Changelog

output_format gains mp3_22050_160 and mp3_24000_160, the highest-fidelity mp3 the format can carry: 160 kbps is the ceiling at these sample rates, so there is no higher mp3 to ask for. A request for mp3_22050_192 or mp3_24000_192 was always encoded at 160 kbps, and the response now reports the mp3_*_160 it actually delivered rather than echoing the 192 back. Nothing about those two requests changes on the wire except the reported value, and no existing integration has to move.

Every mp3_22050_* format also plays at the right speed now. They were being encoded about 8% fast and close to a semitone high; if you compensated for that in your own pipeline, remove the correction. mp3_24000_*, the default for audio_format: "mp3", was never affected.

Behind both: any sample-rate conversion we do is now a high-quality resample from the model’s native 24 kHz rather than the encoder default, which keeps the audio flat to about 10.7 kHz at 22.05 kHz instead of rolling off from 10 kHz. That applies to pcm_22050, pcm_44100, pcm_48000, pcm_8000 and ulaw_8000 as well.

The two mp3_*_160 formats are produced by the Simba 3 models; pairing one with a legacy Simba 1.6 model returns 400.