Apple

On Feb 15, 2009, at 9:28 PM, rethish wrote:

Hi all,

I need to append an newly recorded audio file with the end of an existing file.

I use the function ,     AudioFileOpenURL (   CFURLRef        inFileRef,   SInt8           inPermissions,
                                   AudioFileTypeID inFileTypeHint,   AudioFileID     *outAudioFile);
by setting read write permission to do it.

My idea is to count the packet number of the existing file and set it as the starting packet number of the recording file

Is there any function to get the packet number of the audio file?

I had found a function ,

AudioFileGetProperty (   AudioFileID         inAudioFile,   AudioFilePropertyID   inPropertyID,
                        UInt32        *ioDataSize, void                *outPropertyData);

But this function doesn’t return the correct packet number.

What property are you using? We use the get number of packets property (kAudioFilePropertyAudioDataPacketCount) all the time and this is always correct

When I am setting the starting packet number (some integer number like 49152) manually, the recording file can be appended with the existing file starting from that packet number.

Is I am going in a correct way?

This isn't going to work for all foramts/file types - it should work ok if you are just dealing with linear pcm

References:
	>Reading packets from an audio file (From: rethish <email@hidden>)