Re: [hatari-devel] SDL1 vs. SDL2 sound pausing

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 10/09/2016 à 17:45, Thomas Huth a écrit :
> Am Sat, 10 Sep 2016 17:03:16 +0200
> schrieb Jerome Vernet <vernet.jerome@xxxxxxxxxx>:
>
> > Le 10/09/2016 à 16:09, Nicolas Pomarède a écrit :
> > > printf ( "audio cbk %d %d\n" , nGeneratedSamples ,
> > > CompleteSndBufIdx )
> > You're right, nGeneratedSamples == 0 while in menus (or in other
> > thing, before emulation can be paused), and CompleteSndBufIdx stay on
> > the same value until the release the menu.
>
> I guess we should simply mute audio completely if nGeneratedSamples is
> 0. Jerome, could you please try a patch like this:
>
> diff -r b98a852e12f2 src/audio.c
> --- a/src/audio.c	Sat Sep 10 17:39:20 2016 +0200
> +++ b/src/audio.c	Sat Sep 10 17:43:52 2016 +0200
> @@ -87,7 +87,13 @@
>  		CompleteSndBufIdx += len;
>  		nGeneratedSamples -= len;
>  	}
> -	else  /* Not enough samples available: */
> +	else if (nGeneratedSamples == 0)
> +	{
> +		/* No samples - that could mean that the main thread has been
> +		 * halted. Simply mute audio to avoid annoying audio loops */
> +		memset(pBuffer, 0, len * 4);
> +	}
> +	else  /* Some, but not enough samples available: */
>  	{
>  		for (i = 0; i < nGeneratedSamples; i++)
>  		{

Hi

I was thinking at a similar patch, but I think we should completely 
remove the case that mirror half of the data if we don't have enough 
sample ; I'm not sure that duplicating previous data will give better 
audio result if we don't fill Buffer fast enough, we should as well just 
put 0 bytes in Buffer to complete it (which will have the extra effect 
of silencing audio output in the case of the OSX UI)

for example :

        if (nGeneratedSamples >= len)
        {
		[keep same code]
	}
	else
        {
                for (i = 0; i < nGeneratedSamples; i++)
                {
                        *pBuffer++ = MixBuffer[(CompleteSndBufIdx + i) 
% MIXBUFFER_SIZE][0];
                        *pBuffer++ = MixBuffer[(CompleteSndBufIdx + i) 
% MIXBUFFER_SIZE][1];
                }

		/* Clear rest of buffer */
		int remaining = len - nGeneratedSamples;
		memset(pBuffer, 0, remaining * 4);

                CompleteSndBufIdx += nGeneratedSamples;
                nGeneratedSamples = 0;

        }

Nicolas