Amazon has recently added audio support for elastic transcoder, which provides an ability to convert media files compatible with smart phones, tablets, PCs from one format to another without depending upon servers, storage and scalability.
With the help of the latest update, you will be able to transcode existing music and podcast audio files to new formats including the ability to strip out audio tracks from video files to create audio-only streams.
It is also possible to create audio podcast files from existing videos to provide support for iOS apps that require an audio only HTTP live streaming (HLS) file set including the ability to create audio output using AAC, MP3 or Vorbis audio codecs. According to Amazon, you do not incur data-transfer charges when your Amazon S3 bucket is in the same region as the one in which you submitted your transcoding job.
According to official sources, audio transcoding is billed at the rate of $0.0045 per minute of audio output in the US east (Northern Virginia) region including 20 minutes per month of audio transcoding as part of the AWS free usage tier in addition to 20 minutes of free SD output per month and 10 minutes of free HD output per month.