Tag: amd vs nvidia video encoding

Today a little technical point about video encoding – that is, the last step in creating a view once your editing is complete. The question is often rightly asked because, as well as your editing, mis-coding can completely ruin image quality and undermine both your work and your investment in high-end equipment.

Depending on the editing software used, you can access different options or be presented differently. They can be offered as presets, fully configurable or not. However, you should find the items described below.

Resolution and image format

The resolution of your video is the number of pixels in height and width. It shows width x height. Marketing terms and language simplifications have rebelled, but we find above all:

‘HD’: 720p or 1280 x 720
“Full HD”: 1080p or 1920 x 1080
“Ultra HD”: 4K or 3840 x 2160

These resolutions are for an aspect ratio of 16: 9, which is the current standard for most productions. They may differ if you export in a different format, such as 2.35: 1, which is close to 2.39: 1 or 2.40: 1, which is commonly used in the cinema.

Basically, with this quick little focus done, when exporting you usually know what resolution it will deliver. If you’re just starting out and haven’t done anything specific, it should be the same as your source files. For example, if you recorded in 1080p, it will be displayed in 1080p. You can do this if you want to render 720p, but it would be a shame to lower the resolution.

Unless, of course, you’ve followed my article on 4: 3 filming, which is filming in a format that allows more flexibility in post production before exporting in 16: 9.

Frame rate or frames per second

The number of frames per second (fps or “frames per second”) is not difficult to understand: the more important it is, the more your video has frames (or frames) for a second of video. The default for action video is 30 fps (or 29.97). Some export at 60fps – I personally detest this frame rate for classic video. You could talk about it for hours and maybe write an article about it someday, but whatever it is: it’s up to you to choose what you like and choose the size that suits you best.

But be careful, if you’re shooting at 30fps, rendering at 60fps is useless and counterproductive – source files don’t contain enough images. However, you can export without problems at a lower frame rate than the source files.

Codec or format

It is, to put it simply, the reel that your video goes through to be encoded. It should be noted that we often talk about language abuse codec to invoke the video encoding format or the standard, while originally the codec is the software that allows video encoding in one or more formats using appropriate libraries. . For example, here I will approach H.264, a format used by the x264 encoder or codec. In short, this small development is complete, let’s move on.

The codec attributes define the quality of the output video for a given bit rate (and thus a size) and the compression / decompression performance.

In most cases, the second parameter is of no interest to you. Any modern computer can play 4K video encoded with the leading codecs on the market. On the other hand, for a Blu-Ray export, for example, we come to slightly more specific considerations, because the hardware that reads the data on the disc is much less efficient than a PC. As for compression, it goes without saying that it is an advantage to keep your machine running for a few more hours to gain quality or in the disk space occupied by the final display, this time it will recover when you go watch, share or Save video.

Therefore, the quality of the video is the most important factor when choosing a codec. Currently, H.264 is found everywhere for its good performance, while its successor, H.265, promises to nearly halve the bit rate required to achieve the same quality while supporting 8K / 300fps.

Bitrate

Bitrate is the most important factor that will determine the quality of your video. It corresponds to the volume of data written for a second of video: the more it is, the more disk space is used, but the more the amount of information increases, which improves quality. In fact it is just like for a photo: if it is very compressed, the quality deteriorates, but occupies a very small place in its storage medium, otherwise the quality is preserved.