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Improve Y16 color setup

PATCH In review Hans Verkuil 2 participants 2 messages Jun 5, 2015 Media (V4L/DVB)

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Hans Verkuil

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PATCH v2 1/1 Improve Y16 color setup

Currently the colors for the Y16 and Y16_BE pixelformats are in the range 0x0000-0xff00. So pure white (0xffff) is never created.

Improve this by making white really white. For other colors the lsb remains 0 so vivid can be used to detect endian problems.

Signed-off-by Hans Verkuil <[email protected]>
drivers/media/platform/vivid/vivid-tpg.c +9 -2
index b1147f2..1b94503 100644
@@ -900,12 +900,19 @@ static void gen_twopix(struct tpg_data *tpg,
 		buf[0][offset] = r_y;
 		break;
 	case V4L2_PIX_FMT_Y16:
-		buf[0][offset] = 0;
+		/*
+		 * Ideally both bytes should be set to r_y, but then you won't
+		 * be able to detect endian problems. So keep it 0 except for
+		 * the corner case where r_y is 0xff so white really will be
+		 * white (0xffff).
+		 */
+		buf[0][offset] = r_y == 0xff ? r_y : 0;
 		buf[0][offset+1] = r_y;
 		break;
 	case V4L2_PIX_FMT_Y16_BE:
+		/* See comment for V4L2_PIX_FMT_Y16 above */
 		buf[0][offset] = r_y;
-		buf[0][offset+1] = 0;
+		buf[0][offset+1] = r_y == 0xff ? r_y : 0;
 		break;
 	case V4L2_PIX_FMT_YUV422P:
 	case V4L2_PIX_FMT_YUV420: