Skip ID3 tags in TTA files.

ChangeLog

@@ -1,5 +1,8 @@
 2004-08-01  Moritz Bunkus  <moritz@bunkus.org>
 
+	* mkvmerge: bug fix: Handle TTA files with ID3 tags correctly ( =
+	skip the ID3 tags).
+
 	* mkvmerge: bug fix: There was an illegal free() in the OGM
 	reader.
 

src/common/id3_common.cpp

@@ -0,0 +1,106 @@
+/*
+ * mkvmerge -- utility for splicing together matroska files
+ * from component media subtypes
+ *
+ * Distributed under the GPL
+ * see the file COPYING for details
+ * or visit http://www.gnu.org/copyleft/gpl.html
+ *
+ * $Id$
+ *
+ * helper functions for ID3 tags
+ *
+ * Written by Moritz Bunkus <moritz@bunkus.org>.
+ */
+
+#include "os.h"
+
+#include "mm_io.h"
+
+int
+skip_id3v2_tag(mm_io_c &io) {
+  unsigned char buffer[10];
+  int tag_size;
+
+  io.setFilePointer(0, seek_beginning);
+  if (io.read(buffer, 10) != 10) {
+    io.setFilePointer(0, seek_beginning);
+    return -1;
+  }
+
+  if (strncmp((char *)buffer, "ID3", 3) ||
+      (buffer[3] == 0xff) || (buffer[4] == 0xff) ||
+      (buffer[6] >= 0x80) || (buffer[7] >= 0x80) ||
+      (buffer[7] >= 0x80) || (buffer[8] >= 0x80)) {
+    io.setFilePointer(0, seek_beginning);
+    return 0;
+  }
+
+  tag_size = (buffer[6] << 21) | (buffer[7] << 14) | (buffer[8] << 7) |
+    buffer[9];
+  tag_size += 10;               // tag header
+  if ((buffer[5] & 0x10) != 0)
+    tag_size += 10;             // footer present
+
+  io.setFilePointer(tag_size, seek_beginning);
+  if (io.getFilePointer() == tag_size)
+    return tag_size;
+
+  io.setFilePointer(0, seek_beginning);
+  return -1;
+}
+
+int
+id3v2_tag_present_at_end(mm_io_c &io) {
+  unsigned char buffer[10];
+  int tag_size;
+
+  io.save_pos();
+  io.setFilePointer(-10, seek_end);
+  if (io.read(buffer, 10) != 10) {
+    io.restore_pos();
+    return 0;
+  }
+
+  if (strncmp((char *)buffer, "3DI", 3) ||
+      (buffer[3] == 0xff) || (buffer[4] == 0xff) ||
+      (buffer[6] >= 0x80) || (buffer[7] >= 0x80) ||
+      (buffer[7] >= 0x80) || (buffer[8] >= 0x80)) {
+    io.restore_pos();
+    return 0;
+  }
+
+  tag_size = (buffer[6] << 21) | (buffer[7] << 14) | (buffer[8] << 7) |
+    buffer[9];
+  tag_size += 10;               // tag header
+  tag_size += 10;               // tag footer
+
+  io.restore_pos();
+
+  return tag_size;
+}
+
+int
+id3v1_tag_present_at_end(mm_io_c &io) {
+  unsigned char buffer[3];
+
+  if (io.get_size() < 128)
+    return 0;
+  io.save_pos();
+  io.setFilePointer(-128, seek_end);
+  if (io.read(buffer, 3) != 3) {
+    io.restore_pos();
+    return 0;
+  }
+  io.restore_pos();
+  if (strncmp((char *)buffer, "TAG", 3) == 0)
+    return 128;
+  return 0;
+}
+
+int
+id3_tag_present_at_end(mm_io_c &io) {
+  if (id3v1_tag_present_at_end(io))
+    return 128;
+  return id3v2_tag_present_at_end(io);
+}

src/common/id3_common.h

@@ -0,0 +1,28 @@
+/*
+ * mkvmerge -- utility for splicing together matroska files
+ * from component media subtypes
+ *
+ * Distributed under the GPL
+ * see the file COPYING for details
+ * or visit http://www.gnu.org/copyleft/gpl.html
+ *
+ * $Id$
+ *
+ * helper functions for ID3 tags
+ *
+ * Written by Moritz Bunkus <moritz@bunkus.org>.
+ */
+
+#ifndef __ID3_COMMON_H
+#define __ID3_COMMON_H
+
+#include "os.h"
+
+class mm_io_c;
+
+int MTX_DLL_API skip_id3v2_tag(mm_io_c &io);
+int MTX_DLL_API id3v1_tag_present_at_end(mm_io_c &io);
+int MTX_DLL_API id3v2_tag_present_at_end(mm_io_c &io);
+int MTX_DLL_API id3_tag_present_at_end(mm_io_c &io);
+
+#endif /* __ID3_COMMON_H */

src/input/r_tta.cpp

@@ -21,20 +21,25 @@
 #include "mkvmerge.h"
 #include "common.h"
 #include "error.h"
+#include "id3_common.h"
 #include "p_tta.h"
 #include "r_tta.h"
 
 int
 tta_reader_c::probe_file(mm_io_c *mm_io,
                          int64_t size) {
+  int tag_size;
   unsigned char buf[4];
 
   if (size < 26)
     return 0;
   try {
     mm_io->setFilePointer(0, seek_beginning);
+    tag_size = skip_id3v2_tag(*mm_io);
+    if (tag_size == -1)
+      return 0;
     if (mm_io->read(buf, 4) != 4)
-      mm_io->setFilePointer(0, seek_beginning);
+      return 0;
     mm_io->setFilePointer(0, seek_beginning);
   } catch (exception &ex) {
     return 0;
@@ -49,6 +54,7 @@ tta_reader_c::tta_reader_c(track_info_c *nti)
   generic_reader_c(nti) {
   uint32_t seek_point;
   int64_t seek_sum;
+  int tag_size;
 
   try {
     mm_io = new mm_io_c(ti->fname, MODE_READ);
@@ -57,10 +63,17 @@ tta_reader_c::tta_reader_c(track_info_c *nti)
     if (identifying)
       return;
 
+    tag_size = skip_id3v2_tag(*mm_io);
+    if (tag_size < 0)
+      mxerror(_("tta_reader: tag_size < 0 in the c'tor. %s\n"), BUGMSG);
+    size -= tag_size;
+
     if (mm_io->read(&header, sizeof(tta_file_header_t)) !=
         sizeof(tta_file_header_t))
       mxerror(FMT_FN "The file header is too short.\n", ti->fname);
-    seek_sum = mm_io->getFilePointer() + 4;
+    seek_sum = mm_io->getFilePointer() + 4 - tag_size;
+
+    size -= id3_tag_present_at_end(*mm_io);
 
     do {
       seek_point = mm_io->read_uint32();