特定设备的比特率质量级别

Question

I'm looking mediaconvert service from aws to transcode videos. The value I'm trying to set just now is quality level (QL) for QVBR, according with this it could depends on the platform, for example for 720p/1080p resolution it proposes QL=8/9 (for TV), QL=7 (for tablet), QL=6 (for smartphone).

In fact, the app have a version for the 3 type of devices then I'm asking: I need to keep 3 versions for the same video? I want to save some money in streaming and my app has similar number of users using it in each platform, I want to save in bandwidth but providing good quality videos

Answer 1

Higher QVBR quality levels (QL) correspond to higher bitrates in the output.

For a large display such as a TV, a higher QVBR QL is recommended to help improve the viewer experience. But when viewing the same content on a smaller display such as a phone you may not need all of those extra bits to still have a good experience.

In general, it's recommended to create an output targeted for each of the various devices or resolutions content will be viewed on. This will help save bandwidth for the smaller devices while still delivering high quality for the larger ones.

This concept is referred to as Adaptive Bitrate (ABR) Streaming, and is a common feature of streaming formats such as HLS and DASH (among others). The MediaConvert documentation has a section on how to create ABR outputs as well: https://docs.aws.amazon.com/mediaconvert/latest/ug/video-abr-streaming-outputs.html