Sdl backend (#670)

* [audio] added sdl audio backend and in-tree atrac9 decoder * [input] replaced per-platform pad readers with sdl gamepad input * [video] added sdl window and host display plumbing * [gui] added host display options and per-game render settings * [bink] synced host movie playback to the guest audio clock * [cpu] hooked windows write faults into guest image tracking * [perf] added guest and render profiling, reserved host cpu lanes * [kernel] fixed stale pthread mutex handle alias * [host] wired the sdl session, save-data paths and project references * [audio] hoisted ajm trace stackalloc out of its loop * [video] Add guest image sync setting * [build] Strip native symbols * reuse
2026-07-31 15:09:42 +08:00 · 2026-07-28 03:33:26 +03:00
parent b4cc5f88ca
commit 2b6bd5a532
111 changed files with 9846 additions and 4479 deletions
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: MIT
+#nullable disable
+using System;
+
+namespace LibAtrac9
+{
+    internal static class Quantization
+    {
+        public static void DequantizeSpectra(Block block)
+        {
+            foreach (Channel channel in block.Channels)
+            {
+                Array.Clear(channel.Spectra, 0, channel.Spectra.Length);
+
+                for (int i = 0; i < channel.CodedQuantUnits; i++)
+                {
+                    DequantizeQuantUnit(channel, i);
+                }
+            }
+        }
+
+        private static void DequantizeQuantUnit(Channel channel, int band)
+        {
+            int subBandIndex = Tables.QuantUnitToCoeffIndex[band];
+            int subBandCount = Tables.QuantUnitToCoeffCount[band];
+            double stepSize = Tables.QuantizerStepSize[channel.Precisions[band]];
+            double stepSizeFine = Tables.QuantizerFineStepSize[channel.PrecisionsFine[band]];
+
+            for (int sb = 0; sb < subBandCount; sb++)
+            {
+                double coarse = channel.QuantizedSpectra[subBandIndex + sb] * stepSize;
+                double fine = channel.QuantizedSpectraFine[subBandIndex + sb] * stepSizeFine;
+                channel.Spectra[subBandIndex + sb] = coarse + fine;
+            }
+        }
+
+        public static void ScaleSpectrum(Block block)
+        {
+            foreach (Channel channel in block.Channels)
+            {
+                ScaleSpectrum(channel);
+            }
+        }
+
+        private static void ScaleSpectrum(Channel channel)
+        {
+            int quantUnitCount = channel.Block.QuantizationUnitCount;
+            double[] spectra = channel.Spectra;
+
+            for (int i = 0; i < quantUnitCount; i++)
+            {
+                for (int sb = Tables.QuantUnitToCoeffIndex[i]; sb < Tables.QuantUnitToCoeffIndex[i + 1]; sb++)
+                {
+                    spectra[sb] *= Tables.SpectrumScale[channel.ScaleFactors[i]];
+                }
+            }
+        }
+    }
+}