How to convert base64 wav to base64 mp3 in JavaScript

问题

I have a trouble in my app.

I want to record a sound and store it in iOS using Cordova. I have already a base64/wav file, but it's very heavy so I want to convert it into a base64/mp3.

Which is the algorithm that allows me to do that?

Example:

b64Wavtob64mp3("base64/...");
// Return a mp3 base64

Thanks in advance!

回答1:

I forgot completely base64 because I was looking for a audio compressed

Solved!

I did it with a wav2m4a plugin.

https://github.com/xu-li/phonegap-wav2m4a

But I wanted to go further so I modified CDVSound.m at iOS. I just followed these instructions:

https://gist.github.com/jlsuarezs/d48094d431307a466496

1. Add to the startRecordingAudio method on CDVSound.m this:

   NSDictionary *recordSettings = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt: kAudioFormatMPEG4AAC], AVFormatIDKey, [NSNumber numberWithFloat:16000.0], AVSampleRateKey, [NSNumber numberWithInt: 1], AVNumberOfChannelsKey, nil];

2. Replace:

   audioFile.recorder = [[CDVAudioRecorder alloc] initWithURL:audioFile.resourceURL settings:nil error:&error]; // Default PCM recording

   With:

   audioFile.recorder = [[CDVAudioRecorder alloc] initWithURL:audioFile.resourceURL settings:recordSettings error:&error];

   3. Changing another lines: CDVSound.m checks to make sure you're using a wav file. Simply changing this at the top of the file should prevent that.

   define RECORDING_WAV @"wav"

I changed it to:

#define RECORDING_WAV @"m4a"

or

#define RECORDING_M4A @"m4a" 

and change in the file instances that contains the RECORDING_WAV variable.

来源：https://stackoverflow.com/questions/31532265/how-to-convert-base64-wav-to-base64-mp3-in-javascript