/* *	Xing VBR tagging for LAME. * *	Copyright (c) 1999 A.L. Faber * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */#include "machine.h"#if defined(__riscos__) && defined(FPA10)#include	"ymath.h"#else#include	<math.h>#endif#include "VbrTag.h"#include "version.h"#include "bitstream.h"#ifdef _DEBUG/*  #define DEBUG_VBRTAG */#endifconst static char	VBRTag[]={"Xing"};const int SizeOfEmptyFrame[2][2]={	{17,9},	{32,17},};/**************************************************************************** * AddVbrFrame: Add VBR entry, used to fill the VBR the TOC entries * Paramters: *	nStreamPos: how many bytes did we write to the bitstream so far *				(in Bytes NOT Bits) *****************************************************************************/void AddVbrFrame(lame_global_flags *gfp){  int nStreamPos;  lame_internal_flags *gfc=gfp->internal_flags;  nStreamPos = (gfc->bs.totbit/8);        /* Simple exponential growing buffer */	if (gfp->pVbrFrames==NULL || gfp->nVbrFrameBufferSize==0)	{                /* Start with 100 frames */		gfp->nVbrFrameBufferSize=100;		/* Allocate them */		gfp->pVbrFrames=(int*)malloc((size_t)(gfp->nVbrFrameBufferSize*sizeof(int)));	}	/* Is buffer big enough to store this new frame */	if (gfp->nVbrNumFrames==gfp->nVbrFrameBufferSize)	{                /* Guess not, double th e buffer size */		gfp->nVbrFrameBufferSize*=2;		/* Allocate new buffer */		gfp->pVbrFrames=(int*)realloc(gfp->pVbrFrames,(size_t)(gfp->nVbrFrameBufferSize*sizeof(int)));	}	/* Store values */	gfp->pVbrFrames[gfp->nVbrNumFrames++]=nStreamPos;}/*-------------------------------------------------------------*/static int ExtractI4(unsigned char *buf){	int x;	/* big endian extract */	x = buf[0];	x <<= 8;	x |= buf[1];	x <<= 8;	x |= buf[2];	x <<= 8;	x |= buf[3];	return x;}void CreateI4(unsigned char *buf, int nValue){        /* big endian create */	buf[0]=(nValue>>24)&0xff;	buf[1]=(nValue>>16)&0xff;	buf[2]=(nValue>> 8)&0xff;	buf[3]=(nValue    )&0xff;}/*-------------------------------------------------------------*//* Same as GetVbrTag below, but only checks for the Xing tag.   requires buf to contain only 40 bytes *//*-------------------------------------------------------------*/int CheckVbrTag(unsigned char *buf){	int			h_id, h_mode, h_sr_index;	/* get selected MPEG header data */	h_id       = (buf[1] >> 3) & 1;	h_sr_index = (buf[2] >> 2) & 3;	h_mode     = (buf[3] >> 6) & 3;	/*  determine offset of header */	if( h_id )	{                /* mpeg1 */		if( h_mode != 3 )	buf+=(32+4);		else				buf+=(17+4);	}	else	{                /* mpeg2 */		if( h_mode != 3 ) buf+=(17+4);		else              buf+=(9+4);	}	if( buf[0] != VBRTag[0] ) return 0;    /* fail */	if( buf[1] != VBRTag[1] ) return 0;    /* header not found*/	if( buf[2] != VBRTag[2] ) return 0;	if( buf[3] != VBRTag[3] ) return 0;	return 1;}int GetVbrTag(VBRTAGDATA *pTagData,  unsigned char *buf){	int			i, head_flags;	int			h_id, h_mode, h_sr_index;	static int	sr_table[4] = { 44100, 48000, 32000, 99999 };	/* get Vbr header data */	pTagData->flags = 0;	/* get selected MPEG header data */	h_id       = (buf[1] >> 3) & 1;	h_sr_index = (buf[2] >> 2) & 3;	h_mode     = (buf[3] >> 6) & 3;	/*  determine offset of header */	if( h_id )	{                /* mpeg1 */		if( h_mode != 3 )	buf+=(32+4);		else				buf+=(17+4);	}	else	{                /* mpeg2 */		if( h_mode != 3 ) buf+=(17+4);		else              buf+=(9+4);	}	if( buf[0] != VBRTag[0] ) return 0;    /* fail */	if( buf[1] != VBRTag[1] ) return 0;    /* header not found*/	if( buf[2] != VBRTag[2] ) return 0;	if( buf[3] != VBRTag[3] ) return 0;	buf+=4;	pTagData->h_id = h_id;	pTagData->samprate = sr_table[h_sr_index];	if( h_id == 0 )		pTagData->samprate >>= 1;	head_flags = pTagData->flags = ExtractI4(buf); buf+=4;      /* get flags */	if( head_flags & FRAMES_FLAG )	{		pTagData->frames   = ExtractI4(buf); buf+=4;	}	if( head_flags & BYTES_FLAG )	{		pTagData->bytes = ExtractI4(buf); buf+=4;	}	if( head_flags & TOC_FLAG )	{		if( pTagData->toc != NULL )		{			for(i=0;i<NUMTOCENTRIES;i++)				pTagData->toc[i] = buf[i];		}		buf+=NUMTOCENTRIES;	}	pTagData->vbr_scale = -1;	if( head_flags & VBR_SCALE_FLAG )	{		pTagData->vbr_scale = ExtractI4(buf); buf+=4;	}#ifdef DEBUG_VBRTAG	DEBUGF("\n\n********************* VBR TAG INFO *****************\n");	DEBUGF("tag         :%s\n",VBRTag);	DEBUGF("head_flags  :%d\n",head_flags);	DEBUGF("bytes       :%d\n",pTagData->bytes);	DEBUGF("frames      :%d\n",pTagData->frames);	DEBUGF("VBR Scale   :%d\n",pTagData->vbr_scale);	DEBUGF("toc:\n");	if( pTagData->toc != NULL )	{		for(i=0;i<NUMTOCENTRIES;i++)		{			if( (i%10) == 0 ) DEBUGF("\n");			DEBUGF(" %3d", (int)(pTagData->toc[i]));		}	}	DEBUGF("\n***************** END OF VBR TAG INFO ***************\n");#endif	return 1;       /* success */}/**************************************************************************** * InitVbrTag: Initializes the header, and write empty frame to stream * Paramters: *				fpStream: pointer to output file stream *				nMode	: Channel Mode: 0=STEREO 1=JS 2=DS 3=MONO *****************************************************************************/int InitVbrTag(lame_global_flags *gfp){	int nMode,SampIndex;	lame_internal_flags *gfc = gfp->internal_flags;	u_char pbtStreamBuffer[216];	nMode = gfp->mode;	SampIndex = gfc->samplerate_index;	/* Clear Frame position array variables */	gfp->pVbrFrames=NULL;	gfp->nVbrNumFrames=0;	gfp->nVbrFrameBufferSize=0;	/* Clear stream buffer */	memset(pbtStreamBuffer,0x00,sizeof(pbtStreamBuffer));	/* Reserve the proper amount of bytes */	if (nMode==3)	{		gfp->nZeroStreamSize=SizeOfEmptyFrame[gfp->version][1]+4;	}	else	{		gfp->nZeroStreamSize=SizeOfEmptyFrame[gfp->version][0]+4;	}	/*	// Xing VBR pretends to be a 48kbs layer III frame.  (at 44.1kHz).        // (at 48kHz they use 56kbs since 48kbs frame not big enough for        // table of contents)	// let's always embed Xing header inside a 64kbs layer III frame.	// this gives us enough room for a LAME version string too.	// size determined by sampling frequency (MPEG1)	// 32kHz:    216 bytes@48kbs    288bytes@ 64kbs	// 44.1kHz:  156 bytes          208bytes@64kbs     (+1 if padding = 1)	// 48kHz:    144 bytes          192	//	// MPEG 2 values are the since the framesize and samplerate        // are each reduced by a factor of 2.	*/	{	int tot;	static const int framesize[3]={208,192,288};  /* 64kbs MPEG1 or MPEG2  framesize */	/* static int framesize[3]={156,144,216}; */ /* 48kbs framesize */	if (SampIndex>2) {	  ERRORF("illegal sampling frequency index\n");	  LAME_ERROR_EXIT();	}	gfp->TotalFrameSize= framesize[SampIndex];	tot = (gfp->nZeroStreamSize+VBRHEADERSIZE);	tot += 20;  /* extra 20 bytes for LAME & version string */	if (gfp->TotalFrameSize < tot ) {	  ERRORF("Xing VBR header problem...use -t\n");	  LAME_ERROR_EXIT();	}	}	add_dummy_vbrframe(gfp,8*gfp->TotalFrameSize);	/* Success */	return 0;}/**************************************************************************** * PutVbrTag: Write final VBR tag to the file * Paramters: *				lpszFileName: filename of MP3 bit stream *				nVbrScale	: encoder quality indicator (0..100) *****************************************************************************/int PutVbrTag(lame_global_flags *gfp,char* lpszFileName,int nVbrScale){	int			i;	long lFileSize;	int nStreamIndex;	char abyte;	u_char		btToc[NUMTOCENTRIES];	FILE *fpStream;        u_char pbtStreamBuffer[216];	char str1[80];	if (gfp->nVbrNumFrames==0 || gfp->pVbrFrames==NULL)		return -1;	/* Open the bitstream again */	fpStream=fopen(lpszFileName,"rb+");	/* Assert stream is valid */	if (fpStream==NULL)		return -1;	/* Clear stream buffer */	memset(pbtStreamBuffer,0x00,sizeof(pbtStreamBuffer));	/* Seek to end of file*/	fseek(fpStream,0,SEEK_END);	/* Get file size */	lFileSize=ftell(fpStream);	/* Abort if file has zero length. Yes, it can happen :) */	if (lFileSize==0)		return -1;	/* Seek to first real frame */	fseek(fpStream,(long)gfp->TotalFrameSize,SEEK_SET);	/* Read the header (first valid frame) */	fread(pbtStreamBuffer,4,1,fpStream);	/* the default VBR header.  48kbs layer III, no padding, no crc */	/* but sampling freq, mode andy copyright/copy protection taken */	/* from first valid frame */	pbtStreamBuffer[0]=(u_char) 0xff;	abyte = (pbtStreamBuffer[1] & (char) 0xf0);	if (gfp->version==1) {	  pbtStreamBuffer[1]=abyte | (char) 0x0b;	  abyte = pbtStreamBuffer[2] & (char) 0x0d;   /* AF keep also private bit */	  pbtStreamBuffer[2]=(char) 0x50 | abyte;     /* 64kbs MPEG1 frame */	}else{	  pbtStreamBuffer[1]=abyte | (char) 0x03;	  abyte = pbtStreamBuffer[2] & (char) 0x0d;   /* AF keep also private bit */	  pbtStreamBuffer[2]=(char) 0x80 | abyte;     /* 64kbs MPEG2 frame */	}	/*Seek to the beginning of the stream */	fseek(fpStream,0,SEEK_SET);	/* Clear all TOC entries */	memset(btToc,0,sizeof(btToc));        for (i=1;i<NUMTOCENTRIES;i++) /* Don't touch zero point... */        {                /* Calculate frame from given percentage */                int frameNum=(int)(floor(0.01*i*gfp->nVbrNumFrames));                /*  Calculate relative file postion, normalized to 0..256!(?) */                float fRelStreamPos=(float)256.0*(float)gfp->pVbrFrames[frameNum]/(float)lFileSize;                /* Just to be safe */                if (fRelStreamPos>255) fRelStreamPos=255;                /* Assign toc entry value */                btToc[i]=(u_char) fRelStreamPos;        }	/* Start writing the tag after the zero frame */	nStreamIndex=gfp->nZeroStreamSize;	/* Put Vbr tag */	pbtStreamBuffer[nStreamIndex++]=VBRTag[0];	pbtStreamBuffer[nStreamIndex++]=VBRTag[1];	pbtStreamBuffer[nStreamIndex++]=VBRTag[2];	pbtStreamBuffer[nStreamIndex++]=VBRTag[3];	/* Put header flags */	CreateI4(&pbtStreamBuffer[nStreamIndex],FRAMES_FLAG+BYTES_FLAG+TOC_FLAG+VBR_SCALE_FLAG);	nStreamIndex+=4;	/* Put Total Number of frames */	CreateI4(&pbtStreamBuffer[nStreamIndex],gfp->nVbrNumFrames);	nStreamIndex+=4;	/* Put Total file size */	CreateI4(&pbtStreamBuffer[nStreamIndex],(int)lFileSize);	nStreamIndex+=4;	/* Put TOC */	memcpy(&pbtStreamBuffer[nStreamIndex],btToc,sizeof(btToc));	nStreamIndex+=sizeof(btToc);	/* Put VBR SCALE */	CreateI4(&pbtStreamBuffer[nStreamIndex],nVbrScale);	nStreamIndex+=4;	/* Put LAME id */	sprintf(str1,"LAME%s",get_lame_version());	strncpy((char *)&pbtStreamBuffer[nStreamIndex],str1,(size_t) 20);	nStreamIndex+=20;#ifdef DEBUG_VBRTAG{	VBRTAGDATA TestHeader;	GetVbrTag(&TestHeader,pbtStreamBuffer);}#endif        /* Put it all to disk again */	if (fwrite(pbtStreamBuffer,(unsigned int)gfp->TotalFrameSize,1,fpStream)!=1)	{		return -1;	}	fclose(fpStream);	/* Save to delete the frame buffer */	free(gfp->pVbrFrames);	gfp->pVbrFrames=NULL;	return 0;       /* success */}/*-------------------------------------------------------------*/int SeekPoint(unsigned char TOC[NUMTOCENTRIES], int file_bytes, float percent){/* interpolate in TOC to get file seek point in bytes */int a, seekpoint;float fa, fb, fx;if( percent < (float)0.0 )   percent = (float)0.0;if( percent > (float)100.0 ) percent = (float)100.0;a = (int)percent;if( a > 99 ) a = 99;fa = TOC[a];if( a < 99 ) {    fb = TOC[a+1];}else {    fb = (float)256.0;}fx = fa + (fb-fa)*(percent-a);seekpoint = (int)(((float)(1.0/256.0))*fx*file_bytes);return seekpoint;}/*-------------------------------------------------------------*/