[MMIXER] Further imrovements to volume control support (follow-up of 376708b) Add more improvements and fixes to volume control implementation. - Don't allocate and don't use an array for storing volume level values. Also, get rid from some stuff, which is not used any more (some fields of MIXERVOLUME_DATA structure and MMixerGetVOlumeControlIndex() function). - Use the following formulas to properly convert the volume level values from the logical units range (0 - 65535) to the hardware Decibel (DB) range (defined by audio miniport driver): <decibels> = <units> * <range_in_db> / <range_in_units> + <minimal_level> (for setting the new value) and <units> = (<decibels> - <mimimal_level> + 1) * <range_in_db> / <range_in_units> (for getting the previous value), where <decibels> is a DB hardware value, <units> is logical units value, <rang_in_db> is the hardware range (DB), <range_in_units> is range in the logical units and <minimal_level> is the most minimum volume level value defined by an audio miniport driver. - I've created this formula myself basing on my calculations and investigations (with some help from Hermes Belusca-Maito), so it's tested and confirmed to be working for all possible values range (at least for our official Intel AC97 driver, and, as tested later, Realtek HD audio). - Do this in both cases when setting the new and when getting the previous volume value as well. - Fallback to default values range -96 - 0 DB in case either the volume level property is not supported by audio miniport driver, or the values range is empty (SignedMinimum is equal to SignedMaximum and both of them typically have a 0 (zero) value). Realtek HD audio codec is one of such a drivers, so this fixes the volume control on real hardware too (tested on Asus-F5R notebook with Realtek ALC660 audio controller). Moreover, the volume values set by user are even properly saved (aren't lost) after reboot (unlike with Intel AC97 in VirtualBox or SoundBlaster in VMware)! Realtek probably uses another mechanism to write/read the value(s) to/from Registry, which is handled by the miniport (codec) driver instead. This fixes some remaining bugs when changing the volume level, so now 1) min/max position of the volume bar can be reached correctly and 2) left/right balance sliders are now behaving properly (they don't affect position of each other anymore when moving them manually). CORE-19189, CORE-19190

sdk/lib/drivers/sound/mmixer/controls.c

···
         PKSPROPERTY_DESCRIPTION Desc;
         PKSPROPERTY_MEMBERSHEADER Members;
         PKSPROPERTY_STEPPING_LONG Range;
+        LPMIXERVOLUME_DATA VolumeData;
 
         MixerControl->Control.Bounds.dwMinimum = 0;
         MixerControl->Control.Bounds.dwMaximum = 0xFFFF;
···
         /* get node volume level info */
         Status = MixerContext->Control(hMixer, IOCTL_KS_PROPERTY, (PVOID)&Property, sizeof(KSNODEPROPERTY_AUDIO_CHANNEL), Desc, Length, &BytesReturned);
 
+        VolumeData = (LPMIXERVOLUME_DATA)MixerContext->Alloc(sizeof(*VolumeData));
+        if (!VolumeData)
+            return MM_STATUS_NO_MEMORY;
+
         if (Status == MM_STATUS_SUCCESS)
         {
-            LPMIXERVOLUME_DATA VolumeData;
-            ULONG Steps, MaxRange, Index;
-            LONG Value;
-
             Members = (PKSPROPERTY_MEMBERSHEADER)(Desc + 1);
             Range = (PKSPROPERTY_STEPPING_LONG)(Members + 1);
 
             DPRINT("NodeIndex %u Range Min %d Max %d Steps %x UMin %x UMax %x\n", NodeIndex, Range->Bounds.SignedMinimum, Range->Bounds.SignedMaximum, Range->SteppingDelta, Range->Bounds.UnsignedMinimum, Range->Bounds.UnsignedMaximum);
 
-            MaxRange = Range->Bounds.UnsignedMaximum - Range->Bounds.UnsignedMinimum;
+            /* Store mixer control info there */
+            VolumeData->Header.dwControlID = MixerControl->Control.dwControlID;
+            VolumeData->SignedMinimum = Range->Bounds.SignedMinimum;
+            VolumeData->SignedMaximum = Range->Bounds.SignedMaximum;
 
-            if (MaxRange)
+            /* Fallback to defaults if: 1) the range is not defined (typically is 0) */
+            if (VolumeData->SignedMinimum == VolumeData->SignedMaximum)
             {
-                ASSERT(MaxRange);
-                VolumeData = (LPMIXERVOLUME_DATA)MixerContext->Alloc(sizeof(MIXERVOLUME_DATA));
-                if (!VolumeData)
-                    return MM_STATUS_NO_MEMORY;
-
-                Steps = MaxRange / Range->SteppingDelta + 1;
-
-                /* store mixer control info there */
-                VolumeData->Header.dwControlID = MixerControl->Control.dwControlID;
-                VolumeData->SignedMaximum = Range->Bounds.SignedMaximum;
-                VolumeData->SignedMinimum = Range->Bounds.SignedMinimum;
-                VolumeData->SteppingDelta = Range->SteppingDelta;
-                VolumeData->ValuesCount = Steps;
-                VolumeData->InputSteppingDelta = 0x10000 / Steps;
-
-                VolumeData->Values = (PLONG)MixerContext->Alloc(sizeof(LONG) * Steps);
-                if (!VolumeData->Values)
-                {
-                    MixerContext->Free(Desc);
-                    MixerContext->Free(VolumeData);
-                    return MM_STATUS_NO_MEMORY;
-                }
-
-                Value = Range->Bounds.SignedMinimum;
-                for (Index = 0; Index < Steps; Index++)
-                {
-                    VolumeData->Values[Index] = Value;
-                    Value += Range->SteppingDelta;
-                }
-                MixerControl->ExtraData = VolumeData;
-           }
-       }
-       MixerContext->Free(Desc);
+                VolumeData->SignedMinimum = -96 * 0x10000; // -96 DB
+                VolumeData->SignedMaximum = 0; // 0 DB
+            }
+        }
+        else
+        {
+            /* or 2) when some failure occurs */
+            VolumeData->Header.dwControlID = MixerControl->Control.dwControlID;
+            VolumeData->SignedMinimum = -96 * 0x10000; // -96 DB
+            VolumeData->SignedMaximum = 0; // 0 DB
+        }
+        MixerControl->ExtraData = VolumeData;
+        MixerContext->Free(Desc);
     }
 
     DPRINT("Status %x Name %S\n", Status, MixerControl->Control.szName);

sdk/lib/drivers/sound/mmixer/precomp.h

···
     MIXERCONTROL_DATA Header;
     LONG SignedMinimum;
     LONG SignedMaximum;
-    LONG SteppingDelta;
-    ULONG InputSteppingDelta;
-    ULONG ValuesCount;
-    PLONG Values;
 }MIXERVOLUME_DATA, *LPMIXERVOLUME_DATA;
 
 typedef struct

sdk/lib/drivers/sound/mmixer/sup.c

···
     return MM_STATUS_UNSUCCESSFUL;
 }
 
-ULONG
-MMixerGetVolumeControlIndex(
-    LPMIXERVOLUME_DATA VolumeData,
-    LONG Value)
-{
-    ULONG Index;
-
-    for(Index = 0; Index < VolumeData->ValuesCount; Index++)
-    {
-        if (VolumeData->Values[Index] > Value)
-        {
-            return VolumeData->InputSteppingDelta * Index;
-        }
-    }
-    return VolumeData->InputSteppingDelta * (VolumeData->ValuesCount-1);
-}
-
 VOID
 MMixerNotifyControlChange(
     IN PMIXER_CONTEXT MixerContext,
···
     LPMIXERLINE_EXT MixerLine)
 {
     LPMIXERCONTROLDETAILS_UNSIGNED Input;
-    LONG Value;
-    ULONG Index, Channel;
+    LONG MaxRange, Value;
+    ULONG Channel;
     MIXER_STATUS Status;
     LPMIXERVOLUME_DATA VolumeData;
 
···
     if (!Input)
         return MM_STATUS_UNSUCCESSFUL; /* To prevent dereferencing NULL */
 
+    /* Get maximum available range */
+    MaxRange = VolumeData->SignedMaximum - VolumeData->SignedMinimum;
+
     /* Loop for each channel */
     for (Channel = 0; Channel < MixerControlDetails->cChannels; Channel++)
     {
         if (bSet)
         {
             /* FIXME SEH */
-            Index = Input[Channel].dwValue / VolumeData->InputSteppingDelta;
-
-            if (Index >= VolumeData->ValuesCount)
-            {
-                DPRINT1("Index %u out of bounds %u \n", Index, VolumeData->ValuesCount);
-                return MM_STATUS_INVALID_PARAMETER;
-            }
-
-            Value = VolumeData->Values[Index];
+            /* Convert from logical units to hardware range (DB) */
+            Value = (LONG)((INT64)Input[Channel].dwValue * MaxRange / 0x10000 + VolumeData->SignedMinimum);
         }
 
         /* Get/set control details */
···
         if (!bSet)
         {
             /* FIXME SEH */
-            Input[Channel].dwValue = MMixerGetVolumeControlIndex(VolumeData, Value);
+            /* Convert from hardware range (DB) to logical units */
+            Input[Channel].dwValue = (ULONG)(((INT64)Value - VolumeData->SignedMinimum + 1) * 0x10000 / MaxRange);
         }
     }