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Sound/wav_files in replicators

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Yoon Bai

14 May, 2021 01:39 PM

Hi Chris,

I was wondering if I could get your help with playing audio (WAV) files on MWorks. I would like to put a long list of WAV file in a list/range replicator, but noticed the following compilation error:

Component 'sound/wav_file' is not allowed inside component 'range_replicator' [line 384, column 9]

 - And here are two code snippets I’ve tried so far:

// snippet 1: audio only
    range_replicator (
        variable = filename
        from = 0
        to = num_original_videos - 1
        step = 1
        ) {
        wav_file ${filename} (
            path = 'filenames(audio/audio_*.wav)'
            )
    }

    // snippet 2: audio only
    list_replicator (
        variable = filename
        values = 'filenames(audio/audio_*.wav)'
        ) {
        wav_file ${filename} (
            path = ${filename}
            autoplay = true
            volume = 0
            )
    }

  - I’m not sure if I’m not using the right syntax, or if sound/wav_file is not supported as an indexable stimulus group. Do you have any suggestions?

Thanks!
Yoon

1. Support Staff 1 Posted by Christopher Sta... on 14 May, 2021 02:14 PM

   

   Hi Yoon,

   Like the error message says, sounds aren't allowed inside replicators. Looking at the MWorks source code, it's not immediately clear to me why they aren't allowed. Let me see if I can figure it out and change things so they are allowed.

   In the meantime, I think you're stuck doing things the hard way and defining each sound individually. Sorry!

   Chris

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2. 2 Posted by Yoon Bai on 25 May, 2021 06:50 PM

   

   Hi Chris,

   I wanted to follow up with a workaround, hoping it might help others in the meantime. The workaround is to convert sound clips to video clips. I converted WAV files to MP4 files using ffmpeg <https://ffmpeg.org/> (and added a still image throughout the duration of the sound clip) and this worked well with replicators (verified this on MWorks 0.9 and 0.10).

   Best,
   Yoon

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3. Support Staff 3 Posted by Christopher Sta... on 26 May, 2021 08:15 PM

   

   Hi Yoon,

   That's a clever workaround. Thanks for sharing!

   Chris

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4. Support Staff 4 Posted by Christopher Sta... on 23 Jul, 2021 01:40 PM

   

   Hi Yoon,

   As of the current MWorks nightly build, sounds are now allowed in range and list replicators (example and example, respectively).

   Cheers,
   Chris

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5. Christopher Stawarz closed this discussion on 07 Sep, 2021 03:57 PM.