As the importance of video increases, enterprises are distributing it through multiple channels – broadcasts; digital delivery to platforms like iOS, Android and Windows; even physical media like Blu-ray Discs or DVDs. To support multiple channels, videos are transcoded to deliver a seamless viewing experience. Transcoding digital media files is a process in which tracks are extracted from their containers, decoded, filtered, encoded, and then repackaged into new containers – which means that media is converted from its original format to one that best suits the required channel.
While transcoding is a helpful tool for media delivery, it may result in loss in quality and can be time consuming. Here are a few best practices that will help in striking the right balance between video parameters to deliver the best results.
- Encode from the best quality source – If your source video is interlaced, try enforcing de-interlace settings to achieve best quality.
- Video codecs deliver best performance when the width and height are in multiples of 16. The next choice can be multiples of 8 and finally multiples of 4. Yes, one can use any width or height, but non-optimal settings damage the quality and reduce the frame rates.
- Use 2-Pass VBR method to transcode video to achieve best picture quality. Unlike Constant Bit Rate (CBR), Variable Bit Rate (VBR) methods, 2-pass VBR method does a first pass while encoding and creates a log file. This log is used in the second pass to improve on complex frames.
- Make sure that the video playback is smooth and immediate over all connection speeds. To achieve this, create adaptive sets that are basically transcodes of the same video but with multiple bitrates. Employ adaptive streaming mechanisms to serve a video copy that matches the viewer’s connection speed thus delivering a seamless experience.
- To avoid frame skips, avoid using wrong frame rates while transcoding. If frame rates are wrong, audience will have a choppy viewing experience.
- Try using median filters that improve picture quality by correcting defects without affecting the sharpness.
- If you are transcoding videos for mobile devices, make sure that you use device or platform specific settings.
Transcoding workflows and terminology vary with transcoding applications so refer to the user guides carefully before encoding and save a copy of the settings that work best for you. Good luck!