[Blackwoof]

Could you elaborate?

Are you claiming that converting a 16/44.1 lossless file to a 24/48 MP3 helps in some way?

I don't think it does, the difference between 22.05kHz and 24kHz as frequency ceilings only really benefits in mitigating aliasing on digital equipment as well as infinitesimally small accuracy changes to the waveform approaching the nyquist frequency. It should not change anything in playback, and I have never heard anything but clipping from upsampled lossless -> lossy encodings.

It forces MP3 to use it short blocks from longer scanning since the codec is basically 2 lossy models(Subband + MDCT) duck taped together, It allows the MDCT layer more time to understand what Subband layer handing over without It rushing. It not about forcing MP3 to do 22KHz.

 

[KinGensai]

What is your argument exactly? It sounds like you are saying MP3 uses more blocks to represent the original waveform if the encoding is done at 48k vs 44.1k. From what I'm seeing this isn't true, MP3 splits the signal into 32 bands via PQMF (and subsequently 575 bands via MDCT) in a hybrid bank config. This would mean the blocks are larger to cover more of the available frequency range.

Whether that introduces more room for error or not I don't know, but changing bitrates in between encodes has caused nothing in best case scenario and added noise in worst.

 

[Blackwoof]

It why Opus codec uses 48KHz despite only holding 20KHz. The Musepack devs had a chart showing at 48KHz MP3 being more stable while at 32KHz it was much worse, Voice can trigger pre-echo if they use sharp sounds. In FLAC this Is a non-issue.