VSDSP Forum

When I play a new file a distortion of audio around 500ms is done. I have muted the vs1053b before to send a new audio file but the issue stills present. Is SCI_HDAT1 0 before you start sending the new file? What does the distortion sound like? Is the whole 500ms distorted? What are the formats of ...

For your own tests / use, sure, you can try to power the SD from IOVDD. If you're only reading from the card, and the card goes to idle state at all, then reading will also work (most of the time). Increasing the values of the IOVDD capacitors too much may have an opposite effect instead of helping....

What are the symptoms? Are you using fast-play (and sending all of the data), or skipping?

The vs1053b is rated at 55.3MHz. If you use a high internal clock for the vs1053, then also make sure your CVDD is both stable and high enough.

What kind of completely random errors you get? Are the functions returning error codes, or the data just ends up being garbage?

What do you read from SCI_AUDATA? If you get 0xac45, then the vs1053 probably is in real-time MIDI mode. When I start my program I pull the reset pin high, wait 50ms and then pull it low using digital write xRESET is active low, so there apparently is an inverter in the line of you have the high and...

Timeout and software reset should help. If the decoder stays stuck with DREQ high, what does HDAT1 contain? The mp3 decoder should not get stuck. If there are errors for other formats, there is a larger possibility of getting stuck. If the mp3 file contains an ID3v2 tag, then it may take a long whil...

For Real-Time MIDI latency, see: http://www.vsdsp-forum.com/phpbb/viewtopic.php?p=16081 You're right that the UART FIFO has a chance of being overrun with the ROM code when a lot of notes are active (but see the above for a patch). The MIDI decoder generates output in 64-sample blocks. Volume change...

What happens when we feeding the frame not from beginning but from the middle. The decoder finds the next location that looks like a mp3 header, then decodes and plays it. However, there is this "bit reservoir" option where the mp3 frame can reference data a the end of the previous frame....

There is a trade-off between easyness and error-freeness in jumping backwards in a mp3 file. The easy way is to just jump in the new location and let the decoder resynchronize. You will get some decoding errors. If you decode the mp3 headers yourself (the 4 first bytes contain all of the required da...

VS1053b reads whole mp3 frames, then decodes them (frame decoding cannot be interrupted, not even with SM_CANCEL), then plays the decoded audio. Decoding errors cannot generally be detected, there is no checksum and there are no "holes" in the code space, so the decoded frame is then simpl...