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Minor speed up of mpc requantization.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28563 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Andree Buschmann 2010-11-12 07:09:09 +00:00
parent ee610d47c7
commit bb56bc4ba0
1 changed files with 18 additions and 7 deletions
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25
apps/codecs/libmusepack/mpc_decoder.c
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@ -525,7 +525,8 @@ void mpc_decoder_read_bitstream_sv7(mpc_decoder * d, mpc_bits_reader * r)
for ( n = 0; n < Max_used_Band; n++ ) { for ( n = 0; n < Max_used_Band; n++ ) {
mpc_int16_t *q = d->Q[n].L, Res = d->Res_L[n]; mpc_int16_t *q = d->Q[n].L, Res = d->Res_L[n];
do { do {
mpc_int32_t k; mpc_uint32_t nbit;
mpc_int32_t k, dc;
const mpc_lut_data *Table; const mpc_lut_data *Table;
switch (Res) { switch (Res) {
case -2: case -3: case -4: case -5: case -6: case -7: case -8: case -9: case -2: case -3: case -4: case -5: case -6: case -7: case -8: case -9:
@ -564,8 +565,10 @@ void mpc_decoder_read_bitstream_sv7(mpc_decoder * d, mpc_bits_reader * r)
q[k] = mpc_bits_huff_lut(r, Table); q[k] = mpc_bits_huff_lut(r, Table);
break; break;
case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15: case 16: case 17: case 8: case 9: case 10: case 11: case 12: case 13: case 14: case 15: case 16: case 17:
nbit = Res_bit[Res];
dc = Dc[Res];
for ( k = 0; k < 36; k++ ) for ( k = 0; k < 36; k++ )
q[k] = (mpc_int32_t)mpc_bits_read(r, Res_bit[Res]) - Dc[Res]; q[k] = (mpc_int32_t)mpc_bits_read(r, nbit) - dc;
break; break;
default: default:
return; return;
@ -683,7 +686,8 @@ void mpc_decoder_read_bitstream_sv8(mpc_decoder * d, mpc_bits_reader * r, mpc_bo
mpc_int16_t *q = d->Q[n].L, Res = d->Res_L[n]; mpc_int16_t *q = d->Q[n].L, Res = d->Res_L[n];
static const int thres[] = {0, 0, 3, 0, 0, 1, 3, 4, 8}; static const int thres[] = {0, 0, 3, 0, 0, 1, 3, 4, 8};
do { do {
mpc_int32_t k = 0, idx = 1; mpc_uint32_t nbit;
mpc_int32_t k = 0, idx = 1, dc;
if (Res != 0) { if (Res != 0) {
if (Res == 2) { if (Res == 2) {
Tables[0] = & mpc_can_Q [0][0]; Tables[0] = & mpc_can_Q [0][0];
@ -736,12 +740,19 @@ void mpc_decoder_read_bitstream_sv8(mpc_decoder * d, mpc_bits_reader * r, mpc_bo
q[k] = mpc_bits_can_dec(r, Tables[idx > thres[Res]]); q[k] = mpc_bits_can_dec(r, Tables[idx > thres[Res]]);
idx = (idx >> 1) + absi(q[k]); idx = (idx >> 1) + absi(q[k]);
} }
} else { } else if (Res == 9) {
dc = Dc[Res];
for ( ; k < 36; k++ ) { for ( ; k < 36; k++ ) {
q[k] = (unsigned char) mpc_bits_can_dec(r, & mpc_can_Q9up); q[k] = (unsigned char) mpc_bits_can_dec(r, & mpc_can_Q9up);
if (Res != 9) q[k] -= dc;
q[k] = (q[k] << (Res - 9)) | mpc_bits_read(r, Res - 9); }
q[k] -= Dc[Res]; } else {
nbit = (Res - 9);
dc = Dc[Res];
for ( ; k < 36; k++ ) {
q[k] = (unsigned char) mpc_bits_can_dec(r, & mpc_can_Q9up);
q[k] = (q[k] << nbit) | mpc_bits_read(r, nbit);
q[k] -= dc;
} }
} }
} }