Re: [hatari-devel] 8 runes of aerillion doesn't have sound

[Laurent Sallafranque <laurent.sallafranque@xxxxxxx>]

The VHS sound is bigger than the effect timing.

There's no interruption into the VHS screen.


On the real falcon, I do :

            ; Start the music
            ; ---------------
            bsr.w        music_vhs_start


            Then, when my little lines reach bottom of screen, I jump 
to the 2nd effect (ie the torus effect).

            The VHS sound is still playing.

            I load the DSP code, clear the screen, change the screen 
buffers, init some variables, precalc things, ...

            Then, before starting the TORUS effect, I call :


            ; Set the torus texture
            ; ---------------------
            move.l        demo_big_buffer_ptr,mapping_texture_ptr


            ; Stop the music
            ; --------------
            bsr.w        music_stop

            ; Load the first sample pack into the sound buffer
            ; ------------------------------------------------
            bsr.w        music_load_sample_1

            ; Start the music
            ; ---------------
            bsr.w        music_start



; music_vhs_start:

;    Start the VHS sound
;
            Debug_Label    music.s__music_vhs_start
music_vhs_start:
            ; Set the 1st sample adress to the DMA
            move.l        music_buffer_adr,d6
            move.l        d6,d7
        ;    add.l        #189360,d7                    ; Start adress 
of the sample
            add.l        #310734,d7                    ; Start adress 
of the sample
            bsr.w        music_set_sample_adress

            ; Start the sound
            move.w        #$1,$ffff8900.w                    ; Start 
the DMA music (no interrupt, no loop)
            rts


; music_stop
;    Stop the sound
;
            Debug_Label    music.s__music_stop
music_stop:        ; Stop the current playing music
            clr.w        $ffff8900.w                    ; Start the DMA 
music (no interrupt, no loop)
            rts



; music_start
;    Configure the crossbar
;    start to play the music
;
            Debug_Label    music.s__music_start
music_start:
            ; Set the 1st sample adress to the DMA
            lea.l        music_samples_table,a0
            move.l        music_buffer_adr,d6
            move.l        d6,d7
            add.l        (a0)+,d6                    ; Start adress of 
the sample
            add.l        (a0),d7                        ; End adress of 
the sample
            bsr.w        music_set_sample_adress

            ; Next sample
            addq.w        #8,music_sequence_index

            ; Start the music
            move.w        #$101,$ffff8900.w                ; Set a 
MFP-15 IRQ-7 interruption + Start the DMA music

            rts


So, there's no interrupts involved in the VHS part.

Regards

Laurent



Le 17/03/2024 à 11:10, Nicolas Pomarède a écrit :
> Le 17/03/2024 à 09:32, Laurent Sallafranque a écrit :
> > Hi,
> >
> >
> > I use the same music technic in Electric night and 8 runes of aerillion.
> >
> >
> > I noticed this AER bug when coding "8 runes of aerillion" and I 
> > removed it.
> >
> > It was certainly a bad instruction I added when I first coded the 
> > music in Electric night, but I didn't detect it, as the sound worked 
> > both on hatari and my real falcon.
> >
> >
> > I did a lot of tries by the time, before getting into some code that 
> > worked as I wanted.
> >
> > As it worked like this, I used the code in both the demo and he game. 
> > I had some problems later with the game, and I removed this AER change.
> >
> >
> > But, as it worked for "Electric Night" on the real hardware, I think 
> > it should be emulated, no ?
> >
> > (I can modify the code of electric night and deliver a new version, 
> > but I would prefer Hatari to be closer to the real hardware if 
> > possible).
>
> Hi
>
> AER bit is correctly emulated under hatari, but I think the problem is 
> triggered by lack of cycle accuracy combined with AER.
>
> On real falcon, can you confirm if the sample during vhs-like blue 
> screen is supposed to end before you set vector $13C for GPIP7 ?
>
> Because what I see on Hatari is this :
>
>  - vhs sample plays
>  - demo sets vector 13C
>  - demo calls music_stop
>  - music_stop will stop dma sound, so dma line goes to idle (=1) and 
> this triggers immediately a call to music_mfp_i7_interrupt (because 
> int 13C was enabled just before)
>
> so you get an extra call to music_mfp_i7_interrupt before calling 
> music_start
>
> I think that on real falcon the vhs sample is already played before 
> setting vector 13C, so when you call music_stop it has no effect (dma 
> sound is already idle) and the mfp int is not called.
>
> The problem is that Hatari is not cycle exact, so I guess it runs 
> slightly faster than a real Falcon considering cpu cycles, but audio 
> is played at correct speed :
>  - cpu goes slightly too fast
>  - sound plays at correct speed
>
> so, the vhs-like intro is not synced with audio and ends slightly 
> before what is expected, resulting in calling music_stop when audio is 
> not still playing
>
> Unless Hatari has cycle exact 68030 mode, I think the cpu/audio sync 
> problem can't be resolved.
>
> For less trouble in the future, you should ensure MFP is disabled when 
> you call "music_stop", then do a "bclr #7,$fffffa0b.w" (to be sure 
> that any pending sound interrupt that happened before will be ignored) 
> then init vector 13C after that + set bit 7 in fffa07 and fffa13.
> If not, even on real Falcon you could have a pending gpip7 interrupt 
> from some previous sample that could cause an extra int after you 
> install your own handler.
>
> > Anders wrote
> > Hi, as a sidenote;
> >
> > when you asked me to record Electric Night all those years ago, I 
> > remember you said the demo was out of sync in my recording when I had 
> > captured from a real Falcon.
>
> indeed, this looks like this could be related to what I wrote above. 
> It might have been fixed by inverting AER bit when dma sound is 
> already playing, because this will kind of delay the 1st audio 
> interrupt but cleaner solution would be to clear fffa0b bit 7 (pending 
> A gpip7) to remove any pending sound int :
>  - mask mfp gpip7 in fffa13 (clear bit7)
>  - stop dma sound
>  - clear bit 7 in fffa0b
>  - set new timer A dor gpip7 + enable MFP
>
>
> Nicolas