2012
02.18

Most of the adventure films made in the last few years are produced in high definition. At Steepedge we offer HD as standard if the film is available at this level of quality. The question is, what is HD and then is it possible to stream as well as download?

Even ten years ago it was expensive both in terms of camera equipment and editing software to make a HD film, unless you were a professional film company. Now, small stills cameras, DSLR’s and GoPro’s are being used to produce HD footage, and HD editing software is readily available for the regular outdoor activist to record their exploits. Computers and data storage have kept pace and so have televisions.

But there are many misconceptions and for example many people do not realise that a film on DVD is not HD, nor are most computers or TV’s over 5 years old capable of screening HD.

Many people assume that there are two classes of video: SD and HD. In reality, the quality of HD can vary immensely. A universally accepted standard is that anything over 1280 x 720 pixels is HD. Below this is SD and so typically SD TV and DVD in the older 4:3 ratio is 720 x 576 pixels and in the newer 16:9 ratio is 1024 x 576.

In an interesting article in the British newspaper, ‘The Telegraph’ there is a discussion on SD and HD and in particular the Bitrate used to ‘transmit’ the film. Please read  ‘Steaming video: are you really getting high definition?’

There are so many variables in this discussion, but essentially there is the delivery on one side by BBC, Sky, Steepedge, DVD author etc. who firstly compress a film to a suitable Bitrate quality for their audience and secondly have different technological capabilities of delivering the data. So for example it may have a HD pixel measurement but it could be compressed to a low Bitrate to ‘squeeze the film down the pipe’.

You are on the receiving end and again there are a myriad of variables which affect quality, including your screen size, computer or TV processing capabilities, aerial, satellite or cable reception, or in terms of streaming your internet broadband speed.

The delivery and reception interact and they usually work best when they match. To give an obvious example you will usually get a poorer picture trying to watch a HD 1920 x 1080 delivered film on an older 1280 x 720 HD TV. Likewise the material on the BBC iPlayer HD is technically HD but has been compressed to a low Bitrate to enable it to be streamed so the quality of an SD DVD will normally be much better.

Broadband speed crucially affects the quality of streamed films. When studying the data below it is worth remembering that the UK average (optimistic !) broadband speed is just over 5 Mbps (as Sept 2011) but out of urban areas it is usually well below 5Mbps and some areas see a 69% drop in speeds in the ‘broadband rush hour’. Additionally please be aware there is wide variation between different measurements, but typically the top 6 ranking countries at the end of 2011 were:

South Korea at 13.8 Mbps,  Hong Kong 10.3,  Japan 8.9,   Netherlands 8.5,   Czech Republic 7.4,   Switzerland 7.3 and USA ranked 12th with 5.8 but has huge variations between States and not surprisingly California top with 7.8 Mbps. The UK is 25th!

Now compare a list of common viewing platforms, especially the Bitrate they transmit  SD and HD data.

SD TV 720 x 576 pixels requires 4 Mbps

BBC iPlayer HD 1280 x 720  3.2 Mbps

iTunes streaming HD 1280 x 720   4 Mbps

DVD (SD) 720 x576   9.8 Mbps

You Tube HD 1920 x 1080 6 Mbps

Sky Movies HD 1920 x 1080  10 Mbps

ITV HD 1920 x 1080  10.4 Mbps

Sky HD 1920 x 1080  12 Mbps

Sky Sports HD 1920 x 1080  15 Mbps

Blue Ray 1920 x 1080   40 Mbps

Most of the figures above relate to either transmitted (e.g. aerial, satellite or cable) or disc (e.g. DVD), rather than internet streaming. But it shows that to get comparable quality HD from streaming is not technologically there yet in most countries as the average bandwidth (and the big variation of speed during the day) is not good enough.

At Steepedge we use adaptive streaming for our rental service. The film quality matches the bandwidth speed of your internet connection. At low speeds the film and sound will be of poorer quality (and at worst, out of sync). At higher speeds, HD quality is possible but at the moment, unfortunately, this is for the minority. However broadband speeds are improving rapidly and in the next few years streaming will become much better.

Please refer to the SteepEdge Information section for more details on streaming.

For a reliable service we would always recommend downloading a film. The quality will be constant and the only variation will be the time it takes to download as broadband speeds vary in different areas.

Quoting from ‘The Telegraph’ article:

There is a large variation in the quality of HD platforms and services that is often unknown to consumers. Start watching, however, and you’ll soon see the problems in a poor quality service. ‘Blocky’ pictures and images that stutter, even on so-called high definition video, can ruin the experience of watching a film.

Display resolution is usually the factor used to determine how crisp a picture should be, yet the quality depends just as much on the bitrate at which the video is streamed. Whether the video is being streamed from the web, a disc or a hard drive, bitrate determines how smooth the image is.

Bitrate is the term used to refer to the number of pieces of compressed data processed over a given time. For example, in HD, this number is measured in Megabits per second, or Mbps.

On the other hand, the resolution is the density of pixels on the television or monitor. A greater pixel density can provide a sharper image, with smoother lines.

Different HD services have different resolution outputs, and much of the picture quality will depend on whether this output matches the screen resolution of the computer or television showing the image.

Bitrate and resolution are inter-dependent and a change in one can have either a positive or negative effect on the other. For example, a picture can have a high resolution, but if the bit rate is low, the picture quality will be poor and grainy.

Likewise, no matter how high your bitrate is, there’s only so far you can push a low-resolution recording.

Please also see a UK broadband related Telegraph article.

 

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