RFC: bicubic filtering patch

RFC: bicubic filtering patch

[Ben Skeggs]

[-- Attachment #1: Type: text/plain, Size: 523 bytes --]

Hey,

There's one relevant patch in the F13 DDX package that hasn't been
pushed into git still.

The patch simply switches off the bicubic filtering if we're scaling the
image by less than 200% in either direction in order to prevent some
excessive blurriness in the image (very noticable with the gstreamer
xvideo test).

The patch has been in the Fedora package since F11 as a user reported
the issue as a bug, and the radeon driver has similar code, but I
thought I'd ask for opinions before I pushed this to git.

Ben.

[-- Attachment #2: nouveau-bicubic-2x.patch --]
[-- Type: text/x-patch, Size: 2146 bytes --]

From 9e1f2ff45e5b22406f3575298113f1168b3bde5a Mon Sep 17 00:00:00 2001
From: Ben Skeggs <skeggsb-KEl1lVR6jwNSq9BJjBFyUp/QNRX+jHPU@public.gmane.org>
Date: Mon, 4 May 2009 17:04:34 +1000
Subject: [PATCH 1/2] xv: only use bicubic filtering when scaling >=2x

---
 src/nv30_xv_tex.c |    7 +++++--
 src/nv40_xv_tex.c |    8 ++++++--
 2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/nv30_xv_tex.c b/src/nv30_xv_tex.c
index 617e63b..f4bc1da 100644
--- a/src/nv30_xv_tex.c
+++ b/src/nv30_xv_tex.c
@@ -258,7 +258,7 @@ NV30PutTextureImage(ScrnInfoPtr pScrn, struct nouveau_bo *src, int src_offset,
 	struct nouveau_channel *chan = pNv->chan;
 	struct nouveau_grobj *rankine = pNv->Nv3D;
 	struct nouveau_bo *bo = nouveau_pixmap_bo(ppix);
-	Bool redirected = FALSE;
+	Bool redirected = FALSE, bicubic = pPriv->bicubic;
 	float X1, X2, Y1, Y2;
 	BoxPtr pbox;
 	int nbox;
@@ -342,7 +342,10 @@ NV30PutTextureImage(ScrnInfoPtr pScrn, struct nouveau_bo *src, int src_offset,
 	BEGIN_RING(chan, rankine, NV34TCL_TX_ENABLE(3), 1);
 	OUT_RING  (chan, 0x0);
 
-	if (!NV30_LoadFragProg(pScrn, pPriv->bicubic ?
+	if (drw_w / 2 < src_w || drw_h / 2 < src_h)
+		bicubic = FALSE;
+
+	if (!NV30_LoadFragProg(pScrn, bicubic ?
 			       &nv30_fp_yv12_bicubic :
 			       &nv30_fp_yv12_bilinear)) {
 		MARK_UNDO(chan);
diff --git a/src/nv40_xv_tex.c b/src/nv40_xv_tex.c
index 3a5d439..a46f1e3 100644
--- a/src/nv40_xv_tex.c
+++ b/src/nv40_xv_tex.c
@@ -262,7 +262,7 @@ NV40PutTextureImage(ScrnInfoPtr pScrn,
 	struct nouveau_channel *chan = pNv->chan;
 	struct nouveau_grobj *curie = pNv->Nv3D;
 	struct nouveau_bo *bo = nouveau_pixmap_bo(ppix);
-	Bool redirected = FALSE;
+	Bool redirected = FALSE, bicubic = pPriv->bicubic;
 	float X1, X2, Y1, Y2;
 	BoxPtr pbox;
 	int nbox;
@@ -322,7 +322,11 @@ NV40PutTextureImage(ScrnInfoPtr pScrn,
 	}
 
 	NV40_LoadVtxProg(pScrn, &nv40_vp_video);
-	if (!NV40_LoadFragProg(pScrn, pPriv->bicubic ?
+
+	if (drw_w / 2 < src_w || drw_h / 2 < src_h)
+		bicubic = FALSE;
+
+	if (!NV40_LoadFragProg(pScrn, bicubic ?
 			       &nv40_fp_yv12_bicubic :
 			       &nv30_fp_yv12_bilinear)) {
 		MARK_UNDO(chan);
-- 
1.7.0.1


[-- Attachment #3: Type: text/plain, Size: 181 bytes --]

_______________________________________________
Nouveau mailing list
Nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
http://lists.freedesktop.org/mailman/listinfo/nouveau

Re: RFC: bicubic filtering patch

[Stephane Marchesin]

[-- Attachment #1.1: Type: text/plain, Size: 706 bytes --]

On Sun, Mar 28, 2010 at 23:54, Ben Skeggs <skeggsb-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> Hey,
>
> There's one relevant patch in the F13 DDX package that hasn't been
> pushed into git still.
>
> The patch simply switches off the bicubic filtering if we're scaling the
> image by less than 200% in either direction in order to prevent some
> excessive blurriness in the image (very noticable with the gstreamer
> xvideo test).
>
> The patch has been in the Fedora package since F11 as a user reported
> the issue as a bug, and the radeon driver has similar code, but I
> thought I'd ask for opinions before I pushed this to git.
>
>

Yup, that code was never intended for <2x scaling.

Stephane

[-- Attachment #1.2: Type: text/html, Size: 1082 bytes --]

[-- Attachment #2: Type: text/plain, Size: 181 bytes --]

_______________________________________________
Nouveau mailing list
Nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
http://lists.freedesktop.org/mailman/listinfo/nouveau