[FFmpeg-devel] [PATCH 44/61] avcodec/aacdec_template: Don't init unused table for fixed-point decoder

[Andreas Rheinhardt <andreas.rheinhardt@outlook.com>]

The fixed-point decoder actually does not use the floating-point
tables initialized by ff_aac_tableinit() at all. So don't
initialize them for it; instead merge initializing these tables
into ff_aac_float_common_init() which is already the function
for the common static initializations of the floating-point
AAC decoder and the (also floating-point) AAC encoder.
Doing so saves also one AVOnce.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
 libavcodec/aacdec_template.c |   1 -
 libavcodec/aacenc.c          |   7 ++-
 libavcodec/aactab.c          | 102 +++++++++++++++++------------------
 libavcodec/aactab.h          |   2 -
 4 files changed, 52 insertions(+), 60 deletions(-)

diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index 27be1f896d..4591eac6b9 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -1128,7 +1128,6 @@ static av_cold void aac_static_table_init(void)
     AAC_RENAME(ff_aac_sbr_init)();
 
     ff_aacdec_common_init_once();
-    ff_aac_tableinit();
 
     // window initialization
     AAC_RENAME(avpriv_kbd_window_init)(AAC_RENAME(aac_kbd_long_960), 4.0, 960);
diff --git a/libavcodec/aacenc.c b/libavcodec/aacenc.c
index 2a34685aec..5e6a255a8f 100644
--- a/libavcodec/aacenc.c
+++ b/libavcodec/aacenc.c
@@ -1210,9 +1210,6 @@ static av_cold int dsp_init(AVCodecContext *avctx, AACEncContext *s)
     if (!s->fdsp)
         return AVERROR(ENOMEM);
 
-    // window init
-    ff_aac_float_common_init();
-
     if ((ret = av_tx_init(&s->mdct1024, &s->mdct1024_fn, AV_TX_FLOAT_MDCT, 0,
                           1024, &scale, 0)) < 0)
         return ret;
@@ -1359,6 +1356,9 @@ static av_cold int aac_encode_init(AVCodecContext *avctx)
     if (s->channels > 3)
         s->options.mid_side = 0;
 
+    // Initialize static tables
+    ff_aac_float_common_init();
+
     if ((ret = dsp_init(avctx, s)) < 0)
         return ret;
 
@@ -1393,7 +1393,6 @@ static av_cold int aac_encode_init(AVCodecContext *avctx)
 #endif
 
     ff_af_queue_init(avctx, &s->afq);
-    ff_aac_tableinit();
 
     return 0;
 }
diff --git a/libavcodec/aactab.c b/libavcodec/aactab.c
index d0006eac35..edb51d8810 100644
--- a/libavcodec/aactab.c
+++ b/libavcodec/aactab.c
@@ -36,18 +36,64 @@
 
 #include <stdint.h>
 
-float ff_aac_pow2sf_tab[428];
-float ff_aac_pow34sf_tab[428];
-
 #if CONFIG_AAC_ENCODER || CONFIG_AAC_DECODER
 #include "kbdwin.h"
 #include "sinewin.h"
 
+float ff_aac_pow2sf_tab[428];
+float ff_aac_pow34sf_tab[428];
+
 DECLARE_ALIGNED(32, float,  ff_aac_kbd_long_1024)[1024];
 DECLARE_ALIGNED(32, float,  ff_aac_kbd_short_128)[128];
 
+static av_cold void aac_tableinit(void)
+{
+    /* 2^(i/16) for 0 <= i <= 15 */
+    static const float exp2_lut[] = {
+        1.00000000000000000000,
+        1.04427378242741384032,
+        1.09050773266525765921,
+        1.13878863475669165370,
+        1.18920711500272106672,
+        1.24185781207348404859,
+        1.29683955465100966593,
+        1.35425554693689272830,
+        1.41421356237309504880,
+        1.47682614593949931139,
+        1.54221082540794082361,
+        1.61049033194925430818,
+        1.68179283050742908606,
+        1.75625216037329948311,
+        1.83400808640934246349,
+        1.91520656139714729387,
+    };
+    float t1 = 8.8817841970012523233890533447265625e-16; // 2^(-50)
+    float t2 = 3.63797880709171295166015625e-12; // 2^(-38)
+    int t1_inc_cur, t2_inc_cur;
+    int t1_inc_prev = 0;
+    int t2_inc_prev = 8;
+
+    for (int i = 0; i < 428; i++) {
+        t1_inc_cur = 4 * (i % 4);
+        t2_inc_cur = (8 + 3*i) % 16;
+        if (t1_inc_cur < t1_inc_prev)
+            t1 *= 2;
+        if (t2_inc_cur < t2_inc_prev)
+            t2 *= 2;
+        // A much more efficient and accurate way of doing:
+        // ff_aac_pow2sf_tab[i]  = pow(2, (i - POW_SF2_ZERO) / 4.0);
+        // ff_aac_pow34sf_tab[i] = pow(ff_aac_pow2sf_tab[i], 3.0/4.0);
+        ff_aac_pow2sf_tab[i]  = t1 * exp2_lut[t1_inc_cur];
+        ff_aac_pow34sf_tab[i] = t2 * exp2_lut[t2_inc_cur];
+        t1_inc_prev = t1_inc_cur;
+        t2_inc_prev = t2_inc_cur;
+    }
+}
+
 static av_cold void aac_float_common_init(void)
 {
+    aac_tableinit();
+
     avpriv_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024);
     avpriv_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128);
     ff_init_ff_sine_windows(10);
@@ -3299,53 +3345,3 @@ const DECLARE_ALIGNED(32, int, ff_aac_eld_window_480_fixed)[1800] = {
     0xffecff1c, 0xffed391e, 0xffed740c, 0xffedafb1,
     0xffedebe1, 0xffee287d, 0xffee654e, 0xffeea23f,
 };
-
-static void aac_tableinit(void)
-{
-    /* 2^(i/16) for 0 <= i <= 15 */
-    static const float exp2_lut[] = {
-        1.00000000000000000000,
-        1.04427378242741384032,
-        1.09050773266525765921,
-        1.13878863475669165370,
-        1.18920711500272106672,
-        1.24185781207348404859,
-        1.29683955465100966593,
-        1.35425554693689272830,
-        1.41421356237309504880,
-        1.47682614593949931139,
-        1.54221082540794082361,
-        1.61049033194925430818,
-        1.68179283050742908606,
-        1.75625216037329948311,
-        1.83400808640934246349,
-        1.91520656139714729387,
-    };
-    float t1 = 8.8817841970012523233890533447265625e-16; // 2^(-50)
-    float t2 = 3.63797880709171295166015625e-12; // 2^(-38)
-    int t1_inc_cur, t2_inc_cur;
-    int t1_inc_prev = 0;
-    int t2_inc_prev = 8;
-
-    for (int i = 0; i < 428; i++) {
-        t1_inc_cur = 4 * (i % 4);
-        t2_inc_cur = (8 + 3*i) % 16;
-        if (t1_inc_cur < t1_inc_prev)
-            t1 *= 2;
-        if (t2_inc_cur < t2_inc_prev)
-            t2 *= 2;
-        // A much more efficient and accurate way of doing:
-        // ff_aac_pow2sf_tab[i]  = pow(2, (i - POW_SF2_ZERO) / 4.0);
-        // ff_aac_pow34sf_tab[i] = pow(ff_aac_pow2sf_tab[i], 3.0/4.0);
-        ff_aac_pow2sf_tab[i]  = t1 * exp2_lut[t1_inc_cur];
-        ff_aac_pow34sf_tab[i] = t2 * exp2_lut[t2_inc_cur];
-        t1_inc_prev = t1_inc_cur;
-        t2_inc_prev = t2_inc_cur;
-    }
-}
-
-void ff_aac_tableinit(void)
-{
-    static AVOnce init_static_once = AV_ONCE_INIT;
-    ff_thread_once(&init_static_once, aac_tableinit);
-}
diff --git a/libavcodec/aactab.h b/libavcodec/aactab.h
index 9b1450c2eb..7693876c34 100644
--- a/libavcodec/aactab.h
+++ b/libavcodec/aactab.h
@@ -42,8 +42,6 @@
 extern float ff_aac_pow2sf_tab[428];
 extern float ff_aac_pow34sf_tab[428];
 
-void ff_aac_tableinit(void);
-
 /* @name ltp_coef
  * Table of the LTP coefficients
  */
-- 
2.34.1

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