Opus playback with replay gain is too quiet

[gwa-x]

• I have checked the FAQ for answers.
• I have checked the Changelog that the issue is not already fixed.
• I believe this issue is a bug, and not a general technical issue, question or feature requests that can be discussed on the forum.

Describe the bug
Opus playback is too quiet with replay gain. This is probably because the Opus header gain is applied separately with the Replay Gain tag (e.g, R128_TRACK_GAIN).
Because of this issue, the Replay Gain playback feature is unusable with a library of mixed of Opus and other formats. The pre-amp adjustment cannot be used because it affects other formats as well.
Similar discussions are in Poweramp's forum and Hydrogenaudio.

To Reproduce

• Scan replay gain on an opus file with, e.g., foobar2000, to save Opus header gain and R128_TRACK_GAIN or R128_ALBUM_GAIN.
• Enable "Use Replay Gain metadata..." in Settings-Backend
• Play the opus files

Expected behavior
Strawberry plays opus files at the same perceptible volume as other formats, e.g., MP3.

System Information:

• Operating system: Ubuntu 24.04
• Strawberry Version: 1.2.4