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Missing VS1053b WAV PCM Recorder Application for 24kHz

Posted: Wed 2020-06-24 10:07
by ChipMonk
I'm designing a kind of an audio recorder solution. And using a board with vs1053b chip as a companion to the device's main board with ATmega 2560. The aim of the device is to record high-quality uncompressed audio. So I used "VS1053b / VS1063a WAV PCM Recorder Application" ( ... provided on the official website. Everything is Ok, except one thing. I wanted to try both 48 kHz and 24 kHz encoders. But found that those labeled as 24 kHz are also recording at actually 48 kHz. Very surprised by that fact, I started to look for some errors on my side. But then the idea came to me to just compare the two files. For instance "vs1053b_24k_l.img" against "vs1053b_48k_l.img". And you know what - they are equal! The same situation is with their .plg versions. And with all other files in the package. So it means that all 24k-labeled files are just renamed copies of corresponding 48k-labeled files. The simplest way to check that I'm right is to use md5 or other checksum against the files.
So my questions are:
1. Can somebody of the staff members of VLSI Solutions, who are at the forum, help fixing this situation and updating the archive on the website with correct files?
2. Maybe someone on this forum has customized versions of the 24k profiles that can be shared?
Actually I found bytes that correspond to 48000 in the original plugin image. But modifying the bytes to lets say 24000 is only a half of the solution - the recorded audio becomes distorted as if I used a pitch shift effect on it in some editor. But audio samples are still being generated by the IC and fed through SCI at 48k/sec rate as if nothing was changed. So modifying those 2 bytes in the image affects only how frequently the IC reads its ADC. But to make the whole solution work as it should and generate samples at the specified rate will require additional reverse engineering. So it would save a lot of time if some of my 2 questions will have a positive answer.

Re: Missing VS1053b WAV PCM Recorder Application for 24kHz

Posted: Wed 2020-06-24 10:43
by pasi
Thanks for the report. Due to holidays it will take at least 3 weeks before Henrik is back and can take a look.

You could check if the same issue exists in the older version: ...
At least the profiles have different CRC's in the zip archive. The only difference seems to be that 1.31 provides the app in several formats.

Re: Missing VS1053b WAV PCM Recorder Application for 24kHz

Posted: Wed 2020-06-24 11:08
by ChipMonk
Thanks much, pasi, for this very quick reply!
Yes, the files in the archive you posted seem Ok - the two bytes that I found before are different between 24k and 48k versions. So now, by comparing these files, I can see other bytes that must be changed. So most likely I'll be able to fix the newer 1.3.1 version myself. Wish Henrik have good holidays free from thinking of bytes and bugfixes ))
P.S. I'll report if it worked Ok a bit later.