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audio/mp3: Move L3_Antialias to Go

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This commit is contained in:
Hajime Hoshi 2017-06-15 03:20:00 +09:00
parent 53c2c5d810
commit ef85c9a7bc
3 changed files with 34 additions and 36 deletions
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33
audio/mp3/l3.go
View File

@ -174,6 +174,39 @@ func L3_Stereo(gr C.unsigned) {
}
}
var (
cs = [8]float32{0.857493, 0.881742, 0.949629, 0.983315, 0.995518, 0.999161, 0.999899, 0.999993}
ca = [8]float32{-0.514496, -0.471732, -0.313377, -0.181913, -0.094574, -0.040966, -0.014199, -0.003700}
)
//export L3_Antialias
func L3_Antialias(gr C.unsigned, ch C.unsigned) {
/* No antialiasing is done for short blocks */
if (C.g_side_info.win_switch_flag[gr][ch] == 1) &&
(C.g_side_info.block_type[gr][ch] == 2) &&
(C.g_side_info.mixed_block_flag[gr][ch]) == 0 {
return
}
/* Setup the limit for how many subbands to transform */
sblim := 32
if (C.g_side_info.win_switch_flag[gr][ch] == 1) &&
(C.g_side_info.block_type[gr][ch] == 2) &&
(C.g_side_info.mixed_block_flag[gr][ch] == 1) {
sblim = 2
}
/* Do the actual antialiasing */
for sb := 1; sb < sblim; sb++ {
for i := 0; i < 8; i++ {
li := 18*sb - 1 - i
ui := 18*sb + i
lb := C.g_main_data.is[gr][ch][li]*C.float(cs[i]) - C.g_main_data.is[gr][ch][ui]*C.float(ca[i])
ub := C.g_main_data.is[gr][ch][ui]*C.float(cs[i]) + C.g_main_data.is[gr][ch][li]*C.float(ca[i])
C.g_main_data.is[gr][ch][li] = lb
C.g_main_data.is[gr][ch][ui] = ub
}
}
}
var store = [2][32][18]float32{}
//export L3_Hybrid_Synthesis

36
audio/mp3/pdmp3.c
View File

@ -44,7 +44,6 @@ static void audio_write(unsigned *samples,unsigned nsamples,int sample_rate);
static void audio_write_raw(unsigned *samples,unsigned nsamples);
static void Decode_L3_Init_Song(void);
static void Error(const char *s,int e);
static void L3_Antialias(unsigned gr,unsigned ch);
static void L3_Requantize(unsigned gr,unsigned ch);
static void L3_Reorder(unsigned gr,unsigned ch);
static void Read_Ancillary(void);
@ -65,9 +64,6 @@ static const unsigned g_mpeg1_bitrates[3 /* layer 1-3 */][15 /* header bitrate_i
},
g_sampling_frequency[3] = { 44100 * Hz,48000 * Hz,32000 * Hz };
static const float //ci[8]={-0.6,-0.535,-0.33,-0.185,-0.095,-0.041,-0.0142,-0.0037},
cs[8]={0.857493,0.881742,0.949629,0.983315,0.995518,0.999161,0.999899,0.999993},
ca[8]={-0.514496,-0.471732,-0.313377,-0.181913,-0.094574,-0.040966,-0.014199,-0.003700};
#ifdef POW34_ITERATE
static const float powtab34[32] = {
0.000000f,1.000000f,2.519842f,4.326749f,6.349605f,8.549880f,10.902724f,
@ -422,38 +418,6 @@ static void Decode_L3_Init_Song(void){
synth_init = 1;
}
/**Description: TBD
* Parameters: TBD
* Return value: TBD
* Author: Krister Lagerström(krister@kmlager.com) **/
static void L3_Antialias(unsigned gr,unsigned ch){
unsigned sb /* subband of 18 samples */,i,sblim,ui,li;
float ub,lb;
/* No antialiasing is done for short blocks */
if((g_side_info.win_switch_flag[gr][ch] == 1) &&
(g_side_info.block_type[gr][ch] == 2) &&
(g_side_info.mixed_block_flag[gr][ch]) == 0) {
return; /* Done */
}
/* Setup the limit for how many subbands to transform */
sblim =((g_side_info.win_switch_flag[gr][ch] == 1) &&
(g_side_info.block_type[gr][ch] == 2) &&
(g_side_info.mixed_block_flag[gr][ch] == 1))?2:32;
/* Do the actual antialiasing */
for(sb = 1; sb < sblim; sb++) {
for(i = 0; i < 8; i++) {
li = 18*sb-1-i;
ui = 18*sb+i;
lb = g_main_data.is[gr][ch][li]*cs[i] - g_main_data.is[gr][ch][ui]*ca[i];
ub = g_main_data.is[gr][ch][ui]*cs[i] + g_main_data.is[gr][ch][li]*ca[i];
g_main_data.is[gr][ch][li] = lb;
g_main_data.is[gr][ch][ui] = ub;
}
}
return; /* Done */
}
/**Description: TBD
* Parameters: TBD
* Return value: TBD

1
audio/mp3/pdmp3.h
View File

@ -100,6 +100,7 @@ static int Read_Header(void);
void Read_Huffman(unsigned part_2_start,unsigned gr,unsigned ch);
void L3_Stereo(unsigned gr);
void L3_Antialias(unsigned gr,unsigned ch);
void L3_Hybrid_Synthesis(unsigned gr,unsigned ch);
void L3_Frequency_Inversion(unsigned gr,unsigned ch);
void L3_Subband_Synthesis(unsigned gr,unsigned ch, unsigned* outdata);