New demo uploaded: PCM Multi-Encoding Demo

SlithyMatt · Post by **SlithyMatt** » Fri Feb 12, 2021 5:30 pm

PCM Multi-Encoding Demo

This is a demo of 26 different encodings for PCM audio playback, from the maximum bitrate (48.828 kHz, 16-bit stereo) the minimum (381 Hz, 8-bit mono) using the same non-copyright music track and fitting as much data as possible into 63 RAM banks (504 kB).

Just press different letters to hear different samples.

As seen on YouTube:

Submitter

SlithyMatt

Submitted

02/12/21

Category

Demos

kliepatsch · Post by **kliepatsch** » Mon Feb 15, 2021 3:44 pm

Thanks! I think this is a nice resource for when people want to find the PCM settings that suit their needs best.

kelli217 · Post by **kelli217** » Mon Feb 15, 2021 9:18 pm

I wonder if it would be possible to do some sort of double-buffering. Use only two banks, and play from one while loading new data to the other from storage. Theoretically this would allow arbitrary length PCM sounds.

SlithyMatt · Post by **SlithyMatt** » Tue Feb 16, 2021 3:24 am

You can already do arbitrary length. The sound stops playing once the FIFO is depleted. This demo was to show how long a sound could be in memory, but you could certainly feed the FIFO from a file, if the bit rate isn't too fast. It definitely takes longer than 2 seconds to load 500k from the SD card, so the bit rate would need to be well under maximum to allow "streaming". You might be able to get away with 12kHz.