Zoom on video compression: what is transcoding and why is it essential in OTT?


Kinow offers a complete chain of fully automated video file ingest, including transcoding, storage and distribution (CDN). Let's take a look at video transcoding, which is essential to ensure a positive viewing experience for users.

One year ago, Kinow announced the launch of its video hosting service, based entirely on Amazon Web Services.

Thanks to this service, we offer a complete chain of fully automated video file ingest, including transcoding, storage and distribution (CDN).

Today, we offer an update on video transcoding, which is critical to ensuring a smooth viewing experience for users.

Definition, aspects, process... nothing will be left to chance!

Brief overview: what are the differences between video encoding and transcoding?

With the rise of video on demand (VOD), users expect superior viewing experiences compared to a traditional TV set.

However, the challenge is significant for OTT content providers. For a successful user experience, the usual video quality must be maintained on a variety of consumer devices (mobile, tablet, computer, etc.).

In the video industry, the terms encoding and transcoding are often used in the same situations, yet although they are similar, they are still different in some respects.

What is encoding?

Encoding is the process of extracting data from devices that capture video and audio information and converting it into a digital format. This format can then be sent to streaming platforms.

What is video transcoding?

Video transcoding is the process that converts an audio or video file from one encoding format to another, in order to make multimedia files viewable on different platforms and devices.

Here are different situations where transcoding a video can be useful:

● To help a target device support the original data format.

● To reduce the capacity of the original file so that it can adapt to the new format.

● To convert incompatible files to a format better supported by the new device.

However, it is impossible to obtain a file with a different extension during transcoding. Indeed, this would require changing the file format, a process called transmuxing, whereas transcoding only changes the content of the file.

How does Kinow use transcoding?

To use the transcoding process, the Kinow team uses AWS Elemental MediaConvert. This is a file-based video transcoding service with broadcast capabilities. It makes it easy to create video-on-demand (VOD) content for large-scale multi-screen delivery.

Elemental MediaConvert provides the following functionality:

● Broadcast Capabilities
● Full input and output support
● Automated Resource Provisioning

The process

Here is the classic process, detailed and used by Kinow developers:

  1. The platform administrator uploads his video file on the Kinow platform (represented by the "Uploader" part on the diagram). Then, Kinow stores this file on the AWS S3 service (Simple Storage Service).

2. This process automatically triggers a transcoding via MediaManager. At this level, Kinow recovers the type of outputs and the video quality desired by the administrator (1080p, 720p, 540p, etc.). Using this information, transcoding is started on Elemental MediaConvert and the file is also stored on AWS S3.

3. Once the transcoding is completed, all this information is stored to different outputs in a database.

4. The end of transcoding triggers an event to notify the administrator that the transcoding is complete and the video file is available. At this stage, it is also possible to trigger Hollywood DRMs such as Fairplay, Playready and Widevine on the video file.

Why is video transcoding essential in OTT?

Broadcasting video only at a high bit rate and resolution, without the option of quality degradation, can prevent a significant portion of consumers from accessing it. This is where transcoding comes in, to solve this problem.

Transcoding is a resource-intensive process, but it is essential for widespread distribution and for the satisfaction of the entire viewing public.

Nevertheless, there are transcoding presets for video-on-demand, such as those proposed by Kinow, which allow a video not to be transcoded above the original format. For example, a video downloaded in HD (the resolution is ≥ at 720p but ≤ at 1080p) will not be encoded in UHD (the resolution is > at 1080p). These presets therefore allow the administrator to reduce transcoding costs.

In conclusion

Attracting the most viewers and providing the best possible user experience is primordial for streaming platforms. Transcoding is therefore the tool for successful broadcasting and making content accessible to all.

If you wish to learn more about transcoding techniques and how to improve your viewing quality, the Kinow team can help you transform and improve your video content. Contact our experts!