Does high kbps affect the video quality

Video for websites II: bit rate and resolution

Resolution of the monitors

The monitors on which we watch videos on the Internet have different resolutions. Even smartphones today have full HD resolution. Every look at the distribution of monitor sizes is just a look into the crystal ball. We want a respectable quality that is as high as possible for all visitors who do not overuse the data volume of the mobile devices.

The optimal resolution for video on the Internet is no more available than the best video format.

SD (standard definition)

1024 × 576 pixels

575p

HD (high definition or HD-ready)

1280 × 720 pixels

720p

Full HD

1920 × 1080 pixels

1080p

UHD or 4K (Ultra HD)

at least 3840 × 2160 pixels

4K

Height of the video

The information in the third line (575p, 720p, 1080p) indicates the height of the video.

Now and then we see this designation with an i instead of a p: The "i" stands for interlaced. That was the interlacing process of the old tube TV and is no longer relevant today.

Assess monitors

When it comes to digital television, people cheat with the resolution in order to get the video data across the stage without jerking and dropping out at low data rates. Then the HD resolution of 1280x720 pixels is not delivered, but the video is calculated down and then enlarged again on the monitor. That brings a blurred picture, but who can tell?

4K (also Cinema 4k)4096 × 2160 pixels
QFHD (Quad Full High Definition or 2160p)3840 × 2160 pixels
Full HD resolution1920x1080 pixels
Blue ray1920 × 1080 pixels
HD video1280x720 pixels

As with photographs, the question of how many pixels are optimal depends on the viewing distance. On the mobile phone and on the tablet we see videos at a distance of approx. 40 cm, on the desktop monitor with 40 to 50 cm, in the meeting room on the large monitor at a distance of a few meters.

Calculate and save | Full HD videos should be downsampled for playback on websites.

  • Full HD for the desktop monitor has not been an obstacle for many years, but rather a question of the number of visitors. In addition to the full HD version, the HTML video tag can also deliver an HD version for mobile devices. The browser decides which video is delivered.
  • On the desktop monitor, a resolution of 1280 x 720 pixels (that is HD video) brings great savings in terms of the bandwidth of the video and is already of very good quality.
  • With mobile devices, the SD resolution of 1024 × 576 saves and still brings a reasonable quality.
  • In the meeting room with the large monitor, we sit a few meters away. Full HD or 720p would also be the variants of choice here.

Whether a video in this resolution can be played smoothly on the Internet without major delays is an open question that depends heavily on the viewer's system, on the type of image material and, in the case of mobile devices, of course on the connection.

Data rate or bit rate

The data rate is one of the most important adjusting screws for video on the Internet and is responsible for both the quality and the file size. In general, the higher the data rate, the better the quality and the larger the file.

How big the film is in terms of file size is basically of no interest, because the video does not have to be completely delivered to the viewer before it can be played. Video is transported to the visitor in small bites and can start while it is still being transmitted.

However, we must not forget that the data volume for mobile devices is limited to 0.5 to 1 GB for most contracts. After that, the user can still surf, but the speed will be limited.

If the program offers the option for video editing, choose a variable bit rate:

SD2-5 Mbps
720p5-10 Mbps
1080p10-20 Mbps

Data rate and bandwidth

Digital television allows us a data rate of 12 Mbit / s. However, the broadcasters mostly use this bandwidth for four channels ...

ups. That leaves only around 2.5 to 3.5 Mbit / s per channel. There is still a little push, because the program "The animal doctor comes" may contain little movement and only get 2.5 Mbit / s, but football has fast pictures and needs a higher bandwidth.

Best video quality on the internet? | We can't do that with videos on the Internet (yet). The data rate is limited for dial-up Internet connections. We can treat the video to around 2-5 Mbit / s today if we assume that almost everyone has a fast DSL connection available today. Some codecs (responsible for encoding / decoding the video) allow a data rate that may vary in a range from top to bottom (e.g. H.264).

How good the video looks on the Internet now depends on how good the bandwidth to the visitor is and how fast the video images are.

Responsive video

Even if all browsers play MP4 today and we no longer have to deliver different formats, it makes sense to offer different resolutions depending on the size of the viewport.

The source tag of the video tag supports media queries with the query for the size of the viewport - both in the video tag and in the picture tag.

<video controls> <source src="video-large.mp4" type="video/mp4" media="all and (min-width:680px)"> <source src="video-small.mp4" type="video/mp4" media="all and (min-width:320px)"> </video>

Aspect Ratio of the video

Video on the Internet can use any aspect ratio. Modern computer monitors usually have an aspect ratio of 16: 9, the retina display of the iPad shows 2048 x 1536 pixels at 264 ppi, i.e. an aspect ratio of 4: 3. An iPhone 6s to 8Plus with widescreen has a resolution of 1920 x 1080 pixels at 401 ppi.

If a certain aspect ratio is desired that the input material does not have, the video must be rendered with a letterbox or must be cropped.

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