FFmpeg/libavdevice/timefilter.c
Michael Niedermayer aedc908601 Merge remote-tracking branch 'qatar/master'
* qatar/master: (35 commits)
  flvdec: Do not call parse_keyframes_index with a NULL stream
  libspeexdec: include system headers before local headers
  libspeexdec: return meaningful error codes
  libspeexdec: cosmetics: reindent
  libspeexdec: decode one frame at a time.
  swscale: fix signed shift overflows in ff_yuv2rgb_c_init_tables()
  Move timefilter code from lavf to lavd.
  mov: add support for hdvd and pgapmetadata atoms
  mov: rename function _stik, some indentation cosmetics
  mov: rename function _int8 to remove ambiguity, some indentation cosmetics
  mov: parse the gnre atom
  mp3on4: check for allocation failures in decode_init_mp3on4()
  mp3on4: create a separate flush function for MP3onMP4.
  mp3on4: ensure that the frame channel count does not exceed the codec channel count.
  mp3on4: set channel layout
  mp3on4: fix the output channel order
  mp3on4: allocate temp buffer with av_malloc() instead of on the stack.
  mp3on4: copy MPADSPContext from first context to all contexts.
  fmtconvert: port float_to_int16_interleave() 2-channel x86 inline asm to yasm
  fmtconvert: port int32_to_float_fmul_scalar() x86 inline asm to yasm
  ...

Conflicts:
	libavcodec/arm/h264dsp_init_arm.c
	libavcodec/h264.c
	libavcodec/h264.h
	libavcodec/h264_cabac.c
	libavcodec/h264_cavlc.c
	libavcodec/h264_ps.c
	libavcodec/h264dsp_template.c
	libavcodec/h264idct_template.c
	libavcodec/h264pred.c
	libavcodec/h264pred_template.c
	libavcodec/x86/h264dsp_mmx.c
	libavdevice/Makefile
	libavdevice/jack_audio.c
	libavformat/Makefile
	libavformat/flvdec.c
	libavformat/flvenc.c
	libavutil/pixfmt.h
	libswscale/utils.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2011-10-22 01:16:41 +02:00

152 lines
4.7 KiB
C

/*
* Delay Locked Loop based time filter
* Copyright (c) 2009 Samalyse
* Copyright (c) 2009 Michael Niedermayer
* Author: Olivier Guilyardi <olivier samalyse com>
* Michael Niedermayer <michaelni gmx at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#include "timefilter.h"
#include "libavutil/mem.h"
struct TimeFilter {
/// Delay Locked Loop data. These variables refer to mathematical
/// concepts described in: http://www.kokkinizita.net/papers/usingdll.pdf
double cycle_time;
double feedback2_factor;
double feedback3_factor;
double clock_period;
int count;
};
TimeFilter * ff_timefilter_new(double clock_period, double feedback2_factor, double feedback3_factor)
{
TimeFilter *self = av_mallocz(sizeof(TimeFilter));
self->clock_period = clock_period;
self->feedback2_factor = feedback2_factor;
self->feedback3_factor = feedback3_factor;
return self;
}
void ff_timefilter_destroy(TimeFilter *self)
{
av_freep(&self);
}
void ff_timefilter_reset(TimeFilter *self)
{
self->count = 0;
}
double ff_timefilter_update(TimeFilter *self, double system_time, double period)
{
self->count++;
if (self->count==1) {
/// init loop
self->cycle_time = system_time;
} else {
double loop_error;
self->cycle_time += self->clock_period * period;
/// calculate loop error
loop_error = system_time - self->cycle_time;
/// update loop
self->cycle_time += FFMAX(self->feedback2_factor, 1.0/(self->count)) * loop_error;
self->clock_period += self->feedback3_factor * loop_error / period;
}
return self->cycle_time;
}
#ifdef TEST
#include "libavutil/lfg.h"
#define LFG_MAX ((1LL << 32) - 1)
#undef printf
int main(void)
{
AVLFG prng;
double n0,n1;
#define SAMPLES 1000
double ideal[SAMPLES];
double samples[SAMPLES];
#if 1
for(n0= 0; n0<40; n0=2*n0+1){
for(n1= 0; n1<10; n1=2*n1+1){
#else
{{
n0=7;
n1=1;
#endif
double best_error= 1000000000;
double bestpar0=1;
double bestpar1=0.001;
int better, i;
av_lfg_init(&prng, 123);
for(i=0; i<SAMPLES; i++){
ideal[i] = 10 + i + n1*i/(1000);
samples[i] = ideal[i] + n0 * (av_lfg_get(&prng) - LFG_MAX / 2)
/ (LFG_MAX * 10LL);
}
do{
double par0, par1;
better=0;
for(par0= bestpar0*0.8; par0<=bestpar0*1.21; par0+=bestpar0*0.05){
for(par1= bestpar1*0.8; par1<=bestpar1*1.21; par1+=bestpar1*0.05){
double error=0;
TimeFilter *tf= ff_timefilter_new(1, par0, par1);
for(i=0; i<SAMPLES; i++){
double filtered;
filtered= ff_timefilter_update(tf, samples[i], 1);
error += (filtered - ideal[i]) * (filtered - ideal[i]);
}
ff_timefilter_destroy(tf);
if(error < best_error){
best_error= error;
bestpar0= par0;
bestpar1= par1;
better=1;
}
}
}
}while(better);
#if 0
double lastfil=9;
TimeFilter *tf= ff_timefilter_new(1, bestpar0, bestpar1);
for(i=0; i<SAMPLES; i++){
double filtered;
filtered= ff_timefilter_update(tf, samples[i], 1);
printf("%f %f %f %f\n", i - samples[i] + 10, filtered - samples[i], samples[FFMAX(i, 1)] - samples[FFMAX(i-1, 0)], filtered - lastfil);
lastfil= filtered;
}
ff_timefilter_destroy(tf);
#else
printf(" [%f %f %9f]", bestpar0, bestpar1, best_error);
#endif
}
printf("\n");
}
return 0;
}
#endif