Computing Video

Video formats are important for artists not viewers

Most of the widely used media players were historically produced to showcase the videos produced by the creator’s authoring tools. They usually recognise that other formats exist, and provide some means of plugging these in, but very few attempt to include all popular formats at once. This has the effect that sometimes, when pressing play, I’m presented with a dialog that announces the file is in an ‘unsupported’ format. While they often offer to download a suitable player, I want to watch a video, and I’m not disposed to buying and installing software. I may not even have the ability to do so. As such, most players don’t work well with all formats and I have to choose a player to match a format, although I’m not particularly interested in the format a video is in – I just want to watch it.

Artists, on the other hand, care a lot about the formats used, as they create the visual limits the artist must live within as they create video. All practical formats create visual artefacts when they are pushed beyond their intended limits, which artists must carefully avoid. As an example, some are good at cartoon content, while others are better at fast moving sport. Another important point is that encoding in a particular format is an expensive operation – video format owners typically charge a lot more for the encoder than the decoder.

Miro attempts to include as many codecs as possible, and has a catholic taste in video formats. Rather than focussing on any one codec, or graciously permitting me to add more, Miro uses a video playback subsystem – VLC – that attempts to play anything you throw at it. I’m not annoyed by strange dialogs that announce they first need to download a codec, and artists are free to select among a wide range of codecs for the one that best suits the video they create.

Including many codecs is not the only option – services such as YouTube instead provide one codec, and re-encode all incoming video into it. Whilst pragmatic, this is sure to lose quality. Any digitisation of a performance necessarily involves making decisions about what to keep, and what to throw away. Of course, the highest quality options produce staggeringly large files that are essentially impractical to use on today’s computers and networks. Whilst a lot of the decisions about what not to keep can be made by the encoder, not all of them can be automated, and high quality encoding is more of an art than a science. As I’ve noted the encoder creates the visual limits for a file, and all of the major ones have various options that can be tuned by a careful operator.

Any translation between modern video formats will involve a loss of quality, and visual artefacts appearing. Whilst I’m often grateful this means I can see any video at all, I’m not happy about throwing away all the effort of the original artist. There are interesting risks – who’d want to watch a football clip where the ball has disappeared due to the automated translation?

By allowing Miro Channels to contain any format of video, the artists can choose the codecs that best suit their purpose. They can also publish the content they’ve already created, without having to re-encode it, opening low cost access to their whole portfolio.