X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=include%2Fstretching-regions.html;fp=include%2Fstretching-regions.html;h=f6a88a87280ac3e73fc89c22bf4656fb761b0e31;hb=7717f195fe7bb1ba864bf4d9f552c15cccac7bc1;hp=0000000000000000000000000000000000000000;hpb=14f05f96ea7bd6d602c103c4a4de8042cbfe0949;p=ardour-manual diff --git a/include/stretching-regions.html b/include/stretching-regions.html new file mode 100644 index 0000000..f6a88a8 --- /dev/null +++ b/include/stretching-regions.html @@ -0,0 +1,107 @@ + +

+ The Stretch Mode tool can be switched to by selecting it in the + Toolbox, or simply by hitting the T + key. +

+

+ It allows to extend or reduce the duration of a region, optionnaly maintaining + its pitch. This is one of the few operations in Ardour that affect the underlying + audio data from a region, even if the original audio is kept safely—no data + is lost in the process. +

+

+ This operation is usually used to fit an audio sequence with a different rhythm + into a session, but can be used in a wide area of cases, due to its ability to + maitain or alter the pitch. +

+ +
+ region arrangement before the stretch + region arrangement while stretching + region arrangement after the stretch +
+ Using the Stretch Mode tool. Before stretching, while stretching, and after a stretch +
+
+ +

+ The Stretch Mode tool is very similar in use to doing a trim in grab mode: the + boundary (start or end) is left-clicked and dragged to + its wanted position. Notice a timer appearing, showing the new duration of the + region using the same clock mode as in the + primary transport clock. +

+

+ Stretching is a complex operation (phase vocoding), involving resampling, + frequency analysis and synthesis. The parameters used to transform the audio + data are user tweakable, and exposed to the user as the + left mouse button is released: +

+ +
+ The Time Stretch Audio window +
+ The Time Stretch Audio window +
+
+ +

+ The Time Stretch Audio window is made of: +

+ +
+
Duration
The target duration of the region, expressed using the + primary transport clock's mode
+
Percent
The target duration of the region, expressed as a percentage + of the region's original lenght. Can be either higher than 100% (to + expand the region) or lower (to shrink it)
+
Contents
The type of audio the region is made of. Ardour will fine-tune + its algorithm based on this content, see below
+
Minimize time distortion
Tries to reduce the smearing + of the audio created by the pahse vocoding process
+
a Progress bar
showing the operation in progress.
+
+ +

+ The Contents should be selected to best fit the actual content of the region, amongst: +

+ + + + + + + + + + + + + + + + + +
ContentDisable phase resynchronisation at transientsBand-limit phase resync to extreme frequenciesDisable phase locking to peak frequenciesUse longer processing window (actual size may vary)Use shorter processing window
Mushy XXX
Smooth XX
Balanced multitimbral mixture X
Unpitched percussion with stable notes X
Crisp monophonic instrumental (default)
Unpitched solo percussion XX
Resample without preserving pitch see below
+ +

+ While the table above details how the different kinds of audio material + alter the fine-tuning of the DSP, from an user point of view, the operation often + consists in trying different settings and listening to the result. +

+ +

+ The best way to start experimenting is to consider the material itself: +

+ +