Storyline downgrades the audio sample rate to 22050 Hz

The title tells its own tail. During the process of publishing, audio files with a standard sample rate of 44100 Hz are downgraded to 22050 Hz. Audio files that were professionally recorded in a studio sound like they were spoken through a cookie box. There is no understandable argumentation for this setting because the file size is the same. My original file is encoded with a bitrate of 160 kbit and a sample rate of 44100 Hz. Its file size is 765 KB. After publishing, Storyline also delivers a file with a bitrate of 160 kbit but with a sample rate of 22050 Hz. Its file size is 761 KB. Just a tiny 4 KB difference. But it has a huge affect on sound quality.

Can you please tell me, how to change this MP3 encoder setting in Storyline respectively which progam file I have to change.

The second possibility would be an update on your part that you deliver to your customers.

Thank you very much,
Martin

16 Replies
Leslie McKerchie

Hello Martin and welcome to E-Learning Heroes :)

You have an option to adjust the Publish Quality when publishing your file. You can adjust the Audio bitrate if needed. Just check out the instructions in this documentation.

I've also seen other community members mention a need for no audio compression, so I'm going to submit that as a feature request on your behalf as well.

I wanted to share some information about how we manage these feature requests as that may be helpful. 

Martin Behling

Hey Leslie,

thanks for your reply.

But this topic is not about the audio bitrate compression. The problem is that the quality settings for audio only change the bitrate. For example 56 kbit, 128 kbit or 160 kbit. Everything is fine with this setting. It's important to have this compression to keep the file size small.

But users don't have the possibility to change the sample rate. After publishing, Storyline 360 delivers a file with a sample rate of 22050 Hz. My original audio file has a sample rate of 44100 Hz. Like every other audio you an millions of people listen to day after day through their headphones, TVs and other devices. In contrast 22050 Hz is an extreme downgrade.

There is no setting to change that sample rate in Storyline 360 to the common 44100 Hz. But you should let your customers decide what sample rate they want to use. Please ask your developers to add this option to the settings page or tell me in which Storyline 360 system file I can change the sample rate from 22050 Hz to 44100 Hz.

Thank you very much.

Martin

Steve Flowers

The audio channel in a published video (mp4) is sampled at 44100. Audio by itself (mp3) is sampled at 22050. The lower sample rate *should* save some space but it comes at a cost of aliasing that won't faithfully reproduce sound above 11Khz. It sounds like the audio compressor is doubling the word resolution for the same bitrate. Matt does a good job illustrating the problem in this thread

I did find a config file for the video compressor but not for the audio dll. Should really be set at 44100 with the ability to adjust bitrate through resolution. This would make a bigger difference than it might seem. 

Martin Behling

Thanks for the illustration.

To cut a long story short. Sample rates of 44100 Hz and 48000 Hz are industry standard. The first compact disc introduced in 1982 has a sample rate of 44100 Hz. There is no sense in using 22050 Hz in the year 2019. Especially beause it has no benefit based on the file size.

For a software developer it surely only takes seconds to change this one code line from the number 22050 to 44100.

It's a feature requested so many times before. Please implement a higher sample rate in the next update.

Thank you very much.

Martin Behling

Six months have passed. How long does it take to change this one code line from the number 22050 to 44100. Sample rates of 44100 Hz and 48000 Hz are industry standard. It gives the impression that your team does not care about this product feature.

There are other customers who requested that feature before. When? Three years ago.

https://community.articulate.com/discussions/articulate-storyline/audio-sample-rate-changes-after-publishing

It is time.

Lauren Connelly

Hi everyone!

Great news, we just released Update 33 (Build 3.33.20625.0) for Storyline 360!

Along with other bug fixes and new features, you'll see the option to turn off audio compression!

To dive into using this new feature, you'll need to update Storyline 360 on the desktop app! You can read about the other bug fixes and features included in this update here.