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GStreamer Bad Plugins 0.10 Plugins Reference Manual | ![]() |
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Top | Description | Object Hierarchy | Properties |
"overlap" gdouble : Read / Write "rate" gdouble : Read "search" guint : Read / Write "stride" guint : Read / Write
Scale tempo while maintaining pitch (WSOLA-like technique with cross correlation) Inspired by SoundTouch library by Olli Parviainen
Use Sceletempo to apply playback rates without the chipmunk effect.
filesrc location=media.ext ! decodebin name=d \ d. ! queue ! audioconvert ! audioresample ! scaletempo ! audioconvert ! audioresample ! autoaudiosink \ d. ! queue ! ffmpegcolorspace ! autovideosink
OR
playbin uri=... audio_sink="scaletempo ! audioconvert ! audioresample ! autoaudiosink"
When an application sends a seek event with rate != 1.0, Scaletempo applies the rate change by scaling the tempo without scaling the pitch.
Scaletempo works by producing audio in constant sized chunks ("stride") but consuming chunks proportional to the playback rate.
Scaletempo then smooths the output by blending the end of one stride with the next ("overlap").
Scaletempo smooths the overlap further by searching within the input buffer for the best overlap position. Scaletempo uses a statistical cross correlation (roughly a dot-product). Scaletempo consumes most of its CPU cycles here. One can use the "search" propery to tune how far the algoritm looks.
plugin |
scaletempo |
author |
Rov Juvano <rovjuvano@users.sourceforge.net> |
class |
Filter/Effect/Rate |
name |
sink |
direction |
sink |
presence |
always |
details |
audio/x-raw-float, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], endianness=(int)1234, width=(int)32 |
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], endianness=(int)1234, width=(int)16, depth=(int)16, signed=(boolean)true |
name |
src |
direction |
source |
presence |
always |
details |
audio/x-raw-float, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], endianness=(int)1234, width=(int)32 |
audio/x-raw-int, rate=(int)[ 1, 2147483647 ], channels=(int)[ 1, 2147483647 ], endianness=(int)1234, width=(int)16, depth=(int)16, signed=(boolean)true |
"overlap"
property"overlap" gdouble : Read / Write
Percentage of stride to overlap.
Allowed values: [0,1]
Default value: 0.2
"rate"
property"rate" gdouble : Read
Current playback rate.
Allowed values: [-2.14748e+09,2.14748e+09]
Default value: 1
"search"
property"search" guint : Read / Write
Length in milliseconds to search for best overlap position.
Allowed values: <= 500
Default value: 14
"stride"
property"stride" guint : Read / Write
Length in milliseconds to output each stride.
Allowed values: [1,5000]
Default value: 30