avfilter/vf_blend: implement 16bit support
authorPaul B Mahol <onemda@gmail.com>
Wed, 15 Jul 2015 18:04:28 +0000 (18:04 +0000)
committerPaul B Mahol <onemda@gmail.com>
Sat, 18 Jul 2015 02:07:44 +0000 (02:07 +0000)
Signed-off-by: Paul B Mahol <onemda@gmail.com>
libavfilter/vf_blend.c

index 9c93baf..f359dff 100644 (file)
@@ -169,24 +169,50 @@ static void blend_normal(const uint8_t *top, int top_linesize,
     av_image_copy_plane(dst, dst_linesize, top, top_linesize, width, end - start);
 }
 
-#define DEFINE_BLEND(name, expr)                                      \
-static void blend_## name(const uint8_t *top, int top_linesize,       \
-                          const uint8_t *bottom, int bottom_linesize, \
-                          uint8_t *dst, int dst_linesize,             \
-                          int width, int start, int end,              \
-                          FilterParams *param, double *values)        \
-{                                                                     \
-    double opacity = param->opacity;                                  \
-    int i, j;                                                         \
-                                                                      \
-    for (i = start; i < end; i++) {                                   \
-        for (j = 0; j < width; j++) {                                 \
-            dst[j] = top[j] + ((expr) - top[j]) * opacity;            \
-        }                                                             \
-        dst    += dst_linesize;                                       \
-        top    += top_linesize;                                       \
-        bottom += bottom_linesize;                                    \
-    }                                                                 \
+#define DEFINE_BLEND8(name, expr)                                              \
+static void blend_## name##_8bit(const uint8_t *top, int top_linesize,         \
+                                 const uint8_t *bottom, int bottom_linesize,   \
+                                 uint8_t *dst, int dst_linesize,               \
+                                 int width, int start, int end,                \
+                                 FilterParams *param, double *values)          \
+{                                                                              \
+    double opacity = param->opacity;                                           \
+    int i, j;                                                                  \
+                                                                               \
+    for (i = start; i < end; i++) {                                            \
+        for (j = 0; j < width; j++) {                                          \
+            dst[j] = top[j] + ((expr) - top[j]) * opacity;                     \
+        }                                                                      \
+        dst    += dst_linesize;                                                \
+        top    += top_linesize;                                                \
+        bottom += bottom_linesize;                                             \
+    }                                                                          \
+}
+
+#define DEFINE_BLEND16(name, expr)                                             \
+static void blend_## name##_16bit(const uint8_t *_top, int top_linesize,       \
+                                  const uint8_t *_bottom, int bottom_linesize, \
+                                  uint8_t *_dst, int dst_linesize,             \
+                                  int width, int start, int end,               \
+                                  FilterParams *param, double *values)         \
+{                                                                              \
+    const uint16_t *top = (uint16_t*)_top;                                     \
+    const uint16_t *bottom = (uint16_t*)_bottom;                               \
+    uint16_t *dst = (uint16_t*)_dst;                                           \
+    double opacity = param->opacity;                                           \
+    int i, j;                                                                  \
+    dst_linesize /= 2;                                                         \
+    top_linesize /= 2;                                                         \
+    bottom_linesize /= 2;                                                      \
+                                                                               \
+    for (i = start; i < end; i++) {                                            \
+        for (j = 0; j < width; j++) {                                          \
+            dst[j] = top[j] + ((expr) - top[j]) * opacity;                     \
+        }                                                                      \
+        dst    += dst_linesize;                                                \
+        top    += top_linesize;                                                \
+        bottom += bottom_linesize;                                             \
+    }                                                                          \
 }
 
 #define A top[j]
@@ -197,57 +223,105 @@ static void blend_## name(const uint8_t *top, int top_linesize,       \
 #define BURN(a, b)        (((a) == 0) ? (a) : FFMAX(0, 255 - ((255 - (b)) << 8) / (a)))
 #define DODGE(a, b)       (((a) == 255) ? (a) : FFMIN(255, (((b) << 8) / (255 - (a)))))
 
-DEFINE_BLEND(addition,   FFMIN(255, A + B))
-DEFINE_BLEND(average,    (A + B) / 2)
-DEFINE_BLEND(subtract,   FFMAX(0, A - B))
-DEFINE_BLEND(multiply,   MULTIPLY(1, A, B))
-DEFINE_BLEND(negation,   255 - FFABS(255 - A - B))
-DEFINE_BLEND(difference, FFABS(A - B))
-DEFINE_BLEND(difference128, av_clip_uint8(128 + A - B))
-DEFINE_BLEND(screen,     SCREEN(1, A, B))
-DEFINE_BLEND(overlay,    (A < 128) ? MULTIPLY(2, A, B) : SCREEN(2, A, B))
-DEFINE_BLEND(hardlight,  (B < 128) ? MULTIPLY(2, B, A) : SCREEN(2, B, A))
-DEFINE_BLEND(hardmix,    (A < (255 - B)) ? 0: 255)
-DEFINE_BLEND(darken,     FFMIN(A, B))
-DEFINE_BLEND(lighten,    FFMAX(A, B))
-DEFINE_BLEND(divide,     av_clip_uint8(((float)A / ((float)B) * 255)))
-DEFINE_BLEND(dodge,      DODGE(A, B))
-DEFINE_BLEND(burn,       BURN(A, B))
-DEFINE_BLEND(softlight,  (A > 127) ? B + (255 - B) * (A - 127.5) / 127.5 * (0.5 - FFABS(B - 127.5) / 255): B - B * ((127.5 - A) / 127.5) * (0.5 - FFABS(B - 127.5)/255))
-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,
-                       uint8_t *dst, int dst_linesize,
-                       int width, int start, int end,
-                       FilterParams *param, double *values)
-{
-    AVExpr *e = param->e;
-    int y, x;
-
-    for (y = start; y < end; y++) {
-        values[VAR_Y] = y;
-        for (x = 0; x < width; x++) {
-            values[VAR_X]      = x;
-            values[VAR_TOP]    = values[VAR_A] = top[x];
-            values[VAR_BOTTOM] = values[VAR_B] = bottom[x];
-            dst[x] = av_expr_eval(e, values, NULL);
-        }
-        dst    += dst_linesize;
-        top    += top_linesize;
-        bottom += bottom_linesize;
-    }
+DEFINE_BLEND8(addition,   FFMIN(255, A + B))
+DEFINE_BLEND8(average,    (A + B) / 2)
+DEFINE_BLEND8(subtract,   FFMAX(0, A - B))
+DEFINE_BLEND8(multiply,   MULTIPLY(1, A, B))
+DEFINE_BLEND8(negation,   255 - FFABS(255 - A - B))
+DEFINE_BLEND8(difference, FFABS(A - B))
+DEFINE_BLEND8(difference128, av_clip_uint8(128 + A - B))
+DEFINE_BLEND8(screen,     SCREEN(1, A, B))
+DEFINE_BLEND8(overlay,    (A < 128) ? MULTIPLY(2, A, B) : SCREEN(2, A, B))
+DEFINE_BLEND8(hardlight,  (B < 128) ? MULTIPLY(2, B, A) : SCREEN(2, B, A))
+DEFINE_BLEND8(hardmix,    (A < (255 - B)) ? 0: 255)
+DEFINE_BLEND8(darken,     FFMIN(A, B))
+DEFINE_BLEND8(lighten,    FFMAX(A, B))
+DEFINE_BLEND8(divide,     av_clip_uint8(((float)A / ((float)B) * 255)))
+DEFINE_BLEND8(dodge,      DODGE(A, B))
+DEFINE_BLEND8(burn,       BURN(A, B))
+DEFINE_BLEND8(softlight,  (A > 127) ? B + (255 - B) * (A - 127.5) / 127.5 * (0.5 - FFABS(B - 127.5) / 255): B - B * ((127.5 - A) / 127.5) * (0.5 - FFABS(B - 127.5)/255))
+DEFINE_BLEND8(exclusion,  A + B - 2 * A * B / 255)
+DEFINE_BLEND8(pinlight,   (B < 128) ? FFMIN(A, 2 * B) : FFMAX(A, 2 * (B - 128)))
+DEFINE_BLEND8(phoenix,    FFMIN(A, B) - FFMAX(A, B) + 255)
+DEFINE_BLEND8(reflect,    (B == 255) ? B : FFMIN(255, (A * A / (255 - B))))
+DEFINE_BLEND8(glow,       (A == 255) ? A : FFMIN(255, (B * B / (255 - A))))
+DEFINE_BLEND8(and,        A & B)
+DEFINE_BLEND8(or,         A | B)
+DEFINE_BLEND8(xor,        A ^ B)
+DEFINE_BLEND8(vividlight, (A < 128) ? BURN(2 * A, B) : DODGE(2 * (A - 128), B))
+DEFINE_BLEND8(linearlight,av_clip_uint8((B < 128) ? B + 2 * A - 255 : B + 2 * (A - 128)))
+
+#undef MULTIPLY
+#undef SCREEN
+#undef BURN
+#undef DODGE
+
+#define MULTIPLY(x, a, b) ((x) * (((a) * (b)) / 65535))
+#define SCREEN(x, a, b)   (65535 - (x) * ((65535 - (a)) * (65535 - (b)) / 65535))
+#define BURN(a, b)        (((a) == 0) ? (a) : FFMAX(0, 65535 - ((65535 - (b)) << 16) / (a)))
+#define DODGE(a, b)       (((a) == 65535) ? (a) : FFMIN(65535, (((b) << 16) / (65535 - (a)))))
+
+DEFINE_BLEND16(addition,   FFMIN(65535, A + B))
+DEFINE_BLEND16(average,    (A + B) / 2)
+DEFINE_BLEND16(subtract,   FFMAX(0, A - B))
+DEFINE_BLEND16(multiply,   MULTIPLY(1, A, B))
+DEFINE_BLEND16(negation,   65535 - FFABS(65535 - A - B))
+DEFINE_BLEND16(difference, FFABS(A - B))
+DEFINE_BLEND16(difference128, av_clip_uint16(32768 + A - B))
+DEFINE_BLEND16(screen,     SCREEN(1, A, B))
+DEFINE_BLEND16(overlay,    (A < 32768) ? MULTIPLY(2, A, B) : SCREEN(2, A, B))
+DEFINE_BLEND16(hardlight,  (B < 32768) ? MULTIPLY(2, B, A) : SCREEN(2, B, A))
+DEFINE_BLEND16(hardmix,    (A < (65535 - B)) ? 0: 65535)
+DEFINE_BLEND16(darken,     FFMIN(A, B))
+DEFINE_BLEND16(lighten,    FFMAX(A, B))
+DEFINE_BLEND16(divide,     av_clip_uint16(((float)A / ((float)B) * 65535)))
+DEFINE_BLEND16(dodge,      DODGE(A, B))
+DEFINE_BLEND16(burn,       BURN(A, B))
+DEFINE_BLEND16(softlight,  (A > 32767) ? B + (65535 - B) * (A - 32767.5) / 32767.5 * (0.5 - FFABS(B - 32767.5) / 65535): B - B * ((32767.5 - A) / 32767.5) * (0.5 - FFABS(B - 32767.5)/65535))
+DEFINE_BLEND16(exclusion,  A + B - 2 * A * B / 65535)
+DEFINE_BLEND16(pinlight,   (B < 32768) ? FFMIN(A, 2 * B) : FFMAX(A, 2 * (B - 32768)))
+DEFINE_BLEND16(phoenix,    FFMIN(A, B) - FFMAX(A, B) + 65535)
+DEFINE_BLEND16(reflect,    (B == 65535) ? B : FFMIN(65535, (A * A / (65535 - B))))
+DEFINE_BLEND16(glow,       (A == 65535) ? A : FFMIN(65535, (B * B / (65535 - A))))
+DEFINE_BLEND16(and,        A & B)
+DEFINE_BLEND16(or,         A | B)
+DEFINE_BLEND16(xor,        A ^ B)
+DEFINE_BLEND16(vividlight, (A < 32768) ? BURN(2 * A, B) : DODGE(2 * (A - 32768), B))
+DEFINE_BLEND16(linearlight,av_clip_uint16((B < 32768) ? B + 2 * A - 65535 : B + 2 * (A - 32768)))
+
+#define DEFINE_BLEND_EXPR(type, name, div)                                     \
+static void blend_expr_## name(const uint8_t *_top, int top_linesize,          \
+                               const uint8_t *_bottom, int bottom_linesize,    \
+                               uint8_t *_dst, int dst_linesize,                \
+                               int width, int start, int end,                  \
+                               FilterParams *param, double *values)            \
+{                                                                              \
+    const type *top = (type*)_top;                                             \
+    const type *bottom = (type*)_bottom;                                       \
+    type *dst = (type*)_dst;                                                   \
+    AVExpr *e = param->e;                                                      \
+    int y, x;                                                                  \
+    dst_linesize /= div;                                                       \
+    top_linesize /= div;                                                       \
+    bottom_linesize /= div;                                                    \
+                                                                               \
+    for (y = start; y < end; y++) {                                            \
+        values[VAR_Y] = y;                                                     \
+        for (x = 0; x < width; x++) {                                          \
+            values[VAR_X]      = x;                                            \
+            values[VAR_TOP]    = values[VAR_A] = top[x];                       \
+            values[VAR_BOTTOM] = values[VAR_B] = bottom[x];                    \
+            dst[x] = av_expr_eval(e, values, NULL);                            \
+        }                                                                      \
+        dst    += dst_linesize;                                                \
+        top    += top_linesize;                                                \
+        bottom += bottom_linesize;                                             \
+    }                                                                          \
 }
 
+DEFINE_BLEND_EXPR(uint8_t, 8bit, 1)
+DEFINE_BLEND_EXPR(uint16_t, 16bit, 2)
+
 static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     ThreadData *td = arg;
@@ -311,63 +385,9 @@ static AVFrame *blend_frame(AVFilterContext *ctx, AVFrame *top_buf,
 static av_cold int init(AVFilterContext *ctx)
 {
     BlendContext *b = ctx->priv;
-    int ret, plane;
 
     b->tblend = !strcmp(ctx->filter->name, "tblend");
 
-    for (plane = 0; plane < FF_ARRAY_ELEMS(b->params); plane++) {
-        FilterParams *param = &b->params[plane];
-
-        if (b->all_mode >= 0)
-            param->mode = b->all_mode;
-        if (b->all_opacity < 1)
-            param->opacity = b->all_opacity;
-
-        switch (param->mode) {
-        case BLEND_ADDITION:   param->blend = blend_addition;   break;
-        case BLEND_AND:        param->blend = blend_and;        break;
-        case BLEND_AVERAGE:    param->blend = blend_average;    break;
-        case BLEND_BURN:       param->blend = blend_burn;       break;
-        case BLEND_DARKEN:     param->blend = blend_darken;     break;
-        case BLEND_DIFFERENCE: param->blend = blend_difference; break;
-        case BLEND_DIFFERENCE128: param->blend = blend_difference128; break;
-        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;
-        case BLEND_OR:         param->blend = blend_or;         break;
-        case BLEND_OVERLAY:    param->blend = blend_overlay;    break;
-        case BLEND_PHOENIX:    param->blend = blend_phoenix;    break;
-        case BLEND_PINLIGHT:   param->blend = blend_pinlight;   break;
-        case BLEND_REFLECT:    param->blend = blend_reflect;    break;
-        case BLEND_SCREEN:     param->blend = blend_screen;     break;
-        case BLEND_SOFTLIGHT:  param->blend = blend_softlight;  break;
-        case BLEND_SUBTRACT:   param->blend = blend_subtract;   break;
-        case BLEND_VIVIDLIGHT: param->blend = blend_vividlight; break;
-        case BLEND_XOR:        param->blend = blend_xor;        break;
-        }
-
-        if (b->all_expr && !param->expr_str) {
-            param->expr_str = av_strdup(b->all_expr);
-            if (!param->expr_str)
-                return AVERROR(ENOMEM);
-        }
-        if (param->expr_str) {
-            ret = av_expr_parse(&param->e, param->expr_str, var_names,
-                                NULL, NULL, NULL, NULL, 0, ctx);
-            if (ret < 0)
-                return ret;
-            param->blend = blend_expr;
-        }
-    }
-
     b->dinput.process = blend_frame;
     return 0;
 }
@@ -378,7 +398,11 @@ static int query_formats(AVFilterContext *ctx)
         AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
-        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8,
+        AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
+        AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
+        AV_PIX_FMT_GBRP16, AV_PIX_FMT_GRAY16,
+        AV_PIX_FMT_NONE
     };
 
     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
@@ -408,7 +432,7 @@ static int config_output(AVFilterLink *outlink)
     AVFilterLink *bottomlink = ctx->inputs[BOTTOM];
     BlendContext *b = ctx->priv;
     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(toplink->format);
-    int ret;
+    int ret, plane, is_16bit;
 
     if (toplink->format != bottomlink->format) {
         av_log(ctx, AV_LOG_ERROR, "inputs must be of same pixel format\n");
@@ -438,11 +462,66 @@ static int config_output(AVFilterLink *outlink)
 
     b->hsub = pix_desc->log2_chroma_w;
     b->vsub = pix_desc->log2_chroma_h;
+
+    is_16bit = pix_desc->comp[0].depth_minus1 == 15;
     b->nb_planes = av_pix_fmt_count_planes(toplink->format);
 
     if ((ret = ff_dualinput_init(ctx, &b->dinput)) < 0)
         return ret;
 
+    for (plane = 0; plane < FF_ARRAY_ELEMS(b->params); plane++) {
+        FilterParams *param = &b->params[plane];
+
+        if (b->all_mode >= 0)
+            param->mode = b->all_mode;
+        if (b->all_opacity < 1)
+            param->opacity = b->all_opacity;
+
+        switch (param->mode) {
+        case BLEND_ADDITION:   param->blend = is_16bit ? blend_addition_16bit   : blend_addition_8bit;   break;
+        case BLEND_AND:        param->blend = is_16bit ? blend_and_16bit        : blend_and_8bit;        break;
+        case BLEND_AVERAGE:    param->blend = is_16bit ? blend_average_16bit    : blend_average_8bit;    break;
+        case BLEND_BURN:       param->blend = is_16bit ? blend_burn_16bit       : blend_burn_8bit;       break;
+        case BLEND_DARKEN:     param->blend = is_16bit ? blend_darken_16bit     : blend_darken_8bit;     break;
+        case BLEND_DIFFERENCE: param->blend = is_16bit ? blend_difference_16bit : blend_difference_8bit; break;
+        case BLEND_DIFFERENCE128: param->blend = is_16bit ? blend_difference128_16bit: blend_difference128_8bit; break;
+        case BLEND_DIVIDE:     param->blend = is_16bit ? blend_divide_16bit     : blend_divide_8bit;     break;
+        case BLEND_DODGE:      param->blend = is_16bit ? blend_dodge_16bit      : blend_dodge_8bit;      break;
+        case BLEND_EXCLUSION:  param->blend = is_16bit ? blend_exclusion_16bit  : blend_exclusion_8bit;  break;
+        case BLEND_GLOW:       param->blend = is_16bit ? blend_glow_16bit       : blend_glow_8bit;       break;
+        case BLEND_HARDLIGHT:  param->blend = is_16bit ? blend_hardlight_16bit  : blend_hardlight_8bit;  break;
+        case BLEND_HARDMIX:    param->blend = is_16bit ? blend_hardmix_16bit    : blend_hardmix_8bit;    break;
+        case BLEND_LIGHTEN:    param->blend = is_16bit ? blend_lighten_16bit    : blend_lighten_8bit;    break;
+        case BLEND_LINEARLIGHT:param->blend = is_16bit ? blend_linearlight_16bit: blend_linearlight_8bit;break;
+        case BLEND_MULTIPLY:   param->blend = is_16bit ? blend_multiply_16bit   : blend_multiply_8bit;   break;
+        case BLEND_NEGATION:   param->blend = is_16bit ? blend_negation_16bit   : blend_negation_8bit;   break;
+        case BLEND_NORMAL:     param->blend = blend_normal;                                              break;
+        case BLEND_OR:         param->blend = is_16bit ? blend_or_16bit         : blend_or_8bit;         break;
+        case BLEND_OVERLAY:    param->blend = is_16bit ? blend_overlay_16bit    : blend_overlay_8bit;    break;
+        case BLEND_PHOENIX:    param->blend = is_16bit ? blend_phoenix_16bit    : blend_phoenix_8bit;    break;
+        case BLEND_PINLIGHT:   param->blend = is_16bit ? blend_pinlight_16bit   : blend_pinlight_8bit;   break;
+        case BLEND_REFLECT:    param->blend = is_16bit ? blend_reflect_16bit    : blend_reflect_8bit;    break;
+        case BLEND_SCREEN:     param->blend = is_16bit ? blend_screen_16bit     : blend_screen_8bit;     break;
+        case BLEND_SOFTLIGHT:  param->blend = is_16bit ? blend_softlight_16bit  : blend_softlight_8bit;  break;
+        case BLEND_SUBTRACT:   param->blend = is_16bit ? blend_subtract_16bit   : blend_subtract_8bit;   break;
+        case BLEND_VIVIDLIGHT: param->blend = is_16bit ? blend_vividlight_16bit : blend_vividlight_8bit; break;
+        case BLEND_XOR:        param->blend = is_16bit ? blend_xor_16bit        : blend_xor_8bit;        break;
+        }
+
+        if (b->all_expr && !param->expr_str) {
+            param->expr_str = av_strdup(b->all_expr);
+            if (!param->expr_str)
+                return AVERROR(ENOMEM);
+        }
+        if (param->expr_str) {
+            ret = av_expr_parse(&param->e, param->expr_str, var_names,
+                                NULL, NULL, NULL, NULL, 0, ctx);
+            if (ret < 0)
+                return ret;
+            param->blend = is_16bit? blend_expr_16bit : blend_expr_8bit;
+        }
+    }
+
     return 0;
 }