| Message ID | 20170715172206.10199-1-pegro@friiks.de |
|---|---|
| State | New |
| Headers | show |
On 7/15/17, Peter Grosse <pegro@friiks.de> wrote: > Use alpha value from alpha channel instead of selected component channel. > > Signed-off-by: Peter Grosse <pegro@friiks.de> > --- > libavfilter/vf_overlay.c | 16 ++++++++++------ > 1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/libavfilter/vf_overlay.c b/libavfilter/vf_overlay.c > index 5c9f590957..cde09f5fb3 100644 > --- a/libavfilter/vf_overlay.c > +++ b/libavfilter/vf_overlay.c > @@ -508,7 +508,7 @@ static av_always_inline void blend_plane(AVFilterContext > *ctx, > int dst_hp = AV_CEIL_RSHIFT(dst_h, vsub); > int yp = y>>vsub; > int xp = x>>hsub; > - uint8_t *s, *sp, *d, *dp, *a, *ap; > + uint8_t *s, *sp, *d, *dp, *a, *ap, *da, *dap; > int jmax, j, k, kmax; > > j = FFMAX(-yp, 0); > @@ -517,12 +517,16 @@ static av_always_inline void > blend_plane(AVFilterContext *ctx, > + (yp+j) * dst->linesize[dst_plane] > + dst_offset; > ap = src->data[3] + (j<<vsub) * src->linesize[3]; > + if (main_has_alpha) > + dap = dst->data[3] + (j<<vsub) * dst->linesize[3]; > > for (jmax = FFMIN(-yp + dst_hp, src_hp); j < jmax; j++) { > k = FFMAX(-xp, 0); > d = dp + (xp+k) * dst_step; > s = sp + k; > a = ap + (k<<hsub); > + if (main_has_alpha) > + da = dap + (k<<hsub); > > for (kmax = FFMIN(-xp + dst_wp, src_wp); k < kmax; k++) { > int alpha_v, alpha_h, alpha; > @@ -545,16 +549,16 @@ static av_always_inline void > blend_plane(AVFilterContext *ctx, > // average alpha for color components, improve quality > uint8_t alpha_d; > if (hsub && vsub && j+1 < src_hp && k+1 < src_wp) { > - alpha_d = (d[0] + d[src->linesize[3]] + > - d[1] + d[src->linesize[3]+1]) >> 2; > + alpha_d = (da[0] + da[src->linesize[3]] + > + da[1] + da[src->linesize[3]+1]) >> 2; > } else if (hsub || vsub) { > alpha_h = hsub && k+1 < src_wp ? > - (d[0] + d[1]) >> 1 : d[0]; > + (da[0] + da[1]) >> 1 : da[0]; > alpha_v = vsub && j+1 < src_hp ? > - (d[0] + d[src->linesize[3]]) >> 1 : d[0]; > + (da[0] + da[src->linesize[3]]) >> 1 : da[0]; > alpha_d = (alpha_v + alpha_h) >> 1; > } else > - alpha_d = d[0]; > + alpha_d = da[0]; > alpha = UNPREMULTIPLY_ALPHA(alpha, alpha_d); > } > *d = FAST_DIV255(*d * (255 - alpha) + *s * alpha); > -- > 2.13.0 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel > how can one reproduce this bug?
On Sun, 16 Jul 2017 18:33:33 +0200 Paul B Mahol <onemda@gmail.com> wrote: > > how can one reproduce this bug? ffmpeg -i fate-suite/mfx/track_01_v02.mxf -filter_complex \ "movie=fate-suite/png1/lena-rgba.png[logo];[v:0][logo]overlay" -an -vframes 1 out.png In this example files from the fate suite are used. The source mxf file actually doesn't have an alpha channel, but the autoscaler adds one on adapting pixel formats: [auto_scaler_0 @ 0x2118440] w:1280 h:720 fmt:yuv422p sar:1/1 -> w:1280 h:720 fmt:yuva420p sar:1/1 flags:0x2 As seen here [1] the png file has a almost zero alpha value on the left side, but the output is way too bright without the patch. I hope this helps. Regards Peter [1] http://imgur.com/a/74ZF4
On Sun, Jul 16, 2017 at 08:26:57PM +0200, Peter Große wrote: > On Sun, 16 Jul 2017 18:33:33 +0200 > Paul B Mahol <onemda@gmail.com> wrote: > > > > > how can one reproduce this bug? > > ffmpeg -i fate-suite/mfx/track_01_v02.mxf -filter_complex \ > "movie=fate-suite/png1/lena-rgba.png[logo];[v:0][logo]overlay" -an -vframes 1 out.png > > In this example files from the fate suite are used. > > The source mxf file actually doesn't have an alpha channel, but the autoscaler adds one on adapting pixel formats: > > [auto_scaler_0 @ 0x2118440] w:1280 h:720 fmt:yuv422p sar:1/1 -> w:1280 h:720 fmt:yuva420p sar:1/1 flags:0x2 > > As seen here [1] the png file has a almost zero alpha value on the left side, but the output is way too bright without the patch. > > I hope this helps. > > Regards > Peter > > [1] http://imgur.com/a/74ZF4 please also add a fate test for this [...]
diff --git a/libavfilter/vf_overlay.c b/libavfilter/vf_overlay.c index 5c9f590957..cde09f5fb3 100644 --- a/libavfilter/vf_overlay.c +++ b/libavfilter/vf_overlay.c @@ -508,7 +508,7 @@ static av_always_inline void blend_plane(AVFilterContext *ctx, int dst_hp = AV_CEIL_RSHIFT(dst_h, vsub); int yp = y>>vsub; int xp = x>>hsub; - uint8_t *s, *sp, *d, *dp, *a, *ap; + uint8_t *s, *sp, *d, *dp, *a, *ap, *da, *dap; int jmax, j, k, kmax; j = FFMAX(-yp, 0); @@ -517,12 +517,16 @@ static av_always_inline void blend_plane(AVFilterContext *ctx, + (yp+j) * dst->linesize[dst_plane] + dst_offset; ap = src->data[3] + (j<<vsub) * src->linesize[3]; + if (main_has_alpha) + dap = dst->data[3] + (j<<vsub) * dst->linesize[3]; for (jmax = FFMIN(-yp + dst_hp, src_hp); j < jmax; j++) { k = FFMAX(-xp, 0); d = dp + (xp+k) * dst_step; s = sp + k; a = ap + (k<<hsub); + if (main_has_alpha) + da = dap + (k<<hsub); for (kmax = FFMIN(-xp + dst_wp, src_wp); k < kmax; k++) { int alpha_v, alpha_h, alpha; @@ -545,16 +549,16 @@ static av_always_inline void blend_plane(AVFilterContext *ctx, // average alpha for color components, improve quality uint8_t alpha_d; if (hsub && vsub && j+1 < src_hp && k+1 < src_wp) { - alpha_d = (d[0] + d[src->linesize[3]] + - d[1] + d[src->linesize[3]+1]) >> 2; + alpha_d = (da[0] + da[src->linesize[3]] + + da[1] + da[src->linesize[3]+1]) >> 2; } else if (hsub || vsub) { alpha_h = hsub && k+1 < src_wp ? - (d[0] + d[1]) >> 1 : d[0]; + (da[0] + da[1]) >> 1 : da[0]; alpha_v = vsub && j+1 < src_hp ? - (d[0] + d[src->linesize[3]]) >> 1 : d[0]; + (da[0] + da[src->linesize[3]]) >> 1 : da[0]; alpha_d = (alpha_v + alpha_h) >> 1; } else - alpha_d = d[0]; + alpha_d = da[0]; alpha = UNPREMULTIPLY_ALPHA(alpha, alpha_d); } *d = FAST_DIV255(*d * (255 - alpha) + *s * alpha);
Use alpha value from alpha channel instead of selected component channel. Signed-off-by: Peter Große <pegro@friiks.de> --- libavfilter/vf_overlay.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)