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audio/mp3: Move Read_Huffman to Go

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This commit is contained in:
Hajime Hoshi 2017-06-16 23:41:13 +09:00
parent 4b9242cbd0
commit f6e7e3601f
5 changed files with 141 additions and 111 deletions
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62
audio/mp3/huffman.go
View File

@ -348,27 +348,22 @@ var huffmanMain = [...]huffTables{
{huffmanTable[2261:], 31, 0}, /* Table 33 */
}
//export Huffman_Decode
func Huffman_Decode(table_num C.unsigned, x, y, v, w *C.int32_t) C.int {
func huffmanDecode(table_num int) (x, y, v, w int, err error) {
point := 0
error := 1
bitsleft := 32
treelen := huffmanMain[table_num].treelen
linbits := huffmanMain[table_num].linbits
if treelen == 0 { /* Check for empty tables */
*x = 0
*y = 0
*v = 0
*w = 0
return C.OK
return 0, 0, 0, 0, nil
}
htptr := huffmanMain[table_num].hufftable
for { /* Start reading the Huffman code word,bit by bit */
/* Check if we've matched a code word */
if (htptr[point] & 0xff00) == 0 {
error = 0
*x = C.int32_t((htptr[point] >> 4) & 0xf)
*y = C.int32_t(htptr[point] & 0xf)
x = int((htptr[point] >> 4) & 0xf)
y = int(htptr[point] & 0xf)
break
}
if getMainBit() != 0 { /* Go right in tree */
@ -390,43 +385,38 @@ func Huffman_Decode(table_num C.unsigned, x, y, v, w *C.int32_t) C.int {
if error != 0 { /* Check for error. */
err := fmt.Errorf("mp3: illegal Huff code in data. bleft = %d, point = %d. tab = %d.",
bitsleft, point, table_num)
*x = 0
*y = 0
g_error = err
return 0, 0, 0, 0, err
}
if table_num > 31 { /* Process sign encodings for quadruples tables. */
*v = (*y >> 3) & 1
*w = (*y >> 2) & 1
*x = (*y >> 1) & 1
*y = *y & 1
if (*v > 0) && (getMainBit() == 1) {
*v = -*v
v = (y >> 3) & 1
w = (y >> 2) & 1
x = (y >> 1) & 1
y = y & 1
if (v > 0) && (getMainBit() == 1) {
v = -v
}
if (*w > 0) && (getMainBit() == 1) {
*w = -*w
if (w > 0) && (getMainBit() == 1) {
w = -w
}
if (*x > 0) && (getMainBit() == 1) {
*x = -*x
if (x > 0) && (getMainBit() == 1) {
x = -x
}
if (*y > 0) && (getMainBit() == 1) {
*y = -*y
if (y > 0) && (getMainBit() == 1) {
y = -y
}
} else {
if (linbits > 0) && (*x == 15) {
*x += C.int32_t(getMainBits(linbits)) /* Get linbits */
if (linbits > 0) && (x == 15) {
x += getMainBits(linbits) /* Get linbits */
}
if (*x > 0) && (getMainBit() == 1) {
*x = -*x /* Get sign bit */
if (x > 0) && (getMainBit() == 1) {
x = -x /* Get sign bit */
}
if (linbits > 0) && (*y == 15) {
*y += C.int32_t(getMainBits(linbits)) /* Get linbits */
if (linbits > 0) && (y == 15) {
y += getMainBits(linbits) /* Get linbits */
}
if (*y > 0) && (getMainBit() == 1) {
*y = -*y /* Get sign bit */
if (y > 0) && (getMainBit() == 1) {
y = -y /* Get sign bit */
}
}
if error != 0 {
return C.ERROR
}
return C.OK
return x, y, v, w, nil
}

7
audio/mp3/maindata.go
View File

@ -71,7 +71,7 @@ func Read_Main_L3() C.int {
}
for gr := 0; gr < 2; gr++ {
for ch := 0; ch < nch; ch++ {
part_2_start := Get_Main_Pos()
part_2_start := int(Get_Main_Pos())
/* Number of bits in the bitstream for the bands */
slen1 := mpeg1_scalefac_sizes[C.g_side_info.scalefac_compress[gr][ch]][0]
slen2 := mpeg1_scalefac_sizes[C.g_side_info.scalefac_compress[gr][ch]][1]
@ -149,7 +149,10 @@ func Read_Main_L3() C.int {
}
}
/* Read Huffman coded data. Skip stuffing bits. */
C.Read_Huffman(part_2_start, C.uint(gr), C.uint(ch))
if err := readHuffman(part_2_start, gr, ch); err != nil {
g_error = err
return C.ERROR
}
}
}
/* The ancillary data is stored here,but we ignore it. */

70
audio/mp3/pdmp3.c
View File

@ -350,76 +350,6 @@ static void Decode_L3_Init_Song(void){
synth_init = 1;
}
/**Description: called by Read_Main_L3 to read Huffman coded data from bitstream.
* Parameters: None
* Return value: None. The data is stored in g_main_data.is[ch][gr][freqline].
* Author: Krister Lagerström(krister@kmlager.com) **/
void Read_Huffman(unsigned part_2_start,unsigned gr,unsigned ch){
int32_t x,y,v,w;
unsigned table_num,is_pos,bit_pos_end,sfreq;
unsigned region_1_start,region_2_start; /* region_0_start = 0 */
/* Check that there is any data to decode. If not,zero the array. */
if(g_side_info.part2_3_length[gr][ch] == 0) {
for(is_pos = 0; is_pos < 576; is_pos++)
g_main_data.is[gr][ch][is_pos] = 0.0;
return;
}
/* Calculate bit_pos_end which is the index of the last bit for this part. */
bit_pos_end = part_2_start + g_side_info.part2_3_length[gr][ch] - 1;
/* Determine region boundaries */
if((g_side_info.win_switch_flag[gr][ch] == 1)&&
(g_side_info.block_type[gr][ch] == 2)) {
region_1_start = 36; /* sfb[9/3]*3=36 */
region_2_start = 576; /* No Region2 for short block case. */
}else{
sfreq = g_frame_header.sampling_frequency;
region_1_start =
g_sf_band_indices[sfreq].l[g_side_info.region0_count[gr][ch] + 1];
region_2_start =
g_sf_band_indices[sfreq].l[g_side_info.region0_count[gr][ch] +
g_side_info.region1_count[gr][ch] + 2];
}
/* Read big_values using tables according to region_x_start */
for(is_pos = 0; is_pos < g_side_info.big_values[gr][ch] * 2; is_pos++) {
if(is_pos < region_1_start) {
table_num = g_side_info.table_select[gr][ch][0];
} else if(is_pos < region_2_start) {
table_num = g_side_info.table_select[gr][ch][1];
}else table_num = g_side_info.table_select[gr][ch][2];
/* Get next Huffman coded words */
(void) Huffman_Decode(table_num,&x,&y,&v,&w);
/* In the big_values area there are two freq lines per Huffman word */
g_main_data.is[gr][ch][is_pos++] = x;
g_main_data.is[gr][ch][is_pos] = y;
}
/* Read small values until is_pos = 576 or we run out of huffman data */
table_num = g_side_info.count1table_select[gr][ch] + 32;
for(is_pos = g_side_info.big_values[gr][ch] * 2;
(is_pos <= 572) &&(Get_Main_Pos() <= bit_pos_end); is_pos++) {
/* Get next Huffman coded words */
(void) Huffman_Decode(table_num,&x,&y,&v,&w);
g_main_data.is[gr][ch][is_pos++] = v;
if(is_pos >= 576) break;
g_main_data.is[gr][ch][is_pos++] = w;
if(is_pos >= 576) break;
g_main_data.is[gr][ch][is_pos++] = x;
if(is_pos >= 576) break;
g_main_data.is[gr][ch][is_pos] = y;
}
/* Check that we didn't read past the end of this section */
if(Get_Main_Pos() >(bit_pos_end+1)) /* Remove last words read */
is_pos -= 4;
/* Setup count1 which is the index of the first sample in the rzero reg. */
g_side_info.count1[gr][ch] = is_pos;
/* Zero out the last part if necessary */
for(/* is_pos comes from last for-loop */; is_pos < 576; is_pos++)
g_main_data.is[gr][ch][is_pos] = 0.0;
/* Set the bitpos to point to the next part to read */
(void) Set_Main_Pos(bit_pos_end+1);
return; /* Done */
}
/**Description: output audio data
* Parameters: Pointers to the samples,the number of samples
* Return value: None

3
audio/mp3/pdmp3.h
View File

@ -97,7 +97,6 @@ int Set_Main_Pos(unsigned bit_pos);
int Read_Main_L3(void);
int Read_Audio_L3(void);
static int Read_Header(void);
void Read_Huffman(unsigned part_2_start,unsigned gr,unsigned ch);
void L3_Requantize(unsigned gr,unsigned ch);
void L3_Reorder(unsigned gr,unsigned ch);
@ -109,6 +108,4 @@ void L3_Subband_Synthesis(unsigned gr,unsigned ch, unsigned* outdata);
int Read_CRC(void);
int Huffman_Decode(unsigned table_num, int32_t* x, int32_t*y, int32_t* v, int32_t* w);
#endif

110
audio/mp3/read.go Normal file
View File

@ -0,0 +1,110 @@
// Copyright 2017 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build !js
package mp3
// #include "pdmp3.h"
//
// extern t_mpeg1_main_data g_main_data;
// extern t_mpeg1_side_info g_side_info;
// extern t_mpeg1_header g_frame_header;
import "C"
func readHuffman(part_2_start, gr, ch int) error {
/* Check that there is any data to decode. If not,zero the array. */
if C.g_side_info.part2_3_length[gr][ch] == 0 {
for is_pos := 0; is_pos < 576; is_pos++ {
C.g_main_data.is[gr][ch][is_pos] = 0.0
}
return nil
}
/* Calculate bit_pos_end which is the index of the last bit for this part. */
bit_pos_end := part_2_start + int(C.g_side_info.part2_3_length[gr][ch]) - 1
/* Determine region boundaries */
region_1_start := 0
region_2_start := 0
if (C.g_side_info.win_switch_flag[gr][ch] == 1) && (C.g_side_info.block_type[gr][ch] == 2) {
region_1_start = 36 /* sfb[9/3]*3=36 */
region_2_start = 576 /* No Region2 for short block case. */
} else {
sfreq := C.g_frame_header.sampling_frequency
region_1_start =
sfBandIndicesSet[sfreq].l[C.g_side_info.region0_count[gr][ch]+1]
region_2_start =
sfBandIndicesSet[sfreq].l[C.g_side_info.region0_count[gr][ch]+
C.g_side_info.region1_count[gr][ch]+2]
}
/* Read big_values using tables according to region_x_start */
for is_pos := 0; is_pos < int(C.g_side_info.big_values[gr][ch])*2; is_pos++ {
table_num := 0
if is_pos < region_1_start {
table_num = int(C.g_side_info.table_select[gr][ch][0])
} else if is_pos < region_2_start {
table_num = int(C.g_side_info.table_select[gr][ch][1])
} else {
table_num = int(C.g_side_info.table_select[gr][ch][2])
}
/* Get next Huffman coded words */
x, y, _, _, err := huffmanDecode(table_num)
if err != nil {
return err
}
/* In the big_values area there are two freq lines per Huffman word */
C.g_main_data.is[gr][ch][is_pos] = C.float(x)
is_pos++
C.g_main_data.is[gr][ch][is_pos] = C.float(y)
}
/* Read small values until is_pos = 576 or we run out of huffman data */
table_num := int(C.g_side_info.count1table_select[gr][ch]) + 32
is_pos := int(C.g_side_info.big_values[gr][ch]) * 2
for ; (is_pos <= 572) && (int(Get_Main_Pos()) <= bit_pos_end); is_pos++ {
/* Get next Huffman coded words */
x, y, v, w, err := huffmanDecode(table_num)
if err != nil {
return err
}
C.g_main_data.is[gr][ch][is_pos] = C.float(v)
is_pos++
if is_pos >= 576 {
break
}
C.g_main_data.is[gr][ch][is_pos] = C.float(w)
is_pos++
if is_pos >= 576 {
break
}
C.g_main_data.is[gr][ch][is_pos] = C.float(x)
is_pos++
if is_pos >= 576 {
break
}
C.g_main_data.is[gr][ch][is_pos] = C.float(y)
}
/* Check that we didn't read past the end of this section */
if int(C.Get_Main_Pos()) > (bit_pos_end + 1) {
/* Remove last words read */
is_pos -= 4
}
/* Setup count1 which is the index of the first sample in the rzero reg. */
C.g_side_info.count1[gr][ch] = C.unsigned(is_pos)
/* Zero out the last part if necessary */
for ; /* is_pos comes from last for-loop */ is_pos < 576; is_pos++ {
C.g_main_data.is[gr][ch][is_pos] = 0.0
}
/* Set the bitpos to point to the next part to read */
C.Set_Main_Pos(C.unsigned(bit_pos_end) + 1)
return nil
}