Add MP3 decoding

[nornagon]

wav and caf are too big; I have about 40 sound effects I want to use. In linear pcm that comes to about 17MB.

[zoul]

I’d like to do this, but it’s very low priority, since I don’t need it myself. Not expected to come in the upcoming months.

[nornagon]

I needed it, so I have a patch that does it. I'll clean it up and send
a pull request.

On Fri, May 6, 2011 at 12:15 AM, zoul
reply@reply.github.com
wrote:

I’d like to do this, but it’s very low priority, since I don’t need it myself. Not expected to come in the upcoming months.

Reply to this email directly or view it on GitHub:
#14 (comment)

[pomarec]

nornagon, I would love to use it !

[nornagon]

Don't have the time to clean it up and make a proper pull request right now (or even to test that the code still works) but here's the patch I made. IIRC I copied the code to load mp3s from cocos2d.

diff --git a/Source/PCMDecoder.m b/Source/PCMDecoder.m
index bd885f3..3787b54 100644
--- a/Source/PCMDecoder.m
+++ b/Source/PCMDecoder.m
@@ -1,90 +1,123 @@
 #import "PCMDecoder.h"
-#import  
+#import 
+#import 
 #import "Sample.h"
 #import "Reporter.h"
+#import 
 
 @implementation PCMDecoder
 
 + (Sample*) decodeFile: (NSURL*) fileURL error: (NSError**) error
 {
-    OSStatus errcode = noErr;
-    UInt32 propertySize;
-    AudioFileID fileId = 0;
-    Reporter *reporter = [Reporter forDomain:@"Sample Decoder" error:error];
-    
-    errcode = AudioFileOpenURL((CFURLRef) fileURL, kAudioFileReadPermission, 0, &fileId);
-    if (errcode) {
-        *error = [reporter errorWithCode:kDEFileReadError];
-        return nil;
-    }
-    
-    AudioStreamBasicDescription fileFormat;
-    propertySize = sizeof(fileFormat);
-    errcode = AudioFileGetProperty(fileId, kAudioFilePropertyDataFormat, &propertySize, &fileFormat);
-    if (errcode) {
-        *error = [reporter errorWithCode:kDEFileFormatReadError];
-        AudioFileClose(fileId);
-        return nil;
-    }
-
-    if (fileFormat.mFormatID != kAudioFormatLinearPCM) { 
-        *error = [reporter
-            errorWithCode:kDEInvalidFileFormat
-            description:@"Sound file not linear PCM."];
-        AudioFileClose(fileId);
-        return nil;
-    }
-    
-    UInt64 fileSize = 0;
-    propertySize = sizeof(fileSize);
-    errcode = AudioFileGetProperty(fileId, kAudioFilePropertyAudioDataByteCount, &propertySize, &fileSize);
-    if (errcode) {
-        *error = [reporter
-            errorWithCode:kDEFileFormatReadError
-            description:@"Failed to read sound file size."];
-        AudioFileClose(fileId);
-        return nil;
-    }
-
-    double sampleLength = -1;
-    propertySize = sizeof(sampleLength);
-    errcode = AudioFileGetProperty(fileId, kAudioFilePropertyEstimatedDuration, &propertySize, &sampleLength);
-    if (errcode) {
-        *error = [reporter
-            errorWithCode:kDEFileFormatReadError
-            description:@"Failed to read sound length."];
-        AudioFileClose(fileId);
-        return nil;
-    }
-
-    UInt32 dataSize = (UInt32) fileSize;
-    void *data = malloc(dataSize);
-    if (!data) {
-        *error = [reporter errorWithCode:kDEMemoryAllocationError];
-        AudioFileClose(fileId);
-        return nil;
-    }
-    
-    errcode = AudioFileReadBytes(fileId, false, 0, &dataSize, data);
-    if (errcode) {
-        *error = [reporter
-            errorWithCode:kDEFileFormatReadError
-            description:@"Failed to read sound data."];
-        free(data);
-        AudioFileClose(fileId);
-        return nil;
-    }
-
-    Sample *sample = [[Sample alloc] init];
-    [sample setChannels:fileFormat.mChannelsPerFrame];
-    [sample setEndianity:TestAudioFormatNativeEndian(fileFormat) ? kLittleEndian : kBigEndian];
-    [sample setBitsPerChannel:fileFormat.mBitsPerChannel];
-    [sample setSampleRate:fileFormat.mSampleRate];
-    [sample setDuration:sampleLength];
-    [sample setData:[NSData dataWithBytesNoCopy:data length:dataSize freeWhenDone:YES]];
-    
-    AudioFileClose(fileId);
-    return [sample autorelease];
+   OSStatus errcode = noErr;
+   UInt32 propertySize;
+   ExtAudioFileRef fileRef = 0;
+   Reporter *reporter = [Reporter forDomain:@"Sample Decoder" error:error];
+   
+   errcode = ExtAudioFileOpenURL((CFURLRef) fileURL, &fileRef);
+   if (errcode) {
+       *error = [reporter errorWithCode:kDEFileReadError];
+       return nil;
+   }
+   
+   AudioStreamBasicDescription fileFormat;
+   propertySize = sizeof(fileFormat);
+   errcode = ExtAudioFileGetProperty(fileRef, kExtAudioFileProperty_FileDataFormat, &propertySize, &fileFormat);
+   if (errcode) {
+       *error = [reporter errorWithCode:kDEFileFormatReadError];
+       ExtAudioFileDispose(fileRef);
+       return nil;
+   }
+   
+   if (fileFormat.mChannelsPerFrame > 2) {
+       *error = [reporter
+                           errorWithCode:kDEFileFormatReadError
+                           description:@"Too many channels (better than stereo!)."];
+       ExtAudioFileDispose(fileRef);
+       return nil;
+   }
+   
+   AudioStreamBasicDescription theOutputFormat;
+   
+   theOutputFormat.mSampleRate = fileFormat.mSampleRate;
+   theOutputFormat.mChannelsPerFrame = fileFormat.mChannelsPerFrame;
+   
+   theOutputFormat.mFormatID = kAudioFormatLinearPCM;
+   theOutputFormat.mBytesPerPacket = 2 * theOutputFormat.mChannelsPerFrame;
+   theOutputFormat.mFramesPerPacket = 1;
+   theOutputFormat.mBytesPerFrame = 2 * theOutputFormat.mChannelsPerFrame;
+   theOutputFormat.mBitsPerChannel = 16;
+   theOutputFormat.mFormatFlags = kAudioFormatFlagsNativeEndian | kAudioFormatFlagIsPacked | kAudioFormatFlagIsSignedInteger;
+   
+   errcode = ExtAudioFileSetProperty(fileRef, kExtAudioFileProperty_ClientDataFormat, sizeof(theOutputFormat), &theOutputFormat);
+   if (errcode) {
+       *error = [reporter
+                           errorWithCode:kDEFileFormatReadError
+                           description:@"Couldn't set output format..."];
+       ExtAudioFileDispose(fileRef);
+       return nil;     
+   }
+   
+   
+   // Get the total frame count
+   SInt64 numFrames;
+   propertySize = sizeof(numFrames);
+   errcode = ExtAudioFileGetProperty(fileRef, kExtAudioFileProperty_FileLengthFrames, &propertySize, &numFrames);
+   if (errcode) {
+       *error = [reporter
+                           errorWithCode:kDEFileFormatReadError
+                           description:@"Couldn't set output format..."];
+       ExtAudioFileDispose(fileRef);
+       return nil;
+   }
+   
+   // Read all the data into memory
+   UInt64 dataSize = numFrames * theOutputFormat.mBytesPerFrame;
+   void *data = malloc(dataSize);
+   
+   ALsizei outDataSize;
+   ALenum outFormat;
+   ALsizei outSampleRate;
+   
+   if (data) {
+       AudioBufferList     theDataBuffer;
+       theDataBuffer.mNumberBuffers = 1;
+       theDataBuffer.mBuffers[0].mDataByteSize = dataSize;
+       theDataBuffer.mBuffers[0].mNumberChannels = theOutputFormat.mChannelsPerFrame;
+       theDataBuffer.mBuffers[0].mData = data;
+       
+       // Read the data into an AudioBufferList
+       errcode = ExtAudioFileRead(fileRef, (UInt32*)&numFrames, &theDataBuffer);
+       if(errcode == noErr)
+       {
+           // success
+           outDataSize = (ALsizei)dataSize;
+           outFormat = (theOutputFormat.mChannelsPerFrame > 1) ? AL_FORMAT_STEREO16 : AL_FORMAT_MONO16;
+           outSampleRate = (ALsizei)theOutputFormat.mSampleRate;
+       }
+       else
+       {
+           // failure
+           free (data);
+           data = nil;
+           *error = [reporter
+                               errorWithCode:kDEFileFormatReadError
+                               description:@"Couldn't set output format..."];
+           ExtAudioFileDispose(fileRef);
+           return nil;
+       }
+   }
+   
+   Sample *sample = [[Sample alloc] init];
+   [sample setChannels:theOutputFormat.mChannelsPerFrame];
+   [sample setEndianity:TestAudioFormatNativeEndian(theOutputFormat) ? kLittleEndian : kBigEndian];
+   [sample setBitsPerChannel:theOutputFormat.mBitsPerChannel];
+   [sample setSampleRate:theOutputFormat.mSampleRate];
+   //[sample setDuration:sampleLength];
+   [sample setData:[NSData dataWithBytesNoCopy:data length:dataSize freeWhenDone:YES]];
+   
+   ExtAudioFileDispose(fileRef);
+   return [sample autorelease];
 }
 
 + (void) load
diff --git a/Source/Sound.h b/Source/Sound.h
index 124ee6a..aa4b8ed 100644
--- a/Source/Sound.h
+++ b/Source/Sound.h
@@ -41,5 +41,6 @@ enum SoundError {
 
 - (void) play;
 - (void) stop;
+- (void) pause;
 
 @end
diff --git a/Source/Sound.m b/Source/Sound.m
index b552834..4bc5ff7 100644
--- a/Source/Sound.m
+++ b/Source/Sound.m
@@ -159,4 +159,13 @@
     [self checkSuccessOrLog:@"Failed to stop sound"];
 }
 
+- (void) pause
+{
+   if (!self.playing)
+       return;
+   CLEAR_ERROR_FLAG;
+   alSourcePause(source);
+   [self checkSuccessOrLog:@"Failed to pause sound"];
+}
+
 @end

[BobDG]

Does anybody have a working example with the code from nornagon? I can't seem to get it to work!