AWS S3 + Lambda + Elastic Transcoder to encode incoming media files automagically

lambda-handler.js

/*
 * Copyright (C) 2016 Raecoo Cao
 * See LICENSE for the copy of MIT license
*/
// https://support.google.com/youtube/answer/2853702?hl=zh-Hans
// BEGIN Lambda configuration
//

var pipelineId = '1481448705022-x1efcv'; // change to your pipeline!

// AWS elastic transcoder presets
// Ref: http://docs.aws.amazon.com/elastictranscoder/latest/developerguide/system-presets.html
var webPreset = '1351620000001-200050';
var audio     = '1351620000001-200071';
var video1M   = '1351620000001-200035';
var video2M   = '1351620000001-200015';

// change these to match your S3 setup
// note: transcoder is picky about characters in the metadata
var copyright = '';

// BEGIN Lambda code
var aws = require('aws-sdk');
var s3 = new aws.S3();

var eltr = new aws.ElasticTranscoder({region: 'us-west-2'});

exports.handler = function(event, context) {
  console.log('[*] Received event:', JSON.stringify(event, null, 2));
  // Get the object from the event and show its content type
  var bucket = event.Records[0].s3.bucket.name;
  var key = event.Records[0].s3.object.key;
  var index = key.indexOf('/');
  if(index < 1) {
    context.fail('[*] This wasnt in a path with ID')
    return
  }
  key = key.substr(0,index) + '/manifest.json'
  console.log('[*] Requesting manifest in', bucket, 'key', key)

  s3.getObject({Bucket: bucket, Key: key}, function(err, data) {
    if (err) {
      console.log("[*] Error getting object " + key + " from bucket " + bucket +
          ". Make sure they exist and your bucket is in the same region as this function.");
      context.fail('Error', "Error getting file: " + err);
    } else {
      console.log('[*] Received data:', data.length);

      sendVideoToET(JSON.parse(data.Body.toString()), function(err) {
        if(err) {
          context.fail(err)
        }else {
          context.succeed();
        }
      });
    }
  });
};


function sendVideoToET(manifest, callback){
  console.log('[*] SendVideoToET()', manifest)
  var key = manifest.mediaID + '/' + manifest.media
  var params = {
    PipelineId: pipelineId,
    OutputKeyPrefix: manifest.mediaID + '/',
    Input: {
      Key: key,
      FrameRate: 'auto',
      Resolution: 'auto',
      AspectRatio: 'auto',
      Interlaced: 'auto',
      Container: 'auto'
    },
    Outputs: [
      {
        Key: 'hls1000k_mp4',
        PresetId: video1M,
        Rotate: 'auto',
        SegmentDuration: '10'
      },
      {
        Key: 'hls2000k_mp4',
        PresetId: video2M,
        Rotate: 'auto',
        SegmentDuration: '10'
      }
      ,{
        Key: 'hls64k_m4a',
        PresetId: audio,
        SegmentDuration: '10'
      }
    ],
    UserMetadata: {
      date: '' + manifest.date,
      copyright: copyright
    },
    Playlists: [
      {
        Format: 'HLSv4',
        Name: manifest.mediaID,
        OutputKeys: [
          'hls64k_m4a',
          'hls1000k_mp4',
          'hls2000k_mp4'
        ]
      }
    ]
  };
  console.log('[*] Sending ', params,' to ET', eltr);
  eltr.createJob(params, function (err, data) {
    if (err) {
      console.log('[*] Failed to send new video ' + key + ' to ET');
      console.log(err);
      console.log(err.stack)
      callback("[*] Error creating job: " + err);
    } else {
      console.log('job submitted!')
      console.log("[*] ET request data: " + data);
    }
  });
}

manifest.json

// the original media files metadata
{
   "mediaID":"0daa547b24de47cab0b1fdd20fd5dad0",
   "date":1441257874000,
   "title":"HYBE_S1_teaser1_45s_v2",
   "thumbnails":[
      "0daa547b24de47cab0b1fdd20fd5dad0_small.jpg",
      "0daa547b24de47cab0b1fdd20fd5dad0_large.jpg"
   ],
   "tags":"entrepreneurship,hybe,ideas,innovation,lifestyle,startups",
   "size":23825520,
   "description":"Hybe is a new international media exploring the entrepreneurial lifestyle, fresh ideas and the people behind them.",
   "media":"0daa547b24de47cab0b1fdd20fd5dad0_hybe_teaser_45s-v2.mp4"
}

result.json

{
   "Records":[
      {
         "eventVersion":"2.0",
         "eventSource":"aws:s3",
         "awsRegion":"us-east-1",
         "eventTime":"1970-01-01T00:00:00.000Z",
         "eventName":"ObjectCreated:Put",
         "userIdentity":{
            "principalId":"EXAMPLE"
         },
         "requestParameters":{
            "sourceIPAddress":"127.0.0.1"
         },
         "responseElements":{
            "x-amz-request-id":"C3D13FE58DE4C810",
            "x-amz-id-2":"FMyUVURIY8/IgAtTv8xRjskZQpcIZ9KG4V5Wp6S7S/JRWeUWerMUE5JgHvANOjpD"
         },
         "s3":{
            "s3SchemaVersion":"1.0",
            "configurationId":"testConfigRule",
            "bucket":{
               "name":"bubobox.test",
               "ownerIdentity":{
                  "principalId":"EXAMPLE"
               },
               "arn":"arn:aws:s3:::mybucket"
            },
            "object":{
               "key":"ted.mov",
               "size":1024,
               "eTag":"d41d8cd98f00b204e9800998ecf8427e"
            }
         }
      }
   ]
}