[PATCH] YVYU decoding

[PATCH] YVYU decoding

[Jean-Francois Moine]

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Hi Hans,

Here is a patch for decoding the YVYU frames of the vc0321.

Cheers.

-- 
Ken ar c'hentañ |             ** Breizh ha Linux atav! **
Jef             |               http://moinejf.free.fr/


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This patch adds the decoding of YVYU images generated by vc0321.

Signed-off-by: Jean-Francois Moine <moinejf@free.fr>

--- v4l-dvb-423381bc0d61/v4l2-apps/lib/libv4l/libv4lconvert/libv4lconvert-priv.h.orig	2008-08-29 14:00:57.000000000 +0200
+++ v4l-dvb-423381bc0d61/v4l2-apps/lib/libv4l/libv4lconvert/libv4lconvert-priv.h	2008-08-29 18:24:40.000000000 +0200
@@ -59,6 +59,10 @@
 #define V4L2_PIX_FMT_SRGGB8 v4l2_fourcc('R','G','G','B')
 #endif
 
+#ifndef V4L2_PIX_FMT_YVYU
+#define V4L2_PIX_FMT_YVYU v4l2_fourcc('Y', 'V', 'Y', 'U')
+#endif
+
 #define V4LCONVERT_ERROR_MSG_SIZE 256
 
 #define V4LCONVERT_ERR(...) \
@@ -87,6 +91,12 @@
 void v4lconvert_yuv420_to_bgr24(const unsigned char *src, unsigned char *dst,
   int width, int height);
 
+void v4lconvert_yvyu_to_rgb24(const unsigned char *src, unsigned char *dst,
+  int width, int height);
+
+void v4lconvert_yvyu_to_bgr24(const unsigned char *src, unsigned char *dst,
+  int width, int height);
+
 void v4lconvert_swap_rgb(const unsigned char *src, unsigned char *dst,
   int width, int height);
 
--- v4l-dvb-423381bc0d61/v4l2-apps/lib/libv4l/libv4lconvert/libv4lconvert.c.orig	2008-08-29 14:00:57.000000000 +0200
+++ v4l-dvb-423381bc0d61/v4l2-apps/lib/libv4l/libv4lconvert/libv4lconvert.c	2008-08-29 18:22:10.000000000 +0200
@@ -49,6 +49,7 @@
   V4L2_PIX_FMT_SN9C10X,
   V4L2_PIX_FMT_PAC207,
   V4L2_PIX_FMT_PJPG,
+  V4L2_PIX_FMT_YVYU,
 };
 
 static const unsigned int supported_dst_pixfmts[] = {
@@ -518,6 +519,19 @@
       }
       break;
 
+    case V4L2_PIX_FMT_YVYU:
+      switch (dest_fmt->fmt.pix.pixelformat) {
+      case V4L2_PIX_FMT_RGB24:
+	v4lconvert_yvyu_to_rgb24(src, dest, dest_fmt->fmt.pix.width,
+				   dest_fmt->fmt.pix.height);
+	break;
+      case V4L2_PIX_FMT_BGR24:
+	v4lconvert_yvyu_to_bgr24(src, dest, dest_fmt->fmt.pix.width,
+				   dest_fmt->fmt.pix.height);
+	break;
+      }
+      break;
+
     default:
       V4LCONVERT_ERR("Unknown src format in conversion\n");
       errno = EINVAL;
--- v4l-dvb-423381bc0d61/v4l2-apps/lib/libv4l/libv4lconvert/rgbyuv.c.orig	2008-08-29 14:00:57.000000000 +0200
+++ v4l-dvb-423381bc0d61/v4l2-apps/lib/libv4l/libv4lconvert/rgbyuv.c	2008-08-29 18:40:08.000000000 +0200
@@ -130,6 +130,58 @@
   }
 }
 
+void v4lconvert_yvyu_to_bgr24(const unsigned char *src, unsigned char *dest,
+  int width, int height)
+{
+  int j;
+
+  while (--height >= 0) {
+    for (j = 0; j < width; j += 2) {
+      int u = src[3];
+      int v = src[1];
+      int u1 = (((u - 128) << 7) +  (u - 128)) >> 6;
+      int rg = (((u - 128) << 1) +  (u - 128) +
+		((v - 128) << 2) + ((v - 128) << 1)) >> 3;
+      int v1 = (((v - 128) << 1) +  (v - 128)) >> 1;
+
+      *dest++ = CLIP(*src + u1);
+      *dest++ = CLIP(*src - rg);
+      *dest++ = CLIP(*src + v1);
+
+      *dest++ = CLIP(src[2] + u1);
+      *dest++ = CLIP(src[2] - rg);
+      *dest++ = CLIP(src[2] + v1);
+      src += 4;
+    }
+  }
+}
+
+void v4lconvert_yvyu_to_rgb24(const unsigned char *src, unsigned char *dest,
+  int width, int height)
+{
+  int j;
+
+  while (--height >= 0) {
+    for (j = 0; j < width; j += 2) {
+      int u = src[3];
+      int v = src[1];
+      int u1 = (((u - 128) << 7) +  (u - 128)) >> 6;
+      int rg = (((u - 128) << 1) +  (u - 128) +
+		((v - 128) << 2) + ((v - 128) << 1)) >> 3;
+      int v1 = (((v - 128) << 1) +  (v - 128)) >> 1;
+
+      *dest++ = CLIP(*src + v1);
+      *dest++ = CLIP(*src - rg);
+      *dest++ = CLIP(*src + u1);
+
+      *dest++ = CLIP(src[2] + v1);
+      *dest++ = CLIP(src[2] - rg);
+      *dest++ = CLIP(src[2] + u1);
+      src += 4;
+    }
+  }
+}
+
 void v4lconvert_swap_rgb(const unsigned char *src, unsigned char *dst,
   int width, int height)
 {

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Re: [PATCH] YVYU decoding

[Hans de Goede]

Jean-Francois Moine wrote:
> Hi Hans,
> 
> Here is a patch for decoding the YVYU frames of the vc0321.
> 

Thanks, I'll apply it, but you are missing YVYU (packed) -> YUV420 (planar) 
conversion, while some apps do default to requesting YUV420 (planar) and as 
your patch claims that libv4lconvert supports YUYV (there is no way to claim 
partial support) those apps will get their request granted.

Any chance you could add YVYU (packed) -> YUV420 (planar) conversion, this 
should be easy, just average the U and V values of one YVYU pack from 2 
adjecent rows, and of course do the packed -> planar conversion. If you cannot 
I can write code for this, can you test it then?

Regards,

Hans

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