diff options
Diffstat (limited to 'libavformat')
| -rw-r--r-- | libavformat/timefilter.c | 10 | ||||
| -rw-r--r-- | libavformat/timefilter.h | 11 |
2 files changed, 10 insertions, 11 deletions
diff --git a/libavformat/timefilter.c b/libavformat/timefilter.c index 6fdc148d00..26d57c0617 100644 --- a/libavformat/timefilter.c +++ b/libavformat/timefilter.c @@ -34,10 +34,10 @@ struct TimeFilter { double integrator2_state; }; -TimeFilter * ff_timefilter_new(double period, double feedback2_factor, double feedback3_factor) +TimeFilter * ff_timefilter_new(double feedback2_factor, double feedback3_factor) { TimeFilter *self = av_mallocz(sizeof(TimeFilter)); - self->integrator2_state = period; + self->integrator2_state = 1.0; self->feedback2_factor = feedback2_factor; self->feedback3_factor = feedback3_factor; return self; @@ -53,20 +53,20 @@ void ff_timefilter_reset(TimeFilter *self) self->cycle_time = 0; } -void ff_timefilter_update(TimeFilter *self, double system_time) +void ff_timefilter_update(TimeFilter *self, double system_time, double period) { if (!self->cycle_time) { /// init loop self->cycle_time = system_time; } else { double loop_error; - self->cycle_time+= self->integrator2_state; + self->cycle_time+= self->integrator2_state * period; /// calculate loop error loop_error = system_time - self->cycle_time; /// update loop self->cycle_time += self->feedback2_factor * loop_error; - self->integrator2_state += self->feedback3_factor * loop_error; + self->integrator2_state += self->feedback3_factor * loop_error / period; } } diff --git a/libavformat/timefilter.h b/libavformat/timefilter.h index c5252de3e8..85199fed34 100644 --- a/libavformat/timefilter.h +++ b/libavformat/timefilter.h @@ -37,10 +37,6 @@ typedef struct TimeFilter TimeFilter; /** * Create a new Delay Locked Loop time filter * - * period is the device cycle duration in seconds. For example, at - * 44.1Hz and a buffer size of 512 frames, period = 512 / 44100. The filter - * only works if the cycle duration is fixed. - * * feedback2_factor and feedback3_factor are the factors used for the * multiplications that are respectively performed in the second and third * feedback paths of the loop. @@ -58,19 +54,22 @@ typedef struct TimeFilter TimeFilter; * For more details about these parameters and background concepts please see: * http://www.kokkinizita.net/papers/usingdll.pdf */ -TimeFilter * ff_timefilter_new(double period, double feedback2_factor, double feedback3_factor); +TimeFilter * ff_timefilter_new(double feedback2_factor, double feedback3_factor); /** * Update the filter * * This function must be called in real time, at each process cycle. * + * period is the device cycle duration in seconds. For example, at + * 44.1Hz and a buffer size of 512 frames, period = 512 / 44100. + * * system_time, in seconds, should be the value of the system clock time, * at (or as close as possible to) the moment the device hardware interrupt * occured (or any other event the device clock raises at the beginning of a * cycle). */ -void ff_timefilter_update(TimeFilter *self, double system_time); +void ff_timefilter_update(TimeFilter *self, double system_time, double period); /** * Retrieve the filtered time |