diff options
| -rw-r--r-- | libavcodec/mpegaudio_tablegen.c | 1 | ||||
| -rw-r--r-- | libavcodec/mpegaudio_tablegen.h | 19 |
2 files changed, 14 insertions, 6 deletions
diff --git a/libavcodec/mpegaudio_tablegen.c b/libavcodec/mpegaudio_tablegen.c index 90c9de430a..9a9bb4d056 100644 --- a/libavcodec/mpegaudio_tablegen.c +++ b/libavcodec/mpegaudio_tablegen.c @@ -23,6 +23,7 @@ #include <stdlib.h> #define CONFIG_HARDCODED_TABLES 0 #include "mpegaudio_tablegen.h" +#include "libavutil/tablegen.h" #include "tableprint.h" int main(void) diff --git a/libavcodec/mpegaudio_tablegen.h b/libavcodec/mpegaudio_tablegen.h index 86b2cd32b0..dd67a0977e 100644 --- a/libavcodec/mpegaudio_tablegen.h +++ b/libavcodec/mpegaudio_tablegen.h @@ -45,12 +45,21 @@ static float expval_table_float[512][16]; static av_cold void mpegaudio_tableinit(void) { int i, value, exponent; + double exp2_lut[4] = { + 1.00000000000000000000, /* 2 ^ (0 * 0.25) */ + 1.18920711500272106672, /* 2 ^ (1 * 0.25) */ + M_SQRT2 , /* 2 ^ (2 * 0.25) */ + 1.68179283050742908606, /* 2 ^ (3 * 0.25) */ + }; + double cbrt_lut[16]; + for (i = 0; i < 16; ++i) + cbrt_lut[i] = cbrt(i); + for (i = 1; i < TABLE_4_3_SIZE; i++) { double value = i / 4; double f, fm; int e, m; - /* cbrtf() isn't available on all systems, so we use powf(). */ - f = value / IMDCT_SCALAR * pow(value, 1.0 / 3.0) * pow(2, (i & 3) * 0.25); + f = value / IMDCT_SCALAR * cbrt(value) * exp2_lut[i & 3]; fm = frexp(f, &e); m = (uint32_t)(fm * (1LL << 31) + 0.5); e += FRAC_BITS - 31 + 5 - 100; @@ -61,10 +70,8 @@ static av_cold void mpegaudio_tableinit(void) } for (exponent = 0; exponent < 512; exponent++) { for (value = 0; value < 16; value++) { - /* cbrtf() isn't available on all systems, so we use powf(). */ - double f = (double)value * pow(value, 1.0 / 3.0) * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR; - /* llrint() isn't always available, so round and cast manually. */ - expval_table_fixed[exponent][value] = (long long int) (f < 0xFFFFFFFF ? floor(f + 0.5) : 0xFFFFFFFF); + double f = value * cbrt_lut[value] * pow(2, (exponent - 400) * 0.25 + FRAC_BITS + 5) / IMDCT_SCALAR; + expval_table_fixed[exponent][value] = (f < 0xFFFFFFFF ? llrint(f) : 0xFFFFFFFF); expval_table_float[exponent][value] = f; } exp_table_fixed[exponent] = expval_table_fixed[exponent][1]; |