avfilter/vf_blend: add linearlight and glow mode

Signed-off-by: Paul B Mahol <onemda@gmail.com>

doc/filters.texi

@@ -2748,9 +2748,11 @@ Available values for component modes are:
 @item divide
 @item dodge
 @item exclusion
+@item glow
 @item hardlight
 @item hardmix
 @item lighten
+@item linearlight
 @item multiply
 @item negation
 @item normal

libavfilter/vf_blend.c

@@ -60,6 +60,8 @@ enum BlendMode {
     BLEND_VIVIDLIGHT,
     BLEND_XOR,
     BLEND_HARDMIX,
+    BLEND_LINEARLIGHT,
+    BLEND_GLOW,
     BLEND_NB
 };
 
@@ -117,9 +119,11 @@ typedef struct {
     { "divide",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_DIVIDE},     0, 0, FLAGS, "mode" },\
     { "dodge",      "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_DODGE},      0, 0, FLAGS, "mode" },\
     { "exclusion",  "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_EXCLUSION},  0, 0, FLAGS, "mode" },\
+    { "glow",       "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_GLOW},       0, 0, FLAGS, "mode" },\
     { "hardlight",  "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_HARDLIGHT},  0, 0, FLAGS, "mode" },\
     { "hardmix",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_HARDMIX},    0, 0, FLAGS, "mode" },\
     { "lighten",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_LIGHTEN},    0, 0, FLAGS, "mode" },\
+    { "linearlight","", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_LINEARLIGHT},0, 0, FLAGS, "mode" },\
     { "multiply",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_MULTIPLY},   0, 0, FLAGS, "mode" },\
     { "negation",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_NEGATION},   0, 0, FLAGS, "mode" },\
     { "normal",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_NORMAL},     0, 0, FLAGS, "mode" },\
@@ -214,10 +218,12 @@ DEFINE_BLEND(exclusion,  A + B - 2 * A * B / 255)
 DEFINE_BLEND(pinlight,   (B < 128) ? FFMIN(A, 2 * B) : FFMAX(A, 2 * (B - 128)))
 DEFINE_BLEND(phoenix,    FFMIN(A, B) - FFMAX(A, B) + 255)
 DEFINE_BLEND(reflect,    (B == 255) ? B : FFMIN(255, (A * A / (255 - B))))
+DEFINE_BLEND(glow,       (A == 255) ? A : FFMIN(255, (B * B / (255 - A))))
 DEFINE_BLEND(and,        A & B)
 DEFINE_BLEND(or,         A | B)
 DEFINE_BLEND(xor,        A ^ B)
 DEFINE_BLEND(vividlight, (A < 128) ? BURN(2 * A, B) : DODGE(2 * (A - 128), B))
+DEFINE_BLEND(linearlight,av_clip_uint8((B < 128) ? B + 2 * A - 255 : B + 2 * (A - 128)))
 
 static void blend_expr(const uint8_t *top, int top_linesize,
                        const uint8_t *bottom, int bottom_linesize,
@@ -328,9 +334,11 @@ static av_cold int init(AVFilterContext *ctx)
         case BLEND_DIVIDE:     param->blend = blend_divide;     break;
         case BLEND_DODGE:      param->blend = blend_dodge;      break;
         case BLEND_EXCLUSION:  param->blend = blend_exclusion;  break;
+        case BLEND_GLOW:       param->blend = blend_glow;       break;
         case BLEND_HARDLIGHT:  param->blend = blend_hardlight;  break;
         case BLEND_HARDMIX:    param->blend = blend_hardmix;    break;
         case BLEND_LIGHTEN:    param->blend = blend_lighten;    break;
+        case BLEND_LINEARLIGHT:param->blend = blend_linearlight;break;
         case BLEND_MULTIPLY:   param->blend = blend_multiply;   break;
         case BLEND_NEGATION:   param->blend = blend_negation;   break;
         case BLEND_NORMAL:     param->blend = blend_normal;     break;