FFmpeg  4.3
timefilter.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include <stdio.h>
20 
21 #include "libavutil/common.h"
22 #include "libavutil/lfg.h"
23 
24 #include "libavdevice/timefilter.h"
25 
26 #define LFG_MAX ((1LL << 32) - 1)
27 
28 int main(void)
29 {
30  AVLFG prng;
31  double n0, n1;
32 #define SAMPLES 1000
33  double ideal[SAMPLES];
34  double samples[SAMPLES];
35  double samplet[SAMPLES];
36  for (n0 = 0; n0 < 40; n0 = 2 * n0 + 1) {
37  for (n1 = 0; n1 < 10; n1 = 2 * n1 + 1) {
38  double best_error = 1000000000;
39  double bestpar0 = n0 ? 1 : 100000;
40  double bestpar1 = 1;
41  int better, i;
42 
43  av_lfg_init(&prng, 123);
44  for (i = 0; i < SAMPLES; i++) {
45  samplet[i] = 10 + i + (av_lfg_get(&prng) < LFG_MAX/2 ? 0 : 0.999);
46  ideal[i] = samplet[i] + n1 * i / (1000);
47  samples[i] = ideal[i] + n0 * (av_lfg_get(&prng) - LFG_MAX / 2) / (LFG_MAX * 10LL);
48  if(i && samples[i]<samples[i-1])
49  samples[i]=samples[i-1]+0.001;
50  }
51 
52  do {
53  double par0, par1;
54  better = 0;
55  for (par0 = bestpar0 * 0.8; par0 <= bestpar0 * 1.21; par0 += bestpar0 * 0.05) {
56  for (par1 = bestpar1 * 0.8; par1 <= bestpar1 * 1.21; par1 += bestpar1 * 0.05) {
57  double error = 0;
58  TimeFilter *tf = ff_timefilter_new(1, par0, par1);
59  if (!tf) {
60  printf("Could not allocate memory for timefilter.\n");
61  exit(1);
62  }
63  for (i = 0; i < SAMPLES; i++) {
64  double filtered;
65  filtered = ff_timefilter_update(tf, samples[i], i ? (samplet[i] - samplet[i-1]) : 1);
66  if(filtered < 0 || filtered > 1000000000)
67  printf("filter is unstable\n");
68  error += (filtered - ideal[i]) * (filtered - ideal[i]);
69  }
71  if (error < best_error) {
72  best_error = error;
73  bestpar0 = par0;
74  bestpar1 = par1;
75  better = 1;
76  }
77  }
78  }
79  } while (better);
80  printf(" [%12f %11f %9f]", bestpar0, bestpar1, best_error);
81  }
82  printf("\n");
83  }
84  return 0;
85 }
main
int main(void)
Definition: timefilter.c:28
error
static void error(const char *err)
Definition: target_bsf_fuzzer.c:29
TimeFilter
Opaque type representing a time filter state.
Definition: timefilter.c:30
av_lfg_init
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
samples
FFmpeg Automated Testing Environment ************************************Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server Uploading new samples to the fate suite FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg’s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg’s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass ‘ target exec’ to ‘configure’ or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script ‘tests fate sh’ from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at ‘doc fate_config sh template’ Create a configuration that suits your based on the configuration template The ‘slot’ configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern ‘ARCH OS COMPILER COMPILER VERSION’ The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the ‘fate_recv’ variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration it may help to try out the ‘ssh’ command with one or more ‘ v’ options You should get detailed output concerning your SSH configuration and the authentication process The only thing left is to automate the execution of the fate sh script and the synchronisation of the samples directory Uploading new samples to the fate suite *****************************************If you need a sample uploaded send a mail to samples request This is for developers who have an account on the fate suite server If you upload new samples
Definition: fate.txt:139
ff_timefilter_new
TimeFilter * ff_timefilter_new(double time_base, double period, double bandwidth)
Create a new Delay Locked Loop time filter.
Definition: timefilter.c:46
av_lfg_get
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:53
lfg.h
timefilter.h
AVLFG
Context structure for the Lagged Fibonacci PRNG.
Definition: lfg.h:33
printf
printf("static const uint8_t my_array[100] = {\n")
ff_timefilter_destroy
void ff_timefilter_destroy(TimeFilter *self)
Free all resources associated with the filter.
Definition: timefilter.c:62
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
common.h
ff_timefilter_update
double ff_timefilter_update(TimeFilter *self, double system_time, double period)
Update the filter.
Definition: timefilter.c:72
SAMPLES
#define SAMPLES
tf
#define tf
Definition: regdef.h:73
LFG_MAX
#define LFG_MAX
Definition: timefilter.c:26