Updated dependencies, new audio resampling library, performance improvements and volume control

[sibartel]

Heyho @codetheweb,

as promised some days ago in issue #9, here are my changes open to be discussed:

• Updated dependencies:

  • librespot from 0.2.0 to 0.3.1
  • songbird from 0.1.6 to 0.2.0

• Switched the library for audio resampling from samplerate to rubato:

  Samplerate is based on a c library and the function call used is not recommended for streamed audio because it does not work over chunk boundaries. As written in the docs:

  Perform a simple samplerate conversion of a large chunk of audio. This calls src_simple of libsamplerate which is not suitable for streamed audio.

  Therefore, this switch should make aoede more portable and additionally improve the audio quality.

• Performance improvements:

  • Implemented non blocking EmittedSink::read.
  • Increased EmittedSink internal sync_channel buffer size to fit at least one resampling frame. And therefore, most times no synchronisation is necessary.
  • Changed datatype in internal sync_channel to fit the floats of both channels. This reduces the amount of synchronisations needed between EmittedSink::read and EmittedSink::write.

• Implemented volume control using librespot::SoftMixer. Should close Volume Control not working #9.

I'm looking forward to hear from you.
Best regards!

[codetheweb]

Thank you, this approach makes much more sense than what I was doing. Downsides of learning a language by writing something in it. 😛

Looks like CPU usage while streaming dropped from 10-12% to 5-6% which is excellent as well. 👍

[sibartel]

Heyho @codetheweb,
happy new year! Thx for the review, I made the following changes:

• Added error to inform about minimum buffer size for EmittedSink::read call
• Fixed spelling
• Added comment to explain the upper bound of sync_channel
• Replaced vague calculation of sync_channel upper bound with the correct value for our settings

Should i squash the commits in some ways?

Regarding the CPU usage: Using the release build I have permanently less than 0.3% on my machine. Maybe we can investigate and optimize the cpu usage further in the future.

[codetheweb]

Looks good!

Happy New Year to you too.

I'll squash when merging.

Regarding the CPU usage: Using the release build I have permanently less than 0.3% on my machine. Maybe we can investigate and optimize the cpu usage further in the future.

I should have clarified that my usage stats were assuming full utilization of one core is 100%. If you're measuring based on overall utilization of the CPU, that would explain the difference. I'm on a M1 Max. I'm happy with performance as-is, but if you think it can further be optimized go for it. :)

[codetheweb]

Released in v0.3.0.