(Drum roll) Long awaited support for Musepack

CVS patchset: 7344
CVS date: 2005/01/14 15:24:07

1 files changed, 83 insertions, 0 deletions

diff --git a/src/libmusepack/idtag.c b/src/libmusepack/idtag.c
new file mode 100644
index 000000000..4b02b33f4
--- /dev/null
+++ b/src/libmusepack/idtag.c
@@ -0,0 +1,83 @@
+/*
+  Copyright (c) 2004, The Musepack Development Team
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are
+  met:
+
+  * Redistributions of source code must retain the above copyright
+  notice, this list of conditions and the following disclaimer.
+
+  * Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the following
+  disclaimer in the documentation and/or other materials provided
+  with the distribution.
+
+  * Neither the name of the The Musepack Development Team nor the
+  names of its contributors may be used to endorse or promote
+  products derived from this software without specific prior
+  written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/// \file idtag.c
+/// Rudimentary id3tag handling routines, just enough to skip id3v2 tags,
+/// if present.
+
+#include "musepack/musepack.h"
+#include "musepack/internal.h"
+
+mpc_int32_t
+JumpID3v2 (mpc_reader* r) {
+    unsigned char  tmp [10];
+    mpc_uint32_t   Unsynchronisation;   // ID3v2.4-flag
+    mpc_uint32_t   ExtHeaderPresent;    // ID3v2.4-flag
+    mpc_uint32_t   ExperimentalFlag;    // ID3v2.4-flag
+    mpc_uint32_t   FooterPresent;       // ID3v2.4-flag
+    mpc_int32_t    ret;
+
+    // seek to first byte of mpc data
+    if (!r->seek (r->data, 0)) {
+        return 0;  
+    }
+    
+    r->read(r->data, tmp, sizeof(tmp));
+
+    // check id3-tag
+    if ( 0 != memcmp ( tmp, "ID3", 3) )
+        return 0;
+
+    // read flags
+    Unsynchronisation = tmp[5] & 0x80;
+    ExtHeaderPresent  = tmp[5] & 0x40;
+    ExperimentalFlag  = tmp[5] & 0x20;
+    FooterPresent     = tmp[5] & 0x10;
+
+    if ( tmp[5] & 0x0F )
+        return -1;              // not (yet???) allowed
+    if ( (tmp[6] | tmp[7] | tmp[8] | tmp[9]) & 0x80 )
+        return -1;              // not allowed
+
+    // read HeaderSize (syncsave: 4 * $0xxxxxxx = 28 significant bits)
+    ret  = tmp[6] << 21;
+    ret += tmp[7] << 14;
+    ret += tmp[8] <<  7;
+    ret += tmp[9]      ;
+    ret += 10;
+    if ( FooterPresent )
+        ret += 10;
+
+    return ret;
+}