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1 /*
2  * Copyright (c) 2010 Stefano Sabatini
3  * Copyright (c) 2008 Victor Paesa
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * video presentation timestamp (PTS) modification filter
25  */
26 
27 #include <inttypes.h>
28 
29 #include "libavutil/eval.h"
30 #include "libavutil/internal.h"
31 #include "libavutil/mathematics.h"
32 #include "libavutil/opt.h"
33 #include "libavutil/time.h"
34 #include "audio.h"
35 #include "avfilter.h"
36 #include "filters.h"
37 #include "internal.h"
38 #include "video.h"
39 
40 static const char *const var_names[] = {
41     "FRAME_RATE",  ///< defined only for constant frame-rate video
42     "INTERLACED",  ///< tell if the current frame is interlaced
43     "N",           ///< frame / sample number (starting at zero)
44     "NB_CONSUMED_SAMPLES", ///< number of samples consumed by the filter (only audio)
45     "NB_SAMPLES",  ///< number of samples in the current frame (only audio)
46     "POS",         ///< original position in the file of the frame
47     "PREV_INPTS",  ///< previous  input PTS
48     "PREV_INT",    ///< previous  input time in seconds
49     "PREV_OUTPTS", ///< previous output PTS
50     "PREV_OUTT",   ///< previous output time in seconds
51     "PTS",         ///< original pts in the file of the frame
52     "SAMPLE_RATE", ///< sample rate (only audio)
53     "STARTPTS",    ///< PTS at start of movie
54     "STARTT",      ///< time at start of movie
55     "T",           ///< original time in the file of the frame
56     "TB",          ///< timebase
57     "RTCTIME",     ///< wallclock (RTC) time in micro seconds
58     "RTCSTART",    ///< wallclock (RTC) time at the start of the movie in micro seconds
59     "S",           //   Number of samples in the current frame
60     "SR",          //   Audio sample rate
61     "FR",          ///< defined only for constant frame-rate video
62     NULL
63 };
64 
65 enum var_name {
66     VAR_FRAME_RATE,
67     VAR_INTERLACED,
68     VAR_N,
69     VAR_NB_CONSUMED_SAMPLES,
70     VAR_NB_SAMPLES,
71     VAR_POS,
72     VAR_PREV_INPTS,
73     VAR_PREV_INT,
74     VAR_PREV_OUTPTS,
75     VAR_PREV_OUTT,
76     VAR_PTS,
77     VAR_SAMPLE_RATE,
78     VAR_STARTPTS,
79     VAR_STARTT,
80     VAR_T,
81     VAR_TB,
82     VAR_RTCTIME,
83     VAR_RTCSTART,
84     VAR_S,
85     VAR_SR,
86     VAR_FR,
87     VAR_VARS_NB
88 };
89 
90 typedef struct SetPTSContext {
91     const AVClass *class;
92     char *expr_str;
93     AVExpr *expr;
94     double var_values[VAR_VARS_NB];
95     enum AVMediaType type;
96 } SetPTSContext;
97 
init(AVFilterContext * ctx)98 static av_cold int init(AVFilterContext *ctx)
99 {
100     SetPTSContext *setpts = ctx->priv;
101     int ret;
102 
103     if ((ret = av_expr_parse(&setpts->expr, setpts->expr_str,
104                              var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
105         av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", setpts->expr_str);
106         return ret;
107     }
108 
109     setpts->var_values[VAR_N]           = 0.0;
110     setpts->var_values[VAR_S]           = 0.0;
111     setpts->var_values[VAR_PREV_INPTS]  = NAN;
112     setpts->var_values[VAR_PREV_INT]    = NAN;
113     setpts->var_values[VAR_PREV_OUTPTS] = NAN;
114     setpts->var_values[VAR_PREV_OUTT]   = NAN;
115     setpts->var_values[VAR_STARTPTS]    = NAN;
116     setpts->var_values[VAR_STARTT]      = NAN;
117     return 0;
118 }
119 
config_input(AVFilterLink * inlink)120 static int config_input(AVFilterLink *inlink)
121 {
122     AVFilterContext *ctx = inlink->dst;
123     SetPTSContext *setpts = ctx->priv;
124 
125     setpts->type = inlink->type;
126     setpts->var_values[VAR_TB] = av_q2d(inlink->time_base);
127     setpts->var_values[VAR_RTCSTART] = av_gettime();
128 
129     setpts->var_values[VAR_SR] =
130     setpts->var_values[VAR_SAMPLE_RATE] =
131         setpts->type == AVMEDIA_TYPE_AUDIO ? inlink->sample_rate : NAN;
132 
133     setpts->var_values[VAR_FRAME_RATE] =
134     setpts->var_values[VAR_FR] =         inlink->frame_rate.num &&
135                                          inlink->frame_rate.den ?
136                                             av_q2d(inlink->frame_rate) : NAN;
137 
138     av_log(inlink->src, AV_LOG_VERBOSE, "TB:%f FRAME_RATE:%f SAMPLE_RATE:%f\n",
139            setpts->var_values[VAR_TB],
140            setpts->var_values[VAR_FRAME_RATE],
141            setpts->var_values[VAR_SAMPLE_RATE]);
142     return 0;
143 }
144 
145 #define BUF_SIZE 64
146 
double2int64str(char * buf,double v)147 static inline char *double2int64str(char *buf, double v)
148 {
149     if (isnan(v)) snprintf(buf, BUF_SIZE, "nan");
150     else          snprintf(buf, BUF_SIZE, "%"PRId64, (int64_t)v);
151     return buf;
152 }
153 
eval_pts(SetPTSContext * setpts,AVFilterLink * inlink,AVFrame * frame,int64_t pts)154 static double eval_pts(SetPTSContext *setpts, AVFilterLink *inlink, AVFrame *frame, int64_t pts)
155 {
156     if (isnan(setpts->var_values[VAR_STARTPTS])) {
157         setpts->var_values[VAR_STARTPTS] = TS2D(pts);
158         setpts->var_values[VAR_STARTT  ] = TS2T(pts, inlink->time_base);
159     }
160     setpts->var_values[VAR_PTS       ] = TS2D(pts);
161     setpts->var_values[VAR_T         ] = TS2T(pts, inlink->time_base);
162     setpts->var_values[VAR_POS       ] = !frame || frame->pkt_pos == -1 ? NAN : frame->pkt_pos;
163     setpts->var_values[VAR_RTCTIME   ] = av_gettime();
164 
165     if (frame) {
166         if (inlink->type == AVMEDIA_TYPE_VIDEO) {
167             setpts->var_values[VAR_INTERLACED] = frame->interlaced_frame;
168         } else if (inlink->type == AVMEDIA_TYPE_AUDIO) {
169             setpts->var_values[VAR_S] = frame->nb_samples;
170             setpts->var_values[VAR_NB_SAMPLES] = frame->nb_samples;
171         }
172     }
173 
174     return av_expr_eval(setpts->expr, setpts->var_values, NULL);
175 }
176 #define d2istr(v) double2int64str((char[BUF_SIZE]){0}, v)
177 
filter_frame(AVFilterLink * inlink,AVFrame * frame)178 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
179 {
180     SetPTSContext *setpts = inlink->dst->priv;
181     int64_t in_pts = frame->pts;
182     double d;
183 
184     d = eval_pts(setpts, inlink, frame, frame->pts);
185     frame->pts = D2TS(d);
186 
187     av_log(inlink->dst, AV_LOG_TRACE,
188             "N:%"PRId64" PTS:%s T:%f POS:%s",
189             (int64_t)setpts->var_values[VAR_N],
190             d2istr(setpts->var_values[VAR_PTS]),
191             setpts->var_values[VAR_T],
192             d2istr(setpts->var_values[VAR_POS]));
193     switch (inlink->type) {
194     case AVMEDIA_TYPE_VIDEO:
195         av_log(inlink->dst, AV_LOG_TRACE, " INTERLACED:%"PRId64,
196                 (int64_t)setpts->var_values[VAR_INTERLACED]);
197         break;
198     case AVMEDIA_TYPE_AUDIO:
199         av_log(inlink->dst, AV_LOG_TRACE, " NB_SAMPLES:%"PRId64" NB_CONSUMED_SAMPLES:%"PRId64,
200                 (int64_t)setpts->var_values[VAR_NB_SAMPLES],
201                 (int64_t)setpts->var_values[VAR_NB_CONSUMED_SAMPLES]);
202         break;
203     }
204     av_log(inlink->dst, AV_LOG_TRACE, " -> PTS:%s T:%f\n", d2istr(d), TS2T(d, inlink->time_base));
205 
206     if (inlink->type == AVMEDIA_TYPE_VIDEO) {
207         setpts->var_values[VAR_N] += 1.0;
208     } else {
209         setpts->var_values[VAR_N] += frame->nb_samples;
210     }
211 
212     setpts->var_values[VAR_PREV_INPTS ] = TS2D(in_pts);
213     setpts->var_values[VAR_PREV_INT   ] = TS2T(in_pts, inlink->time_base);
214     setpts->var_values[VAR_PREV_OUTPTS] = TS2D(frame->pts);
215     setpts->var_values[VAR_PREV_OUTT]   = TS2T(frame->pts, inlink->time_base);
216     if (setpts->type == AVMEDIA_TYPE_AUDIO) {
217         setpts->var_values[VAR_NB_CONSUMED_SAMPLES] += frame->nb_samples;
218     }
219     return ff_filter_frame(inlink->dst->outputs[0], frame);
220 }
221 
activate(AVFilterContext * ctx)222 static int activate(AVFilterContext *ctx)
223 {
224     SetPTSContext *setpts = ctx->priv;
225     AVFilterLink *inlink = ctx->inputs[0];
226     AVFilterLink *outlink = ctx->outputs[0];
227     AVFrame *in;
228     int status;
229     int64_t pts;
230     int ret;
231 
232     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
233 
234     ret = ff_inlink_consume_frame(inlink, &in);
235     if (ret < 0)
236         return ret;
237     if (ret > 0)
238         return filter_frame(inlink, in);
239 
240     if (ff_inlink_acknowledge_status(inlink, &status, &pts)) {
241         double d = eval_pts(setpts, inlink, NULL, pts);
242 
243         av_log(ctx, AV_LOG_TRACE, "N:EOF PTS:%s T:%f POS:%s -> PTS:%s T:%f\n",
244                d2istr(setpts->var_values[VAR_PTS]),
245                setpts->var_values[VAR_T],
246                d2istr(setpts->var_values[VAR_POS]),
247                d2istr(d), TS2T(d, inlink->time_base));
248         ff_outlink_set_status(outlink, status, D2TS(d));
249         return 0;
250     }
251 
252     FF_FILTER_FORWARD_WANTED(outlink, inlink);
253 
254     return FFERROR_NOT_READY;
255 }
256 
uninit(AVFilterContext * ctx)257 static av_cold void uninit(AVFilterContext *ctx)
258 {
259     SetPTSContext *setpts = ctx->priv;
260     av_expr_free(setpts->expr);
261     setpts->expr = NULL;
262 }
263 
264 #define OFFSET(x) offsetof(SetPTSContext, x)
265 #define V AV_OPT_FLAG_VIDEO_PARAM
266 #define A AV_OPT_FLAG_AUDIO_PARAM
267 #define F AV_OPT_FLAG_FILTERING_PARAM
268 
269 #if CONFIG_SETPTS_FILTER
270 static const AVOption setpts_options[] = {
271     { "expr", "Expression determining the frame timestamp", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "PTS" }, .flags = V|F },
272     { NULL }
273 };
274 AVFILTER_DEFINE_CLASS(setpts);
275 
276 static const AVFilterPad avfilter_vf_setpts_inputs[] = {
277     {
278         .name         = "default",
279         .type         = AVMEDIA_TYPE_VIDEO,
280         .config_props = config_input,
281     },
282     { NULL }
283 };
284 
285 static const AVFilterPad avfilter_vf_setpts_outputs[] = {
286     {
287         .name = "default",
288         .type = AVMEDIA_TYPE_VIDEO,
289     },
290     { NULL }
291 };
292 
293 AVFilter ff_vf_setpts = {
294     .name      = "setpts",
295     .description = NULL_IF_CONFIG_SMALL("Set PTS for the output video frame."),
296     .init      = init,
297     .activate  = activate,
298     .uninit    = uninit,
299 
300     .priv_size = sizeof(SetPTSContext),
301     .priv_class = &setpts_class,
302 
303     .inputs    = avfilter_vf_setpts_inputs,
304     .outputs   = avfilter_vf_setpts_outputs,
305 };
306 #endif /* CONFIG_SETPTS_FILTER */
307 
308 #if CONFIG_ASETPTS_FILTER
309 
310 static const AVOption asetpts_options[] = {
311     { "expr", "Expression determining the frame timestamp", OFFSET(expr_str), AV_OPT_TYPE_STRING, { .str = "PTS" }, .flags = A|F },
312     { NULL }
313 };
314 AVFILTER_DEFINE_CLASS(asetpts);
315 
316 static const AVFilterPad asetpts_inputs[] = {
317     {
318         .name         = "default",
319         .type         = AVMEDIA_TYPE_AUDIO,
320         .config_props = config_input,
321     },
322     { NULL }
323 };
324 
325 static const AVFilterPad asetpts_outputs[] = {
326     {
327         .name = "default",
328         .type = AVMEDIA_TYPE_AUDIO,
329     },
330     { NULL }
331 };
332 
333 AVFilter ff_af_asetpts = {
334     .name        = "asetpts",
335     .description = NULL_IF_CONFIG_SMALL("Set PTS for the output audio frame."),
336     .init        = init,
337     .activate    = activate,
338     .uninit      = uninit,
339     .priv_size   = sizeof(SetPTSContext),
340     .priv_class  = &asetpts_class,
341     .inputs      = asetpts_inputs,
342     .outputs     = asetpts_outputs,
343 };
344 #endif /* CONFIG_ASETPTS_FILTER */
345