aacenc: move the generation of ff_aac_pow34sf_tab[]

This commit moves the generation of ff_aac_pow34sf_tab[] out of the
encoder and into the table generator. The original commit log for
this table in 2011 actually mentions that it should be moved outside
but this never happened.

This is the first commit which cleans up the encoder a little.

Reviewed-by: Claudio Freire <klaussfreire@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/aac_tablegen.c

@@ -33,5 +33,7 @@ int main(void)
 
     WRITE_ARRAY("const", float, ff_aac_pow2sf_tab);
 
+    WRITE_ARRAY("const", float, ff_aac_pow34sf_tab);
+
     return 0;
 }

libavcodec/aac_tablegen.h

@@ -30,12 +30,15 @@
 #else
 #include "libavutil/mathematics.h"
 float ff_aac_pow2sf_tab[428];
+float ff_aac_pow34sf_tab[428];
 
 av_cold void ff_aac_tableinit(void)
 {
     int i;
-    for (i = 0; i < 428; i++)
+    for (i = 0; i < 428; i++) {
         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);
+    }
 }
 #endif /* CONFIG_HARDCODED_TABLES */
 

libavcodec/aac_tablegen_decl.h

@@ -28,9 +28,11 @@
 #if CONFIG_HARDCODED_TABLES
 #define ff_aac_tableinit()
 extern const float ff_aac_pow2sf_tab[428];
+extern const float ff_aac_pow34sf_tab[428];
 #else
 void ff_aac_tableinit(void);
 extern       float ff_aac_pow2sf_tab[428];
+extern       float ff_aac_pow34sf_tab[428];
 #endif /* CONFIG_HARDCODED_TABLES */
 
 #endif /* AVCODEC_AAC_TABLEGEN_DECL_H */

libavcodec/aaccoder.c

@@ -39,6 +39,7 @@
 #include "aac.h"
 #include "aacenc.h"
 #include "aactab.h"
+#include "aac_tablegen_decl.h"
 
 /** Frequency in Hz for lower limit of noise substitution **/
 #define NOISE_LOW_LIMIT 4500

libavcodec/aacenc.c

@@ -58,7 +58,6 @@
         av_log(avctx, AV_LOG_WARNING, __VA_ARGS__); \
     }
 
-float ff_aac_pow34sf_tab[428];
 
 static const uint8_t swb_size_1024_96[] = {
     4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 8, 8, 8, 8, 8,
@@ -855,9 +854,6 @@ static av_cold int aac_encode_init(AVCodecContext *avctx)
 
     ff_aac_tableinit();
 
-    for (i = 0; i < 428; i++)
-        ff_aac_pow34sf_tab[i] = sqrt(ff_aac_pow2sf_tab[i] * sqrt(ff_aac_pow2sf_tab[i]));
-
     avctx->initial_padding = 1024;
     ff_af_queue_init(avctx, &s->afq);
 

libavcodec/aacenc.h

@@ -95,8 +95,6 @@ typedef struct AACEncContext {
     } buffer;
 } AACEncContext;
 
-extern float ff_aac_pow34sf_tab[428];
-
 void ff_aac_coder_init_mips(AACEncContext *c);
 
 #endif /* AVCODEC_AACENC_H */