More options for MP4 file customization

- Add own property for album - Add gapless play option - Add trackno/total tracks options
gonzoua · Jul 21, 2010 · 27a4b2d · 27a4b2d
1 parent f8bea98
commit 27a4b2d
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Showing 3 changed files with 44 additions and 11 deletions.
diff --git a/MP4Atom.h b/MP4Atom.h
@@ -27,8 +27,10 @@
 
 #import <Cocoa/Cocoa.h>
 
+#define ITUNES_METADATA_IMPLICIT_CLASS  0x00
 #define ITUNES_METADATA_STRING_CLASS    0x01
 #define ITUNES_METADATA_IMAGE_CLASS     0x0e
+#define ITUNES_METADATA_UINT8_CLASS     0x15
 
 @interface MP4Atom : NSObject {
     NSString *name;

diff --git a/MP4File.h b/MP4File.h
@@ -33,12 +33,18 @@
     NSFileHandle *_fh;
     NSString *artist;
     NSString *title;
+    NSString *album;
     NSString *coverFile;
+    unsigned short track, tracksTotal;
+    BOOL gaplessPlay;
 }
 
 @property (readwrite, copy) NSString *artist;
+@property (readwrite, copy) NSString *album;
 @property (readwrite, copy) NSString *title;
 @property (readwrite, copy) NSString *coverFile;
+@property (readwrite, assign) unsigned short track, tracksTotal;
+@property (readwrite, assign) BOOL gaplessPlay;
 
 -(void) dealloc;
 -(id) initWithFileName: (NSString*)fileName;

diff --git a/MP4File.m b/MP4File.m
@@ -34,18 +34,22 @@
 
 @implementation MP4File
 
-@synthesize artist;
-@synthesize title;
-@synthesize coverFile;
+@synthesize artist, album, title, coverFile;
+@synthesize track, tracksTotal, gaplessPlay;
+
 
 -(id) initWithFileName: (NSString*)fileName
 {
     [super init];
 
     _fh = [NSFileHandle fileHandleForUpdatingAtPath:fileName];
     self.artist = nil;
+    self.album = nil;
     self.title = nil;
     self.coverFile = nil;
+
+    track = tracksTotal = 0;
+    gaplessPlay = NO;
 
     UInt64 pos = 0;
     NSData *buffer;
@@ -142,21 +146,41 @@ -(BOOL) updateFile
 
     NSMutableData *newAtomsData = [[NSMutableData alloc] init];
     if (title != nil)
-    {
         [newAtomsData appendData:[self encodeMetaDataAtom:@"©nam" 
                                                 value:[title dataUsingEncoding:NSUTF8StringEncoding]
                                                  type:ITUNES_METADATA_STRING_CLASS]];
 
+    if (album != nil)
         [newAtomsData appendData:[self encodeMetaDataAtom:@"©alb" 
-                                                value:[title dataUsingEncoding:NSUTF8StringEncoding] 
-                                                 type:ITUNES_METADATA_STRING_CLASS]];        
-    }   
-
+                                                value:[album dataUsingEncoding:NSUTF8StringEncoding] 
+                                                 type:ITUNES_METADATA_STRING_CLASS]];    
     if (artist != nil)
         [newAtomsData appendData:[self encodeMetaDataAtom:@"©ART" 
                                                 value:[artist dataUsingEncoding:NSUTF8StringEncoding] 
                                                  type:ITUNES_METADATA_STRING_CLASS]];
 
+
+    if (track) {
+        short bytes[4];
+        bytes[0] = bytes[3] = 0;
+        bytes[1] = htons(track);
+        bytes[2] = htons(tracksTotal);
+        NSData * data = [[NSData alloc] initWithBytes:bytes length:8];
+        [newAtomsData appendData:[self encodeMetaDataAtom:@"trkn" 
+                                                value:data
+                                                 type:ITUNES_METADATA_IMPLICIT_CLASS]];
+        [data release];
+    }
+
+    if (gaplessPlay) {        
+        char pgap = 1;
+        NSData * data = [[NSData alloc] initWithBytes:&pgap length:1];
+        [newAtomsData appendData:[self encodeMetaDataAtom:@"pgap" 
+                                                    value:data
+                                                     type:ITUNES_METADATA_UINT8_CLASS]];
+        [data release];
+    }
+
     [newAtomsData appendData:[self encodeMetaDataAtom:@"©gen" 
                                             value:[@"Audiobooks" dataUsingEncoding:NSUTF8StringEncoding] 
                                              type:ITUNES_METADATA_STRING_CLASS]];
@@ -262,7 +286,8 @@ -(void) fixupAtom: (MP4Atom*)atom
  * Encode iTunes metadata atoms
  */
 -(NSData*) encodeMetaDataAtom: (NSString*)name value:(NSData*)value 
-    type:(UInt32) type;
+                         type:(UInt32)type
+
 {
     UInt32 dataAtomSize = 
             [value length] + 
@@ -274,8 +299,8 @@ -(NSData*) encodeMetaDataAtom: (NSString*)name value:(NSData*)value
                                             andLength:dataAtomSize];
     [data appendData:[dataAtom encode]];
     // version and flags
-    UInt32 flags = htonl(type);
-    [data appendBytes:&flags length:4];
+    type = htonl(type);
+    [data appendBytes:&type length:4];
     // null data
     UInt32 zeroData = 0;
     [data appendBytes:&zeroData length:4];