Add source properties for Super Stereo

When playing a stereo format, enabling Super Stereo causes the source to behave
as a B-Format source, with a variable width control.

3 files changed, 22 insertions, 7 deletions

diff --git a/core/buffer_storage.h b/core/buffer_storage.h
index cde7704e..ec934681 100644
--- a/core/buffer_storage.h
+++ b/core/buffer_storage.h
@@ -93,14 +93,7 @@ struct BufferStorage {
     { return ChannelsFromFmt(mChannels, mAmbiOrder); }
     inline uint frameSizeFromFmt() const noexcept { return channelsFromFmt() * bytesFromFmt(); }
 
-    inline uint mixerChannelsFromFmt() const noexcept
-    {
-        if(mChannels == FmtUHJ2 || mChannels == FmtSuperStereo) return 3;
-        return ChannelsFromFmt(mChannels, minu(mAmbiOrder, MaxAmbiOrder));
-    }
-
     inline bool isBFormat() const noexcept { return IsBFormat(mChannels); }
-    inline bool isUhj() const noexcept { return IsUHJ(mChannels); }
 };
 
 #endif /* CORE_BUFFER_STORAGE_H */
diff --git a/core/voice.cpp b/core/voice.cpp
index 44ba897a..d93a4a18 100644
--- a/core/voice.cpp
+++ b/core/voice.cpp
@@ -814,6 +814,27 @@ void Voice::mix(const State vstate, ContextBase *Context, const uint SamplesToDo
 
 void Voice::prepare(DeviceBase *device)
 {
+    /* Even if storing really high order ambisonics, we only mix channels for
+     * orders up to MaxAmbiOrder. The rest are simply dropped.
+     */
+    uint num_channels{(mFmtChannels == FmtUHJ2 || mFmtChannels == FmtSuperStereo) ? 3 :
+        ChannelsFromFmt(mFmtChannels, minu(mAmbiOrder, MaxAmbiOrder))};
+    if(unlikely(num_channels > device->mSampleData.size()))
+    {
+        ERR("Unexpected channel count: %u (limit: %zu, %d:%d)\n", num_channels,
+            device->mSampleData.size(), mFmtChannels, mAmbiOrder);
+        num_channels = static_cast<uint>(device->mSampleData.size());
+    }
+    if(mChans.capacity() > 2 && num_channels < mChans.capacity())
+    {
+        decltype(mChans){}.swap(mChans);
+        decltype(mPrevSamples){}.swap(mPrevSamples);
+    }
+    mChans.reserve(maxu(2, num_channels));
+    mChans.resize(num_channels);
+    mPrevSamples.reserve(maxu(2, num_channels));
+    mPrevSamples.resize(num_channels);
+
     if(IsUHJ(mFmtChannels))
     {
         mDecoder = std::make_unique<UhjDecoder>();
diff --git a/core/voice.h b/core/voice.h
index ba5e82cc..8866f8d4 100644
--- a/core/voice.h
+++ b/core/voice.h
@@ -138,6 +138,7 @@ struct VoiceProps {
     std::array<float,2> StereoPan;
 
     float Radius;
+    float EnhWidth;
 
     /** Direct filter and auxiliary send info. */
     struct {