AssumeSampleRate
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| − | + | <div {{BlueBox2|40|0|3px solid purple}} > | |
| + | {{AvsPlusFullname}}<br> | ||
| + | Up-to-date documentation: [https://avisynthplus.readthedocs.io/en/latest/avisynthdoc/corefilters/assumerate.html https://avisynthplus.readthedocs.io] | ||
| + | </div> | ||
| − | |||
| − | # Let's say that this | + | {{Template:FuncDef|AssumeSampleRate(clip ''clip'', int ''samplerate'')}} |
| − | AviSource("video_audio.avi") | + | |
| + | Changes the sample rate of the current clip without changing the number of samples. | ||
| + | :This changes the sample rate, pitch, playback speed and running time of the audio. | ||
| + | :It will also affect synchronization with the video. | ||
| + | |||
| + | ==== Examples ==== | ||
| + | * Fix an audio sync problem: | ||
| + | <div {{BoxWidthIndent|56|1}} > | ||
| + | [[AviSource]]("video_audio.avi") | ||
| + | # Let's say that this clip loses audio sync: | ||
| + | # by the end, the audio is behind by 200 milliseconds. | ||
| + | |||
| + | Ar = [[Clip_properties|AudioRate]] # original audio sample rate | ||
| + | dur = [[Clip_properties|AudioDuration]] # total duration in seconds | ||
| + | adj = -0.200 # correction needed (decrease audio duration by 200 msec) | ||
| + | |||
| + | # Adjust audio duration: | ||
| + | '''AssumeSampleRate'''([[Internal_functions#Round|Round]](dur / (dur+adj) * Ar)) | ||
| + | |||
| + | # Video and audio are now in sync. | ||
| + | |||
| + | # (optional) restore original sample rate. | ||
| + | #[[ResampleAudio]](Ar) | ||
| + | </div> | ||
| + | |||
| + | * Play video and audio at half speed: | ||
| + | <div {{BoxWidthIndent|56|1}} > | ||
| + | [[AviSource]]("video_audio.avi") | ||
| − | # Play | + | # Play video at half speed: audio will be out of sync |
| − | + | [[AssumeFPS]]([[Clip_properties|FrameRate]]/2) | |
| − | # Play | + | # Play audio at half speed: (pitch will be lowered by an [[wikipedia:Octave|octave]]) |
| − | + | '''AssumeSampleRate'''([[Clip_properties|AudioRate]]/2) | |
| − | # Video and audio | + | # Video and audio are now in sync. |
| + | # Equivalent to calling [[AssumeFPS]](..., sync_audio=true) (see below) | ||
| + | </div> | ||
| + | ==== See Also ==== | ||
| + | * [[AssumeFPS]]: {{FuncArg|''sync_audio''}} | ||
| + | :If ''true'', the audio sample rate is changed by the same amount; the pitch of the resulting audio is shifted. | ||
| + | :If ''false'' (the default), the audio is unchanged; this means the audio will lose synchronization over time. | ||
[[Category:Internal filters]] | [[Category:Internal filters]] | ||
| + | [[Category:Audio_filters]] | ||
| + | [[Category:Timeline_editing_filters]] | ||
Latest revision as of 04:24, 18 September 2022
AviSynth+
Up-to-date documentation: https://avisynthplus.readthedocs.io
AssumeSampleRate(clip clip, int samplerate)
Changes the sample rate of the current clip without changing the number of samples.
- This changes the sample rate, pitch, playback speed and running time of the audio.
- It will also affect synchronization with the video.
[edit] Examples
- Fix an audio sync problem:
AviSource("video_audio.avi") # Let's say that this clip loses audio sync: # by the end, the audio is behind by 200 milliseconds. Ar = AudioRate # original audio sample rate dur = AudioDuration # total duration in seconds adj = -0.200 # correction needed (decrease audio duration by 200 msec) # Adjust audio duration: AssumeSampleRate(Round(dur / (dur+adj) * Ar)) # Video and audio are now in sync. # (optional) restore original sample rate. #ResampleAudio(Ar)
- Play video and audio at half speed:
AviSource("video_audio.avi") # Play video at half speed: audio will be out of sync AssumeFPS(FrameRate/2) # Play audio at half speed: (pitch will be lowered by an octave) AssumeSampleRate(AudioRate/2) # Video and audio are now in sync. # Equivalent to calling AssumeFPS(..., sync_audio=true) (see below)
[edit] See Also
- AssumeFPS: sync_audio
- If true, the audio sample rate is changed by the same amount; the pitch of the resulting audio is shifted.
- If false (the default), the audio is unchanged; this means the audio will lose synchronization over time.
