From e1af275ed3fc5a3ab2e50be325e44bd2de705bea Mon Sep 17 00:00:00 2001
From: deva <deva>
Date: Thu, 20 Jul 2006 15:11:45 +0000
Subject: Added the transcoder, formalized the video and audio formats in
 format.h

---
 lib/transcoder.cc | 100 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 lib/transcoder.cc

(limited to 'lib/transcoder.cc')

diff --git a/lib/transcoder.cc b/lib/transcoder.cc
new file mode 100644
index 0000000..edb4449
--- /dev/null
+++ b/lib/transcoder.cc
@@ -0,0 +1,100 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            transcoder.cc
+ *
+ *  Wed Jul 19 22:11:02 CEST 2006
+ *  Copyright  2006 Bent Bisballe Nyeng
+ *  deva@aasimon.org
+ ****************************************************************************/
+
+/*
+ *  This file is part of MIaV.
+ *
+ *  MIaV is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  MIaV is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with MIaV; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include "transcoder.h"
+
+/*
+  R = Y + 1.4075 * (V - 128)
+  G = Y - (0.3455 * (U - 128) - (0.7169 * (V - 128))
+  B = Y + 1.7790 * (U - 128)
+*/
+#define RED(y, u, v)   (y + 1.4075 * (v - 128))
+#define GREEN(y, u, v) (y - (0.3455 * (u - 128)) - (0.7169 * (v - 128)))
+#define BLUE(y, u, v)  (y + 1.7790 * (u - 128))
+
+/*
+  R = 1.164(Y - 16) + 1.596(V - 128) 
+  G = 1.164(Y - 16) - 0.813(V - 128) - 0.391(U - 128)
+  B = 1.164(Y - 16)                  + 2.018(U - 128)
+*/
+//#define RED(y, u, v)   (1.164 * (y - 16) + 1.596 * (v - 128))
+//#define GREEN(y, u, v) (1.164 * (y - 16) - 0.813 * (v - 128) - 0.391 * (u - 128))
+//#define BLUE(y, u, v)  (1.164 * (y - 16)                     + 2.018 * (u - 128))
+static Frame *transcode_yuv2brg0(Frame *input, char* rgb, int bufsz)
+{
+  if(!rgb) { // No buffer supplied, creating one.
+    rgb = new char[720 * 576 * 4];
+    bufsz = 720 * 576 * 4;
+  }
+  if(bufsz < 720 * 576 * 4) return NULL; // Buffer is too small.
+
+  unsigned char Y0, Y1, U, V;
+
+  unsigned int byte = 0;
+  unsigned int pos = 0;
+
+  char *pframe = input->vframe;
+
+  while(pos < 720*576*4) {
+    // YUV 4:2:2 packing
+    // Y0 U0 Y1 V1 Y2 U2 Y3 V3
+    // [Y0 U0 V1] [Y1 U0 V1] [Y2 U2 V3] [Y3 U2 V3]
+
+    Y0 = pframe[byte]; byte++;
+    U = pframe[byte]; byte++;
+    Y1 = pframe[byte]; byte++;
+    V = pframe[byte]; byte++;
+
+    rgb[pos+3] = 0; // Alpha
+    rgb[pos+2] = (unsigned char)RED(Y0, U, V); // Red
+    rgb[pos+1] = (unsigned char)GREEN(Y0, U, V); // Green
+    rgb[pos+0] = (unsigned char)BLUE(Y0, U, V); // Blue
+    pos+=4;
+
+    rgb[pos+3] = 0; // Alpha
+    rgb[pos+2] = (unsigned char)RED(Y1, U, V); // Red
+    rgb[pos+1] = (unsigned char)GREEN(Y1, U, V); // Green
+    rgb[pos+0] = (unsigned char)BLUE(Y1, U, V); // Blue
+    pos+=4;
+  }
+
+  return new Frame(rgb, bufsz, VF_BRG0, NULL, 0, AF_NONE);
+}
+
+
+Frame *transcode(Frame *input,
+                 video_format_t vformat, char *vbuffer, int vbuffer_size, 
+                 audio_format_t aformat, char *abuffer, int abuffer_size)
+{
+
+  // YUV422 => BRG0
+  if(vformat == VF_BRG0 && input->vformat == VF_YUV422 && 
+     aformat == AF_NONE && abuffer == NULL)
+    return transcode_yuv2brg0(input, vbuffer, vbuffer_size);
+
+  // Unknown transcoding!
+  return NULL;
+}
-- 
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