Not perfectly gapless?

[Chewy]

Today, I noticed a really small but audible artifact/glitch during the transition between two tracks that are supposed to be played gaplessly. This glitch happens every single time I play those tracks, which means it is easily reproductible.

Both tracks are in 16-bit 44.1kHz FLAC format and are perfectly gapless when playing on other music players.

My settings should allow gapless playback without issues, I made sure to disable any resampling, fading and even equalizer, to be sure I have the "cleanest", most "direct" output:

I even increased the "Preload Gapless Tracks" option, to be the largest value but the same glitch happens.

To understand the issue, I recorded the Poweramp output using Audacity and compared it to the original files, here is the result (top is the recording from Poweramp output, bottom is the original tracks combined):

The tracks I played are "Klaus I Love You" and "Outro" from M83's album titled "Hurry Up, We're Dreaming", I can provide my FLAC files if needed.

 

Do you think this is an additional setting to set or a bug inherent to Poweramp?

[Chewy]

Additional useful information:

• Poweramp build number: build-930-bundle-play
• Device model: Samsung Galaxy S10+
• Android version: Android 12

[maxmp]

If you're using some rather slow sd card storage, check "Preload Gapless Tracks" option in Poweramp Settings. Flac tracks are always gapless, Poweramp doesn't insert silence between tracks, obviously, unless you specifically set "Silence Between Tracks" option. Thanks!

[Chewy]

6 hours ago, maxmp said:

If you're using some rather slow sd card storage, check "Preload Gapless Tracks" option in Poweramp Settings. Flac tracks are always gapless, Poweramp doesn't insert silence between tracks, obviously, unless you specifically set "Silence Between Tracks" option. Thanks!

I made sure to set "Preload Gapless Tracks" to the maximum value to be sure that wasn't a slow SD problem but the problem still occured.

As you can see on the waveforms, silence doesn't seem to be "inserted" but actually "erased" over the very beginning of the next track.

Let me know if you want the FLACs files, I believe this is easily reproducible, it happens everytime on my phone.

Thank you!

[maxmp]

@Chewy please share couple of such tracks with imperfect gapless (preferable from the device/Poweramp itself via Send menu action - gpmaxmpz@gmail.com) - I'll try to investigate those. Poweramp do inter-track gapless smoothing by interpolating last and first samples a bit, but this improves audible gapless perception. Thanks!

[Chewy]

12 hours ago, maxmp said:

@Chewy please share couple of such tracks with imperfect gapless (preferable from the device/Poweramp itself via Send menu action - gpmaxmpz@gmail.com) - I'll try to investigate those. Poweramp do inter-track gapless smoothing by interpolating last and first samples a bit, but this improves audible gapless perception. Thanks!

Files sent!

This inter-track gapless smoothing feature could be the cause! Is there a way to disable it?

Thanks

[maxmp]

@Chewy thanks for the test tracks. Some minor glitch exists between tracks, I will try to investigate this.

[maxmp]

@Chewy it seems the artifact is introduced by the (default SwR) resampler flushing. You can try to switch to SoX resampler in Poweramp settings in the current Poweramp builds to workaround the issue. I hope the issue for SwR resampler will be resolved in the next builds. Thanks!

[Chewy]

1 hour ago, maxmp said:

@Chewy it seems the artifact is introduced by the (default SwR) resampler flushing. You can try to switch to SoX resampler in Poweramp settings in the current Poweramp builds to workaround the issue. I hope the issue for SwR resampler will be resolved in the next builds. Thanks!

Unfortunately, switching to SoX didn't change anything for me. I guess it makes sense since I'm using the Samsung Hi-Res output directly at 44.1kHz, without resampling!

Changing the sample rate to 48KHz and using the SoX resampler did not solve the issue either

[maxmp]

@Chewy right, this is for the disabled smoothing which is not available in current Poweramp builds. The next builds will be better polished for such tracks.

[maxmp]

@Chewy please check this build, let me know it works for you

 

[Chewy]

3 hours ago, maxmp said:

@Chewy please check this build, let me know it works for you

 

It's working a lot better with this build, yes!! No audible glitches anymore  Thanks!!

 

Comparing the waveforms shows there are still minor differences between the two tracks combined and what Poweramp plays. I guess those come from the "smoothing" feature you were referring to. Out of curiosity, what's the point of such a feature when playing 100% gapless FLAC files?