Refactored the LAME interop.

CUETools.Codecs.LAME/Interop/LHV1.cs

@@ -0,0 +1,130 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace CUETools.Codecs.LAME.Interop
+{
+    [StructLayout(LayoutKind.Sequential, Size = 327), Serializable]
+    public struct LHV1 // BE_CONFIG_LAME LAME header version 1
+    {
+        public const uint MPEG1 = 1;
+        public const uint MPEG2 = 0;
+
+        // STRUCTURE INFORMATION
+        public uint dwStructVersion;
+        public uint dwStructSize;
+        // BASIC ENCODER SETTINGS
+        public uint dwSampleRate;		// SAMPLERATE OF INPUT FILE
+        public uint dwReSampleRate;		// DOWNSAMPLERATE, 0=ENCODER DECIDES	
+        public MpegMode nMode;	// STEREO, MONO
+        public uint dwBitrate;			// CBR bitrate, VBR min bitrate
+        public uint dwMaxBitrate;		// CBR ignored, VBR Max bitrate
+        public LAME_QUALITY_PRESET nPreset;			// Quality preset
+        public uint dwMpegVersion;		// MPEG-1 OR MPEG-2
+        public uint dwPsyModel;			// FUTURE USE, SET TO 0
+        public uint dwEmphasis;			// FUTURE USE, SET TO 0
+        // BIT STREAM SETTINGS
+        public int bPrivate;			// Set Private Bit (TRUE/FALSE)
+        public int bCRC;	// Insert CRC (TRUE/FALSE)
+        public int bCopyright;			// Set Copyright Bit (TRUE/FALSE)
+        public int bOriginal;			// Set Original Bit (TRUE/FALSE)
+        // VBR STUFF
+        public int bWriteVBRHeader;	// WRITE XING VBR HEADER (TRUE/FALSE)
+        public int bEnableVBR;			// USE VBR ENCODING (TRUE/FALSE)
+        public int nVBRQuality;		// VBR QUALITY 0..9
+        public uint dwVbrAbr_bps;		// Use ABR in stead of nVBRQuality
+        public VBRMETHOD nVbrMethod;
+        public int bNoRes;	// Disable Bit resorvoir (TRUE/FALSE)
+        // MISC SETTINGS
+        public int bStrictIso;			// Use strict ISO encoding rules (TRUE/FALSE)
+        public ushort nQuality;			// Quality Setting, HIGH BYTE should be NOT LOW byte, otherwhise quality=5
+        // FUTURE USE, SET TO 0, align strucutre to 331 bytes
+        //[ MarshalAs( UnmanagedType.ByValArray, SizeConst=255-4*4-2 )]
+        //public byte[]	 btReserved;//[255-4*sizeof(DWORD) - sizeof( WORD )];
+
+        public LHV1(AudioPCMConfig format, uint MpeBitRate, uint quality)
+        {
+            dwStructVersion = 1;
+            dwStructSize = (uint)Marshal.SizeOf(typeof(BE_CONFIG));
+            switch (format.SampleRate)
+            {
+                case 16000:
+                case 22050:
+                case 24000:
+                    dwMpegVersion = MPEG2;
+                    break;
+                case 32000:
+                case 44100:
+                case 48000:
+                    dwMpegVersion = MPEG1;
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException("format", "Unsupported sample rate");
+            }
+            dwSampleRate = (uint)format.SampleRate;	// INPUT FREQUENCY
+            dwReSampleRate = 0;		// DON'T RESAMPLE
+            switch (format.ChannelCount)
+            {
+                case 1:
+                    nMode = MpegMode.MONO;
+                    break;
+                case 2:
+                    nMode = MpegMode.STEREO;
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException("format", "Invalid number of channels");
+            }
+            switch (MpeBitRate)
+            {
+                case 0:
+                case 32:
+                case 40:
+                case 48:
+                case 56:
+                case 64:
+                case 80:
+                case 96:
+                case 112:
+                case 128:
+                case 160: //Allowed bit rates in MPEG1 and MPEG2
+                    break;
+                case 192:
+                case 224:
+                case 256:
+                case 320: //Allowed only in MPEG1
+                    if (dwMpegVersion != MPEG1)
+                    {
+                        throw new ArgumentOutOfRangeException("MpsBitRate", "Bit rate not compatible with input format");
+                    }
+                    break;
+                case 8:
+                case 16:
+                case 24:
+                case 144: //Allowed only in MPEG2
+                    if (dwMpegVersion != MPEG2)
+                    {
+                        throw new ArgumentOutOfRangeException("MpsBitRate", "Bit rate not compatible with input format");
+                    }
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException("MpsBitRate", "Unsupported bit rate");
+            }
+            dwBitrate = MpeBitRate;		// MINIMUM BIT RATE
+            nPreset = LAME_QUALITY_PRESET.LQP_NORMAL_QUALITY;		// QUALITY PRESET SETTING
+            dwPsyModel = 0;		// USE DEFAULT PSYCHOACOUSTIC MODEL 
+            dwEmphasis = 0;		// NO EMPHASIS TURNED ON
+            bOriginal = 1;		// SET ORIGINAL FLAG
+            bWriteVBRHeader = 0;
+            bNoRes = 0;		// No Bit resorvoir
+            bCopyright = 0;
+            bCRC = 0;
+            bEnableVBR = 0;
+            bPrivate = 0;
+            bStrictIso = 0;
+            dwMaxBitrate = 0;
+            dwVbrAbr_bps = 0;
+            nQuality = (ushort)(quality | ((~quality) << 8));
+            nVbrMethod = VBRMETHOD.VBR_METHOD_NONE;
+            nVBRQuality = 0;
+        }
+    }
+}