Pitch / Speed Shifter for VS1010d

Designing hardware and software for systems that use the VS1010 MP3 Audio DSP Microcontroller.
Post Reply
User avatar
Henrik
VLSI Staff
Posts: 1199
Joined: Tue 2010-06-22 14:10

Pitch / Speed Shifter for VS1010d

Post by Henrik » Thu 2021-02-18 13:23

Hello!

It is with greate pleasure that I bring to you the Pitch / Speed Shifter for VS1010d. This device driver has earlier existed for VS1005, but now it has been ported for VS1010, too.

The Pitch / Speed shifter allows for independent control of an MP3 file's playback speed and pitch. It can be used in various applications, including but not limited to:
  • DJ usage where it is very useful to be able to control playback speed and pitch independently.
  • Language learning where adjusting speed without affecting pitch is very useful.
  • Audio book devices where speed control without affecting pitch is convenient.
  • Karaoke devices where pitch control can be used to match the range of the karaoke singer.
I hope this piece of software proves useful to you!

Kind regards,
- Henrik
Attachments
FtPitch.zip
Pitch / Speed Shifter driver and control program. See README.TXT for details.
(54.26 KiB) Downloaded 8 times
TreePlayer3.zip
Example player that demonstrated speed and pitch controls. See README.TXT for details.
(31.91 KiB) Downloaded 5 times
ParamSpl.zip
Support function required by SetPitch. Install to S:SYS/
(7.2 KiB) Downloaded 6 times
Good signatures never die. They just fade away.

kenc
User
Posts: 10
Joined: Tue 2021-02-09 3:41
Location: Ontario, Canada

Re: Pitch / Speed Shifter for VS1010d

Post by kenc » Thu 2021-02-18 22:00

Henrik,

Thank you for your work on this!

I have the ftpitch driver + TreePlayer3 running on my 1010D Minidemo board, and I noticed an artifact (click sound) when the speed is first slowed down or pitch increased. I've tried this with different MP3 files (all 16-bit, 44.1Khz sample rate, 192Kbps CBR). It also happens playing WAV/LPCM files (16-bit, both 44.1Khz and 48Khz files). I also tried using two different microSD cards, a Sandisk consumer-grade card and a Sandisk Industrial card for embedded systems.

TP3
Base pitch & speed playback ok
Press s (*CLICK* sound)
Press b (back at base speed, playback ok)
Press f (playback ok)
Press b (playback still ok)
Press s (*CLICK* sound)
Press s (playback ok)
etc.

So fbfbfb... is fine, but sbsbsb... causes clicks

TP3
Base pitch & speed playback ok
Press + (*CLICK* sound)
Press + (playback ok)
Press - (playback ok)
Press - (back at base pitch, playback ok)
Press - (below base pitch, playback still ok)
Press + (back to base pitch, playback ok)
Press + (*CLICK* sound)

So -=-=-=... is fine, but +=+=+=... causes clicks.

EDIT: I noticed that there's no clicking the first time I press s or + after rebooting the minidemo board, but after a couple times pressing s or + the clicking gets louder.

Thanks!
Ken

User avatar
Henrik
VLSI Staff
Posts: 1199
Joined: Tue 2010-06-22 14:10

Re: Pitch / Speed Shifter for VS1010d

Post by Henrik » Mon 2021-02-22 6:33

Hello Ken,

excellent that you have already tried the Pitch / Speed Shifter!

I'll have to see whether I can repeat your issue and if so, what the solution would be.

Kind regards,
- Henrik
Good signatures never die. They just fade away.

kenc
User
Posts: 10
Joined: Tue 2021-02-09 3:41
Location: Ontario, Canada

Re: Pitch / Speed Shifter for VS1010d

Post by kenc » Mon 2021-02-22 6:40

Thank you, Henrik. I can make an audio recording,
if it would help. Or send you the files I’m testing with.

Best,
Ken

Post Reply