Sound/wav_files in replicators

Support
1

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

2

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

3

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

4

Hi Yoon,

That’s a clever workaround. Thanks for sharing!

Chris

5

Hi Yoon,

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

Cheers,
Chris