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Code Issues Releases Activity

aac: Fix low delay windowing.

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AAC LD uses a low overlap sine window instead of a KBD window.
This commit is contained in:
Alex Converse 2013-12-24 13:03:26 -08:00
parent 42d1b41983
commit 7f29644108
3 changed files with 8 additions and 5 deletions
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11
libavcodec/aacdec.c
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@ -1065,7 +1065,6 @@ static av_cold int aac_decode_init(AVCodecContext *avctx)
ff_mdct_init(&ac->mdct_ltp, 11, 0, -2.0 * 32768.0);
// window initialization
ff_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024);
ff_kbd_window_init(ff_aac_kbd_long_512, 4.0, 512);
ff_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128);
ff_init_ff_sine_windows(10);
ff_init_ff_sine_windows( 9);
@ -2430,14 +2429,20 @@ static void imdct_and_windowing_ld(AACContext *ac, SingleChannelElement *sce)
float *in = sce->coeffs;
float *out = sce->ret;
float *saved = sce->saved;
const float *lwindow_prev = ics->use_kb_window[1] ? ff_aac_kbd_long_512 : ff_sine_512;
float *buf = ac->buf_mdct;
// imdct
ac->mdct.imdct_half(&ac->mdct_ld, buf, in);
// window overlapping
ac->fdsp.vector_fmul_window(out, saved, buf, lwindow_prev, 256);
if (ics->use_kb_window[1]) {
// AAC LD uses a low overlap sine window instead of a KBD window
memcpy(out, saved, 192 * sizeof(float));
ac->fdsp.vector_fmul_window(out + 192, saved + 192, buf, ff_sine_128, 64);
memcpy( out + 320, buf + 64, 192 * sizeof(float));
} else {
ac->fdsp.vector_fmul_window(out, saved, buf, ff_sine_512, 256);
}
// buffer update
memcpy(saved, buf + 256, 256 * sizeof(float));

1
libavcodec/aactab.c
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@ -34,7 +34,6 @@
#include <stdint.h>
DECLARE_ALIGNED(32, float, ff_aac_kbd_long_1024)[1024];
DECLARE_ALIGNED(32, float, ff_aac_kbd_long_512 )[512];
DECLARE_ALIGNED(32, float, ff_aac_kbd_short_128)[128];
const uint8_t ff_aac_num_swb_1024[] = {

1
libavcodec/aactab.h
View File

@ -45,7 +45,6 @@
* @{
*/
DECLARE_ALIGNED(32, extern float, ff_aac_kbd_long_1024)[1024];
DECLARE_ALIGNED(32, extern float, ff_aac_kbd_long_512 )[512];
DECLARE_ALIGNED(32, extern float, ff_aac_kbd_short_128)[128];
const DECLARE_ALIGNED(32, extern float, ff_aac_eld_window)[1920];
// @}