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avfilter/vf_overlay: split blend_image into functions for each overlay format

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Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol
2016-09-10 12:17:08 +02:00
parent 054f912c0d
commit 140a0485d3
1 changed files with 195 additions and 175 deletions
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96
libavfilter/vf_overlay.c
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@ -132,6 +132,8 @@ typedef struct OverlayContext {
int eof_action; ///< action to take on EOF from source
AVExpr *x_pexpr, *y_pexpr;
void (*blend_image)(AVFilterContext *ctx, AVFrame *dst, const AVFrame *src, int x, int y);
} OverlayContext;
static av_cold void uninit(AVFilterContext *ctx)
@ -304,22 +306,6 @@ static const enum AVPixelFormat alpha_pix_fmts[] = {
AV_PIX_FMT_BGRA, AV_PIX_FMT_NONE
};
static int config_input_main(AVFilterLink *inlink)
{
OverlayContext *s = inlink->dst->priv;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
av_image_fill_max_pixsteps(s->main_pix_step, NULL, pix_desc);
s->hsub = pix_desc->log2_chroma_w;
s->vsub = pix_desc->log2_chroma_h;
s->main_is_packed_rgb =
ff_fill_rgba_map(s->main_rgba_map, inlink->format) >= 0;
s->main_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts);
return 0;
}
static int config_input_overlay(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
@ -397,22 +383,17 @@ static int config_output(AVFilterLink *outlink)
/**
* Blend image in src to destination buffer dst at position (x, y).
*/
static void blend_image(AVFilterContext *ctx,
static void blend_image_packed_rgb(AVFilterContext *ctx,
AVFrame *dst, const AVFrame *src,
int x, int y)
{
OverlayContext *s = ctx->priv;
int i, imax, j, jmax, k, kmax;
int i, imax, j, jmax;
const int src_w = src->width;
const int src_h = src->height;
const int dst_w = dst->width;
const int dst_h = dst->height;
if (x >= dst_w || x+src_w < 0 ||
y >= dst_h || y+src_h < 0)
return; /* no intersection */
if (s->main_is_packed_rgb) {
uint8_t alpha; ///< the amount of overlay to blend on to main
const int dr = s->main_rgba_map[R];
const int dg = s->main_rgba_map[G];
@ -425,7 +406,7 @@ static void blend_image(AVFilterContext *ctx,
const int sa = s->overlay_rgba_map[A];
const int sstep = s->overlay_pix_step[0];
const int main_has_alpha = s->main_has_alpha;
uint8_t *s, *sp, *d, *dp;
uint8_t *S, *sp, *d, *dp;
i = FFMAX(-y, 0);
sp = src->data[0] + i * src->linesize[0];
@ -433,11 +414,11 @@ static void blend_image(AVFilterContext *ctx,
for (imax = FFMIN(-y + dst_h, src_h); i < imax; i++) {
j = FFMAX(-x, 0);
s = sp + j * sstep;
S = sp + j * sstep;
d = dp + (x+j) * dstep;
for (jmax = FFMIN(-x + dst_w, src_w); j < jmax; j++) {
alpha = s[sa];
alpha = S[sa];
// if the main channel has an alpha channel, alpha has to be calculated
// to create an un-premultiplied (straight) alpha value
@ -450,37 +431,49 @@ static void blend_image(AVFilterContext *ctx,
case 0:
break;
case 255:
d[dr] = s[sr];
d[dg] = s[sg];
d[db] = s[sb];
d[dr] = S[sr];
d[dg] = S[sg];
d[db] = S[sb];
break;
default:
// main_value = main_value * (1 - alpha) + overlay_value * alpha
// since alpha is in the range 0-255, the result must divided by 255
d[dr] = FAST_DIV255(d[dr] * (255 - alpha) + s[sr] * alpha);
d[dg] = FAST_DIV255(d[dg] * (255 - alpha) + s[sg] * alpha);
d[db] = FAST_DIV255(d[db] * (255 - alpha) + s[sb] * alpha);
d[dr] = FAST_DIV255(d[dr] * (255 - alpha) + S[sr] * alpha);
d[dg] = FAST_DIV255(d[dg] * (255 - alpha) + S[sg] * alpha);
d[db] = FAST_DIV255(d[db] * (255 - alpha) + S[sb] * alpha);
}
if (main_has_alpha) {
switch (alpha) {
case 0:
break;
case 255:
d[da] = s[sa];
d[da] = S[sa];
break;
default:
// apply alpha compositing: main_alpha += (1-main_alpha) * overlay_alpha
d[da] += FAST_DIV255((255 - d[da]) * s[sa]);
d[da] += FAST_DIV255((255 - d[da]) * S[sa]);
}
}
d += dstep;
s += sstep;
S += sstep;
}
dp += dst->linesize[0];
sp += src->linesize[0];
}
} else {
}
static void blend_image_yuv(AVFilterContext *ctx,
AVFrame *dst, const AVFrame *src,
int x, int y)
{
OverlayContext *s = ctx->priv;
int i, imax, j, jmax, k, kmax;
const int src_w = src->width;
const int src_h = src->height;
const int dst_w = dst->width;
const int dst_h = dst->height;
const int main_has_alpha = s->main_has_alpha;
if (main_has_alpha) {
uint8_t alpha; ///< the amount of overlay to blend on to main
uint8_t *s, *sa, *d, *da;
@ -582,7 +575,32 @@ static void blend_image(AVFilterContext *ctx,
ap += (1 << vsub) * src->linesize[3];
}
}
}
static int config_input_main(AVFilterLink *inlink)
{
OverlayContext *s = inlink->dst->priv;
const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
av_image_fill_max_pixsteps(s->main_pix_step, NULL, pix_desc);
s->hsub = pix_desc->log2_chroma_w;
s->vsub = pix_desc->log2_chroma_h;
s->main_is_packed_rgb =
ff_fill_rgba_map(s->main_rgba_map, inlink->format) >= 0;
s->main_has_alpha = ff_fmt_is_in(inlink->format, alpha_pix_fmts);
switch (s->format) {
case OVERLAY_FORMAT_YUV420:
case OVERLAY_FORMAT_YUV422:
case OVERLAY_FORMAT_YUV444:
s->blend_image = blend_image_yuv;
break;
case OVERLAY_FORMAT_RGB:
s->blend_image = blend_image_packed_rgb;
break;
}
return 0;
}
static AVFrame *do_blend(AVFilterContext *ctx, AVFrame *mainpic,
@ -611,7 +629,9 @@ static AVFrame *do_blend(AVFilterContext *ctx, AVFrame *mainpic,
s->var_values[VAR_Y], s->y);
}
blend_image(ctx, mainpic, second, s->x, s->y);
if (s->x < mainpic->width && s->x + second->width >= 0 ||
s->y < mainpic->height && s->y + second->height >= 0)
s->blend_image(ctx, mainpic, second, s->x, s->y);
return mainpic;
}