mpadecl3.cpp

著名的 helix realplayer 基于手机 symbian 系统的 播放器全套源代码

n1 = n2 = nsamp[igr][1];   /* total number bands */
if( side_info.gr[igr][1].block_type == 2 ) { /* long bands */
    n1 = 0;     
    if( side_info.gr[igr][1].mixed_block_flag ) 
                n1 = sfBandIndex[0][ncbl_mixed-1];
}
if( n1 > band_limit ) n1 = band_limit;
if( n2 > band_limit ) n2 = band_limit;
igr_prev = igr^1;
nsamp[igr][1] = hybrid(sample[1][igr], sample[1][igr_prev], 
      yout, side_info.gr[igr][1].block_type, n1, n2, nsamp[igr_prev][1], band_limit_nsb);
FreqInvert(yout, nsamp[igr][1]);
sbt_L3(yout, pcm, 0, vbuf, vb_ptr);

}
/*--------------------------------------------------------------------*/
void CMpaDecoderL3::Xform_dual(unsigned char *pcm, int igr)
{
int ch;
int igr_prev, n1, n2;


/*--- hybrid + sbt ---*/
igr_prev = igr^1;
for(ch=0;ch<nchan;ch++) {
    n1 = n2 = nsamp[igr][ch];   /* total number bands */
    if( side_info.gr[igr][ch].block_type == 2 ) { /* long bands */
        n1 = 0;     
        if( side_info.gr[igr][ch].mixed_block_flag ) 
                    n1 = sfBandIndex[0][ncbl_mixed-1];
    }
    if( n1 > band_limit ) n1 = band_limit;
    if( n2 > band_limit ) n2 = band_limit;
    nsamp[igr][ch] = hybrid(sample[ch][igr], sample[ch][igr_prev], 
        yout, side_info.gr[igr][ch].block_type, n1, n2, nsamp[igr_prev][ch], band_limit_nsb);
    FreqInvert(yout, nsamp[igr][ch]);
    sbt_L3(yout, pcm, ch, vbuf, vb_ptr);
}

}
/*--------------------------------------------------------------------*/
void CMpaDecoderL3::Xform_dual_mono(unsigned char *pcm, int igr)
{
int igr_prev, n1, n2, n3;

/*--- hybrid + sbt ---*/
igr_prev = igr^1;
if( (side_info.gr[igr][0].block_type == side_info.gr[igr][1].block_type)
      && (side_info.gr[igr][0].mixed_block_flag == 0)
      && (side_info.gr[igr][1].mixed_block_flag == 0) ) 
{

    n2 = nsamp[igr][0];   /* total number bands max of L R */
    if( n2 < nsamp[igr][1] ) n2 = nsamp[igr][1];
    if( n2 > band_limit ) n2 = band_limit;
    n1 = n2;  /* n1 = number long bands */
    if( side_info.gr[igr][0].block_type == 2 ) n1 = 0;
    sum_f_bands(sample[0][igr], sample[1][igr], n2);
    n3 = nsamp[igr][0] = hybrid(sample[0][igr], sample[0][igr_prev], 
        yout, side_info.gr[igr][0].block_type, n1, n2, nsamp[igr_prev][0], band_limit_nsb);
}
else 
{       /* transform and then sum (not tested - never happens in test)*/
    /*-- left chan --*/
    n1 = n2 = nsamp[igr][0];   /* total number bands */
    if( side_info.gr[igr][0].block_type == 2 ) { 
        n1 = 0;     /* long bands */
        if( side_info.gr[igr][0].mixed_block_flag ) 
                    n1 = sfBandIndex[0][ncbl_mixed-1];
    }
    n3 = nsamp[igr][0] = hybrid(sample[0][igr], sample[0][igr_prev], 
        yout, side_info.gr[igr][0].block_type, n1, n2, nsamp[igr_prev][0], band_limit_nsb);
    /*-- right chan --*/
    n1 = n2 = nsamp[igr][1];   /* total number bands */
    if( side_info.gr[igr][1].block_type == 2 ) { 
        n1 = 0;     /* long bands */
        if( side_info.gr[igr][1].mixed_block_flag ) 
                    n1 = sfBandIndex[0][ncbl_mixed-1];
    }
    nsamp[igr][1] = hybrid_sum(sample[1][igr], sample[0][igr], 
        yout, side_info.gr[igr][1].block_type, n1, n2);
    if( n3 < nsamp[igr][1] ) n1 = nsamp[igr][1];
}

/*--------*/
FreqInvert(yout, n3);
sbt_L3(yout, pcm, 0, vbuf, vb_ptr);

}
/*------------------------------------------------------------------*/
/*==================================================================*/
/*====================concealment/reformatted frames================*/
/*==================================================================*/
#ifdef REFORMAT
// test routine - reformats frame
IN_OUT CMpaDecoderL3::audio_decode_reformat(unsigned char *bs, 
                                            unsigned char *bs_out)
{
    if( h_id )  {
        return L3reformat_MPEG1(bs, bs_out);
    }
    else {
        return L3reformat_MPEG2(bs, bs_out);
    }
}
//============================================================
// test routine - reformats frame
IN_OUT CMpaDecoderL3::L3reformat_MPEG1(unsigned char *bs, 
                                       unsigned char *bs_out)
{
int sync;
IN_OUT in_out;
int side_bytes;
int nbytes, nbytes_r;

//iframe++;


bitget_init(bs);          /* initialize bit getter */
/* test sync */
in_out.in_bytes = 0;     /* assume fail */
in_out.out_bytes = 0;
sync = bitget(&bitdat, 12);

if( sync != 0xFFF ) return in_out;       /* sync fail */
/*-----------*/

/*-- unpack side info --*/
side_bytes = unpack_side_MPEG1();
if( framebytes <= 0 ) return in_out;  // fail bad sr or br index

padframebytes = framebytes+pad;

in_out.in_bytes = padframebytes;

/*-- load main data and update buf pointer --*/
/*------------------------------------------- 
   if start point < 0, must just cycle decoder 
   if jumping into middle of stream, 
---------------------------------------------*/

nbytes_r = reformat_side_bytes + reformat_bytes - side_info.main_data_begin;
if( nbytes_r > 0 ) {
    memmove(bs_out, reformat_buf, nbytes_r);
    in_out.out_bytes = nbytes_r;
}


buf_ptr0 = buf_ptr1 - side_info.main_data_begin;   /* decode start point */
if( buf_ptr1 > BUF_TRIGGER ) {          /* shift buffer */
    memmove(buf, buf+buf_ptr0, side_info.main_data_begin);
    buf_ptr0 = 0;
    buf_ptr1 = side_info.main_data_begin;
}
nbytes = padframebytes - side_bytes - crcbytes;
memmove(buf+buf_ptr1, bs+side_bytes+crcbytes, nbytes);
buf_ptr1 += nbytes;
/*-----------------------*/

if( buf_ptr0 >= 0 ) {
    reformat_side_bytes = side_bytes+crcbytes;
    memmove(reformat_buf, bs, reformat_side_bytes);
    reformat_buf[4+crcbytes]    = 0;      // set main data begin = 0
    reformat_buf[4+crcbytes+1] &= 0x7F;   // set main data begin = 0
    reformat_bytes = buf_ptr1 - buf_ptr0;
    if( reformat_bytes > 0 ) {
        memmove(reformat_buf+reformat_side_bytes, 
            buf+buf_ptr0, reformat_bytes);
    }
}
else {
    reformat_side_bytes = 0;
    reformat_bytes = 0;
}

return in_out;
}
/*=========================================================*/
// test routine - reformats frame
IN_OUT CMpaDecoderL3::L3reformat_MPEG2(unsigned char *bs, 
                                       unsigned char *bs_out)
{
int sync;
IN_OUT in_out;
int side_bytes;
int nbytes, nbytes_r;

//iframe++;

bitget_init(bs);          /* initialize bit getter */
/* test sync */
in_out.in_bytes = 0;     /* assume fail */
in_out.out_bytes = 0;
sync = bitget(&bitdat, 12);

//if( sync != 0xFFF ) return in_out;       /* sync fail */
mpeg25_flag = 0;
if( sync != 0xFFF ) {
    mpeg25_flag = 1;       /* mpeg 2.5 sync */
    if( sync != 0xFFE ) return in_out;  /* sync fail */
}

/*-- unpack side info --*/
side_bytes = unpack_side_MPEG2(igr);
if( framebytes <= 0 ) return in_out;  // fail bad sr or br index

padframebytes = framebytes+pad;

in_out.in_bytes = padframebytes;

nbytes_r = reformat_side_bytes + reformat_bytes - side_info.main_data_begin;
if( nbytes_r > 0 ) {
    memmove(bs_out, reformat_buf, nbytes_r);
    in_out.out_bytes = nbytes_r;
}


buf_ptr0 = buf_ptr1 - side_info.main_data_begin;   /* decode start point */
if( buf_ptr1 > BUF_TRIGGER ) {          /* shift buffer */
    memmove(buf, buf+buf_ptr0, side_info.main_data_begin);
    buf_ptr0 = 0;
    buf_ptr1 = side_info.main_data_begin;
}
nbytes = padframebytes - side_bytes - crcbytes;
memmove(buf+buf_ptr1, bs+side_bytes+crcbytes, nbytes);
buf_ptr1 += nbytes;
/*-----------------------*/

if( buf_ptr0 >= 0 ) {
    reformat_side_bytes = side_bytes+crcbytes;
    memmove(reformat_buf, bs, reformat_side_bytes);
    reformat_buf[4+crcbytes]    = 0;      // set main data begin = 0
    reformat_bytes = buf_ptr1 - buf_ptr0;
    if( reformat_bytes > 0 ) {
        memmove(reformat_buf+reformat_side_bytes, 
            buf+buf_ptr0, reformat_bytes);
    }
}
else {
    reformat_side_bytes = 0;
    reformat_bytes = 0;
}

//igr = igr^1;   //  must be done by decode_reformatted

return in_out;
}
#endif  // REFORMAT 
//=========================================================================
//=========================================================================
IN_OUT CMpaDecoderL3::audio_decode(unsigned char *bs, unsigned char *pcm, int size)
{
    if (!size)
        return audio_decode(bs, pcm);

// overloaded for reformatted frames.   main_data_begin == 0

    if( h_id )  {
        return L3audio_decode_reformattedMPEG1(bs, pcm, size);
    }
    else {
        return L3audio_decode_reformattedMPEG2(bs, pcm, size);
    }
}
/*====================================================================*/
IN_OUT CMpaDecoderL3::L3audio_decode_reformattedMPEG1(unsigned char *bs, 
                           unsigned char *pcm, int size)
{
int sync;
IN_OUT in_out;
int side_bytes;

// decode reformatted (self contained) frame 
// fails if main_data_begin != 0


iframe++;

in_out.in_bytes  = 0;   // assume fail  e.g. sync fail
in_out.out_bytes = 0;

if( size > 0 ) {

    bitget_init(&bitdat, bs);          /* initialize bit getter */
    /* test sync */
    sync = bitget(&bitdat, 12);
    if( sync != 0xFFF ) return in_out;       /* sync fail */
    /*-----------*/

    /*-- unpack side info --*/
    side_bytes = unpack_side_MPEG1();
    if( framebytes <= 0 ) return in_out;  // fail bad sr or br index
    if( side_info.main_data_begin ) return in_out;  // fail if data not self contained

    in_out.in_bytes = size;
    in_out.out_bytes = outbytes;

    main_pos_bit = (side_bytes+crcbytes) << 3;  // set for unpack_main
    unpack_main(bs, 0);          // first granule
    conceal_insert(0);
    Xform(pcm, 0);
    unpack_main(bs, 1);          // second granule
    conceal_insert(1);
    Xform(pcm+half_outbytes, 1);

}
else {      // size <= 0, missing frame 
    in_out.in_bytes = size;
    in_out.out_bytes = outbytes;
    conceal_fixup(0);
    Xform(pcm, 0);
    conceal_fixup(1);
    Xform(pcm+half_outbytes, 1);
}




return in_out;
}
//=========================================================================
IN_OUT CMpaDecoderL3::L3audio_decode_reformattedMPEG2(unsigned char *bs, 
                             unsigned char *pcm, int size)
{
int sync;
IN_OUT in_out;
int side_bytes;

// decode reformatted (self contained) frame 
// fails if main_data_begin != 0

iframe++;

in_out.in_bytes = 0;     /* assume fail */
in_out.out_bytes = 0;

if( size > 0 ) {
    bitget_init(&bitdat, bs);          /* initialize bit getter */
    /* test sync */
    sync = bitget(&bitdat, 12);
    //if( sync != 0xFFF ) return in_out;       /* sync fail */
    mpeg25_flag = 0;
    if( sync != 0xFFF ) {
        mpeg25_flag = 1;       /* mpeg 2.5 sync */
        if( sync != 0xFFE ) return in_out;  /* sync fail */
    }

    /*-- unpack side info --*/
    side_bytes = unpack_side_MPEG2(igr);
    if( framebytes <= 0 ) return in_out;  // fail bad sr or br index
    if( side_info.main_data_begin ) return in_out;  // fail if data not self contained

    in_out.in_bytes = size;
    in_out.out_bytes = outbytes;

    main_pos_bit = (side_bytes+crcbytes) << 3;  // set for unpack_main
    unpack_main(bs, igr);
    conceal_insert(igr);
    Xform(pcm, igr);
}
else {      // size <= 0, missing frame 
    in_out.in_bytes = size;
    in_out.out_bytes = outbytes;
    conceal_fixup(igr);
    Xform(pcm, igr);
}

igr = igr^1;
return in_out;
}
/*====================================================================*/
void CMpaDecoderL3::conceal_insert(int igr)
{
int ch, nlines, blockType, i;

if( conceal_flag ) {
    for(ch=0;ch<nchan;ch++) {

#if defined (MP3_CONCEAL_LOSS)        
        conceal[ch]->insert(&sample[ch][igr][0].x, 
            side_info.gr[igr][ch].block_type, nsamp[igr][ch]);
        nlines = conceal[ch]->retrieve(&sample[ch][igr][0].x, blockType);
#endif //MP3_CONCEAL_LOSS
        
        side_info.gr[igr][ch].mixed_block_flag      = 0;
        side_info.gr[igr][ch].block_type            = blockType;
        side_info.gr[igr][ch].window_switching_flag = (blockType != 0) ? 1 : 0;
        nsamp[igr][ch] = nlines;
        for(i=nlines;i<576;i++) sample[ch][igr][i].x = 0.0f;
    }
}
}
/*====================================================================*/
void CMpaDecoderL3::conceal_fixup(int igr)
{
int ch, nlines, blockType, i;

if( conceal_flag ) {
    for(ch=0;ch<nchan;ch++) {

#if defined (MP3_CONCEAL_LOSS)        
        conceal[ch]->insert();
        nlines = conceal[ch]->retrieve(&sample[ch][igr][0].x, blockType);
#endif //MP3_CONCEAL_LOSS
        
        side_info.gr[igr][ch].mixed_block_flag      = 0;
        side_info.gr[igr][ch].block_type            = blockType;
        side_info.gr[igr][ch].window_switching_flag = (blockType != 0) ? 1 : 0;
        nsamp[igr][ch] = nlines;
        for(i=nlines;i<576;i++) sample[ch][igr][i].x = 0.0f;
    }
}
else {       // mute
    for(ch=0;ch<nchan;ch++) {
        side_info.gr[igr][ch].mixed_block_flag      = 0;
        side_info.gr[igr][ch].block_type            = 0;
        side_info.gr[igr][ch].window_switching_flag = 0;
        for(i=0;i<576;i++) sample[ch][igr][i].x = 0.0f;
    }

}

}
/*====================================================================*/