// 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"

#include "constants.h"

//

// Brands.

// Some (most) brands have Release information - e.g. 3gp6, 3gp5 etc.

// Therefore, to match the brand, we only look at the characters that don't

// represent Release information (in the above case, the 4th character).

// The Release character is set to zero.

//

static const TUint32 KMP4Brand = MAKE_INT32('m', 'p', '4', 0);

static const TUint32 K3GPBrand = MAKE_INT32('3', 'g', 'p', 0);

static const TUint32 K3G2Brand = MAKE_INT32('3', 'g', '2', 0);

static const TUint32 K3GSBrand = MAKE_INT32('3', 'g', 's', 0);	// Streaming servers.

static const TUint32 K3GRBrand = MAKE_INT32('3', 'g', 'r', 0);	// Progresive download and MMS.

//

// Box identifiers.

//

static const TUint32 KFtyp = MAKE_INT32('f', 't', 'y', 'p');

static const TUint32 KMoov = MAKE_INT32('m', 'o', 'o', 'v');

static const TUint32 KTrak = MAKE_INT32('t', 'r', 'a', 'k');

static const TUint32 KTkhd = MAKE_INT32('t', 'k', 'h', 'd');

static const TUint32 KMdia = MAKE_INT32('m', 'd', 'i', 'a');

static const TUint32 KHdlr = MAKE_INT32('h', 'd', 'l', 'r');

static const TUint32 KVide = MAKE_INT32('v', 'i', 'd', 'e');

static const TUint32 KUuid = MAKE_INT32('u', 'u', 'i', 'd');

//

// This truth table maps the following flags to a confidence level.

//

// A - trak box present

// B - moov box present

//

// A B -> Confidence

// =================

// 0 0 -> EPossible

// 0 1 -> EProbable

// 1 0 -> EProbable

// 1 1 -> ECertain

//

static const TInt KMPEG4FlagsToConfidence[] =

	{

	KConfPossible,

	KConfProbable,

	KConfProbable,

	KConfCertain,

	};

#define KMPEG4ConfidenceMask	0x03	// 00000011

#define KMPEG4BoxTitleLen		4

#define KMPEG4TRAKBit			KBit0	// 00000001

#define KMPEG4MOOVBit			KBit1	// 00000010

#define KMPEG4VideoBit			KBit2	// 00000100

static const TInt KMPEG4BoxIntroLen = 8;

//

// In order to find out the type of MPEG4 file it is

// we need to be able to map known extensions, expected

// ftyp expressions with MIME-types.

//

typedef struct

	{

	const TText* iExt;

	TUint32 iBrand;

	const TText8* iAudioMime;

	const TText8* iVideoMime;

	}

TMPEG4File;

//

// A table of ftyp's, extensions and mime-types.

//

// .mp4 - can contain either audio or video.

// .m4a - should contain (unprotected) audio only.

// .m4p - should contain protected audio only.

// .3gp - can contain either audio or video.

//

static const TMPEG4File KMPEG4Files[] =

	{

		{KExtMP4,	KMP4Brand,	KMimeMP4_A,	KMimeMP4_V},

		{KExt3GP,	K3GPBrand,	KMime3GP_A,	KMime3GP_V},

		{KExtM4A,	KMP4Brand,	KMimeMP4_A,	NULL},

		{KExt3G2,	K3G2Brand,	KMime3G2_A,	KMime3G2_V},

		{KExt3GP,	K3GSBrand,	KMime3GP_A,	KMime3GP_V},

		{KExt3GP,	K3GRBrand,	KMime3GP_A,	KMime3GP_V},

	};

static const TInt KMPEG4FileTypeCount = sizeof(KMPEG4Files) / sizeof(TMPEG4File);

//

//

//

TMPEG4Parser::TMPEG4Parser(CReader& aReader, TFlags& aFlags)

 :	iBrandIndex(KErrNotFound),

 	iIsFinished(EFalse),

 	iReader(aReader),

 	iFlags(aFlags),

 	iVideoAssumed(EFalse)

	{

	}

//

// Compare a brand with the ones this recogniser knows about.

//

TInt TMPEG4Parser::IsCompatibleBrand(TUint32 aBrand, TInt aStartPos)

	{

	for (TInt i = aStartPos; i < KMPEG4FileTypeCount; i++)

		{

		TUint32 knownBrand = KMPEG4Files[i].iBrand;

		if ((aBrand & knownBrand) == knownBrand)

			{

			return i;

			}

		}

	return KErrNotFound;

	}

//

// Try to determine the mime-type from the extension, and

// if that isn't matched, from the FTYP field if present.

// If none of these are matched, NULL is returned and the

// file isn't a valid MPEG4 file.

//

const TText8* TMPEG4Parser::MatchFileType(const TDesC& aExt)

	{

	TBool videoFound = iFlags.GetBitField(KMPEG4VideoBit);

	TBool video = (videoFound || iVideoAssumed);

	// Try to match the extension.

	if (aExt.Length() > 0)

		{

		for (TInt i = 0; i < KMPEG4FileTypeCount; i++)

			{

			TPtrC ext(KMPEG4Files[i].iExt);

			if (aExt.MatchF(ext) != KErrNotFound)

				{

				// Extension match. If the extension is for an audio-only format

				// we must make sure there is no video content in the file. If

				// video content is present then ignore the extension match.

				if (KMPEG4Files[i].iVideoMime == NULL)

					{

					if (videoFound)

						{

						// Try to match another extension.

						continue;

						}

					return KMPEG4Files[i].iAudioMime;

					}

				return (video ? KMPEG4Files[i].iVideoMime : KMPEG4Files[i].iAudioMime);

				}

			}

		}

	// Unknown or no extension. Try to match the brand

	while (iBrandIndex != KErrNotFound)

		{

		if (KMPEG4Files[iBrandIndex].iVideoMime == NULL)

			{

			if (videoFound)

				{

				// Try to match another brand.

				TUint32 brand = KMPEG4Files[iBrandIndex].iBrand;

				iBrandIndex = TMPEG4Parser::IsCompatibleBrand(brand, iBrandIndex + 1);

				continue;

				}

			return KMPEG4Files[iBrandIndex].iAudioMime;

			}

		return (video ? KMPEG4Files[iBrandIndex].iVideoMime : KMPEG4Files[iBrandIndex].iAudioMime);

		}

	// If there is no brand and an unknown extension look at the flags.

	// (There are some files that have no ftyp).

	// Only return a potential mime-type if all flag bits have been set.

	if (iFlags.GetBitField(KMPEG4ConfidenceMask) == KMPEG4ConfidenceMask)

		{

		return (video ? KMimeMP4_V : KMimeMP4_A);

		}

	return NULL;

	}

//

//

//

void TMPEG4Parser::DoRecognise(const TDesC& aFileExt, CReader& aReader, TMatch& aMatch)

	{

	TFlags flags;

	TMPEG4Parser parser(aReader, flags);

	TRAP_IGNORE(parser.ParseL());

	// The extension determines the mime-type.

	// The flags say if it's a valid MPEG4 file and if video is present.

	const TText8* extMime = parser.MatchFileType(aFileExt);

	if (extMime != NULL)

		{

		TInt confIndex = flags.GetBitField(KMPEG4ConfidenceMask);

		aMatch.iConfidence = KMPEG4FlagsToConfidence[confIndex];

		if (aMatch.iConfidence != KConfNotRecognised)

			{

			aMatch.iMime = extMime;

			}

		}

	}

//

//

//

void TMPEG4Parser::ParseL()

	{

	// If we have only buffer data, we must assume the video

	// content (if any) has been missed. This is because an

	// audio-only file recognised as video should play in a

	// video application, but a video file recognised as audio

	// will not play in a audio application.

	if (iReader.Type() == CReader::EBuffer)

		{

		iVideoAssumed = ETrue;

		}

	do

		{		

		ReadBoxHeaderL();

		if (iTitle == KFtyp)

			{

			ReadFileTypeL();

			}

		else if (iTitle == KMoov)

			{

			iFlags.SetBit(KMPEG4MOOVBit);

			ReadMovieL();

			}

		else

			{

			SkipCurrentBoxL();

			}

		}

	while (!iIsFinished);

	}

//

//

//

void TMPEG4Parser::SkipCurrentBoxL()

	{

	// Intro: [size][title] = 8 bytes.

	if (iSize == 0)

		{

		// The current box extends to the end of file.

		iIsFinished = ETrue;

		return;

		}

	iReader.SeekL(iSize - KMPEG4BoxIntroLen);

	}

//

// Parses the 'moov' box.

// This box contains sub-boxes we're interested in.

//

void TMPEG4Parser::ReadMovieL()

	{

	// This box holds no information.

	// It contains 'trak' boxes, which we want.

	TInt64 dataInBox = iSize - KMPEG4BoxIntroLen;

	while ((dataInBox > 0) && !iIsFinished)

		{

		ReadBoxHeaderL();

		dataInBox -= iSize;

		if (iTitle == KTrak)

			{

			iFlags.SetBit(KMPEG4TRAKBit);

			ReadTrackL();

			}

		else

			{

			SkipCurrentBoxL();

			}

		}

	}

//

// Parses the 'trak' box.

// This box contains sub-boxes we're interested in.

//

void TMPEG4Parser::ReadTrackL()

	{

	// This box holds no information.

	// It contains 'tkhd' boxes, which we want.

	TInt64 dataInBox = iSize - KMPEG4BoxIntroLen;

	while ((dataInBox > 0) && !iIsFinished) 

		{

		ReadBoxHeaderL();

		dataInBox -= iSize;

		if (iTitle == KTkhd)

			{

			ReadTrackHeaderL();

			}

		else if (iTitle == KMdia)

			{

			ReadMediaL();

			}

		else

			{

			SkipCurrentBoxL();

			}

		}

	}

//

// Parses a 'mdia' box.

// This box contains sub-boxes we're interested in.

//

void TMPEG4Parser::ReadMediaL()

	{

	TInt64 dataInBox = iSize - KMPEG4BoxIntroLen;

	while ((dataInBox > 0) && !iIsFinished)

		{

		ReadBoxHeaderL();

		dataInBox -= iSize;

		if (iTitle == KHdlr)

			{

			ReadHandlerL();

			}

		else

			{

			SkipCurrentBoxL();

			}

		}

	}

//

// Parses a 'hdlr' box.

// This is a stand-alone box.

//

void TMPEG4Parser::ReadHandlerL()

	{

	// Intro: [size][title][versionFlags][predefined][handler_type] = 20 bytes.

	const TInt KMPEG4HandlerIntroLen = 20;

	TUint32 versionFlags;

	TUint32 predefined;

	TUint32 handler;

	iReader.Read32L(versionFlags);

	iReader.Read32L(predefined);

	if (predefined != 0)

		{

		User::Leave(KErrCorrupt);

		}

	iReader.Read32L(handler);

	if (handler == KVide)

		{

		iFlags.SetBit(KMPEG4VideoBit);

		}

	iReader.SeekL(iSize - KMPEG4HandlerIntroLen);

	}

//

//

//

void TMPEG4Parser::ReadTrackHeaderL()

	{

	const TUint8 KMPEG4TrackVersion0 = 0;

	const TUint8 KMPEG4TrackVersion1 = 1;

	const TInt KMPEG4Version0ToVolume = 32; // Distance to volume field from version=0 field.

	const TInt KMPEG4Version1ToVolume = 44; // Distance to volume field from version=1 field.

	const TInt KMPEG4VolumeToWidth = 38;	// Distance to width field from volume field.

	TUint32 versionFlags;

	TUint16 volume;

	TUint32 width;

	TUint32 height;

	// This box contains information about a single track.

	iReader.Read32L(versionFlags);

	// The highest 8 bits contains the version.

	switch (HIGH_BYTE32(versionFlags))

		{

		case KMPEG4TrackVersion0:

			iReader.SeekL(KMPEG4Version0ToVolume);

			break;

		case KMPEG4TrackVersion1:

			iReader.SeekL(KMPEG4Version1ToVolume);

			break;

		default:

			User::Leave(KErrCorrupt);

		}

	// Volume can not be used to distinguish between audio and video anymore.

	iReader.Read16L(volume);

	// We want to seek ahead to read the 'width' and 'height' fields.

	iReader.SeekL(KMPEG4VolumeToWidth);

	iReader.Read32L(width);		// 16.16 fixed-point

	iReader.Read32L(height);	// 16.16 fixed-point

	if ((width != 0) && (height != 0))

		{

		iFlags.SetBit(KMPEG4VideoBit);

		}

	}

//

// Parses the 'ftyp' box.

// Records the first recognised brand that helps to

// identify the mime-type.

//

void TMPEG4Parser::ReadFileTypeL()

	{

	// Intro = [size][title][majorBrand] = 12 bytes.

	const TInt KMPEG4FtypIntroLen = 12;

	TUint32 brand;

	// If the majorBrand isn't recognised we should also

	// search the compatible brand list.

	TInt64 bytesRemaining = iSize - KMPEG4FtypIntroLen;

	iReader.Read32L(brand);

	iBrandIndex = TMPEG4Parser::IsCompatibleBrand(brand);

	if (iBrandIndex != KErrNotFound)

		{

		// The major brand was recognised.

		// Skip to the end of the ftyp box.

		iReader.SeekL(bytesRemaining);

		return;

		}

	// The major brand wasn't recognised.

	// Skip over the version info (32 bit) to the start of the

	// compatible brands list.

	TInt skip = sizeof(TUint32);

	iReader.SeekL(skip);

	bytesRemaining -= skip;

	while ((iBrandIndex == KErrNotFound) && (bytesRemaining > 0))

		{

		iReader.Read32L(brand);

		bytesRemaining -= skip;

		iBrandIndex = TMPEG4Parser::IsCompatibleBrand(brand);

		}

	iReader.SeekL(bytesRemaining);

	}

//

// Reads the first few bytes of a box.

// The exact amount read depends on the box.

//

void TMPEG4Parser::ReadBoxHeaderL()

	{

	const TInt KMPEG4ExtendedTypeLen = 16;

	TUint32 word1;

	iReader.Read32L(word1);

	iReader.Read32L(iTitle);

	switch (word1)

		{

		case 0:

			// Box extends to the end of file.

			iSize = MAKE_TINT64(0, 0);

			break;

		case 1:

			// Size is specified in a 64-bit field.

			iReader.Read64L(iSize);

			break;