--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mmlibs/mmfw/Recogniser/src/mpeg2parser.cpp	Thu Oct 07 22:34:12 2010 +0100
@@ -0,0 +1,299 @@
+// 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"
+
+static const TUint8 KISOEndCode = 0xB9;
+static const TUint8 KPackStartCode = 0xBA;
+static const TUint8 KVideoElementaryStream = 0xE0;
+
+#define KMPEG1PackHeaderLen		8
+#define KMPEG2PackHeaderLen		10
+
+#define KMPEG1PackHeaderID		0x21	// 0010xxx1. See Doc Link 2.
+#define KMPEG2PackHeaderID		0x44	// 01xxx1xx. See Doc Link 2.
+
+#define KStartCodeMask			0xffffff00
+#define KStartCodeIntro			0x00000100
+
+#define KMPEG2StartCode1Bit	KBit1
+#define KMPEG2StartCode2Bit	KBit2
+#define KMPEG2VideoBit		KBit3
+#define KMPEG2MPEG1Bit		KBit4
+
+//
+// Mapping flags to a confidence level.
+//
+// A: extension match
+// B: start-code1
+// C: start-code2
+//
+// C B A -> Confidence
+// -------------------
+// 0 0 0 -> ENotRecognised
+// 0 0 1 -> EPossible
+// 0 1 0 -> EPossible
+// 0 1 1 -> EProbable
+// 1 0 0 -> ENotRecognised
+// 1 0 1 -> ENotRecognised
+// 1 1 0 -> EProbable
+// 1 1 1 -> ECertain
+//
+static const TInt KMPEG2FlagsToConfidence[] =
+	{
+	KConfNotRecognised,
+	KConfPossible,
+	KConfPossible,
+	KConfProbable,
+	KConfNotRecognised,
+	KConfNotRecognised,
+	KConfProbable,
+	KConfCertain
+	};
+
+#define KMPEG2ConfidenceMask	0x07	// 00000111
+#define KMPEG2MimeMask	 		0x18	// 00011000
+#define KMPEG2MimeShift			0x03	
+
+static const TInt KMPEG2ExtOnlyIndex = 1;
+	
+//
+// The 'ED' bits of the flags member are used as an index into
+// this table of possible MIME-types.
+//
+// E: MPEG1 instead of MPEG2
+// D: Video content present
+//
+// E D -> Mime
+// -----------
+// 0 0 -> audio/mpeg2
+// 0 1 -> video/mpeg2
+// 1 0 -> audio/mpeg1
+// 1 1 -> video/mpeg1
+//
+static const TText8* const KMPEG2Mimes[] = 
+	{
+	KMimeMPEG2_A,
+	KMimeMPEG2_V,
+	KMimeMPEG1_A,
+	KMimeMPEG1_V
+	};
+
+//
+// A list of known MPEG2 file extensions.
+// MPEG1 file extensions are also listed.
+//
+typedef struct
+	{
+	const TText* iExt;
+	const TText8* iMime;
+	}
+TMPEG2Types;
+
+static const TMPEG2Types KMPEG2Types[] = 
+	{
+		{ KExtMPEG_1, KMimeMPEG2_V },
+		{ KExtMPEG_2, KMimeMPEG2_V },
+		{ KExtMPEG_3, KMimeMPEG2_V },
+		{ KExtMPEG_4, KMimeMPEG2_V },
+		{ KExtMPEG_5, KMimeMPEG2_V },
+		{ KExtMPEG_6, KMimeMPEG2_V },
+		{ KExtMPEG_7, KMimeMPEG1_V },
+		{ KExtMPEG_8, KMimeMPEG2_A }
+	};
+	
+#define KMPEG2ExtCount sizeof(KMPEG2Types) / sizeof(TMPEG2Types)
+	
+
+//
+//
+//
+TMPEG2Parser::TMPEG2Parser(CReader& aReader, TFlags& aFlags)
+ :	iReader(aReader),
+ 	iFlags(aFlags)
+	{
+	}
+
+
+//
+// Match the file's extension to known MPEG2 file extensions.
+//
+const TText8* TMPEG2Parser::MatchExtension(const TDesC& aExt)
+	{
+	if (aExt.Length() > 0)
+		{
+		for (TInt i = 0; i < KMPEG2ExtCount; i++)
+			{
+			if (aExt.MatchF(TPtrC(KMPEG2Types[i].iExt)) != KErrNotFound)
+				{
+				iFlags.SetExtensionFlag();
+				return KMPEG2Types[i].iMime;
+				}
+			}
+		}
+	
+	return NULL;
+	}
+
+
+//
+//
+//
+void TMPEG2Parser::DoRecognise(const TDesC& aExt, CReader& aReader, TMatch& aMatch)
+	{
+	TFlags flags;
+	TMPEG2Parser parser(aReader, flags);
+	
+	const TText8* extMime = parser.MatchExtension(aExt);
+	TRAP_IGNORE(parser.ParseL());
+	
+	TInt confIndex = flags.GetBitField(KMPEG2ConfidenceMask);
+	aMatch.iConfidence = KMPEG2FlagsToConfidence[confIndex];
+	if (aMatch.iConfidence != KConfNotRecognised)
+		{
+		if (confIndex == KMPEG2ExtOnlyIndex)
+			{
+			// The content is corrupt, but the extension was recognised.
+			aMatch.iMime = extMime;
+			}
+		else
+			{
+			TInt mimeIndex = flags.GetBitField(KMPEG2MimeMask, KMPEG2MimeShift);
+			aMatch.iMime = KMPEG2Mimes[mimeIndex];
+			}
+		}
+	}
+
+
+//
+// Attempts to parse an MPEG2 file by looking for start-codes.
+//
+void TMPEG2Parser::ParseL()
+	{
+	TBool finished;
+	
+	// Assume there's video content if we only have a buffer.
+	if (iReader.Type() == CReader::EBuffer)
+		{
+		iFlags.SetBit(KMPEG2VideoBit);
+		}
+	
+	do
+		{
+		finished = NextStartCodeL();
+		}
+	while (!finished);
+	}
+
+
+//
+// Skips over the current start-code box.
+//
+void TMPEG2Parser::SkipL()
+	{
+	TUint16 size;
+	
+	iReader.Read16L(size);
+	iReader.SeekL((TInt)size);
+	}
+
+
+/*
+** Expects an MPEG2 Pack Header at the current location.
+** The Pack Header is used to determine between MPEG1 and MPEG2.
+*/
+void TMPEG2Parser::ReadPackHeaderL()
+	{
+	TUint8 byte;
+	TBuf8<KMPEG2PackHeaderLen> header;	// Size is of whichever is larger.
+	
+	iReader.ReadByteL(byte);
+	
+	if ((byte & KMPEG1PackHeaderID) == KMPEG1PackHeaderID)
+		{
+		iFlags.SetBit(KMPEG2MPEG1Bit);
+		header.SetLength(KMPEG1PackHeaderLen - 1);	// We've already read a byte.
+		iReader.ReadBytesL(header);
+		}
+	else if ((byte & KMPEG2PackHeaderID) == KMPEG2PackHeaderID)
+		{
+		header.SetLength(KMPEG2PackHeaderLen - 1);	// We've already read a byte.
+		iReader.ReadBytesL(header);
+		
+		// The lowest 3 bits of the last byte say how much stuffing is present.
+		TInt stuffing = header[8] & 0x07; // 00000111
+		if (stuffing)
+			{
+			iReader.SeekL(stuffing);
+			}
+		}
+	else
+		{
+		User::Leave(KErrCorrupt);
+		}
+		
+	}
+
+//
+// Start codes are bit patterns that do not occur in the video stream.
+// The start-code sequence is expected to be at the current CReader position.
+//
+TBool TMPEG2Parser::NextStartCodeL()
+	{
+	TUint32 data;
+
+	iReader.Read32L(data);
+	
+	// Start codes must begin with 0x000001ss, where 'ss' is the start code.
+	if ((data & KStartCodeMask) != KStartCodeIntro)
+		{
+		User::Leave(KErrCorrupt);
+		}
+		
+	if (!iFlags.GetBitField(KMPEG2StartCode1Bit))
+		{
+		iFlags.SetBit(KMPEG2StartCode1Bit);
+		}
+	else
+		{
+		if (!iFlags.GetBitField(KMPEG2StartCode2Bit))
+			{
+			iFlags.SetBit(KMPEG2StartCode2Bit);
+			}
+		}
+		
+	// Try to identify the start code.
+	switch (LOW_BYTE(data))
+		{
+		case KPackStartCode:
+			ReadPackHeaderL();
+			break;
+			
+		case KVideoElementaryStream:
+			iFlags.SetBit(KMPEG2VideoBit);
+			return ETrue;
+			
+		case KISOEndCode:
+			// This code should occur at the end of the file and
+			// it cannot be skipped over.
+			return ETrue;
+			
+		default:
+			SkipL();
+		}
+		
+	return EFalse;
+	}
+