Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

AAC: Unswitch loop over window groups in decode_spectrum_and_dequant()

Browse Source 
GCC should be able to do this, but doesn't.  Slightly faster code.

Originally committed as revision 21190 to svn://svn.ffmpeg.org/ffmpeg/trunk
release/0.6
Måns Rullgård 15 years ago
parent 05f9d8fcaa
commit 95dff4aced
1 changed files with 39 additions and 15 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 30
      libavcodec/aac.c

30
libavcodec/aac.c
Unescape View File

@ -982,13 +982,12 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
VLC_TYPE (*vlc_tab)[2] = vlc_spectral[cbt_m1].table; VLC_TYPE (*vlc_tab)[2] = vlc_spectral[cbt_m1].table;
const int cb_size = ff_aac_spectral_sizes[cbt_m1]; const int cb_size = ff_aac_spectral_sizes[cbt_m1];
switch (cbt_m1 >> 1) {
case 0:
for (group = 0; group < g_len; group++, cfo+=128) { for (group = 0; group < g_len; group++, cfo+=128) {
float *cf = cfo; float *cf = cfo;
uint32_t *icf = (uint32_t *) cf;
int len = off_len; int len = off_len;
switch (cbt_m1 >> 1) {
case 0:
do { do {
const int index = get_vlc2(gb, vlc_tab, 6, 3); const int index = get_vlc2(gb, vlc_tab, 6, 3);
unsigned cb_idx; unsigned cb_idx;
@ -1001,8 +1000,14 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
cb_idx = cb_vector_idx[index]; cb_idx = cb_vector_idx[index];
cf = VMUL4(cf, vq, cb_idx, sf + idx); cf = VMUL4(cf, vq, cb_idx, sf + idx);
} while (len -= 4); } while (len -= 4);
}
break; break;
case 1: case 1:
for (group = 0; group < g_len; group++, cfo+=128) {
float *cf = cfo;
int len = off_len;
do { do {
const int index = get_vlc2(gb, vlc_tab, 6, 3); const int index = get_vlc2(gb, vlc_tab, 6, 3);
unsigned nnz; unsigned nnz;
@ -1019,8 +1024,14 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
bits = get_bits(gb, nnz) << (32-nnz); bits = get_bits(gb, nnz) << (32-nnz);
cf = VMUL4S(cf, vq, cb_idx, bits, sf + idx); cf = VMUL4S(cf, vq, cb_idx, bits, sf + idx);
} while (len -= 4); } while (len -= 4);
}
break; break;
case 2: case 2:
for (group = 0; group < g_len; group++, cfo+=128) {
float *cf = cfo;
int len = off_len;
do { do {
const int index = get_vlc2(gb, vlc_tab, 6, 3); const int index = get_vlc2(gb, vlc_tab, 6, 3);
unsigned cb_idx; unsigned cb_idx;
@ -1033,9 +1044,15 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
cb_idx = cb_vector_idx[index]; cb_idx = cb_vector_idx[index];
cf = VMUL2(cf, vq, cb_idx, sf + idx); cf = VMUL2(cf, vq, cb_idx, sf + idx);
} while (len -= 2); } while (len -= 2);
}
break; break;
case 3: case 3:
case 4: case 4:
for (group = 0; group < g_len; group++, cfo+=128) {
float *cf = cfo;
int len = off_len;
do { do {
const int index = get_vlc2(gb, vlc_tab, 6, 3); const int index = get_vlc2(gb, vlc_tab, 6, 3);
unsigned nnz; unsigned nnz;
@ -1052,8 +1069,15 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
sign = get_bits(gb, nnz) << (cb_idx >> 12); sign = get_bits(gb, nnz) << (cb_idx >> 12);
cf = VMUL2S(cf, vq, cb_idx, sign, sf + idx); cf = VMUL2S(cf, vq, cb_idx, sign, sf + idx);
} while (len -= 2); } while (len -= 2);
}
break; break;
default: default:
for (group = 0; group < g_len; group++, cfo+=128) {
float *cf = cfo;
uint32_t *icf = (uint32_t *) cf;
int len = off_len;
do { do {
const int index = get_vlc2(gb, vlc_tab, 6, 3); const int index = get_vlc2(gb, vlc_tab, 6, 3);
unsigned nzt, nnz; unsigned nzt, nnz;

Write Preview
Loading…
Cancel
Save