diff options
Diffstat (limited to 'libavdevice/timefilter.h')
-rw-r--r-- | libavdevice/timefilter.h | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/libavdevice/timefilter.h b/libavdevice/timefilter.h index 8cadd8b..6662959 100644 --- a/libavdevice/timefilter.h +++ b/libavdevice/timefilter.h @@ -5,20 +5,20 @@ * Author: Olivier Guilyardi <olivier samalyse com> * Michael Niedermayer <michaelni gmx at> * - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * 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. * - * Libav is distributed in the hope that it will be useful, + * 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 Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -45,16 +45,18 @@ typedef struct TimeFilter TimeFilter; * * Unless you know what you are doing, you should set these as follow: * - * o = 2 * M_PI * bandwidth * period - * feedback2_factor = sqrt(2 * o) + * o = 2 * M_PI * bandwidth * period_in_seconds + * feedback2_factor = sqrt(2) * o * feedback3_factor = o * o * * Where bandwidth is up to you to choose. Smaller values will filter out more * of the jitter, but also take a longer time for the loop to settle. A good * starting point is something between 0.3 and 3 Hz. * - * @param clock_period period of the hardware clock in seconds - * (for example 1.0/44100) + * @param time_base period of the hardware clock in seconds + * (for example 1.0/44100) + * @param period expected update interval, in input units + * @param brandwidth filtering bandwidth, in Hz * * For more details about these parameters and background concepts please see: * http://www.kokkinizita.net/papers/usingdll.pdf @@ -80,6 +82,15 @@ TimeFilter * ff_timefilter_new(double clock_period, double feedback2_factor, dou double ff_timefilter_update(TimeFilter *self, double system_time, double period); /** + * Evaluate the filter at a specified time + * + * @param delta difference between the requested time and the current time + * (last call to ff_timefilter_update). + * @return the filtered time + */ +double ff_timefilter_eval(TimeFilter *self, double delta); + +/** * Reset the filter * * This function should mainly be called in case of XRUN. |