yuv4mpeg2 (mjpegtools) support by Rik Snel <rsnel@cube.dyndns.org>

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@3787 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 113 insertions, 0 deletions

diff --git a/libmpdemux/yuv4mpeg_ratio.c b/libmpdemux/yuv4mpeg_ratio.c
new file mode 100644
index 0000000000..e4a3d5a3a6
--- /dev/null
+++ b/libmpdemux/yuv4mpeg_ratio.c
@@ -0,0 +1,113 @@
+/*
+ *  yuv4mpeg_ratio.c:  Functions for dealing with y4m_ratio_t datatype.
+ *
+ *  Copyright (C) 2001 Matthew J. Marjanovic <maddog@mir.com>
+ *
+ *  This file is part of the lavtools packaged (mjpeg.sourceforge.net)
+ *
+ *  This program 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.
+ *
+ *  This program 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 this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ */
+
+#include "config.h"
+
+#include <string.h>
+#include "yuv4mpeg.h"
+#include "yuv4mpeg_intern.h"
+
+
+/* useful list of standard framerates */
+const y4m_ratio_t y4m_fps_UNKNOWN    = Y4M_FPS_UNKNOWN;
+const y4m_ratio_t y4m_fps_NTSC_FILM  = Y4M_FPS_NTSC_FILM;
+const y4m_ratio_t y4m_fps_FILM       = Y4M_FPS_FILM;
+const y4m_ratio_t y4m_fps_PAL        = Y4M_FPS_PAL;
+const y4m_ratio_t y4m_fps_NTSC       = Y4M_FPS_NTSC;
+const y4m_ratio_t y4m_fps_30         = Y4M_FPS_30;
+const y4m_ratio_t y4m_fps_PAL_FIELD  = Y4M_FPS_PAL_FIELD;
+const y4m_ratio_t y4m_fps_NTSC_FIELD = Y4M_FPS_NTSC_FIELD;
+const y4m_ratio_t y4m_fps_60         = Y4M_FPS_60;
+
+/* useful list of standard pixel aspect ratios */
+const y4m_ratio_t y4m_sar_UNKNOWN        = Y4M_SAR_UNKNOWN;
+const y4m_ratio_t y4m_sar_SQUARE         = Y4M_SAR_SQUARE;
+const y4m_ratio_t y4m_sar_NTSC_CCIR601   = Y4M_SAR_NTSC_CCIR601;
+const y4m_ratio_t y4m_sar_NTSC_16_9      = Y4M_SAR_NTSC_16_9;
+const y4m_ratio_t y4m_sar_NTSC_SVCD_4_3  = Y4M_SAR_NTSC_SVCD_4_3;
+const y4m_ratio_t y4m_sar_NTSC_SVCD_16_9 = Y4M_SAR_NTSC_SVCD_16_9;
+const y4m_ratio_t y4m_sar_PAL_CCIR601    = Y4M_SAR_PAL_CCIR601;
+const y4m_ratio_t y4m_sar_PAL_16_9       = Y4M_SAR_PAL_16_9;
+const y4m_ratio_t y4m_sar_PAL_SVCD_4_3   = Y4M_SAR_PAL_SVCD_4_3;
+const y4m_ratio_t y4m_sar_PAL_SVCD_16_9  = Y4M_SAR_PAL_SVCD_16_9;
+
+
+/*
+ *  Euler's algorithm for greatest common divisor
+ */
+
+static int gcd(int a, int b)
+{
+  a = (a >= 0) ? a : -a;
+  b = (b >= 0) ? b : -b;
+
+  while (b > 0) {
+    int x = b;
+    b = a % b;
+    a = x;
+  }
+  return a;
+}
+    
+
+/*************************************************************************
+ *
+ * Remove common factors from a ratio
+ *
+ *************************************************************************/
+
+
+void y4m_ratio_reduce(y4m_ratio_t *r)
+{
+  int d;
+  if ((r->n == 0) && (r->d == 0)) return;  /* "unknown" */
+  d = gcd(r->n, r->d);
+  r->n /= d;
+  r->d /= d;
+}
+
+
+
+/*************************************************************************
+ *
+ * Parse "nnn:ddd" into a ratio
+ *
+ * returns:         Y4M_OK  - success
+ *           Y4M_ERR_RANGE  - range error 
+ *
+ *************************************************************************/
+
+int y4m_parse_ratio(y4m_ratio_t *r, const char *s)
+{
+  char *t = strchr(s, ':');
+
+  if (t == NULL) return Y4M_ERR_RANGE;
+  r->n = atoi(s);
+  r->d = atoi(t+1);
+  if (r->d < 0) return Y4M_ERR_RANGE;
+  /* 0:0 == unknown, so that is ok, otherwise zero denominator is bad */
+  if ((r->d == 0) && (r->n != 0)) return Y4M_ERR_RANGE;
+  y4m_ratio_reduce(r);
+  return Y4M_OK;
+}
+