Bitmovin Delivers Content Aware Multi-Pass Encoding for Hulu in Japan

Bitmovin encoding 3 pass

Hulu in Japan has recently improved their ability to meet demand from consumers to access content in any location, at any time and on any device. They wanted to compete with other providers on quality of experience by optimising the video bitrates they used to deliver their library of about 50,000 titles to subscribers. Titles range from movies and TV shows to documentaries and anime.

Hulu worked with online video platform specialists PLAY Inc and chose Bitmovin Encoding through Bitmovin’s local integration partner Itochu Cable Systems. The optimisation process in this case consisted of Bitmovin’s Per-Title, 3-Pass and Multi-Codec encoding systems and aimed to supply the best possible video quality at the lowest possible bitrate, and reduce costs at the same time.    

Bitmovin per title encoding

               Per-title encoding
The combination of these approaches worked well because of the agile nature of the systems and associated APIs.  Bitmovin Per-Title encoding instructs the encoder with algorithms that contextually adjust the bitrate according to the complexity of each individual piece of content, so that video quality is consistent across the entire platform, and only necessary bits are used to meet the target.

A particular bitrate for a video may not show encoding artefacts, but if the viewer is watching on an HD device, the upsampled video won’t look sharp. Conversely, if the video is encoded at 1080p, the images are sent at a higher resolution video, but the bitrate may be so low that most scenes contain encoding artefacts.

This technique means Hulu can supply content on the platform faster, improve picture quality and reduce their own running costs by using less storage at the origin and lowering CDN delivery charges.

Bitmovin complexity comparison2

Complex scenes with motion and textures require higher bitrates than scenes with less movement.
Working with this type of encoding is another approach that Hulu has adopted, Bitmovin’s 3-Pass encoding, which starts the encoding process by first analysing the asset as a whole, followed by chunking (or segmenting) the asset into smaller components, in order to identify appropriate encoding settings as well as pre- and post-processing steps required for each part of the video. From there the video can be encoded in a parallel manner - at the chunk level - leading to an average bitrate reduction of 10 to 15 percent over a standard single or multi-pass encode, without impacting video quality.
Itochu Cable Systems worked with Bitmovin to customise a version of content aware multi pass encoding for Hulu in Japan, making it compatible with their business model and resolution-based subscription packages. The combination of Per-Title and 3-Pass encoding has made it possible for HJ to deploy multiple codecs, allowing the entire library to be optimised for each piece of content and for every device, leading to an efficient high-bandwidth workflow.