VSDSP Forum

There is no sample memory you could load instruments to. There are some instruments using samples or wavetables, but those are in ROM. There is no standard mechanism to replace instruments. I have patched some instruments in the RT MIDI Application, but generating new ones require a lot of informati...

The vs1053-rtmidistart code only works with vs1053b, because the code is linked against vs1053b ROM symbols. I recommend using the vs1003/vs1053 RT-Midi Input application package (from https://www.vlsi.fi/en/support/software/vs10xxapplications.html ) and either writing 0x30 (for vs1003b) to AIADDR a...

GPIO0 down, GPIO1 up. Release reset, DREQ should go up and the analog outputs bias to about 1.2V. Do you see these happening? RX then receives MIDI commands. Logic-level UART transmission is idle high, bits at 31250bps (32us per bit), start bit (low), 8 data bits least-significant bit first, 1 stop ...

You can only have volume settings for actual audio channels coming from the USB, but USB Audio descriptor can describe mixers and other elements that can "publish" subwoofer level control to the USB Audio Interface. Selector units could be used to switch between amplifier and headphone out...

Because if the amplifier are note muted, the noise will still be amplified and can be heard at high volume. If the amplifier has volume control, you don't need to perform volume on the vs1010. You can receive the Volume/mute commands from the USB host and then forward the commands to the amplifier/...

USB Audio Device implements USB Audio 1.0 or USB Audio 2.0 and both can have audio controls that adjust volume and mute. So, it's a matter of implementing the USB Audio device and configuration descriptors and the corresponding functionality. We've done it with most VLSI chips that have USB. If Hann...

The player would be a reimplementation of the wav decoder. You need to read the RIFF WAVE header to get all of the information (sample rate, number of channels, bytes per sample, start and size of the data), then you can seek in the data chunk and read and play accordingly.

I know next to nothing about VSOS, but would ioctl(stdaudioin, IOCTL_AUDIO_SET_ICHANNELS, 1); do it?

or

AUIADC m 96000 line1_3

It looks like you're writing a mono WAV header, but the data remains stereo. Thus, every other sample is from the left and every other from the right channel, producing a double-length file.

Don't you need to switch the stdoudioin to mono first?

Most formats cannot be played in reverse order without first decoding them and storing the result (in significant chunks). To reverse play without decoding the whole file first would need to decode from the end of the file to the front. You could do this with linear PCM WAV and vs1005 with a special...