name(void * ptr)31 static const char *framesync_name(void *ptr)
32 {
33     return "framesync";
34 }
35 
36 static const AVOption framesync_options[] = {
37     { "eof_action", "Action to take when encountering EOF from secondary input ",
38         OFFSET(opt_eof_action), AV_OPT_TYPE_INT, { .i64 = EOF_ACTION_REPEAT },
39         EOF_ACTION_REPEAT, EOF_ACTION_PASS, .flags = FLAGS, "eof_action" },
40         { "repeat", "Repeat the previous frame.",   0, AV_OPT_TYPE_CONST, { .i64 = EOF_ACTION_REPEAT }, .flags = FLAGS, "eof_action" },
41         { "endall", "End both streams.",            0, AV_OPT_TYPE_CONST, { .i64 = EOF_ACTION_ENDALL }, .flags = FLAGS, "eof_action" },
42         { "pass",   "Pass through the main input.", 0, AV_OPT_TYPE_CONST, { .i64 = EOF_ACTION_PASS },   .flags = FLAGS, "eof_action" },
43     { "shortest", "force termination when the shortest input terminates", OFFSET(opt_shortest), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
44     { "repeatlast", "extend last frame of secondary streams beyond EOF", OFFSET(opt_repeatlast), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS },
45     { NULL }
46 };
47 static const AVClass framesync_class = {
48     .version                   = LIBAVUTIL_VERSION_INT,
49     .class_name                = "framesync",
50     .item_name                 = framesync_name,
51     .category                  = AV_CLASS_CATEGORY_FILTER,
52     .option                    = framesync_options,
53     .parent_log_context_offset = OFFSET(parent),
54 };
55 
56 enum {
57     STATE_BOF,
58     STATE_RUN,
59     STATE_EOF,
60 };
61 
62 static int consume_from_fifos(FFFrameSync *fs);
63 
ff_framesync_get_class(void)64 const AVClass *ff_framesync_get_class(void)
65 {
66     return &framesync_class;
67 }
68 
ff_framesync_preinit(FFFrameSync * fs)69 void ff_framesync_preinit(FFFrameSync *fs)
70 {
71     if (fs->class)
72         return;
73     fs->class  = &framesync_class;
74     av_opt_set_defaults(fs);
75 }
76 
ff_framesync_init(FFFrameSync * fs,AVFilterContext * parent,unsigned nb_in)77 int ff_framesync_init(FFFrameSync *fs, AVFilterContext *parent, unsigned nb_in)
78 {
79     /* For filters with several outputs, we will not be able to assume which
80        output is relevant for ff_outlink_frame_wanted() and
81        ff_outlink_set_status(). To be designed when needed. */
82     av_assert0(parent->nb_outputs == 1);
83 
84     ff_framesync_preinit(fs);
85     fs->parent = parent;
86     fs->nb_in  = nb_in;
87 
88     fs->in = av_calloc(nb_in, sizeof(*fs->in));
89     if (!fs->in)
90         return AVERROR(ENOMEM);
91     return 0;
92 }
93 
framesync_eof(FFFrameSync * fs)94 static void framesync_eof(FFFrameSync *fs)
95 {
96     fs->eof = 1;
97     fs->frame_ready = 0;
98     ff_outlink_set_status(fs->parent->outputs[0], AVERROR_EOF, AV_NOPTS_VALUE);
99 }
100 
framesync_sync_level_update(FFFrameSync * fs)101 static void framesync_sync_level_update(FFFrameSync *fs)
102 {
103     unsigned i, level = 0;
104 
105     for (i = 0; i < fs->nb_in; i++)
106         if (fs->in[i].state != STATE_EOF)
107             level = FFMAX(level, fs->in[i].sync);
108     av_assert0(level <= fs->sync_level);
109     if (level < fs->sync_level)
110         av_log(fs, AV_LOG_VERBOSE, "Sync level %u\n", level);
111     if (level)
112         fs->sync_level = level;
113     else
114         framesync_eof(fs);
115 }
116 
ff_framesync_configure(FFFrameSync * fs)117 int ff_framesync_configure(FFFrameSync *fs)
118 {
119     unsigned i;
120 
121     if (!fs->opt_repeatlast || fs->opt_eof_action == EOF_ACTION_PASS) {
122         fs->opt_repeatlast = 0;
123         fs->opt_eof_action = EOF_ACTION_PASS;
124     }
125     if (fs->opt_shortest || fs->opt_eof_action == EOF_ACTION_ENDALL) {
126         fs->opt_shortest = 1;
127         fs->opt_eof_action = EOF_ACTION_ENDALL;
128     }
129     if (!fs->opt_repeatlast) {
130         for (i = 1; i < fs->nb_in; i++) {
131             fs->in[i].after = EXT_NULL;
132             fs->in[i].sync  = 0;
133         }
134     }
135     if (fs->opt_shortest) {
136         for (i = 0; i < fs->nb_in; i++)
137             fs->in[i].after = EXT_STOP;
138     }
139 
140     if (!fs->time_base.num) {
141         for (i = 0; i < fs->nb_in; i++) {
142             if (fs->in[i].sync) {
143                 if (fs->time_base.num) {
144                     fs->time_base = av_gcd_q(fs->time_base, fs->in[i].time_base,
145                                              AV_TIME_BASE / 2, AV_TIME_BASE_Q);
146                 } else {
147                     fs->time_base = fs->in[i].time_base;
148                 }
149             }
150         }
151         if (!fs->time_base.num) {
152             av_log(fs, AV_LOG_ERROR, "Impossible to set time base\n");
153             return AVERROR(EINVAL);
154         }
155         av_log(fs, AV_LOG_VERBOSE, "Selected %d/%d time base\n",
156                fs->time_base.num, fs->time_base.den);
157     }
158 
159     for (i = 0; i < fs->nb_in; i++)
160         fs->in[i].pts = fs->in[i].pts_next = AV_NOPTS_VALUE;
161     fs->sync_level = UINT_MAX;
162     framesync_sync_level_update(fs);
163 
164     return 0;
165 }
166 
framesync_advance(FFFrameSync * fs)167 static int framesync_advance(FFFrameSync *fs)
168 {
169     unsigned i;
170     int64_t pts;
171     int ret;
172 
173     while (!(fs->frame_ready || fs->eof)) {
174         ret = consume_from_fifos(fs);
175         if (ret <= 0)
176             return ret;
177 
178         pts = INT64_MAX;
179         for (i = 0; i < fs->nb_in; i++)
180             if (fs->in[i].have_next && fs->in[i].pts_next < pts)
181                 pts = fs->in[i].pts_next;
182         if (pts == INT64_MAX) {
183             framesync_eof(fs);
184             break;
185         }
186         for (i = 0; i < fs->nb_in; i++) {
187             if (fs->in[i].pts_next == pts ||
188                 (fs->in[i].before == EXT_INFINITY &&
189                  fs->in[i].state == STATE_BOF)) {
190                 av_frame_free(&fs->in[i].frame);
191                 fs->in[i].frame      = fs->in[i].frame_next;
192                 fs->in[i].pts        = fs->in[i].pts_next;
193                 fs->in[i].frame_next = NULL;
194                 fs->in[i].pts_next   = AV_NOPTS_VALUE;
195                 fs->in[i].have_next  = 0;
196                 fs->in[i].state      = fs->in[i].frame ? STATE_RUN : STATE_EOF;
197                 if (fs->in[i].sync == fs->sync_level && fs->in[i].frame)
198                     fs->frame_ready = 1;
199                 if (fs->in[i].state == STATE_EOF &&
200                     fs->in[i].after == EXT_STOP)
201                     framesync_eof(fs);
202             }
203         }
204         if (fs->frame_ready)
205             for (i = 0; i < fs->nb_in; i++)
206                 if ((fs->in[i].state == STATE_BOF &&
207                      fs->in[i].before == EXT_STOP))
208                     fs->frame_ready = 0;
209         fs->pts = pts;
210     }
211     return 0;
212 }
213 
framesync_pts_extrapolate(FFFrameSync * fs,unsigned in,int64_t pts)214 static int64_t framesync_pts_extrapolate(FFFrameSync *fs, unsigned in,
215                                          int64_t pts)
216 {
217     /* Possible enhancement: use the link's frame rate */
218     return pts + 1;
219 }
220 
framesync_inject_frame(FFFrameSync * fs,unsigned in,AVFrame * frame)221 static void framesync_inject_frame(FFFrameSync *fs, unsigned in, AVFrame *frame)
222 {
223     int64_t pts;
224 
225     av_assert0(!fs->in[in].have_next);
226     av_assert0(frame);
227     pts = av_rescale_q(frame->pts, fs->in[in].time_base, fs->time_base);
228     frame->pts = pts;
229     fs->in[in].frame_next = frame;
230     fs->in[in].pts_next   = pts;
231     fs->in[in].have_next  = 1;
232 }
233 
framesync_inject_status(FFFrameSync * fs,unsigned in,int status,int64_t pts)234 static void framesync_inject_status(FFFrameSync *fs, unsigned in, int status, int64_t pts)
235 {
236     av_assert0(!fs->in[in].have_next);
237     pts = fs->in[in].state != STATE_RUN || fs->in[in].after == EXT_INFINITY
238         ? INT64_MAX : framesync_pts_extrapolate(fs, in, fs->in[in].pts);
239     fs->in[in].sync = 0;
240     framesync_sync_level_update(fs);
241     fs->in[in].frame_next = NULL;
242     fs->in[in].pts_next   = pts;
243     fs->in[in].have_next  = 1;
244 }
245 
ff_framesync_get_frame(FFFrameSync * fs,unsigned in,AVFrame ** rframe,unsigned get)246 int ff_framesync_get_frame(FFFrameSync *fs, unsigned in, AVFrame **rframe,
247                             unsigned get)
248 {
249     AVFrame *frame;
250     unsigned need_copy = 0, i;
251     int64_t pts_next;
252     int ret;
253 
254     if (!fs->in[in].frame) {
255         *rframe = NULL;
256         return 0;
257     }
258     frame = fs->in[in].frame;
259     if (get) {
260         /* Find out if we need to copy the frame: is there another sync
261            stream, and do we know if its current frame will outlast this one? */
262         pts_next = fs->in[in].have_next ? fs->in[in].pts_next : INT64_MAX;
263         for (i = 0; i < fs->nb_in && !need_copy; i++)
264             if (i != in && fs->in[i].sync &&
265                 (!fs->in[i].have_next || fs->in[i].pts_next < pts_next))
266                 need_copy = 1;
267         if (need_copy) {
268             if (!(frame = av_frame_clone(frame)))
269                 return AVERROR(ENOMEM);
270             if ((ret = av_frame_make_writable(frame)) < 0) {
271                 av_frame_free(&frame);
272                 return ret;
273             }
274         } else {
275             fs->in[in].frame = NULL;
276         }
277         fs->frame_ready = 0;
278     }
279     *rframe = frame;
280     return 0;
281 }
282 
ff_framesync_uninit(FFFrameSync * fs)283 void ff_framesync_uninit(FFFrameSync *fs)
284 {
285     unsigned i;
286 
287     for (i = 0; i < fs->nb_in; i++) {
288         av_frame_free(&fs->in[i].frame);
289         av_frame_free(&fs->in[i].frame_next);
290     }
291 
292     av_freep(&fs->in);
293 }
294 
consume_from_fifos(FFFrameSync * fs)295 static int consume_from_fifos(FFFrameSync *fs)
296 {
297     AVFilterContext *ctx = fs->parent;
298     AVFrame *frame = NULL;
299     int64_t pts;
300     unsigned i, nb_active, nb_miss;
301     int ret, status;
302 
303     nb_active = nb_miss = 0;
304     for (i = 0; i < fs->nb_in; i++) {
305         if (fs->in[i].have_next || fs->in[i].state == STATE_EOF)
306             continue;
307         nb_active++;
308         ret = ff_inlink_consume_frame(ctx->inputs[i], &frame);
309         if (ret < 0)
310             return ret;
311         if (ret) {
312             av_assert0(frame);
313             framesync_inject_frame(fs, i, frame);
314         } else {
315             ret = ff_inlink_acknowledge_status(ctx->inputs[i], &status, &pts);
316             if (ret > 0) {
317                 framesync_inject_status(fs, i, status, pts);
318             } else if (!ret) {
319                 nb_miss++;
320             }
321         }
322     }
323     if (nb_miss) {
324         if (nb_miss == nb_active && !ff_outlink_frame_wanted(ctx->outputs[0]))
325             return FFERROR_NOT_READY;
326         for (i = 0; i < fs->nb_in; i++)
327             if (!fs->in[i].have_next && fs->in[i].state != STATE_EOF)
328                 ff_inlink_request_frame(ctx->inputs[i]);
329         return 0;
330     }
331     return 1;
332 }
333 
ff_framesync_activate(FFFrameSync * fs)334 int ff_framesync_activate(FFFrameSync *fs)
335 {
336     int ret;
337 
338     ret = framesync_advance(fs);
339     if (ret < 0)
340         return ret;
341     if (fs->eof || !fs->frame_ready)
342         return 0;
343     ret = fs->on_event(fs);
344     if (ret < 0)
345         return ret;
346     fs->frame_ready = 0;
347 
348     return 0;
349 }
350 
ff_framesync_init_dualinput(FFFrameSync * fs,AVFilterContext * parent)351 int ff_framesync_init_dualinput(FFFrameSync *fs, AVFilterContext *parent)
352 {
353     int ret;
354 
355     ret = ff_framesync_init(fs, parent, 2);
356     if (ret < 0)
357         return ret;
358     fs->in[0].time_base = parent->inputs[0]->time_base;
359     fs->in[1].time_base = parent->inputs[1]->time_base;
360     fs->in[0].sync   = 2;
361     fs->in[0].before = EXT_STOP;
362     fs->in[0].after  = EXT_INFINITY;
363     fs->in[1].sync   = 1;
364     fs->in[1].before = EXT_NULL;
365     fs->in[1].after  = EXT_INFINITY;
366     return 0;
367 }
368 
ff_framesync_dualinput_get(FFFrameSync * fs,AVFrame ** f0,AVFrame ** f1)369 int ff_framesync_dualinput_get(FFFrameSync *fs, AVFrame **f0, AVFrame **f1)
370 {
371     AVFilterContext *ctx = fs->parent;
372     AVFrame *mainpic = NULL, *secondpic = NULL;
373     int ret;
374 
375     if ((ret = ff_framesync_get_frame(fs, 0, &mainpic,   1)) < 0 ||
376         (ret = ff_framesync_get_frame(fs, 1, &secondpic, 0)) < 0) {
377         av_frame_free(&mainpic);
378         return ret;
379     }
380     av_assert0(mainpic);
381     mainpic->pts = av_rescale_q(fs->pts, fs->time_base, ctx->outputs[0]->time_base);
382     if (ctx->is_disabled)
383         secondpic = NULL;
384     *f0 = mainpic;
385     *f1 = secondpic;
386     return 0;
387 }
388 
ff_framesync_dualinput_get_writable(FFFrameSync * fs,AVFrame ** f0,AVFrame ** f1)389 int ff_framesync_dualinput_get_writable(FFFrameSync *fs, AVFrame **f0, AVFrame **f1)
390 {
391     int ret;
392 
393     ret = ff_framesync_dualinput_get(fs, f0, f1);
394     if (ret < 0)
395         return ret;
396     ret = ff_inlink_make_frame_writable(fs->parent->inputs[0], f0);
397     if (ret < 0) {
398         av_frame_free(f0);
399         *f1 = NULL;
400         return ret;
401     }
402     return 0;
403 }
404