What Is the Process of Video Transcoding? Are There Any Gaps in Such Processes?
The life of a video starts in a recording device. Initially, it features a format that is unique to the program or camera used to capture the video. However, this format is of little use when it comes to playing the video online or on another device.
Video transcoding allows the original format to be converted into a new one that will enable the video and audio files to play on any device, whether it is a smartphone, tablet or computer. Transcoding real-time video content or a discrete video file becomes indispensable when its format is not supported by a target device or in case there are storage capacity constraints. Video transcoding is also an amazing way to convert obsolete or incompatible data formats of media files to more acceptable ones.
The video transcoding process is carried out by what is known as a transcoder. One of the most common applications of transcoders is OTT services. Here, a file- based or live video source is first decoded and then again encoded by a transcoder into various versions having different resolutions and bitrates ideal for adaptive bitrate streaming protocols like MPEG-DASH and HLS.
Video transcoding makes it possible to deliver a single video content to various types of devices featuring their own requirements for input video standards. Transcoding is also used for making older videos suitable for viewing on modern devices.
The process of transcoding involves two steps. In the first step, the original data is decoded and given an intermediate format. In the second step, this decoded video is resized and re-encoded to one or multiple new formats. Certain transcoders also function as encoders when they directly accept uncompressed video sources like SDI and encode them into different formats.
Video transcoding doesn’t mean video encoding
It’s worth noting here that the process of video transcoding is often referred to as video encoding. Although the two terms are used interchangeably, they are not one and the same thing.
Video encoding is a process in which a raw video file is compressed and offered a new format, and all the devices that support this format are able to play the encoded video.
But transcoding works a little differently. Video transcoding, as discussed above, is the process of converting a video content from one digital format to another. During the process of transcoding, all the three elements of the video—its file format, the audio and the video data—get translated.
Generally speaking, encoding is a prerequisite for transcoding. That means, raw files first need to undergo encoding to be transcoded for playback.
The process of transcoding can be divided into 3 broad categories
- Lossless-to-lossless—In this type of transcoding, there is no loss of information. You can compress a video file losslessly with the help of high- end hardware support and advanced compression techniques. In this type of transcoding, video data is encoded into newer formats without any quality loss. The only drawback is that the files that you receive are excessively large and are not compatible for viewing on a lot of portable devices.
- Lossy-to-lossy —This is the least recommended transcoding type. In lossy-to-lossy transcoding, a video file that is already low-quality is transcoded due to which its quality further deteriorates. You should go for this kind of transcoding only when your only goal is to save storage space and reduce the bit rate. This form of transcoding may be required when a particular video content needs to be specifically viewed on portable players.
- Lossless-to-lossy— Although the transported video lacks some of the information originally present in the source video, this form of transcoding offers better quality results as compared to lossy- to- lossy transcoding. The resulting file sizes are also reasonably small and can be played on portable devices.
These are the only three methods of transcoding known; and there is no such thing as “lossy-to-lossless” as it’s not possible to convert a lossy video content into a lossless one through transcoding. That’s because data lost during encoding or transcoding is lost forever and can’t be restored.
Why is transcoding so important?
Transcoding serves the general purpose of enabling video content to reach the largest number of viewers possible. However, it’s your requirements that actually determine the true importance of transcoding for you.If you want your content to have a greater reach, video transcoding is simply indispensable for you.
Below are some of the reasons why transcoding may be required
- It facilitates Adaptive Bitrate Streaming—
HLS allows video players to switch between different video sources dynamically depending on the strength of the internet connection. But for HLS stream to work, videos need to be transcoded.
- Streaming under limited bandwidth—
Transcoding is a way to create multiple video sources for ABR using a single input video. This is great for live streaming in areas with low upload speeds.
- Live streaming across platforms—
Live streaming to multiple platforms can be complicated because different input requirements may apply to different platforms. For instance, Periscope recommends a resolution of 540p for live streaming. In such a scenario, transcoding can prove extremely helpful—instead of reducing all streams’ resolution to 540p, you can transcode the original source video to a separate stream with a lower resolution meant only for Periscope.
What are formats and file types in video transcoding?
In the context of video transcoding, three aspects of a video file matter the most— codec, file type and file format.
- File format—A file format is nothing but a standard for encoding a media file for storage. It tells how audio and video have been clubbed together in the file and instructs how a playback device should display its content.
- Codec—Audio and video codecs are essentially file compression technologies. These technologies are used not just to create but also to playback digital audio and video. Codec is a portmanteau that entails the words “encoder” and “decoder.”
- File type— File types are names given to specific types of files. There are various file types including Flash Video (FLV), Quicktime (MOV) and MPEG-4 (MP4).
It’s important to note here that different streaming platforms have different requirements for codecs and formats. And that is why it’s important that you check if your desired platform supports the codec and file format of your videos. This will tell you if you need to convert your videos to a different format supported by your target streaming platform. DaCast requires, for instance, an MPEG-4 file format (MP4) with an H.264 codec.
Some formats offer better compression than others. Meaning, they are able to feature better quality visuals as compared to other formats against the same file size. A competent video transcoding software will be capable of converting multiple file formats and codecs.
The future of video transcoding— the picture looks rosier from where we stand today
The demand for video transcoding has increased exponentially, so, this technology is clearly here to stay. The reason? Growing popularity of video streaming services.But how is the popularity of video streaming services linked to the growing demand of the video transcoding technology?
First, no one likes to be tied to a schedule. Streaming services let users watch their favorite shows whenever and wherever they are. The content can even be viewed on the go. And since transcoding is such an important facilitator of online video streaming, this technology is only going to get bigger and better with time. After all, streaming services are on course for a boom.
Secondly, millennials are leading the way as far as consuming video streams is concerned. 63% of millennials view live videos. It is the streaming services that we have today which make it possible.
Thirdly, there is an easy availability of tailored content today. Based on the user’s viewing history, video streaming apps and services make recommendations. And they personalize the content recommendations based on viewers’ interests. This makes video streaming services all the more attractive, and transcoding all the more important.
Also, people love scalable services. Thankfully, most video streaming services are scalable. You can pick and choose which features and functions you wish to use on many streaming video services. Then you only have to pay for them. This indicates why OTT services are rapidly growing in popularity, and why non-transcoded videos are soon going to be a passé.
Although video transcoding has almost become irreplaceable as far as content delivery is conserved, there are still some issues with this technology
- Increased need for storage –
Transcoding video is an elaborate process, which can lead to a shortage of storage space, particularly with increasing video usage. 82% of internet storage consists of videos.
- Growing online traffic –
Online videos account for a considerable chunk of all internet traffic. This has incredibly increased over the past customer of years. It’s easy to tell that video is the biggest source of network bandwidth usage.
- A growing bandwidth demand—
With billions of people making and using massive amounts of video data, bandwidth demands are skyrocketing. Although video compression is a crucial technology that helps to manage this growing need, it also encourages more players to enter the video streaming market.
- The process of transcoding is cumbersome—
Yes, it takes a long time especially when you want to undertake lossless transcoding of videos.
- Loss in information—
Most transcoding types produce results that lack some information originally present in the source videos. True, lossless transcoding is also an option, but it’s time consuming and lossless videos are comparatively bulkier.
The good news is, there are solutions being developed to improve transcoding performance.
Mogi’s Superior Transcoding Technique
Mogi I/O (www.mogiio.com) is an AI enabled Video & Image Delivery SaaS that helps Content Platforms to Improve Customer Engagement by enabling Buffer free Streaming Experience for the user through a patented multi-CDN upstream architecture called Mogi Streaming Engine, Enhanced experience through quality enhancement and compression of up to 50% both during transcoding itself and Deeper user insights through Advanced Video Analytics.
Mogi’s solutions are available end-to-end (Video Transcoding + Video Player + Mogi Streaming Engine (Multi-CDN delivery) + DRM + Video Analytics) or you can use individual products from the entire suite like just the Video Transcoding. Mogi also provides white label end-to-end plug n play solutions for OTT and Edtech Platforms, with Web, Android and iOS apps as well as a dedicated CMS for OTT and LMS for EdTech.
One of the best individual products we have is our Transcoding Architecture, which in a unique cluster based process, does the transcoding within 30% of the content length. The transcoding architecture’s result includes a highly compressed video of up to 50% with no loss in quality, and if you choose quality enhancement, a 40% compression with enhanced video quality.
The pricing for Transcoding is very competitive as well, and along with it you get a highly compressed output with the same or higher quality. This means not only your contractual pricing is low due to competitive pricing, your bandwidth consumption reduces, and user experiences increases multifold. It’s a win win for all of us (Users, Clients, Mogi).
If you want to partner with us and access our products, reach out to susheel.srinivas@mogiio.com