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POTime Stretching and Pitch shifting with IOS
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19575470
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2013-10-24T20:00:30.930
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2013-10-28T05:58:08.840
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2013-10-28T05:58:08.840
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Body
In short: How to do Time Stretching and Pitch Shifting in iOS? <blockquote> In Detail: </blockquote> What am i trying to do? The app will show the video thumbnails to the users to select a certain range of frames from the video file. I have to Apply the ramp slow Mo, only to the selected duration or frames of the video. Ramp Slow Mo: (Time Stretching + Pitch shifting) dynamically. I have to vary the Time and pitch in a for loop say for some 10 iteration. Its nothing but the behaviour of English letter "U". So, i will increase the time and pitch and decrease them. How am I trying: <ol> <li>Finding the Start/End time for the user selected videos.</li> <li>Splitting the video and audio separately through AVFoundation Mutable Composition.</li> <li>For Video: Applying Time Stretching for only for the duration in between Start/End time. *No problem* in it,Its happening as i expect.</li> <li>For Audio: Doing Time Stretching and Pitch shifting dynamically, which is also for the selected time frame. I am using Dirac for this. Now, i would like to use IOS SDK itself.</li> <li>Merging audio and video post slow mo as a file and storing it.</li> </ol> Analysis: Hitherto, I've found that OpenAl or Audio Units(Using AUVarispeed alone or AUTimePitch and Time Rate together) can help. After splitting the video and audio, i will have the audio URL to proceed further, either with OpenAL or Audio Units. My questions: <ol> <li>Can anybody help me to avoid Dirac(ref bullet 4)? So how to do Time Stretching and Pitch shifting dynamically?</li> <li>How to do *only for the selected frame*s (in between start and end time)?</li> <li>I am not sure how to combine *AVFoundataion's* URL with OpenAL or Audio Unit's buffer and after slow mo effect, how to merge finally with AVFoundation's video reference URL?</li> </ol> Any kind of reference or sample codes helps a lot.
Tags
<ios><iphone><core-audio><openal><audiounit>
Title
Time Stretching and Pitch shifting with IOS
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 POTime Stretching and Pitch shifting with IOS
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1. COCan anybody help me out?
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 POTime Stretching and Pitch shifting with IOS
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