How to use Elastic Transcoder with the AWS-SDK for Ruby

Question

I am completely stuck. I need to be walked through the process for using the AWS-SDK for Ruby to transcode video. I'm not sure where to even begin. I'm uploading files using CarrierWave-Direct to an s3 bucket. The records are uploaded and recalled fine. The uploading is done in the background using Sidekiq. Where do I go from here? How do I kick off the Transcoding job? How do I maintain a record of the files for later streaming in my database? Can I transcode along with my uploading Sidekiq process? I'm ripping my hair out for trying to find a solution for this.

Answer 1

The transcoding actions are defined inside the class AWS::ElasticTranscoder.

Transcoding process can be initiated once your upload to s3 has been completed. For a simple transcoder to work, you need to have

1. A pipeline on which the transcoding will be carried out.
2. Presets which determines the output video properties (You can either create a preset or use the system presets provided by AWS)

Now initiate AWS::ElasticTranscoder::Client class

transcoder = AWS::ElasticTranscoder::Client.new(:access_key_id => AwsKeyId,:secret_access_key => AwsAccessKey,:region=>TranscoderRegion)

Create pipeline:

transcoder.create_pipeline(options = {
        :name => “test_pipeline”,
        :input_bucket => “bucket_name” , 
        :output_bucket => “bucket_name”,
        :role => Elastic-Transcoder-Default-Role,
        :content_config => {
            :bucket => “bucket_name”,
            :storage_class => Standard
        }
        :thumbnail_config => {
            :bucket => “bucket_name”,
            :storage_class => Standard 
        }
})

This will return a pipelineId that can be used for creating jobs.

Now you can create a job as follows:

 transcoder_obj.create_job({
    :pipeline_id=>PipelineId,
    :input=> {
       :key=>"video_path",
       :frame_rate=> "auto",
       :resolution => "auto",
       :aspect_ratio => "auto",
       :container => 'auto'
    },
    :outputs=>[{
       :key=>"output_file_location",
       :preset_id=>1351620000001-000010,
       :thumbnail_pattern=>"thumbnails/thumb_{count}"
    }]
})

This will start the transcoding process. You can check the status of the job by using read_job method. Once the status becomes 'Completed' from 'Progressing', the output files will be there in the specified output bucket.

Please go through these links:

http://docs.aws.amazon.com/AWSRubySDK/latest/AWS/ElasticTranscoder/Client.html http://docs.aws.amazon.com/elastictranscoder/latest/developerguide/system-presets.html

AWS::SNS provides a better way of getting notified about the transcoding job status. You can subscribe to an sns topic for getting the jobs status. The response for a completed job will contain the necessary details about the output files, so that you can store it in database for future streaming.

For more info, refer this link