Roman Black Sound (btc)

[Darrel Taylor]

I did some experimenting with storing the sound in external EEPROM.
And for sure, you have to be using the MSSP module to read the data.
SHIFTIN or I2CREAD can't keep up with the higher bitrates.

I tried contacting Roman several times by email, and never got an answer, so I kind of forgot about it, and haven't done anymore with it.
<br>

[sirvo]

I recorded a 5 sec 8-bit mono 22050Hz sound... then I stored it in the 24C512..

then I put this on the 16F877:

LOOP:   
      I2CREAD DPIN,CPIN,$A0,B0,[ATUAL, PROX] ' Read 2 locations in a row
      B0 = 2
      REPEAT
        while F_nova = 0 : wend
            f_nova = 0
            I2CREAD DPIN,CPIN,$A0,B0,[PROX]
            b0 = b0 + 1
      'UNTIL B0 = 4997
goto loop 
  
disable
PPL:    PIR1.0 = 0 
        TMR1H = LOAD.HIGHBYTE
        TMR1L = LOAD.LOWBYTE
        BUFFER.6 = ATUAL.7
        PORTD.1 = BUFFER.6
        PORTD.0 = BUFFER.7
        BUFFER = BUFFER << 1
        ATUAL = ATUAL << 1
        f_ctrl = F_Ctrl + 1
        if F_ctrl = 8 then
            F_NOVA = 1  
            f_ctrl = 0
            atual = prox
        endif
RETURN
ENABLE

Well, what I get is a slow and noise sound of what I had recorded. It is recognizable but isn't that good..

I've tried increasing TMR1 interrupt but it did not make a difference...

So, next steps:

I'll try to user asm interrupts (instant interrupt..DT)
try not to use I2CREAD..(editing: So, i've got to use MSSP..... Well, I suspect that there is no @ HI2CREAD yet, right? )

Well, that is all..

danke schön..

[Ioannis]

Darrel, have a look at the attached files. It might help on the audio compression project.

Please rename the files to *.rar and then de-compress them.

Ioannis

[Darrel Taylor]

Hi Ioannis,

What are they?

Roman's btc convertor creates the smallest sound files I've ever seen.
Can't imagine more compression being able to do anything without ruining the sound.

I don't use RAR.
Not brave enough to download free programs from a couple of brothers in Russia.
<br>

[Ioannis]

Hi Darrel. This is an article from the EDN magazine, February 1999. I thought to save you from the trouble to search the site and download it.

It uses the PIC16C556/12C672 and ADPCM DECODER/ENCODER techniques.

I don't know if they produce smaller files than Romans as I have not tested yet.

OK, i will try to zip it and break it into 2 files. I hope windows ZIP can do that.

Ioannis

[Ioannis]

I made the files *png. Hope that are readable.

Ioannis

[Agent36]

Hi,
How do you convert the .BTC file generated by Romans BTC Sound encoder to a hex file?
Just done a quick search on here and using google, could not find anything that helped.....Found a HEX editor, going to see if I can encode some sound!!
regards