是否有任何npn包将wav文件转换为节点js中的mp3文件？我想在aws lambda函数中运行这个脚本。我试过sox和sox-audio包，但lambda不支持它。我google了ffmpeg，没有找到wav和mp3之间的任何转换。
是否有人在节点js中提供了良好的转换包？
console.log('New Lambda Call');
var async = require('async');
var aws = require('aws-sdk');
var fs = require('fs');
var uuid = require('node-uuid');
var SoxCommand = require('sox-audio');
var sox = require('sox');
var s3 = new aws.S3({ apiVersion: '2006-03-01' });
exports.handler = function(event, context) {
//console.log('Reading event option : ', JSON.stringify(event, null, 2));
var src_bucket = event.Records[0].s3.bucket.name;
var key = event.Records[0].s3.object.key;
var src_key = decodeURIComponent(event.Records[0].s3.object.key.replace(/\+/g, " "));
var dest_bucket = "dmlambda";
var desk_key = src_key;
var params = {
Bucket: src_bucket,
Key: src_key
};
if (src_bucket == dest_bucket) {
console.error("Destination bucket must not match source bucket.");
return;
}
var typeMatch = src_key.match(/\.([^.]*)$/);
if (!typeMatch) {
console.error('unable to infer audio type for key ' + src_key);
return;
}
console.log()
var audioType = typeMatch[1];
if (audioType != "wav") {
console.log('skipping non wav audio ' + src_key);
return;
}
s3.getObject(params, function(err, data){
if (err) {
console.log(err);
var message = "Error getting object " + src_key + " from bucket " + src_bucket +
". Make sure they exist and your bucket is in the same region as this function.";
console.log(message);
} else {
console.log('Audio Content type:', data.ContentType);
fs.writeFile('./tmp/temp_'+src_key, data.Body, {encoding: null}, function(err){
if(err){
console.log("download file write error"+ err);
} else {
console.log('Added temp_'+src_key+' to queue');
var arr = src_key.split(".");
var filename = arr[0];
var command = SoxCommand()
.input('./tmp/temp_'+src_key)
.output('./tmp/'+filename+'.mp3')
.outputFileType('mp3')
.outputSampleRate(44100)
.outputBits(192 * 1024)
.outputChannels(2);
command.on('prepare', function(args) {
console.log('Preparing sox command with args ' + args.join(' '));
});
command.on('start', function(commandLine) {
console.log('Spawned sox with command ' + commandLine);
});
command.on('progress', function(progress) {
console.log('Processing progress: ', progress);
});
command.on('error', function(err, stdout, stderr) {
console.log('Cannot process audio: ' + err.message);
console.log('Sox Command Stdout: ', stdout);
console.log('Sox Command Stderr: ', stderr);
});
command.on('end', function() {
fs.unlink('./tmp/temp_'+src_key, function(err){
if(err){
console.log("delete error : ",err);
} else {
console.log('Moved temp_'+src_key);
}
});
console.log('Sox command succeeded!');
var stream = fs.createReadStream('./tmp/'+filename+'.mp3');
s3.putObject({
Bucket: dest_bucket,
Key: filename+'.mp3',
Body: stream
}, function(err, data){
if(err){
console.log("upload error : ",err);
} else {
fs.unlink('./tmp/'+filename+'.mp3', function(err){
if(err){
console.log("delete error : ",err);
} else {
console.log('Moved '+filename+'.mp3');
}
});
}
});
});
command.run();
}
});
}
});
};
Lambda日志是：
2015-08-13T05:39:21.845Z vg7ewk1gk1bjvn30 New Lambda Call
START RequestId: a5ec9286-417d-11e5-9a79-310ba41a5a40
2015-08-13T05:39:21.990Z a5ec9286-417d-11e5-9a79-310ba41a5a40
2015-08-13T05:39:22.285Z a5ec9286-417d-11e5-9a79-310ba41a5a40 Audio Content type: audio/x-wav
2015-08-13T05:39:22.320Z a5ec9286-417d-11e5-9a79-310ba41a5a40 Added temp_RE4bc9f41b1738c6def250a58e32d473aa.wav to queue
2015-08-13T05:39:22.322Z a5ec9286-417d-11e5-9a79-310ba41a5a40 Preparing sox command with args ./tmp/temp_RE4bc9f41b1738c6def250a58e32d473aa.wav -t mp3 -r 44100 -b 196608 -c 2 ./tmp/RE4bc9f41b1738c6def250a58e32d473aa.mp3
2015-08-13T05:39:22.366Z a5ec9286-417d-11e5-9a79-310ba41a5a40 Cannot process audio: Cannot find sox
2015-08-13T05:39:22.366Z a5ec9286-417d-11e5-9a79-310ba41a5a40 Sox Command Stdout: null
2015-08-13T05:39:22.366Z a5ec9286-417d-11e5-9a79-310ba41a5a40 Sox Command Stderr:
END RequestId: a5ec9286-417d-11e5-9a79-310ba41a5a40
Process exited before completing request
答案 0 :(得分：4)
sox npm package只是 sox CLI的界面。
在错误日志中，它显示Cannot process audio: Cannot find sox。这是因为您没有安装实际的sox CLI。安装它。
为了在the AWS blog中包含sox CLI，来自here：
包含您自己的可执行文件很容易;只需将它们打包到您上传的ZIP文件中，然后在从Node.js或之前启动的其他进程中调用它们时引用它们（包括您创建的ZIP文件中的相对路径）。确保在功能代码的开头包含以下内容：
process.env ['PATH'] = process.env ['PATH'] +'：'+ process.env ['LAMBDA_TASK_ROOT']
总结一下，您想要：
process.env ...行，并答案 1 :(得分：1)
因为您已经在使用AWS。为什么不使用elastic transcoder代替Lambda。弹性转码器专门用于转码音频/视频文件。
您甚至可以根据放入s3存储桶的文件来触发它。