The subject matter herein generally relates to transcoding content, typically audio/video files though not limited to such, from one version to another in preparation for online streaming or other delivery to end users. Such transcoding may involve converting from one format to another (e.g., changing codecs or container formats), or creating multiple versions of an original source file in different bitrates, frame-sizes, or otherwise, to support distribution to a wide array of devices and to utilize performance-enhancing technologies like adaptive bitrate streaming. A transcoding platform is described herein that, in certain embodiments, leverages distributed computing techniques to transcode content in parallel across a platform of machines that are preferably idle or low-utilization resources of a content delivery network. The transcoding system also utilizes, in certain embodiments, improved techniques for segmenting the original source file so as to enable different segments to be sent to different machines for parallel transcodes.