Fix blend_subrect to respect the boundaries of the destination image

Originally committed as revision 10019 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Reimar Döffinger 2007-08-09 16:15:59 +00:00
parent 44f46a698e
commit 9cb5a11ea8

View File

@ -422,31 +422,36 @@ void fill_border(VideoState *s, int x, int y, int w, int h, int color)
#define BPP 1
static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect)
static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect, int imgw, int imgh)
{
int wrap, wrap3, width2, skip2;
int y, u, v, a, u1, v1, a1, w, h;
uint8_t *lum, *cb, *cr;
const uint8_t *p;
const uint32_t *pal;
int dstx, dsty, dstw, dsth;
lum = dst->data[0] + rect->y * dst->linesize[0];
cb = dst->data[1] + (rect->y >> 1) * dst->linesize[1];
cr = dst->data[2] + (rect->y >> 1) * dst->linesize[2];
dstx = FFMIN(FFMAX(rect->x, 0), imgw);
dstw = FFMIN(FFMAX(rect->w, 0), imgw - dstx);
dsty = FFMIN(FFMAX(rect->y, 0), imgh);
dsth = FFMIN(FFMAX(rect->h, 0), imgh - dsty);
lum = dst->data[0] + dsty * dst->linesize[0];
cb = dst->data[1] + (dsty >> 1) * dst->linesize[1];
cr = dst->data[2] + (dsty >> 1) * dst->linesize[2];
width2 = (rect->w + 1) >> 1;
skip2 = rect->x >> 1;
width2 = (dstw + 1) >> 1;
skip2 = dstx >> 1;
wrap = dst->linesize[0];
wrap3 = rect->linesize;
p = rect->bitmap;
pal = rect->rgba_palette; /* Now in YCrCb! */
if (rect->y & 1) {
lum += rect->x;
if (dsty & 1) {
lum += dstx;
cb += skip2;
cr += skip2;
if (rect->x & 1) {
if (dstx & 1) {
YUVA_IN(y, u, v, a, p, pal);
lum[0] = ALPHA_BLEND(a, lum[0], y, 0);
cb[0] = ALPHA_BLEND(a >> 2, cb[0], u, 0);
@ -456,7 +461,7 @@ static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect)
lum++;
p += BPP;
}
for(w = rect->w - (rect->x & 1); w >= 2; w -= 2) {
for(w = dstw - (dstx & 1); w >= 2; w -= 2) {
YUVA_IN(y, u, v, a, p, pal);
u1 = u;
v1 = v;
@ -481,17 +486,17 @@ static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect)
cb[0] = ALPHA_BLEND(a >> 2, cb[0], u, 0);
cr[0] = ALPHA_BLEND(a >> 2, cr[0], v, 0);
}
p += wrap3 + (wrap3 - rect->w * BPP);
lum += wrap + (wrap - rect->w - rect->x);
p += wrap3 + (wrap3 - dstw * BPP);
lum += wrap + (wrap - dstw - dstx);
cb += dst->linesize[1] - width2 - skip2;
cr += dst->linesize[2] - width2 - skip2;
}
for(h = rect->h - (rect->y & 1); h >= 2; h -= 2) {
lum += rect->x;
for(h = dsth - (dsty & 1); h >= 2; h -= 2) {
lum += dstx;
cb += skip2;
cr += skip2;
if (rect->x & 1) {
if (dstx & 1) {
YUVA_IN(y, u, v, a, p, pal);
u1 = u;
v1 = v;
@ -511,7 +516,7 @@ static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect)
p += -wrap3 + BPP;
lum += -wrap + 1;
}
for(w = rect->w - (rect->x & 1); w >= 2; w -= 2) {
for(w = dstw - (dstx & 1); w >= 2; w -= 2) {
YUVA_IN(y, u, v, a, p, pal);
u1 = u;
v1 = v;
@ -566,18 +571,18 @@ static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect)
p += -wrap3 + BPP;
lum += -wrap + 1;
}
p += wrap3 + (wrap3 - rect->w * BPP);
lum += wrap + (wrap - rect->w - rect->x);
p += wrap3 + (wrap3 - dstw * BPP);
lum += wrap + (wrap - dstw - dstx);
cb += dst->linesize[1] - width2 - skip2;
cr += dst->linesize[2] - width2 - skip2;
}
/* handle odd height */
if (h) {
lum += rect->x;
lum += dstx;
cb += skip2;
cr += skip2;
if (rect->x & 1) {
if (dstx & 1) {
YUVA_IN(y, u, v, a, p, pal);
lum[0] = ALPHA_BLEND(a, lum[0], y, 0);
cb[0] = ALPHA_BLEND(a >> 2, cb[0], u, 0);
@ -587,7 +592,7 @@ static void blend_subrect(AVPicture *dst, const AVSubtitleRect *rect)
lum++;
p += BPP;
}
for(w = rect->w - (rect->x & 1); w >= 2; w -= 2) {
for(w = dstw - (dstx & 1); w >= 2; w -= 2) {
YUVA_IN(y, u, v, a, p, pal);
u1 = u;
v1 = v;
@ -705,7 +710,8 @@ static void video_image_display(VideoState *is)
pict.linesize[2] = vp->bmp->pitches[1];
for (i = 0; i < sp->sub.num_rects; i++)
blend_subrect(&pict, &sp->sub.rects[i]);
blend_subrect(&pict, &sp->sub.rects[i],
vp->bmp->w, vp->bmp->h);
SDL_UnlockYUVOverlay (vp->bmp);
}