Transcoding - Why Is It Vital For Streaming

Transcoding - Why Is It Vital For Streaming

In the event you’re thinking about streaming media, you probably fall into one in every of two camps: Either you already know something about transcoding, otherwise you’re wondering why you keep hearing about it. If you happen to aren’t certain you need it, bear with me for just a few paragraphs. I’ll explain what transcoding is (and isn’t), and why it is perhaps critical to your streaming success — particularly if you wish to deliver adaptive streams to any device.

So, What Is Transcoding?
First, the word transcoding is commonly used as an umbrella term that covers a number of digital media tasks:

Transcoding, at a high level, is taking already-compressed (or encoded) content; decompressing (decoding) it; after which by some means altering and recompressing it. For instance, you would possibly change the audio and/or video format (codec) from one to a different, such as changing from an MPEG2 source (commonly utilized in broadcast television) to H.264 video and AAC audio (the preferred codecs for streaming). Different fundamental tasks could embody adding watermarks, logos, or different graphics to your video.
Transrating refers specifically to changing bitrates, resembling taking a 4K video input stream at 13 Mbps and changing it into one or more decrease-bitrate streams (also known as renditions): HD at 6Mbps, or different renditions at three Mbps, 1.8 Mbps, 1 Mbps, 600 kbps, etc.
Transsizing refers specifically to resizing the video frame; say, from a decision of 3840×2160 (fourK UHD) down to 1920×1080 (1080p) or 1280×720 (720p).

So, while you say "transcoding," you is likely to be referring to any combination of the above tasks — and typically are. Video conversion is computationally intensive, so transcoding usually requires more highly effective hardware resources, including faster CPUs or graphics acceleration capabilities.

What Transcoding Is Not
Transcoding should not be confused with transmuxing, which will also be referred to as repackaging, packetizing or rewrapping. Transmuxing is if you take compressed audio and video and — without changing the precise audio or video content material — (re)package it into different delivery formats.

For example, you might have H.264/AAC content, and by changing the container it’s packaged in, you'll be able to deliver it as HTTP Live Streaming (HLS), Clean Streaming, HTTP Dynamic Streaming (HDS) or Dynamic Adaptive Streaming over HTTP (DASH). The computational overhead for transmuxing is way smaller than for transcoding.

When Is Transcoding Critical?
Simply put: Transcoding is critical when you want your content material to achieve more finish users.

For instance, let’s say you need to do a live broadcast using a camera and encoder. You may be compressing your content with a RTMP encoder, and choose the H.264 video codec at 1080p.

This must be delivered to online viewers. However in case you attempt to stream it directly, you will have a couple of problems. First, viewers without sufficient bandwidth aren’t going to be able to view the stream. Their players will be buffering constantly as they wait for packets of that 1080p video to arrive. Secondly, the RTMP protocol is no longer widely supported for playback. Apple’s HLS is far more widely used. Without transcoding and transmuxing the video, you will exclude virtually anybody with slower data speeds, tablets, mobile phones, and linked TV devices.

Using a transcoding software or service, you possibly can concurrently create a set of time-aligned video streams, each with a unique bitrate and frame size, while converting the codecs and protocols to reach additional viewers. This set of internet-friendly streams can then be packaged into several adaptive streaming codecs (e.g., HLS), permitting playback on almost any screen on the planet.

One other frequent instance is broadcasting live streams utilizing an IP camera, as can be the case with surveillance cameras and visitors cams. Again, to achieve the largest number of viewers with the best possible quality allowed by their bandwidth and units, you’d want to support adaptive streaming. You’d deliver one HD H.264/AAC stream to your transcoder (typically situated on a server image within the cloud), which in flip would create a number of H.264/AAC renditions at completely different bitrates and resolutions. Then you’d have your media server (which may be the identical server as your transcoder) package these renditions into one or more adaptive streaming formats before delivering them to end users.

If you have any concerns about where and how to use Security Center Transcoding, you can make contact with us at our own page.