winealsa.drv patch to enum all software devices from .asoundrc

Нискородов Серёжа sghpunk at gmail.com
Thu Feb 9 14:08:39 CST 2012


> Thanks, I've been wanting to do this for a while. I've been hesitating
> because ALSA doesn't document the format of their device names. If a
> device name contains a colon, is it _always_ a hardware device that
> will be returned by the snd_card_* family? Who knows...

To check whether the device is a hardware, I can call a function
snd_pcm_type. But first I need to get handle of pcm device using the
snd_pcm_open. Okay, but then I have to cancel calling the function
alsa_try_open and rewrite checking availability of the device to not
to opening it twice... Or maybe rewrite function alsa_try_open to
return a snd_pcm_type_t?
Huh ... I decided to just check for the presence of a colon in the
name of the device. So it was easier.

> You can probably come up with a better name than "n" ("hint"? "cur"?).

Heh )) This code was copied from aplay source code with variable
names. But you are right, I will rename a variable.

> Why do you create stream2? It looks like stream does what you wanted
> already.

Honestly, I just do not understand the syntax of its assignment. So I
just copied stream variable from aplay source to.

>> +            if(strstr(name, ":") != NULL )
>> +                goto __end;
>> +            if (io != NULL && strcmp(io, filter) != 0)
>> +                goto __end;
>
> Instead of using goto, just use regular if/else. You may have to
> indent everything once more, but that's fine.

This goto was copied from aplay source to ))
Ok. I will try to rewrite this code.

>> +                    ids[*num] = HeapAlloc(GetProcessHeap(), 0, len * sizeof(WCHAR));
>> +                    if(!ids[*num]){
>> +                        return E_OUTOFMEMORY;
>> +                    }
>
> Doing correct cleanup after HeapAlloc() failure is complicated here.
> Since things are going to crash badly if HeapAlloc() fails anyway, I
> think you can just assume success and get rid of the error checking.

Are you sure? This piece of code was taken from function
alsa_get_card_devices() (mmdevdrv.c), I just copied the way of
assigning and checking for errors. I think if the check is performed
there, I also have to fulfill it.

>> +            if (name != NULL)
>> +                free(name);
>
> free() checks for NULL anyway, so the if() is not needed.

This is from aplay source to. ))
Ok. I will correct this.

> If snd_device_name_hint() fails, you should print a WARN message so we
> can know if something went wrong.

You think this is really necessary? If snd_device_name_hint() fails, I
just skip of enumeration of software devices. Does it really need to
print WARN message here?

> And finally, you should use snd_device_name_free_hint(hints) to clean
> up those resources.

Yes, I just forget about it.

> One more thing, this messes up the default device selection, which
> remains hard-coded for the first device. I'd suggest something like
> the following to add to your patch. It chooses "default" as the
> default device, or "pulse" if that doesn't exist.

The point is that the device "default" is already listed with the
function snd_device_name_hint (). So I thought it unnecessary to add a
device "default" in the first place, and deleted the code. After all,
if you select in winecfg "(System default)" then in any case, the
sound goes to the"default" device.Or am I wrong?

> It's not bad at all! After fixing the little stuff above, you can send
> it to wine-patches yourself. Please read
> <http://wiki.winehq.org/SubmittingPatches>;

Thanks for your support. ))
I read it, but there are so many instructions, I'm afraid to make a
mistake in some ...

By the way, I have created a bug on http://bugs.winehq.org/show_bug.cgi?id=29839

> your wine-devel mail was
> not formatted correctly.

I was trying to Follow all instructions. What is my mistake?

And one more question for the mailing list. Why did not I received my
first letter, though in the settings of the mailing list stands to
receive? If it's because of my mistake in formatting, how you received
it?



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