diff -r 000000000000 -r bde4ae8d615e os/mm/mmlibs/mmfw/Recogniser/src/mp3parser.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/os/mm/mmlibs/mmfw/Recogniser/src/mp3parser.cpp	Fri Jun 15 03:10:57 2012 +0200
@@ -0,0 +1,348 @@
+// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+//
+
+
+#include "parsers.h"
+
+//
+// Masks used for reading bits.
+//
+static const TInt KMP3Sync1Mask = 0xff;			// 11111111
+static const TInt KMP3Sync2Mask = 0xe0;			// 11100000
+static const TInt KMP3VersionMask = 0x18;		// 00011000
+static const TInt KMP3LayerMask = 0x06;			// 00000110
+static const TInt KMP3BitrateMask = 0xf0;		// 11110000
+static const TInt KMP3SampleRateMask = 0x0c;	// 00001100
+static const TInt KMP3PaddingMask = 0x02;		// 00000010
+
+static const TInt KBitsPerByte = 8;
+
+//
+// Macros for retrieving the values.
+//
+#define MP3_GET_SYNC1(d)				(d & KMP3Sync1Mask)
+#define MP3_GET_SYNC2(d)				((d & KMP3Sync2Mask) >> 5)
+#define MP3_GET_VERSION(d)				((d & KMP3VersionMask) >> 3)
+#define MP3_GET_LAYER(d)				((d & KMP3LayerMask) >> 1)
+#define MP3_GET_BITRATE(d)				((d & KMP3BitrateMask) >> 4)
+#define MP3_GET_SAMPLE_RATE(d)			((d & KMP3SampleRateMask) >> 2)
+#define MP3_GET_PADDING(d)				((d & KMP3PaddingMask) >> 1)
+
+
+//
+// Macros used for checking various bitfields.
+//
+#define IS_BAD_MP3_FRAME_SYNC1(s)		((s) != 0xff)
+#define IS_BAD_MP3_FRAME_SYNC2(s)		((s) != 0x07)	
+#define IS_BAD_MP3_VERSION(v)			((v) <  0x02)
+#define IS_BAD_MP3_LAYER(l)				((l) == 0x00) 
+#define IS_BAD_MP3_BITRATE(b)			((b) == 0x0f)	
+#define IS_BAD_MP3_SAMPLE_RATE(s)		((s) == 0x03)
+
+
+// 
+// Meanings of the 'Version' field.
+// --------------------------------
+// 00 - MPEG Version 2.5 (Unofficial standard. We don't support it.)
+// 01 - Reserved
+// 10 - MPEG Version 2
+// 11 - MPEG Version 1
+//
+static const TInt8 KMP3Version2 = 2;
+static const TInt8 KMP3Version1 = 3;
+
+
+// 
+// Meanings of the 'Layer' field.
+// ------------------------------
+// 00 - Reserved
+// 01 - Layer III
+// 10 - Layer II
+// 11 - Layer I
+//
+
+static const TUint16 KBad = 0;
+static const TUint16 KFree = 0;
+
+//
+// MPEG Version 1 bitrates. Measured in kilobits per second.
+//
+static const TUint16 KBitrateVersion1[4][16] =
+	{
+	{ KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad}, // Reserved layer
+	{KFree,   32,   40,   48,   56,   64,   80,   96,  112,  128,  160,  192,  224,  256,  320, KBad}, // Layer III
+	{KFree,   32,   48,   56,   64,   80,   96,  112,  128,  160,  192,  224,  256,  320,  384, KBad}, // Layer II
+	{KFree,   32,   64,   96,  128,  160,  192,  224,  256,  288,  320,  352,  384,  416,  448, KBad}  // Layer I
+	};
+
+//
+// MPEG Version 2 bitrates. Measured in kilobits per second.
+//
+static const TUint16 KBitrateVersion2[4][16] =
+	{
+	{ KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad, KBad}, // Reserved layer
+	{KFree,    8,   16,   24,   32,   40,   48,   56,   64,   80,   96,  112,  128,  144,  160, KBad}, // Layer III 
+	{KFree,    8,   16,   24,   32,   40,   48,   56,   64,   80,   96,  112,  128,  144,  160, KBad}, // Layer II
+	{KFree,   32,   48,   56,   64,   80,   96,  112,  128,  144,  160,  176,  192,  224,  256, KBad}  // Layer I
+	};
+
+//
+// Sample rates for the MPEG versions.
+//
+static const TUint16 KSampleRate[4][4] = 
+	{
+		{11025, 12000,  8000, KBad}, // Version 2.5
+		{ KBad,  KBad,  KBad, KBad}, // Reserved
+		{22050, 24000, 16000, KBad}, // Version 2
+		{44100, 48000, 32000, KBad}  // Version 1
+	};
+
+//
+// Sample rates per frame for the MPEG layers.
+//
+static const TUint16 KSamplesPerFrame[4][4] = 
+	{
+		{KBad, KBad, KBad, KBad}, // Reserved layer
+		{ 576, KBad,  576, 1152}, // Layer III
+		{1152, KBad, 1152, 1152}, // Layer II
+		{ 384, KBad,  384,  384}  // Layer I
+	};
+
+//
+// The various states the recognition process goes through.
+//
+typedef enum
+	{
+	ESearchFrame1,
+	ESearchFrame2
+	}
+TMP3State;
+
+//
+// This truth table maps the following flags to a confidence level.
+// -----------------------------------------------------------------
+// A: Frame2 found.
+// B: Frame1 found.
+// C: Extension recognised.
+//
+// A B C -> Confidence
+// ===================
+// 0 0 0 -> ENotRecognized
+// 0 0 1 -> EPossible
+// 0 1 0 -> ENotRecognized
+// 0 1 1 -> ECertain
+// 1 0 0 -> EPossible
+// 1 0 1 -> EProbable
+// 1 1 0 -> EProbable
+// 1 1 1 -> ECertain
+//
+// In the case where two consecutive mp3 frames
+// are found, ECertain is automatically returned.
+//
+static const TInt KMP3FlagsToConfidence[8] = 
+	{
+	KConfNotRecognised,
+	KConfPossible,
+	KConfNotRecognised,
+	KConfCertain,
+	KConfPossible,
+	KConfProbable,
+	KConfProbable,
+	KConfCertain
+	};
+
+#define KMP3ConfidenceMask	0x07	// 00000111
+#define KMP3Frame1Bit		KBit1
+#define KMP3Frame2Bit		KBit2
+
+//
+//
+//
+TMP3Parser::TMP3Parser(CReader& aReader, TFlags& aFlags)
+ : 	iReader(aReader),
+ 	iFlags(aFlags)
+	{
+	}
+
+
+//
+// MP3 recogition function.
+//
+void TMP3Parser::DoRecognise(const TDesC& aExt, CReader& aReader, TMatch& aMatch)
+	{
+	TFlags flags;
+	
+	// Try to match the extension.
+	if (aExt.MatchF(TPtrC(KExtMP3)) != KErrNotFound)
+		{
+		flags.SetExtensionFlag();
+		}
+
+	// Parse the data.
+	TMP3Parser parser(aReader, flags);
+	TRAP_IGNORE(parser.ParseL());
+	
+	TInt confIndex = flags.GetBitField(KMP3ConfidenceMask);
+	aMatch.iConfidence = KMP3FlagsToConfidence[confIndex];
+	if (aMatch.iConfidence != KConfNotRecognised)
+		{
+		aMatch.iMime = KMimeMP3;
+		}
+	}
+
+
+//
+// Attempts to parse an mp3 file.
+// First of all it checks if there is an ID3 metadata header
+// present at the current reader position. Then it checks for up to
+// two consecutive mp3 audio frames.
+//
+void TMP3Parser::ParseL()
+	{
+	TInt length;
+	TMP3State state = ESearchFrame1;
+
+	FOREVER
+		{
+		TID3Parser::ReadAndSkipID3L(iReader);
+		
+		TInt err = CheckForFrameHeaderL(length);
+		if (err == KErrNotFound)
+			{
+			return;
+			}
+			
+		switch (state)
+			{
+			case ESearchFrame1:
+				iFlags.SetBit(KMP3Frame1Bit);
+				state = ESearchFrame2;
+				break;
+					
+			case ESearchFrame2:
+				iFlags.SetBit(KMP3Frame2Bit);
+				return;
+			}
+				
+		// Skip over the audio frame.
+		// This should be done after flags have been set.
+		iReader.SeekL(length - KMP3FrameHeaderSize);
+		}
+	}
+	
+
+//
+// Checks for an MP3 frame header at the current reader position.
+// If one is not found KErrNotFound is returned and aFrameLength
+// remains unchanged. If one is found KErrNone is retured and
+// aFrameLength is set to the length of the frame.
+//
+TInt TMP3Parser::CheckForFrameHeaderL(TInt& aFrameLength)
+	{
+	TBuf8<KMP3FrameHeaderSize> data;
+	TUint8 versionIndex;
+	TUint8 layerIndex;
+	TUint8 bitrateIndex;
+	TUint8 sampleRateIndex;
+	TUint8 padding;
+	TUint8 sync;
+	
+	data.SetLength(KMP3FrameHeaderSize);
+	iReader.ReadBytesL(data);
+	
+	do
+		{
+		sync = MP3_GET_SYNC1(data[0]);
+		if (IS_BAD_MP3_FRAME_SYNC1(sync))
+			{
+			break;
+			}
+			
+		sync = MP3_GET_SYNC2(data[1]);
+		if (IS_BAD_MP3_FRAME_SYNC2(sync))
+			{
+			break;
+			}
+		
+		versionIndex = MP3_GET_VERSION(data[1]);
+		if (IS_BAD_MP3_VERSION(versionIndex))
+			{
+			break;
+			}
+			
+		layerIndex = MP3_GET_LAYER(data[1]);
+		if (IS_BAD_MP3_LAYER(layerIndex))
+			{
+			break;
+			}
+			
+		bitrateIndex = MP3_GET_BITRATE(data[2]);
+		if (IS_BAD_MP3_BITRATE(bitrateIndex))
+			{
+			break;
+			}
+			
+		sampleRateIndex = MP3_GET_SAMPLE_RATE(data[2]);
+		if (IS_BAD_MP3_SAMPLE_RATE(sampleRateIndex))
+			{
+			break;
+			}
+			
+		padding = MP3_GET_PADDING(data[2]);
+		
+		// All the data is valid.
+		// Compute the audio data length.
+		TUint32 bitRate = KBad;
+		TUint16 sampleRate = KBad;
+		TUint16 samplesPerFrame = KBad;
+		
+		if (versionIndex == KMP3Version1)
+			{
+			bitRate = KBitrateVersion1[layerIndex][bitrateIndex];
+			}
+		else if (versionIndex == KMP3Version2)
+			{
+			bitRate = KBitrateVersion2[layerIndex][bitrateIndex];
+			}
+		else 
+			{
+			// Version 2.5 is not supported.
+			break;
+			}
+
+		sampleRate = KSampleRate[versionIndex][sampleRateIndex];
+		samplesPerFrame = KSamplesPerFrame[layerIndex][versionIndex];
+		
+		// Check we have valid values.
+		if ((bitRate == KBad) || (sampleRate == KBad) || (samplesPerFrame == KBad))
+			{
+			break;
+			}
+
+		bitRate *= 1000; // Convert to kilobits.
+		aFrameLength = (((samplesPerFrame / KBitsPerByte) * bitRate) / sampleRate) + padding;
+		return KErrNone;
+		}
+	while (EFalse);
+	
+	// No valid frame header was found.
+	aFrameLength = 0;
+	iReader.SeekL(-KMP3FrameHeaderSize);
+	return KErrNotFound;
+	}
+	
+
+
+