From 8bc708fcee137ead6d0773fad8e24ab471ab2122 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 7 Oct 2015 15:03:32 +0200 Subject: [PATCH] avfilter/delogo: Set default band to 1 The original interpolation algorithm behaved poorly on the borders and did not even guarantee continuity at the borders. For this reason, a second interpolation/blending pass was required on the borders to make them seamless. However, since the interpolation algorithm was improved in June 2013, the border issues no longer exist. The new algorithm does guarantee continuity at the borders, making the second pass useless. A larger band always increases the cumulated interpolation error. In most cases it also increases the average interpolation error, even though the samples in the band are only partially interpolated. For this reason I would like to get rid of the "band" parameter. As a first step, let's change its default value from 4 to 1 and document it as deprecated. I have benchmarked this change on a combination of input sources and realistic logo areas. Lowering the band value from 4 to 1 resulted in 8 to 39 % less interpolation error per frame (or 1 to 34 % less interpolation error per luma sample.) Signed-off-by: Jean Delvare Signed-off-by: Stefano Sabatini --- doc/filters.texi | 4 +++- libavfilter/vf_delogo.c | 17 +++++++++++++++-- 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/doc/filters.texi b/doc/filters.texi index 47fd44d610..506b5a64e9 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -4590,7 +4590,9 @@ specified. @item band, t Specify the thickness of the fuzzy edge of the rectangle (added to -@var{w} and @var{h}). The default value is 4. +@var{w} and @var{h}). The default value is 1. This option is +deprecated, setting higher values should no longer be necessary and +is not recommended. @item show When set to 1, a green rectangle is drawn on the screen to simplify diff --git a/libavfilter/vf_delogo.c b/libavfilter/vf_delogo.c index 3258493236..c7fb6e3f38 100644 --- a/libavfilter/vf_delogo.c +++ b/libavfilter/vf_delogo.c @@ -165,8 +165,11 @@ static const AVOption delogo_options[]= { { "y", "set logo y position", OFFSET(y), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS }, { "w", "set logo width", OFFSET(w), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS }, { "h", "set logo height", OFFSET(h), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS }, - { "band", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, { .i64 = 4 }, 1, INT_MAX, FLAGS }, - { "t", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, { .i64 = 4 }, 1, INT_MAX, FLAGS }, +#if LIBAVFILTER_VERSION_MAJOR < 7 + /* Actual default value for band/t is 1, set in init */ + { "band", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS }, + { "t", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS }, +#endif { "show", "show delogo area", OFFSET(show), AV_OPT_TYPE_BOOL,{ .i64 = 0 }, 0, 1, FLAGS }, { NULL } }; @@ -201,6 +204,16 @@ static av_cold int init(AVFilterContext *ctx) CHECK_UNSET_OPT(w); CHECK_UNSET_OPT(h); +#if LIBAVFILTER_VERSION_MAJOR < 7 + if (s->band == 0) { /* Unset, use default */ + av_log(ctx, AV_LOG_WARNING, "Note: default band value was changed from 4 to 1.\n"); + s->band = 1; + } else if (s->band != 1) { + av_log(ctx, AV_LOG_WARNING, "Option band is deprecated.\n"); + } +#else + s->band = 1; +#endif av_log(ctx, AV_LOG_VERBOSE, "x:%d y:%d, w:%d h:%d band:%d show:%d\n", s->x, s->y, s->w, s->h, s->band, s->show);