integrated Tim Ferguson's native CYUV decoder

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@3970 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 85 insertions, 0 deletions

diff --git a/cyuv.c b/cyuv.c
new file mode 100644
index 0000000000..86d597af7d
--- /dev/null
+++ b/cyuv.c
@@ -0,0 +1,85 @@
+/* ------------------------------------------------------------------------
+ * Creative YUV Video Decoder
+ *
+ * Dr. Tim Ferguson, 2001.
+ * For more details on the algorithm:
+ *         http://www.csse.monash.edu.au/~timf/videocodec.html
+ *
+ * This is a very simple predictive coder.  A video frame is coded in YUV411
+ * format.  The first pixel of each scanline is coded using the upper four
+ * bits of its absolute value.  Subsequent pixels for the scanline are coded
+ * using the difference between the last pixel and the current pixel (DPCM).
+ * The DPCM values are coded using a 16 entry table found at the start of the
+ * frame.  Thus four bits per component are used and are as follows:
+ *     UY VY YY UY VY YY UY VY...
+ * This code assumes the frame width will be a multiple of four pixels.  This
+ * should probably be fixed.
+ * ------------------------------------------------------------------------ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+/* ------------------------------------------------------------------------
+ * This function decodes a buffer containing a CYUV encoded frame.
+ *
+ * buf - the input buffer to be decoded
+ * size - the size of the input buffer
+ * frame - the output frame buffer (UYVY format)
+ * width - the width of the output frame
+ * height - the height of the output frame
+ * bit_per_pixel - ignored for now: may be used later for conversions.
+ */
+void decode_cyuv(unsigned char *buf, int size, unsigned char *frame, int width, int height, int bit_per_pixel)
+{
+int i, xpos, ypos, cur_Y = 0, cur_U = 0, cur_V = 0;
+char *delta_y_tbl, *delta_c_tbl, *ptr;
+
+	delta_y_tbl = buf + 16;
+	delta_c_tbl = buf + 32;
+	ptr = buf + (16 * 3);
+
+	for(ypos = 0; ypos < height; ypos++)
+		for(xpos = 0; xpos < width; xpos += 4)
+			{
+			if(xpos == 0)		/* first pixels in scanline */
+				{
+				cur_U = *(ptr++);
+				cur_Y = (cur_U & 0x0f) << 4;
+				cur_U = cur_U & 0xf0;
+				*frame++ = cur_U;
+				*frame++ = cur_Y;
+
+				cur_V = *(ptr++);
+				cur_Y = (cur_Y + delta_y_tbl[cur_V & 0x0f]) & 0xff;
+				cur_V = cur_V & 0xf0;
+				*frame++ = cur_V;
+				*frame++ = cur_Y;
+				}
+			else			/* subsequent pixels in scanline */
+				{
+				i = *(ptr++);
+				cur_U = (cur_U + delta_c_tbl[i >> 4]) & 0xff;
+				cur_Y = (cur_Y + delta_y_tbl[i & 0x0f]) & 0xff;
+				*frame++ = cur_U;
+				*frame++ = cur_Y;
+
+				i = *(ptr++);
+				cur_V = (cur_V + delta_c_tbl[i >> 4]) & 0xff;
+				cur_Y = (cur_Y + delta_y_tbl[i & 0x0f]) & 0xff;
+				*frame++ = cur_V;
+				*frame++ = cur_Y;
+				}
+
+			i = *(ptr++);
+			cur_Y = (cur_Y + delta_y_tbl[i & 0x0f]) & 0xff;
+			*frame++ = cur_U;
+			*frame++ = cur_Y;
+
+			cur_Y = (cur_Y + delta_y_tbl[i >> 4]) & 0xff;
+			*frame++ = cur_V;
+			*frame++ = cur_Y;
+			}
+}
+