Crackling Noise starting Audio with theplayer routine

[Emufr3ak]

Hi Fellow Amiga Coders


I'm at Mountainbytes a Demo Party in Switzerland trying to finish my Demo. I do have an issue with my Sound. It works just fine on the emulator. However on real hardware "A1200 Vanilla" I do have a crackling noise when Sound is starting. This only happens on a cold start. Not after a reboot.



I'm using theplayer routine. Also tried lightspeed player but I'm having even more issues here and I don't want to get into this right now.



Any Ideas how to fix this?


Many Thanks

[paraj]

Ask the organizers to reboot machine before running your demo, and fix it after the party. (seriously)

Hard to know exactly what problem is without more info, but I'd look for the usual culprits: uninitialized variables, sections in fast that should be in chip, loop points cleared in samples (don't know if that's a thing for the player), etc..

[Emufr3ak]

Thanks paraj. I think I get away with it after all. On the target platform A500 I don't have the issue. Still want to fix it. But this can wait till after the party.

[paraj]

Party version only needs to work on one machine at exactly right time
Good luck with the compo. I'm sure you'll spot the mistake two weeks after the party.

[Don_Adan]

In startup code start to play empty/null 2 bytes sample stored in chip ram at all channels. Set correct sample address, sample length, volume and set period to 128.

[Emufr3ak]

This sounds very specific. You don't happen to have an example :-)

[Don_Adan]

Something like this, if my memory not failed.

 lea Empty, a0
 lea $dff000,a6
 move.l a0,$a0(a6)
 move.l a0,$b0(a6)
 move.l a0,$c0(a6)
 move.l a0,$d0(a6)
 moveq #1,d0
 move.w d0,$a4(a6)
 move.w d0,$b4(a6)
 move.w d0,$c4(a6)
 move.w d0,$d4(a6) 
 moveq #127,d0
 move.w d0,$a6(a6)
 move.w d0,$b6(a6)
 move.w d0,$c6(a6)
 move.w d0,$d6(a6) 
 moveq #64,d0
 move.w d0,$a8(a6)
 move.w d0,$b8(a6)
 move.w d0,$c8(a6)
 move.w d0,$d8(a6) 
 move.w #$800F,$96(a6)
 rts

 Section Null, BSS_C
Empty
 ds.b 2

[Emufr3ak]

Thanks. A reintegration from source solved the problem with the crackling sound. On A1200 the Sound is off a bit now however. I'm using CIA Interrupts with theplayer

[a/b]

"theplayer"? Do you mean P61?
If so, did you trying increasing the timer value for DMA-on interrupt? Look for "P61_dmason" around line 1700 and then for values hi=$01/lo=$f0 (written to CIA $600/700 or a system structure, don't know whether you're using a system friendly or hardware banging config; there are multiple instances because of lots of nested ifdef's so make sure you change the right one), and increase them.
Maybe you need a longer delay before turning on the audio DMA since it's known that some A1200s have a problem with lower values.

[Don_Adan]

Originally Posted by Emufr3ak

Thanks. A reintegration from source solved the problem with the crackling sound. On A1200 the Sound is off a bit now however. I'm using CIA Interrupts with theplayer

Sound can not be off, if you call this routine from right place. Must be called before ThePlayer init routine is called. Anyway it seems that ThePlayer init routine is buggy or you made any fault when calling ThePlayer routines.

[Emufr3ak]

Just listened to it again. This time all sounded well. First part of the song is a bit otherworldly so it might have been that and some soundsettings on my amiga or pc. By the way i'm talking about this demo :-) https://www.pouet.net/prod.php?which=96200. Thanks for your help to all of you