How can I play sound backwards and count the played sampels?

[sthiemt]

Hello

I just want to develop a small subVI. It should play a *.wav File until the user push a button. Then I want it to play that sound from this position backward until the beginning of the wave file is reached.

It tried different methods. E.g.. I created a reverse Copy of the wave file with Audacity and cut the beginning of this file... but there must be better ways to do this.

Further it is pretty important that the reverse Playback starts exactly with the sample the normal playback stops. 

So my questions are:

How can I play a waveform backward Labview?

and

How can I get the number of samples, that were played until the user push the button and stops the playback?

Thank u for ur help

sthiemt

[Coq_Rouge]

Yes It can be done. And is not that hard to do to. But not if your idea of Labview programming are spreading out some Express VIs and quickly wire them together. It would help if you posted what you have done so far (in Labview code) even if it do not work. Have you looked at the sound examples in Labview. They may give you some clues

[sthiemt]

It is not my intention get an easy soulution by using express vis. I just tried to express my problem in general. 

Anyway I've found a way to play a waveform backwarts. Use the "get waveform Componets" (first function in the array menu) and get the component "Y". This should be an array. Use the "invert array" function to invert it and put everthing with the "create waveform" (second function in the array menu). I try to upload the vi tomorrow.

Solved this Problem. But there are still problems with the timing.:(

Greetz

PS: I can not upload my entire program. But I will try to make an extra VI to explain what I've tried so far...

[Coq_Rouge]

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@sthiemt wrote:

It is not my intention get an easy soulution by using express vis. I just tried to express my problem in general. 

Anyway I've found a way to play a waveform backwarts. Use the "get waveform Componets" (first function in the array menu) and get the component "Y". This should be an array. Use the "invert array" function to invert it and put everthing with the "create waveform" (second function in the array menu). I try to upload the vi tomorrow.

Solved this Problem. But there are still problems with the timing.:(

Greetz

PS: I can not upload my entire program. But I will try to make an extra VI to explain what I've tried so far...

---

The Express VI concept is just some flimflams that NI have glued on top of Labview using very cheap glue. So instead of solving problems they create problems for the programmer.

And please post your program (or part of it). Very often in Labview the problem is poor programming style. But do not think about that. We all have to learn and make mistakes in order to get better