RFC: implementation of driver functionality in msacm (RESEND)

Eric Pouech eric.pouech at wanadoo.fr
Tue Jan 10 14:15:01 CST 2006

Alex Villací­s Lasso wrote:
> (resent because previous attempt never appeared in wine-devel)
> This patch is the preliminary result of some work I have been doing in 
> order to add missing functionality to builtin msacm32.dll. I am 
> submitting this to wine-devel rather than wine-patches, and in one big 
> patch rather than several because I would like comments on some choices 
> I made while adding features. 
Even for review it's easier by small chunks...
> The following is the list of features 
> added by the patch:
> * Implementation of acmDriverAddW(), and delegation of acmDriverAddA() 
> to acmDriverAddW()
- you shouldn't compute the length of the necessary unicode buffer with 
strlen * sizeof(WCHAR). See rest of the code for good example
- when you free lParamW, lParamW can be another non null value (a window 
handle for example) and you shouldn't free it
> * Working implementation of modes of operation of acmDriverAdd[AW]: add 
> driver by new registry entry (ACM_DRIVERADDF_NAME), add (local) driver 
> by combination of hModule/acmDriverProc (ACM_DRIVERADDF_FUNCTION), add 
> notification window for event broadcasts (ACM_DRIVERADDF_NOTIFYHWND)
- I wonder if we should really (internally) register the nofication 
windows the same ways as the other drivers... this is only used for 
notification (one way). I'd rather use a separate internal type
> * Implementation of broadcasts to notification windows on driver 
> add/remove, enabling/disabling, and priority changes
- MSDN seems to state that differed notification is actually a counter, 
not a simple boolean (whereas enable/disable is a boolean)
> * Fix for implementation quirks of acmDriverMessage() in order to allow 
> native codecs to display configuration dialogs
this seems rather hackish. did you actually tested this on Windows ? 
Moreover, the size bits look especially suspicious. Where did you get 
the 16 value from ?
> * Working implementation of acmDriverPriority(), with support of delayed 
> notification broadcasts (for one process only). Includes saving new 
> priorities and enabled status to registry
> * Loading of codec priorities and enabled status from registry
> * Support for ACM_METRIC_DRIVER_SUPPORT in acmMetrics()
> I must note that in order to provide support for acmDriverAddW() in 
> ACM_DRIVERADDF_FUNCTION mode, it is necessary to treat an 
> application-supplied module with an application-supplied driverProc as a 
> full-blown winmm driver. Therefore, the patch includes a new procedure 
> in winmm called wineAddDriver(), that instructs winmm to build a hDrvr 
> from a supplied hModule/driverProc pair, rather than loading both from a 
> DLL, as OpenDriver() does. This allows the rest of the code to continue 
> using SendDriverMessage() as usual.
this shouldn't be done that way, but rather by reimplementing 
senddrivermessage in msacm32


Eric Pouech

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