diff options
Diffstat (limited to 'libavfilter')
| -rw-r--r-- | libavfilter/af_afade.c | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/libavfilter/af_afade.c b/libavfilter/af_afade.c index ca9f2c4f74..c8b6ed8cbe 100644 --- a/libavfilter/af_afade.c +++ b/libavfilter/af_afade.c @@ -92,6 +92,7 @@ static int query_formats(AVFilterContext *ctx) static double fade_gain(int curve, int64_t index, int range) { +#define CUBE(a) ((a)*(a)*(a)) double gain; gain = av_clipd(1.0 * index / range, 0, 1.0); @@ -101,22 +102,25 @@ static double fade_gain(int curve, int64_t index, int range) gain = sin(gain * M_PI / 2.0); break; case IQSIN: - gain = 0.636943 * asin(gain); + /* 0.6... = 2 / M_PI */ + gain = 0.6366197723675814 * asin(gain); break; case ESIN: - gain = 1.0 - cos(M_PI / 4.0 * (pow(2.0*gain - 1, 3) + 1)); + gain = 1.0 - cos(M_PI / 4.0 * (CUBE(2.0*gain - 1) + 1)); break; case HSIN: gain = (1.0 - cos(gain * M_PI)) / 2.0; break; case IHSIN: - gain = 0.318471 * acos(1 - 2 * gain); + /* 0.3... = 1 / M_PI */ + gain = 0.3183098861837907 * acos(1 - 2 * gain); break; case EXP: - gain = pow(0.1, (1 - gain) * 5.0); + /* -11.5... = 5*ln(0.1) */ + gain = exp(-11.512925464970227 * (1 - gain)); break; case LOG: - gain = av_clipd(0.0868589 * log(100000 * gain), 0, 1.0); + gain = av_clipd(1 + 0.2 * log10(gain), 0, 1.0); break; case PAR: gain = 1 - sqrt(1 - gain); @@ -128,7 +132,7 @@ static double fade_gain(int curve, int64_t index, int range) gain *= gain; break; case CUB: - gain = gain * gain * gain; + gain = CUBE(gain); break; case SQU: gain = sqrt(gain); @@ -137,10 +141,10 @@ static double fade_gain(int curve, int64_t index, int range) gain = cbrt(gain); break; case DESE: - gain = gain <= 0.5 ? pow(2 * gain, 1/3.) / 2: 1 - pow(2 * (1 - gain), 1/3.) / 2; + gain = gain <= 0.5 ? cbrt(2 * gain) / 2: 1 - cbrt(2 * (1 - gain)) / 2; break; case DESI: - gain = gain <= 0.5 ? pow(2 * gain, 3) / 2: 1 - pow(2 * (1 - gain), 3) / 2; + gain = gain <= 0.5 ? CUBE(2 * gain) / 2: 1 - CUBE(2 * (1 - gain)) / 2; break; } |