|A/V Bit Rate||Video Bit Rate||Audio Bit Rate||Width||Height||Type||Key Frame Interval||Frames Per Second|
Screen size / Screen Resolution (click for full size)
2. Keep the frame size in multiples of 16 to avoid unnecessary performance degradation or CPU consumption. If not possible, resort only to multiples of 8, not 4.
3. Keep the content in progressive output mode. Deinterlace whenever possible. Use Motion Compensated deinterlacing for best results. If not possible, use Motion Adaptive deinterlacing instead.
4. Use content that was deliberately shot for smaller screens for best user experience and fidelity. If not possible, scale with multi-tap filters (10 taps or more). The higher the tap the greater the sampling area (it is presumed that the filter is sophisticated enough to extract the necessary information to resample a better new image). High quality scaling filters utilize a higher sampling area from surrounding pixels (10 or more) and, thus, are able to derive higher quality output. Lower quality scaling filters (2-4 taps) create mediocre results, with images often being soft and blurry.
Lower filter results are OK for streaming on the larger screen sizes of computers and laptops, but will give you very poor picture quality on smaller screen sizes of mobile devices. Lower end filters are faster than higher end filters due their smaller sampling area. Use high quality scaling filters.
5. Use two pass encoding, or multi-pass encoding. Seriously. Typically a transcoder/encoder will use the first pass to index complex scenes and use the second pass for actual encoding. This process provides the best predictability for the encoder and improves your mobile video. Depending on the complexity of the video, the perceptual video quality results from single pass to two pass encoding can vary as much as 10–30 percent. That’s signficant because you’re dealing with lower bitrate resources with mobile video.
7. If the H.264 encoder supports “look_ahead” logic, use it.
8. Do not use content encoded at a larger frame size and then scale it down. Create separate versions at the frame sizes when you encode or transcode.
If higher frame size content is encoded and delivered, the mobile device will try to scale it down, burning more CPU resources — 40% in some cases. This slows performance, reduces battery life, and degrades mobile video playbook.
9. Do not use multiple slices mode in H.264. You should use 0 slices or 1 slice, or turn it off all together. If slices are in the video, the mobile video player will try to reproduce them while consuming unnecessary processor / RAM resources.
10. If your source is interlaced and it needs to be scaled, deinterlace first then scale second.
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