[FFmpeg-devel] [PATCH] avfilter/acrossfade: allow skipping fade on inputs
Gyan
ffmpeg at gyani.pro
Wed Jan 23 10:11:15 EET 2019
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From 1aa1db056e1e9887e6467a0c9e10276be78ff623 Mon Sep 17 00:00:00 2001
From: Gyan Doshi <ffmpeg at gyani.pro>
Date: Wed, 23 Jan 2019 13:35:23 +0530
Subject: [PATCH] avfilter/acrossfade: allow skipping fade on inputs
---
doc/filters.texi | 2 ++
libavfilter/af_afade.c | 10 +++++++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index d06dfe089f..9e805bc1cd 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -475,6 +475,8 @@ Set curve for cross fade transition for first stream.
Set curve for cross fade transition for second stream.
For description of available curve types see @ref{afade} filter description.
+In addition, acrossfade supports skipping application of fade to an input,
+if curve value is set to @code{nofade}.
@end table
@subsection Examples
diff --git a/libavfilter/af_afade.c b/libavfilter/af_afade.c
index 751db7da4d..f1e80013d9 100644
--- a/libavfilter/af_afade.c
+++ b/libavfilter/af_afade.c
@@ -51,7 +51,7 @@ 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, LOSI, NB_CURVES };
+enum CurveType { TRI, QSIN, ESIN, HSIN, LOG, IPAR, QUA, CUB, SQU, CBR, PAR, EXP, IQSIN, IHSIN, DESE, DESI, LOSI, NONE, NB_CURVES };
#define OFFSET(x) offsetof(AudioFadeContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
@@ -153,6 +153,9 @@ static double fade_gain(int curve, int64_t index, int64_t range)
gain = (A - B) / (C - B);
}
break;
+ case NONE:
+ gain = 1.0;
+ break;
}
return gain;
@@ -241,8 +244,8 @@ static const AVOption afade_options[] = {
{ "st", "set time to start fading", OFFSET(start_time), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT64_MAX, FLAGS },
{ "duration", "set fade duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT64_MAX, FLAGS },
{ "d", "set fade duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0. }, 0, INT64_MAX, FLAGS },
- { "curve", "set fade curve type", OFFSET(curve), AV_OPT_TYPE_INT, {.i64 = TRI }, 0, NB_CURVES - 1, FLAGS, "curve" },
- { "c", "set fade curve type", OFFSET(curve), AV_OPT_TYPE_INT, {.i64 = TRI }, 0, NB_CURVES - 1, FLAGS, "curve" },
+ { "curve", "set fade curve type", OFFSET(curve), AV_OPT_TYPE_INT, {.i64 = TRI }, 0, NB_CURVES - 2, FLAGS, "curve" },
+ { "c", "set fade curve type", OFFSET(curve), AV_OPT_TYPE_INT, {.i64 = TRI }, 0, NB_CURVES - 2, FLAGS, "curve" },
{ "tri", "linear slope", 0, AV_OPT_TYPE_CONST, {.i64 = TRI }, 0, 0, FLAGS, "curve" },
{ "qsin", "quarter of sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = QSIN }, 0, 0, FLAGS, "curve" },
{ "esin", "exponential sine wave", 0, AV_OPT_TYPE_CONST, {.i64 = ESIN }, 0, 0, FLAGS, "curve" },
@@ -380,6 +383,7 @@ static const AVOption acrossfade_options[] = {
{ "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" },
+ { "nofade", "no fade; keep audio as-is", 0, AV_OPT_TYPE_CONST, {.i64 = NONE }, 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 }
--
2.19.2
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