Video quality is worth its weight in gold, as the saying goes when it comes to satisfying viewers. Picture clarity is an essential feature of any video-watching experience. Live-streamed video content is no exception! HD live streaming is likely a goal for anyone who wants to broadcast live.
However, the nature of streaming live makes achieving this goal a bit more complex than with simple video files. That’s where we come in. This article offers some basic tips and advice for achieving quality HD live streaming. Before we get started, let’s consider what constitutes HD, or High-definition, content in the first place.
What is HD Content?
What defines High-definition content? Most simply put, HD video is of a higher quality and resolution than Standard-definition video.
More technically speaking, the industry generally considers a video image HD if it has considerably more than 480 vertical lines (North America) or 576 vertical lines (Europe). In reality, the majority of systems actually far surpass 480 vertical lines.
Both prerecorded and broadcast live video stream in HD tend to be defined by three factors:
- the number of lines in the vertical display resolution (generally 720 lines for HDTV)
- the type scanning system (progressive or interlaced)
- the number of frames or fields per second (usually 60 Hz in the US and 50 Hz in Europe).
HDTV is now the current standard video format for almost all broadcasts. There are several distinct formats through which to transmit HDTV, including:
- 720p (HD Ready): 1280×720p: 923,600 pixels (~0.92 MP) per frame
- 1080i (Full HD, “interlaced”): 1920×1080i: 1,036,800 pixels (~1.04 MP) per field, or 2,073,600 pixels (~2.07 MP) per frame
- 1080p (Full HD, “progressive”): 1920×1080p: 2,073,600 pixels (~2.07 megapixels) per frame
HD Video: A Summary
At its core, this all means that HD videos cover each image with 720 lines of pixel on the screen from top to bottom. More pixel lines mean more a detailed image on the screen. The number of pixel lines can increase up to 1080 in some cases. This will deliver rich, detailed video, assuming viewers have enough bandwidth to support it.
If viewers have low bandwidth, the image may buffer constantly. Alternatively, the stream will become degraded in terms of quality. Fortunately for you, improved technology and faster internet speeds mean that broadcasting HD live streaming is easier to achieve than ever before.
Now, let’s jump into considering some of the factors that affect the delivery of HD live streaming to your viewers.
Connection Speed Requirements for HD Live Streaming
Video delivery depends on a few factors, spanning the broadcasting to the viewing side of the equation. Two main factors that yield a “laggy” or “choppy” video include:
- the viewer’s bandwidth, and
- the broadcaster’s internet speed.
To get the best quality stream, video broadcasters must pay attention to their own upload speeds. In general, you want the upload speed of your connection to be at least double that of the anticipated stream. In theory, you can raise this speed up to 80% of the internet’s connection speed. However, at those levels, you’ll need to test the stream first to make sure it’s successful.
Factors like shared connections and streaming from a wireless network also have a negative impact on your overall upload speed. One important reminder: If you are streaming at more than half of your internet connection speed, do not try to watch your own feed at the same time. If you do, it will quickly exceed your internet capabilities.
Not sure of your upload speed? You can do a quick test at testmy.net.
Can All Your Viewers Watch in HD?
Trying to decide if HD live streaming is the right fit for you and your viewers? First, you need to know your own upload broadband speed.
Second, you need to know your viewers. In order to successfully watch via HD streaming, your viewers need a strong download bandwidth. According to a 2010 FCC (Federal Communications Commission) study, 80% of broadband internet users didn’t know their own speeds. The FCC provides a broadband speed guide for average US households. This guide suggests that standard streaming videos require rates of 0.7 Mbps–if streaming that video is the only activity happening. Generally, we recommend an internet connection of over 2Mb/s for standard video watching. Your viewers will often require even higher speeds for watching HD video.
What’s the take-away here? While HD live streaming is optimal, you need to account for potential viewers without the connection speed to support HD.
Some broadcasting platforms, including Dacast’s video and audio streaming service, offer multi-bitrate streaming for video broadcasting. This is relevant for both on-demand and live-streamed content. Multi-bitrate streaming enables viewers to access the video format their systems can support. With multi-bitrate streaming, viewers with fast connection speeds can watch HD live streaming. At the same time, viewers with lower connection speeds can enjoy the same content at a lower quality.
Live Broadcasting in HD
All the factors described above are infinitely more important when it comes to live streaming (versus HD on-demand video content). Live streaming content doesn’t have a pause or buffer feature as with VOD content. For this reason, it’s especially important to provide the best quality video before you live stream it. It’s also a good idea to have a ready-to-implement backup plan for those viewers with slower connections.
If the internet connection is not a constant factor on the viewer’s end, we recommend multi-bitrate HD live streaming. If you as a broadcaster don’t have a fast enough upload speed, however, you have two options. You can:
- get a faster internet connection, or
- lower your streaming quality.
Finally, keep in mind that a broadcaster’s encoding preferences can also impact the experience of viewers. We recommend reading up on the best encoding software settings to help ensure successful HD live streaming for all your viewers.
In a world that now includes 4K and Ultra HD resolutions, keeping up with the times is more important than ever. Except for news streaming, we know that the average US viewers watch HD content for about three times as long as SD content. And the benefits of HD live streaming go on and on.
We’ve walked you through some of the factors that enhance or detract from HD live streaming for you and your viewers. We hope this article has helped you to understand the basics of HD live streaming and the factors that can affect streaming quality. For more tips and updates on live streaming, join our LinkedIn group.
Still have questions or thoughts to share? We love to hear from our readers! Feel free to “sound off” in the comments section below, and we’ll do our best to get back to you. Already a Dacast customer and needing support? You can log-in to your account to access 24/7 support from our technical team.
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By Suprita Kochhar.