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audio/mp3: Refactoring

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Hajime Hoshi 2017-06-18 18:15:56 +09:00
parent 7b1f3fae99
commit cf05a581a4
1 changed files with 73 additions and 73 deletions
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146
audio/mp3/l3.go
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@ -96,14 +96,14 @@ var (
) )
func (f *frame) l3Requantize(gr int, ch int) { func (f *frame) l3Requantize(gr int, ch int) {
/* Setup sampling frequency index */ // Setup sampling frequency index
sfreq := f.header.sampling_frequency sfreq := f.header.sampling_frequency
/* Determine type of block to process */ // Determine type of block to process
if (f.sideInfo.win_switch_flag[gr][ch] == 1) && (f.sideInfo.block_type[gr][ch] == 2) { /* Short blocks */ if (f.sideInfo.win_switch_flag[gr][ch] == 1) && (f.sideInfo.block_type[gr][ch] == 2) { // Short blocks
/* Check if the first two subbands // Check if the first two subbands
*(=2*18 samples = 8 long or 3 short sfb's) uses long blocks */ // (=2*18 samples = 8 long or 3 short sfb's) uses long blocks
if f.sideInfo.mixed_block_flag[gr][ch] != 0 { /* 2 longbl. sb first */ if f.sideInfo.mixed_block_flag[gr][ch] != 0 { // 2 longbl. sb first
/* First process the 2 long block subbands at the start */ // First process the 2 long block subbands at the start
sfb := 0 sfb := 0
next_sfb := sfBandIndicesSet[sfreq].l[sfb+1] next_sfb := sfBandIndicesSet[sfreq].l[sfb+1]
for i := 0; i < 36; i++ { for i := 0; i < 36; i++ {
@ -113,15 +113,15 @@ func (f *frame) l3Requantize(gr int, ch int) {
} }
f.requantizeProcessLong(gr, ch, i, sfb) f.requantizeProcessLong(gr, ch, i, sfb)
} }
/* And next the remaining,non-zero,bands which uses short blocks */ // And next the remaining,non-zero,bands which uses short blocks
sfb = 3 sfb = 3
next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3 next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3
win_len := sfBandIndicesSet[sfreq].s[sfb+1] - win_len := sfBandIndicesSet[sfreq].s[sfb+1] -
sfBandIndicesSet[sfreq].s[sfb] sfBandIndicesSet[sfreq].s[sfb]
for i := 36; i < int(f.sideInfo.count1[gr][ch]); /* i++ done below! */ { for i := 36; i < int(f.sideInfo.count1[gr][ch]); /* i++ done below! */ {
/* Check if we're into the next scalefac band */ // Check if we're into the next scalefac band
if i == next_sfb { /* Yes */ if i == next_sfb {
sfb++ sfb++
next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3 next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3
win_len = sfBandIndicesSet[sfreq].s[sfb+1] - win_len = sfBandIndicesSet[sfreq].s[sfb+1] -
@ -135,13 +135,13 @@ func (f *frame) l3Requantize(gr int, ch int) {
} }
} }
} else { /* Only short blocks */ } else { // Only short blocks
sfb := 0 sfb := 0
next_sfb := sfBandIndicesSet[sfreq].s[sfb+1] * 3 next_sfb := sfBandIndicesSet[sfreq].s[sfb+1] * 3
win_len := sfBandIndicesSet[sfreq].s[sfb+1] - win_len := sfBandIndicesSet[sfreq].s[sfb+1] -
sfBandIndicesSet[sfreq].s[sfb] sfBandIndicesSet[sfreq].s[sfb]
for i := 0; i < int(f.sideInfo.count1[gr][ch]); /* i++ done below! */ { for i := 0; i < int(f.sideInfo.count1[gr][ch]); /* i++ done below! */ {
/* Check if we're into the next scalefac band */ // Check if we're into the next scalefac band
if i == next_sfb { if i == next_sfb {
sfb++ sfb++
next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3 next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3
@ -156,7 +156,7 @@ func (f *frame) l3Requantize(gr int, ch int) {
} }
} }
} }
} else { /* Only long blocks */ } else { // Only long blocks
sfb := 0 sfb := 0
next_sfb := sfBandIndicesSet[sfreq].l[sfb+1] next_sfb := sfBandIndicesSet[sfreq].l[sfb+1]
for i := 0; i < int(f.sideInfo.count1[gr][ch]); i++ { for i := 0; i < int(f.sideInfo.count1[gr][ch]); i++ {
@ -172,13 +172,13 @@ func (f *frame) l3Requantize(gr int, ch int) {
func (f *frame) l3Reorder(gr int, ch int) { func (f *frame) l3Reorder(gr int, ch int) {
re := make([]float32, 576) re := make([]float32, 576)
sfreq := f.header.sampling_frequency /* Setup sampling freq index */ sfreq := f.header.sampling_frequency // Setup sampling freq index
/* Only reorder short blocks */ // Only reorder short blocks
if (f.sideInfo.win_switch_flag[gr][ch] == 1) && (f.sideInfo.block_type[gr][ch] == 2) { /* Short blocks */ if (f.sideInfo.win_switch_flag[gr][ch] == 1) && (f.sideInfo.block_type[gr][ch] == 2) { // Short blocks
/* Check if the first two subbands // Check if the first two subbands
*(=2*18 samples = 8 long or 3 short sfb's) uses long blocks */ // (=2*18 samples = 8 long or 3 short sfb's) uses long blocks
sfb := 0 sfb := 0
/* 2 longbl. sb first */ // 2 longbl. sb first
if f.sideInfo.mixed_block_flag[gr][ch] != 0 { if f.sideInfo.mixed_block_flag[gr][ch] != 0 {
sfb = 3 sfb = 3
} }
@ -189,13 +189,13 @@ func (f *frame) l3Reorder(gr int, ch int) {
i = 0 i = 0
} }
for i < 576 { for i < 576 {
/* Check if we're into the next scalefac band */ // Check if we're into the next scalefac band
if i == next_sfb { if i == next_sfb {
/* Copy reordered data back to the original vector */ // Copy reordered data back to the original vector
for j := 0; j < 3*win_len; j++ { for j := 0; j < 3*win_len; j++ {
f.mainData.is[gr][ch][3*sfBandIndicesSet[sfreq].s[sfb]+j] = re[j] f.mainData.is[gr][ch][3*sfBandIndicesSet[sfreq].s[sfb]+j] = re[j]
} }
/* Check if this band is above the rzero region,if so we're done */ // Check if this band is above the rzero region,if so we're done
if i >= f.sideInfo.count1[gr][ch] { if i >= f.sideInfo.count1[gr][ch] {
return return
} }
@ -203,14 +203,14 @@ func (f *frame) l3Reorder(gr int, ch int) {
next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3 next_sfb = sfBandIndicesSet[sfreq].s[sfb+1] * 3
win_len = sfBandIndicesSet[sfreq].s[sfb+1] - sfBandIndicesSet[sfreq].s[sfb] win_len = sfBandIndicesSet[sfreq].s[sfb+1] - sfBandIndicesSet[sfreq].s[sfb]
} }
for win := 0; win < 3; win++ { /* Do the actual reordering */ for win := 0; win < 3; win++ { // Do the actual reordering
for j := 0; j < win_len; j++ { for j := 0; j < win_len; j++ {
re[j*3+win] = f.mainData.is[gr][ch][i] re[j*3+win] = f.mainData.is[gr][ch][i]
i++ i++
} }
} }
} }
/* Copy reordered data of last band back to original vector */ // Copy reordered data of last band back to original vector
for j := 0; j < 3*win_len; j++ { for j := 0; j < 3*win_len; j++ {
f.mainData.is[gr][ch][3*sfBandIndicesSet[sfreq].s[12]+j] = re[j] f.mainData.is[gr][ch][3*sfBandIndicesSet[sfreq].s[12]+j] = re[j]
} }
@ -224,20 +224,20 @@ var (
func (f *frame) stereoProcessIntensityLong(gr int, sfb int) { func (f *frame) stereoProcessIntensityLong(gr int, sfb int) {
is_ratio_l := float32(0) is_ratio_l := float32(0)
is_ratio_r := float32(0) is_ratio_r := float32(0)
/* Check that((is_pos[sfb]=scalefac) != 7) => no intensity stereo */ // Check that((is_pos[sfb]=scalefac) != 7) => no intensity stereo
is_pos := f.mainData.scalefac_l[gr][0][sfb] is_pos := f.mainData.scalefac_l[gr][0][sfb]
if is_pos != 7 { if is_pos != 7 {
sfreq := f.header.sampling_frequency /* Setup sampling freq index */ sfreq := f.header.sampling_frequency // Setup sampling freq index
sfb_start := sfBandIndicesSet[sfreq].l[sfb] sfb_start := sfBandIndicesSet[sfreq].l[sfb]
sfb_stop := sfBandIndicesSet[sfreq].l[sfb+1] sfb_stop := sfBandIndicesSet[sfreq].l[sfb+1]
if is_pos == 6 { /* tan((6*PI)/12 = PI/2) needs special treatment! */ if is_pos == 6 { // tan((6*PI)/12 = PI/2) needs special treatment!
is_ratio_l = 1.0 is_ratio_l = 1.0
is_ratio_r = 0.0 is_ratio_r = 0.0
} else { } else {
is_ratio_l = isRatios[is_pos] / (1.0 + isRatios[is_pos]) is_ratio_l = isRatios[is_pos] / (1.0 + isRatios[is_pos])
is_ratio_r = 1.0 / (1.0 + isRatios[is_pos]) is_ratio_r = 1.0 / (1.0 + isRatios[is_pos])
} }
/* Now decode all samples in this scale factor band */ // Now decode all samples in this scale factor band
for i := sfb_start; i < sfb_stop; i++ { for i := sfb_start; i < sfb_stop; i++ {
f.mainData.is[gr][0][i] *= is_ratio_l f.mainData.is[gr][0][i] *= is_ratio_l
f.mainData.is[gr][1][i] *= is_ratio_r f.mainData.is[gr][1][i] *= is_ratio_r
@ -248,24 +248,24 @@ func (f *frame) stereoProcessIntensityLong(gr int, sfb int) {
func (f *frame) stereoProcessIntensityShort(gr int, sfb int) { func (f *frame) stereoProcessIntensityShort(gr int, sfb int) {
is_ratio_l := float32(0) is_ratio_l := float32(0)
is_ratio_r := float32(0) is_ratio_r := float32(0)
sfreq := f.header.sampling_frequency /* Setup sampling freq index */ sfreq := f.header.sampling_frequency // Setup sampling freq index
/* The window length */ // The window length
win_len := sfBandIndicesSet[sfreq].s[sfb+1] - sfBandIndicesSet[sfreq].s[sfb] win_len := sfBandIndicesSet[sfreq].s[sfb+1] - sfBandIndicesSet[sfreq].s[sfb]
/* The three windows within the band has different scalefactors */ // The three windows within the band has different scalefactors
for win := 0; win < 3; win++ { for win := 0; win < 3; win++ {
/* Check that((is_pos[sfb]=scalefac) != 7) => no intensity stereo */ // Check that((is_pos[sfb]=scalefac) != 7) => no intensity stereo
is_pos := f.mainData.scalefac_s[gr][0][sfb][win] is_pos := f.mainData.scalefac_s[gr][0][sfb][win]
if is_pos != 7 { if is_pos != 7 {
sfb_start := sfBandIndicesSet[sfreq].s[sfb]*3 + win_len*win sfb_start := sfBandIndicesSet[sfreq].s[sfb]*3 + win_len*win
sfb_stop := sfb_start + win_len sfb_stop := sfb_start + win_len
if is_pos == 6 { /* tan((6*PI)/12 = PI/2) needs special treatment! */ if is_pos == 6 { // tan((6*PI)/12 = PI/2) needs special treatment!
is_ratio_l = 1.0 is_ratio_l = 1.0
is_ratio_r = 0.0 is_ratio_r = 0.0
} else { } else {
is_ratio_l = isRatios[is_pos] / (1.0 + isRatios[is_pos]) is_ratio_l = isRatios[is_pos] / (1.0 + isRatios[is_pos])
is_ratio_r = 1.0 / (1.0 + isRatios[is_pos]) is_ratio_r = 1.0 / (1.0 + isRatios[is_pos])
} }
/* Now decode all samples in this scale factor band */ // Now decode all samples in this scale factor band
for i := sfb_start; i < sfb_stop; i++ { for i := sfb_start; i < sfb_stop; i++ {
// https://github.com/technosaurus/PDMP3/issues/3 // https://github.com/technosaurus/PDMP3/issues/3
f.mainData.is[gr][0][i] *= is_ratio_l f.mainData.is[gr][0][i] *= is_ratio_l
@ -276,19 +276,19 @@ func (f *frame) stereoProcessIntensityShort(gr int, sfb int) {
} }
func (f *frame) l3Stereo(gr int) { func (f *frame) l3Stereo(gr int) {
/* Do nothing if joint stereo is not enabled */ // Do nothing if joint stereo is not enabled
if (f.header.mode != 1) || (f.header.mode_extension == 0) { if (f.header.mode != 1) || (f.header.mode_extension == 0) {
return return
} }
/* Do Middle/Side("normal") stereo processing */ // Do Middle/Side("normal") stereo processing
if (f.header.mode_extension & 0x2) != 0 { if (f.header.mode_extension & 0x2) != 0 {
/* Determine how many frequency lines to transform */ // Determine how many frequency lines to transform
i := 0 i := 0
if f.sideInfo.count1[gr][0] > f.sideInfo.count1[gr][1] { if f.sideInfo.count1[gr][0] > f.sideInfo.count1[gr][1] {
i = 1 i = 1
} }
max_pos := int(f.sideInfo.count1[gr][i]) max_pos := int(f.sideInfo.count1[gr][i])
/* Do the actual processing */ // Do the actual processing
const invSqrt2 = math.Sqrt2 / 2 const invSqrt2 = math.Sqrt2 / 2
for i := 0; i < max_pos; i++ { for i := 0; i < max_pos; i++ {
left := (f.mainData.is[gr][0][i] + f.mainData.is[gr][1][i]) * invSqrt2 left := (f.mainData.is[gr][0][i] + f.mainData.is[gr][1][i]) * invSqrt2
@ -297,45 +297,45 @@ func (f *frame) l3Stereo(gr int) {
f.mainData.is[gr][1][i] = right f.mainData.is[gr][1][i] = right
} }
} }
/* Do intensity stereo processing */ // Do intensity stereo processing
if (f.header.mode_extension & 0x1) != 0 { if (f.header.mode_extension & 0x1) != 0 {
/* Setup sampling frequency index */ // Setup sampling frequency index
sfreq := f.header.sampling_frequency sfreq := f.header.sampling_frequency
/* First band that is intensity stereo encoded is first band scale factor // First band that is intensity stereo encoded is first band scale factor
* band on or above count1 frequency line. N.B.: Intensity stereo coding is // band on or above count1 frequency line. N.B.: Intensity stereo coding is
* only done for higher subbands, but logic is here for lower subbands. */ // only done for higher subbands, but logic is here for lower subbands.
/* Determine type of block to process */ // Determine type of block to process
if (f.sideInfo.win_switch_flag[gr][0] == 1) && if (f.sideInfo.win_switch_flag[gr][0] == 1) &&
(f.sideInfo.block_type[gr][0] == 2) { /* Short blocks */ (f.sideInfo.block_type[gr][0] == 2) { // Short blocks
/* Check if the first two subbands // Check if the first two subbands
*(=2*18 samples = 8 long or 3 short sfb's) uses long blocks */ // (=2*18 samples = 8 long or 3 short sfb's) uses long blocks
if f.sideInfo.mixed_block_flag[gr][0] != 0 { /* 2 longbl. sb first */ if f.sideInfo.mixed_block_flag[gr][0] != 0 { // 2 longbl. sb first
for sfb := 0; sfb < 8; sfb++ { /* First process 8 sfb's at start */ for sfb := 0; sfb < 8; sfb++ { // First process 8 sfb's at start
/* Is this scale factor band above count1 for the right channel? */ // Is this scale factor band above count1 for the right channel?
if sfBandIndicesSet[sfreq].l[sfb] >= f.sideInfo.count1[gr][1] { if sfBandIndicesSet[sfreq].l[sfb] >= f.sideInfo.count1[gr][1] {
f.stereoProcessIntensityLong(gr, sfb) f.stereoProcessIntensityLong(gr, sfb)
} }
} }
/* And next the remaining bands which uses short blocks */ // And next the remaining bands which uses short blocks
for sfb := 3; sfb < 12; sfb++ { for sfb := 3; sfb < 12; sfb++ {
/* Is this scale factor band above count1 for the right channel? */ // Is this scale factor band above count1 for the right channel?
if sfBandIndicesSet[sfreq].s[sfb]*3 >= f.sideInfo.count1[gr][1] { if sfBandIndicesSet[sfreq].s[sfb]*3 >= f.sideInfo.count1[gr][1] {
f.stereoProcessIntensityShort(gr, sfb) /* intensity stereo processing */ f.stereoProcessIntensityShort(gr, sfb) // intensity stereo processing
} }
} }
} else { /* Only short blocks */ } else { // Only short blocks
for sfb := 0; sfb < 12; sfb++ { for sfb := 0; sfb < 12; sfb++ {
/* Is this scale factor band above count1 for the right channel? */ // Is this scale factor band above count1 for the right channel?
if sfBandIndicesSet[sfreq].s[sfb]*3 >= f.sideInfo.count1[gr][1] { if sfBandIndicesSet[sfreq].s[sfb]*3 >= f.sideInfo.count1[gr][1] {
f.stereoProcessIntensityShort(gr, sfb) /* intensity stereo processing */ f.stereoProcessIntensityShort(gr, sfb) // intensity stereo processing
} }
} }
} }
} else { /* Only long blocks */ } else { // Only long blocks
for sfb := 0; sfb < 21; sfb++ { for sfb := 0; sfb < 21; sfb++ {
/* Is this scale factor band above count1 for the right channel? */ // Is this scale factor band above count1 for the right channel?
if sfBandIndicesSet[sfreq].l[sfb] >= f.sideInfo.count1[gr][1] { if sfBandIndicesSet[sfreq].l[sfb] >= f.sideInfo.count1[gr][1] {
/* Perform the intensity stereo processing */ // Perform the intensity stereo processing
f.stereoProcessIntensityLong(gr, sfb) f.stereoProcessIntensityLong(gr, sfb)
} }
} }
@ -349,20 +349,20 @@ var (
) )
func (f *frame) l3Antialias(gr int, ch int) { func (f *frame) l3Antialias(gr int, ch int) {
/* No antialiasing is done for short blocks */ // No antialiasing is done for short blocks
if (f.sideInfo.win_switch_flag[gr][ch] == 1) && if (f.sideInfo.win_switch_flag[gr][ch] == 1) &&
(f.sideInfo.block_type[gr][ch] == 2) && (f.sideInfo.block_type[gr][ch] == 2) &&
(f.sideInfo.mixed_block_flag[gr][ch]) == 0 { (f.sideInfo.mixed_block_flag[gr][ch]) == 0 {
return return
} }
/* Setup the limit for how many subbands to transform */ // Setup the limit for how many subbands to transform
sblim := 32 sblim := 32
if (f.sideInfo.win_switch_flag[gr][ch] == 1) && if (f.sideInfo.win_switch_flag[gr][ch] == 1) &&
(f.sideInfo.block_type[gr][ch] == 2) && (f.sideInfo.block_type[gr][ch] == 2) &&
(f.sideInfo.mixed_block_flag[gr][ch] == 1) { (f.sideInfo.mixed_block_flag[gr][ch] == 1) {
sblim = 2 sblim = 2
} }
/* Do the actual antialiasing */ // Do the actual antialiasing
for sb := 1; sb < sblim; sb++ { for sb := 1; sb < sblim; sb++ {
for i := 0; i < 8; i++ { for i := 0; i < 8; i++ {
li := 18*sb - 1 - i li := 18*sb - 1 - i
@ -553,36 +553,36 @@ func (f *frame) l3SubbandSynthesis(gr int, ch int, out []uint8) {
s_vec := make([]float32, 32) s_vec := make([]float32, 32)
nch := f.header.numberOfChannels() nch := f.header.numberOfChannels()
/* Setup the n_win windowing vector and the v_vec intermediate vector */ // Setup the n_win windowing vector and the v_vec intermediate vector
for ss := 0; ss < 18; ss++ { /* Loop through 18 samples in 32 subbands */ for ss := 0; ss < 18; ss++ { // Loop through 18 samples in 32 subbands
for i := 1023; i > 63; i-- { /* Shift up the V vector */ for i := 1023; i > 63; i-- { // Shift up the V vector
f.v_vec[ch][i] = f.v_vec[ch][i-64] f.v_vec[ch][i] = f.v_vec[ch][i-64]
} }
for i := 0; i < 32; i++ { /* Copy next 32 time samples to a temp vector */ for i := 0; i < 32; i++ { // Copy next 32 time samples to a temp vector
s_vec[i] = f.mainData.is[gr][ch][i*18+ss] s_vec[i] = f.mainData.is[gr][ch][i*18+ss]
} }
for i := 0; i < 64; i++ { /* Matrix multiply input with n_win[][] matrix */ for i := 0; i < 64; i++ { // Matrix multiply input with n_win[][] matrix
sum := float32(0) sum := float32(0)
for j := 0; j < 32; j++ { for j := 0; j < 32; j++ {
sum += synthNWin[i][j] * s_vec[j] sum += synthNWin[i][j] * s_vec[j]
} }
f.v_vec[ch][i] = sum f.v_vec[ch][i] = sum
} }
for i := 0; i < 8; i++ { /* Build the U vector */ for i := 0; i < 8; i++ { // Build the U vector
for j := 0; j < 32; j++ { /* <<7 == *128 */ for j := 0; j < 32; j++ { // <<7 == *128
u_vec[(i<<6)+j] = f.v_vec[ch][(i<<7)+j] u_vec[(i<<6)+j] = f.v_vec[ch][(i<<7)+j]
u_vec[(i<<6)+j+32] = f.v_vec[ch][(i<<7)+j+96] u_vec[(i<<6)+j+32] = f.v_vec[ch][(i<<7)+j+96]
} }
} }
for i := 0; i < 512; i++ { /* Window by u_vec[i] with synthDtbl[i] */ for i := 0; i < 512; i++ { // Window by u_vec[i] with synthDtbl[i]
u_vec[i] *= synthDtbl[i] u_vec[i] *= synthDtbl[i]
} }
for i := 0; i < 32; i++ { /* Calc 32 samples,store in outdata vector */ for i := 0; i < 32; i++ { // Calc 32 samples,store in outdata vector
sum := float32(0) sum := float32(0)
for j := 0; j < 16; j++ { /* sum += u_vec[j*32 + i]; */ for j := 0; j < 16; j++ { // sum += u_vec[j*32 + i];
sum += u_vec[(j<<5)+i] sum += u_vec[(j<<5)+i]
} }
/* sum now contains time sample 32*ss+i. Convert to 16-bit signed int */ // sum now contains time sample 32*ss+i. Convert to 16-bit signed int
samp := int(sum * 32767) samp := int(sum * 32767)
if samp > 32767 { if samp > 32767 {
samp = 32767 samp = 32767