1 files changed, 157 insertions, 0 deletions

diff --git a/src/plugins/riff_extractor.c b/src/plugins/riff_extractor.c
new file mode 100644
index 0000000..b9cb5b3
--- /dev/null
+++ b/src/plugins/riff_extractor.c
@@ -0,0 +1,157 @@
+/*
+     This file is part of libextractor.
+     (C) 2004, 2009, 2012 Vidyut Samanta and Christian Grothoff
+
+     libextractor 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 3, or (at your
+     option) any later version.
+
+     libextractor 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 libextractor; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+
+     This code was based on AVInfo 1.0 alpha 11
+     (c) George Shuklin, gs]AT[shounen.ru, 2002-2004
+     http://shounen.ru/soft/avinfo/
+
+     and bitcollider 0.6.0
+     (PD) 2004 The Bitzi Corporation
+     http://bitzi.com/
+ */
+/**
+ * @file plugins/riff_extractor.c
+ * @brief plugin to support RIFF files (ms-video)
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "extractor.h"
+#include <math.h>
+
+
+/**
+ * Read an uint32_t as a little-endian (least
+ * significant byte first) integer from 'data'
+ *
+ * @param data input data
+ * @return integer read
+ */
+static uint32_t
+fread_le (const char *data)
+{
+  unsigned int x;
+  uint32_t result = 0;
+
+  for (x = 0; x < 4; x++)
+    result |= ((unsigned char) data[x]) << (x * 8);
+  return result;
+}
+
+
+/**
+ * We implement our own rounding function, because the availability of
+ * C99's round(), nearbyint(), rint(), etc. seems to be spotty, whereas
+ * floor() is available in math.h on all C compilers.
+ *
+ * @param num value to round
+ * @return rounded-to-nearest value
+ */
+static double
+round_double (double num)
+{
+  return floor (num + 0.5);
+}
+
+
+/**
+ * Pass the given UTF-8 string to the 'proc' callback using
+ * the given type.  Uses 'return' if 'proc' returns non-0.
+ *
+ * @param s 0-terminated UTF8 string value with the meta data
+ * @param t libextractor type for the meta data
+ */
+#define ADD(s,t) do { if (0 != ec->proc (ec->cls, "riff", t, EXTRACTOR_METAFORMAT_UTF8, "text/plain", s, strlen (s) + 1)) return; } while (0)
+
+
+/**
+ * Main entry method for the 'video/x-msvideo' extraction plugin.  
+ *
+ * @param ec extraction context provided to the plugin
+ */
+void 
+EXTRACTOR_riff_extract_method (struct EXTRACTOR_ExtractContext *ec)
+{
+  ssize_t xsize;
+  void *data;
+  char *xdata;
+  uint32_t blockLen;
+  unsigned int fps;
+  unsigned int duration;
+  uint64_t pos;
+  uint32_t width;
+  uint32_t height;
+  char codec[5];
+  char format[256];
+  
+  /* read header */
+  if (72 > (xsize = ec->read (ec->cls, &data, 72)))
+    return;
+  xdata = data;
+  
+  /* check magic values */
+  if ( (0 != memcmp (&xdata[0],
+                     "RIFF", 4)) || 
+       (0 != memcmp (&xdata[8], "AVI ", 4)) ||
+       (0 != memcmp (&xdata[12], "LIST", 4)) ||
+       (0 != memcmp (&xdata[20], "hdrlavih", 8)) )
+    return;
+  
+  blockLen = fread_le (&xdata[28]);
+  
+  /* begin of AVI header at 32 */
+  fps = (unsigned int) round_double ((double) 1.0e6 / fread_le (&xdata[32]));
+  duration = (unsigned int) round_double ((double) fread_le (&xdata[48])
+                                          * 1000 / fps);
+  width = fread_le (&xdata[64]);
+  height = fread_le (&xdata[68]);
+
+  /* pos: begin of video stream header */
+  pos = blockLen + 32;
+
+  if (pos !=
+      ec->seek (ec->cls, pos, SEEK_SET))
+    return; 
+  if (32 > ec->read (ec->cls, &data, 32))
+    return;
+  xdata = data;
+
+  /* check magic */
+  if ( (0 != memcmp (xdata, "LIST", 4)) ||
+       (0 != memcmp (&xdata[8], "strlstrh", 8)) ||
+       (0 != memcmp (&xdata[20], "vids", 4)) )
+    return;
+
+  /* pos + 24: video stream header with codec */
+  memcpy (codec, &xdata[24], 4);
+  codec[4] = '\0';
+  snprintf (format,
+            sizeof (format),
+            _("codec: %s, %u fps, %u ms"), 
+            codec, fps, duration);
+  ADD (format, EXTRACTOR_METATYPE_FORMAT);
+  snprintf (format, 
+            sizeof (format), 
+            "%ux%u", 
+            (unsigned int) width,
+            (unsigned int) height);
+  ADD (format, EXTRACTOR_METATYPE_IMAGE_DIMENSIONS);
+  ADD ("video/x-msvideo", EXTRACTOR_METATYPE_MIMETYPE);
+}
+
+/* end of riff_extractor.c */