[PATCH] winealsa: fix input sound distortion and heap corruption

[Andrew Eikum]

On Fri, Nov 07, 2014 at 02:38:00PM +0000, Mark Harmstone wrote:
> Thanks. I've attached a non-mangled version, changed so it excludes
> all capture devices from remapping.
> 

Looks good. Make sure to throw it at wine-patches for inclusion. Also,
I'd tweak the subject to something more descriptive like "Disable
channel remapping for capture devices" or whatever.

Andrew

> On 07/11/14 14:12, Andrew Eikum wrote:
> >On Fri, Nov 07, 2014 at 04:06:55AM +0000, Mark Harmstone wrote:
> >>At present, winealsa attempts to call map_channels when a capture
> >>device is opened. If a microphone can be opened in either stereo or
> >>mono mode, and mono is requested, Wine will still return stereo
> >>data. Not only does this result in distorted in audio, it also very
> >>frequently results in heap corruption when snd_pcm_readi overruns
> >>the buffer allocated by the program.
> >>
> >Thanks for fixing this.
> >
> >The patch doesn't apply because it got mangled in transit:
> >
> >http://source.winehq.org/patches/data/107529
> >
> >The idea look OK to me, but don't we want to disable channel remapping
> >for _all_ capture devices? Your patch only disables it if the
> >application is using WAVE_FORMAT_EXTENSIBLE
> >
> >I don't think we can do capture channel remapping reliably without
> >switching to the new ALSA channel mapping API. So it makes sense to
> >disable it entirely for now.
> >
> >Andrew
> >
> >>I don't have a copy of World of Warcraft to test this on, but this
> >>may also fix bug 31684. It's the same symptoms, at least.
> >>
> >>---
> >>  dlls/winealsa.drv/mmdevdrv.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >>diff --git a/dlls/winealsa.drv/mmdevdrv.c b/dlls/winealsa.drv/mmdevdrv.c
> >>index a4c02bf..91fba2f 100644
> >>--- a/dlls/winealsa.drv/mmdevdrv.c
> >>+++ b/dlls/winealsa.drv/mmdevdrv.c
> >>@@ -1164,7 +1164,7 @@ static DWORD get_channel_mask(unsigned int channels)
> >>
> >>  static HRESULT map_channels(ACImpl *This, const WAVEFORMATEX *fmt)
> >>  {
> >>-    if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE || fmt->nChannels > 2){
> >>+    if( (This->dataflow != eCapture && fmt->wFormatTag ==
> >>WAVE_FORMAT_EXTENSIBLE) || fmt->nChannels > 2){
> >>          WAVEFORMATEXTENSIBLE *fmtex = (void*)fmt;
> >>          DWORD mask, flag = SPEAKER_FRONT_LEFT;
> >>          UINT i = 0;
> >>-- 
> >>2.0.4
> >>
> >>
> 

> From 1b07897dd4da96dc1ede03ebe47a4d4a50b7a68a Mon Sep 17 00:00:00 2001
> From: Mark Harmstone <mark at harmstone.com>
> Date: Fri, 7 Nov 2014 03:41:35 +0000
> Subject: [PATCH] winealsa: fix input sound distortion and heap corruption
> 
> ---
>  dlls/winealsa.drv/mmdevdrv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/dlls/winealsa.drv/mmdevdrv.c b/dlls/winealsa.drv/mmdevdrv.c
> index a4c02bf..91fba2f 100644
> --- a/dlls/winealsa.drv/mmdevdrv.c
> +++ b/dlls/winealsa.drv/mmdevdrv.c
> @@ -1164,7 +1164,7 @@ static DWORD get_channel_mask(unsigned int channels)
>  
>  static HRESULT map_channels(ACImpl *This, const WAVEFORMATEX *fmt)
>  {
> -    if(fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE || fmt->nChannels > 2){
> +    if(This->dataflow != eCapture && (fmt->wFormatTag == WAVE_FORMAT_EXTENSIBLE || fmt->nChannels > 2) ){
>          WAVEFORMATEXTENSIBLE *fmtex = (void*)fmt;
>          DWORD mask, flag = SPEAKER_FRONT_LEFT;
>          UINT i = 0;
> -- 
> 2.0.4
>