In essence, you’re telling the encoder to average 2 Mbps over the duration of the video file, but in no cases let the video bitrate exceed 4 Mbps.
In operation, as shown below, you assign both a target bitrate and a maximum bitrate, with some encoders also allowing you to set a minimum bitrate. In contrast, with variable bitrate encoding, the encoder varies the bitrate allocation over the file according to encoding complexity, stealing bits from easy-to-encode scenes to apply to hard-to-encode scenes so they look better. As the name suggests, the encoder maintains a constant bitrate over the duration of the file, which doesn’t vary by the complexity or motion in the video. As shown in the first screen below, CBR assigns a single data rate to the file and encodes in a single pass. Let’s use the interface of the Adobe Media Encoder to define our terms. Use CBR for live encoding on-site and transcoding in the cloud, and 200% CVBR for on-demand video in most geographic regions. This article defines the terms, briefly discusses their history, and provides recommendations for when to use all three. There are three common approaches: constant bitrate encoding (CBR), variable bitrate encoding (VBR), and constrained variable bitrate encoding (CVBR). One of the most common encoding parameters available for live and on-demand streaming is bitrate control, which dictates how the encoder allocates the encoded audio and video data within the file.
0 kommentar(er)
