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| author | Paul B Mahol <onemda@gmail.com> | 2018-10-07 17:38:22 +0200 |
|---|---|---|
| committer | Paul B Mahol <onemda@gmail.com> | 2018-10-07 17:38:22 +0200 |
| commit | 3d308746eb4517ed368c8b6949768ed8b2dc91e1 (patch) | |
| tree | 47bdf669299e90ec8f24631bc97fccc86762611e /libavfilter/af_afade.c | |
| parent | 9c120b4d4201edad9381ec7fe292de36c785fab7 (diff) | |
| download | ffmpeg-3d308746eb4517ed368c8b6949768ed8b2dc91e1.tar.gz | |
avfilter/af_afade: add logistic sigmoid curve
Diffstat (limited to 'libavfilter/af_afade.c')
| -rw-r--r-- | libavfilter/af_afade.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/libavfilter/af_afade.c b/libavfilter/af_afade.c index d823e82d39..7216cea31d 100644 --- a/libavfilter/af_afade.c +++ b/libavfilter/af_afade.c @@ -57,7 +57,7 @@ typedef struct AudioFadeContext { int curve0, int curve1); } AudioFadeContext; -enum CurveType { TRI, QSIN, ESIN, HSIN, LOG, IPAR, QUA, CUB, SQU, CBR, PAR, EXP, IQSIN, IHSIN, DESE, DESI, NB_CURVES }; +enum CurveType { TRI, QSIN, ESIN, HSIN, LOG, IPAR, QUA, CUB, SQU, CBR, PAR, EXP, IQSIN, IHSIN, DESE, DESI, LOSI, NB_CURVES }; #define OFFSET(x) offsetof(AudioFadeContext, x) #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM @@ -151,6 +151,14 @@ static double fade_gain(int curve, int64_t index, int64_t range) case DESI: gain = gain <= 0.5 ? CUBE(2 * gain) / 2: 1 - CUBE(2 * (1 - gain)) / 2; break; + case LOSI: { + const double a = 1. / (1. - 0.787) - 1; + double A = 1. / (1.0 + exp(0 -((gain-0.5) * a * 2.0))); + double B = 1. / (1.0 + exp(a)); + double C = 1. / (1.0 + exp(0-a)); + gain = (A - B) / (C - B); + } + break; } return gain; @@ -257,6 +265,7 @@ static const AVOption afade_options[] = { { "ihsin", "inverted half of sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = IHSIN}, 0, 0, FLAGS, "curve" }, { "dese", "double-exponential seat", 0, AV_OPT_TYPE_CONST, {.i64 = DESE }, 0, 0, FLAGS, "curve" }, { "desi", "double-exponential sigmoid", 0, AV_OPT_TYPE_CONST, {.i64 = DESI }, 0, 0, FLAGS, "curve" }, + { "losi", "logistic sigmoid", 0, AV_OPT_TYPE_CONST, {.i64 = LOSI }, 0, 0, FLAGS, "curve" }, { NULL } }; @@ -376,6 +385,7 @@ static const AVOption acrossfade_options[] = { { "ihsin", "inverted half of sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = IHSIN}, 0, 0, FLAGS, "curve" }, { "dese", "double-exponential seat", 0, AV_OPT_TYPE_CONST, {.i64 = DESE }, 0, 0, FLAGS, "curve" }, { "desi", "double-exponential sigmoid", 0, AV_OPT_TYPE_CONST, {.i64 = DESI }, 0, 0, FLAGS, "curve" }, + { "losi", "logistic sigmoid", 0, AV_OPT_TYPE_CONST, {.i64 = LOSI }, 0, 0, FLAGS, "curve" }, { "curve2", "set fade curve type for 2nd stream", OFFSET(curve2), AV_OPT_TYPE_INT, {.i64 = TRI }, 0, NB_CURVES - 1, FLAGS, "curve" }, { "c2", "set fade curve type for 2nd stream", OFFSET(curve2), AV_OPT_TYPE_INT, {.i64 = TRI }, 0, NB_CURVES - 1, FLAGS, "curve" }, { NULL } |