1 files changed, 207 insertions, 0 deletions

diff --git a/src/plugins/mp4_extractor.c b/src/plugins/mp4_extractor.c
new file mode 100644
index 0000000..f486a89
--- /dev/null
+++ b/src/plugins/mp4_extractor.c
@@ -0,0 +1,207 @@
+/*
+     This file is part of libextractor.
+     (C) 2012 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.
+ */
+
+/**
+ * @file plugins/mp4_extractor.c
+ * @brief plugin to support MP4 files
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "extractor.h"
+#include <mp4v2/mp4v2.h>
+
+
+/**
+ * Callback invoked by libmp4v2 to open the file. 
+ * We cheated and passed our extractor context as
+ * the filename (fingers crossed) and will simply
+ * return it again to make it the handle.
+ *
+ * @param name "filename" to open
+ * @param open mode, only reading allowed
+ * @return NULL if the file is not opened for reading
+ */
+static void*
+open_cb (const char *name,
+         MP4FileMode mode)
+{
+  void *ecp;
+
+  if (FILEMODE_READ != mode)
+    return NULL;
+  if (1 != sscanf (name, "%p", &ecp))
+    return NULL;
+  return ecp;
+}
+
+
+/**
+ * Seek callback for libmp4v2.
+ *
+ * @param handle the 'struct EXTRACTOR_ExtractContext'
+ * @param pos target seek position (relative or absolute?)
+ * @return true on failure, false on success
+ */
+static int
+seek_cb (void *handle,
+         int64_t pos)
+{
+  struct EXTRACTOR_ExtractContext *ec = handle;
+
+  fprintf (stderr, "Seek: %lld!\n", (long long) pos);
+  if (-1 == 
+      ec->seek (ec->cls,
+                pos,
+                SEEK_CUR))
+    return true; /* failure */
+  return false;
+}
+
+
+/**
+ * Read callback for libmp4v2.
+ *
+ * @param handle the 'struct EXTRACTOR_ExtractContext'
+ * @param buffer where to write data read
+ * @param size desired number of bytes to read
+ * @param nin where to write number of bytes read
+ * @param maxChunkSize some chunk size (ignored)
+ * @return true on failure, false on success
+ */
+static int 
+read_cb (void *handle,
+         void *buffer,
+         int64_t size,
+         int64_t *nin,
+         int64_t maxChunkSize)
+{
+  struct EXTRACTOR_ExtractContext *ec = handle;
+  void *buf;
+  ssize_t ret;
+ 
+ fprintf (stderr, "read!\n");
+  *nin = 0;
+  if (-1 == 
+      (ret = ec->read (ec->cls,
+                       &buf,
+                       size)))
+    return true; /* failure */
+  memcpy (buffer, buf, ret);
+  *nin = ret;
+  return false; /* success */
+}
+
+
+/**
+ * Write callback for libmp4v2.
+ *
+ * @param handle the 'struct EXTRACTOR_ExtractContext'
+ * @param buffer data to write
+ * @param size desired number of bytes to write
+ * @param nin where to write number of bytes written
+ * @param maxChunkSize some chunk size (ignored)
+ * @return true on failure (always fails)
+ */
+static int
+write_cb (void *handle,
+          const void *buffer,
+          int64_t size,
+          int64_t *nout,
+          int64_t maxChunkSize)
+{
+  fprintf (stderr, "Write!?\n");
+  return true; /* failure  */
+}
+
+
+/**
+ * Write callback for libmp4v2.  Does nothing.
+ *
+ * @param handle the 'struct EXTRACTOR_ExtractContext'
+ * @return false on success (always succeeds)
+ */
+static int
+close_cb (void *handle)
+{
+  fprintf (stderr, "Close!\n");
+  return false; /* success */
+}
+
+
+#if 0
+/**
+ * Wrapper to replace 'stat64' call by libmp4v2.
+ */
+int 
+stat_cb (const char * path,
+         struct stat64 * buf) 
+{
+  void *ecp;
+  struct EXTRACTOR_ExtractContext *ec;
+
+  fprintf (stderr, "stat!\n");
+  if (1 != sscanf (path, "%p", &ecp))
+    {
+      errno = EINVAL;
+      return -1;
+    }
+  ec = ecp;
+  memset (buf, 0, sizeof (struct stat));
+  buf->st_size = ec->get_size (ec->cls);
+  return 0;
+}
+#endif
+
+
+/**
+ * Main entry method for the MP4 extraction plugin.
+ *
+ * @param ec extraction context provided to the plugin
+ */
+void 
+EXTRACTOR_mp4_extract_method (struct EXTRACTOR_ExtractContext *ec)
+{
+  MP4FileProvider fp;
+  MP4FileHandle mp4;
+  const MP4Tags *tags;
+  char ecp[128];
+  void *dl;
+
+  if (1)
+    return; /* plugin is known not to work yet;
+               see issue 138 filed against MP4v2 lib */
+  snprintf (ecp, sizeof (ecp), "%p", ec);
+  fp.open = &open_cb;
+  fp.seek = &seek_cb;
+  fp.read = &read_cb;
+  fp.write = &write_cb;
+  fp.close = &close_cb;
+  if (NULL == (mp4 = MP4ReadProvider (ecp,
+                                      &fp)))
+    return;
+  tags = MP4TagsAlloc ();
+  if (MP4TagsFetch (tags, mp4))
+    {
+      fprintf (stderr, "got tags!\n");
+    }
+  MP4Close (mp4, 0);
+}
+
+/* end of mp4_extractor.c */