Considerations for encoding YouTube videos at the highest quality

YouTube boasts over one billion viewers every month so it shouldn’t be dismissed as an important distribution channel and powerful marketing tool especially when combined with SEO and Google analytics. However if your video doesn’t play properly, continually buffers or has poor sound then you are in danger of losing your audience before your message is imparted. So to get the best out of your You Tube channel then there are some important considerations to be aware of.

Inside the Tube

When a video is uploaded to YouTube the video file is transcoded into optimised video streams. This optimisation allows the video to playback smoothly on everything from mobile phones to desktop computers. The resolution of a video stream can vary in quality but by far the most common is 1080p allowing for full high definition playback on devices which are capable of playing HD, for any other devices the video stream is reduced automatically to allow it to be replayed on that device. The important point here is that anything uploaded to YouTube will be transcoded. In that context you should not upload a highly compressed, low bit rate video as it will get compressed again so it’s important to upload the best quality, highest resolution video that you can.

Codecs used by YouTube

Codec stands for code/decode and allows the video and audio streams to be compressed to the smallest size manageable but retains enough information to allow the video and audio to replay with clarity. YouTube uses more than just one codec, and each codec is encoded to multiple resolutions and bit rates so that the video is playable on multiple devices.
H.264 is the codec most commonly used by most of YouTube’s video streams, but other codecs are available and many new ones are currently being developed so that, for example, YouTube can handle the much larger files for 4K (Ultra High Definition). Some legacy codecs are still in use for compatibility with older smartphones.

What video formats are accepted by YouTube

You can upload any kind of video to YouTube, even those shot straight from your Smartphone. The currently supported video formats include: MOV, MP4, AVI and WMV. In actual fact YouTube will even accept high quality video formats like ProRes, DNxHD and uncompressed 10-bit HD video. However these larger files will take a lot longer to upload.
The other important consideration is that if your video is interlaced you will need to deinterlace it before uploading, and scale it to the right resolution.

Quality versus upload time

If quality is of paramount, then you can upload ProRes, DNxHD or uncompressed HD video. This will produce fewer video compression artifacts on YouTube. However it will take much longer to upload these files and the difference between a ProRes and an uncompressed file is indiscernible, the only real difference being file size. Be aware that you can’t change the file to increase its video quality at a later stage unless you don’t mind losing all your analytics if the video has been published for a while.

The H.264 codec with the MP4 file format is currently the best choice and is YouTube’s recommendation. If YouTube introduces a new codec then they’ll automatically transcode your video for you using the original upload, so the quality will not be any better than your original file.

File size and duration

Be aware of your video’s file size. This will be determined by the length of the programme and the codec you used. A standard YouTube account allows for no more than 15 minutes duration. But by verifying your account, which is a straight forward and simple procedure there is unlimited duration. To verify your account you’ll need a mobile phone number, and YouTube will send an activation code that will allow you to upload longer videos. The other way to achieve this with a standard account would be to split the video into shorter sections.

In Part Two of this Guide to encoding your videos for YouTube we will look at:

Getting the Right Format
Resolution and pixel ratio
Deinterlacing
Bit rates
Codecs
Encoding software

and several other useful areas of technical expertise that will help you get the best delivery for your videos on YouTube.

Any questions in the meanwhile, give us a call on 01494 898919 and speak to John or Steve our Technical Gurus!