First Audio Frame ‘Eaten’ When Using Crossfade / Cue Points

[unudelaradio]

Hello!

I’m wondering if, in the most recent versions, the very first audio frame of a track might sometimes be getting cut off. While using Liquidsoap in AzuraCast, I noticed this behavior.

I’ve noticed that on some tracks — especially certain MP3 files with a very strong first beat — the punch sounds different depending on whether crossfade is enabled or not. When crossfade is enabled, it feels like the first "micro-frame" is “eaten” or absorbed (even when fade in and cue in are both set to 0).

When I disable crossfade and all custom cue points, that first beat plays cleanly and sounds normal again.

Scenario 1 – Crossfade Disabled:
The previous track has custom cue points (start next + fade out).
The next track plays with the first frame “eaten,” regardless of whether it has custom cue points or not.

Scenario 2 – AutoCue Enabled:
The previous track has no custom cue points.
The next track still plays with the first frame “eaten.”

Scenario 3 – No Custom Cue Points and Crossfade Disabled:
The first beat of the next track plays cleanly.

@toots If this seems relevant, I can provide the MP3 files and the script needed to reproduce the issue.

[unudelaradio]

This is how the waveforms look when recording the differences.
You can clearly see how the first frame is affected:

[toots]

Thanks for reporting. Please email files to toots@rastageeks.org or as PM via discord. I'll have a look thanks!

[toots]

Thanks for the files. I have started an issue here: #4887

Could you report the following:

• Liquidsoap version used
• Liquidsoap script logs

In particular I'm interested in the first part of the logs and the exact annotate:... uris with the cue point to be able to reproduce locally.

Thanks!

[toots]

It's fixed thanks!

[unudelaradio]

Many thanks for your help! I truly appreciate it. I hope I’ll be able to test this soon in AzuraCast, and I sincerely hope that the latency issue AzuraCast/AzuraCast#8353, which causes interruptions after one or two weeks, will be resolved in the near future.