1 files changed, 167 insertions, 0 deletions
diff --git a/gst-libs/ext/mplex/yuv4mpeg_ratio.cc b/gst-libs/ext/mplex/yuv4mpeg_ratio.cc
new file mode 100644
index 00000000..a20a2373
--- /dev/null
+++ b/gst-libs/ext/mplex/yuv4mpeg_ratio.cc
@@ -0,0 +1,167 @@
+/*
+ *  yuv4mpeg_ratio.c:  Functions for dealing with y4m_ratio_t datatype.
+ *
+ *  Copyright (C) 2001 Matthew J. Marjanovic <maddog@mir.com>
+ *
+ *
+ *  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 sample 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_SQR_ANA_16_9 = Y4M_SAR_SQR_ANA_16_9;
+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;
+
+/* useful list of standard display aspect ratios */
+const y4m_ratio_t y4m_dar_4_3 = Y4M_DAR_4_3;
+const y4m_ratio_t y4m_dar_16_9 = Y4M_DAR_16_9;
+const y4m_ratio_t y4m_dar_221_100 = Y4M_DAR_221_100;
+
+/*
+ *  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;
+}
+
+
+
+/*************************************************************************
+ *
+ * Guess the true SAR (sample aspect ratio) from a list of commonly 
+ * encountered values, given the "suggested" display aspect ratio, and
+ * the true frame width and height.
+ *
+ * Returns y4m_sar_UNKNOWN if no match is found.
+ *
+ *************************************************************************/
+
+/* this is big enough to accommodate the difference between 720 and 704 */
+#define GUESS_ASPECT_TOLERANCE 0.03
+
+y4m_ratio_t
+y4m_guess_sar (int width, int height, y4m_ratio_t dar)
+{
+  int i;
+  double implicit_sar = (double) (dar.n * height) / (double) (dar.d * width);
+  y4m_ratio_t sarray[] = {
+    y4m_sar_SQUARE,
+    y4m_sar_NTSC_CCIR601,
+    y4m_sar_NTSC_16_9,
+    y4m_sar_NTSC_SVCD_4_3,
+    y4m_sar_NTSC_SVCD_16_9,
+    y4m_sar_PAL_CCIR601,
+    y4m_sar_PAL_16_9,
+    y4m_sar_PAL_SVCD_4_3,
+    y4m_sar_PAL_SVCD_16_9,
+    y4m_sar_UNKNOWN
+  };
+
+  for (i = 0; !(Y4M_RATIO_EQL (sarray[i], y4m_sar_UNKNOWN)); i++) {
+    double ratio = implicit_sar / Y4M_RATIO_DBL (sarray[i]);
+
+    if ((ratio > (1.0 - GUESS_ASPECT_TOLERANCE)) && (ratio < (1.0 + GUESS_ASPECT_TOLERANCE)))
+      return sarray[i];
+  }
+  return y4m_sar_UNKNOWN;
+}