![\"constant](\"http:\/\/www.web3.lu\/wp-content\/uploads\/2011\/10\/vbr.jpg\")
<\/p>\n<\/p>\n
CBR (constant bit rate)
\nVBR (variable bit rate)
\nABR (average bit rate)
\nThere are three types.<\/p>\n
![\"Constant](\"https:\/\/www.researchgate.net\/profile\/Jordi-Gimenez-3\/publication\/309512260\/figure\/fig9\/AS:422399721119752@1477719349743\/Constant-bit-rate-CBR-encoding-vs-Variable-bit-rate-VBR-encoding-with-statistical.png\")
<\/p>\n
I will present the differences between them.<\/p>\n
See the following article for the “bit rate”.<\/p>\n
Reference: What is a bit rate? Relationship between image quality and sound quality [Video \/ Audio]
\nRelated: Difference Between VFR (Variable) and CFR (Fixed) [Frame Rate]<\/p>\n
Every feature
\nI will briefly explain each feature.<\/p>\n
CBR (constant bit rate)
\nCBR (constant bit rate) is<\/p>\n
A video with a constant video bit rate.<\/p>\n
for instance,<\/p>\n
Scenes with intense movement
\nScenes with complex audio
\nEven in “scenes that require a large number of bit rates”, for example, the bit rate to be assigned is constant and<\/p>\n
Motionless scene
\nScene without audio
\nEven in “scenes that do not require a lot of bit rate”, the bit rate to be assigned is constant.<\/p>\n
In this way, a video that assigns a constant bitrate to “Assign a constant bitrate!” In any scene it is called CBR (constant bit rate) video.<\/p>\n
The following are the characteristics of CBR.<\/p>\n
(\u25cb) Search (fast forward \/ rewind) is fast
\nSince the transfer rate is the same, you can search instantly.
\n(\u25cb) File size can be predicted
\nIf you decide beforehand to “encode at XX bit rate”, you can predict the file size from resolution, frame rate, video length, codec, and so on.
\n(\u25cb) Easy to use as a material
\nIn the case of video, there is no need to worry so much, but in the case of the sound source, various problems can occur such as drift of sound with VBR or ABR (so if there is a possibility that it will be used later to video edit material, etc. Better to encode with CBR)
\n(\u25cb) Fast encoding speed
\nIt doesn’t change much, but unlike VBR and ABR, you don’t need to “predict” it, so encoding is faster.
\n(X) Image quality and sound quality are not very good for the file size
\nEven a monotonous scene that does not require a lot of bit rate allocation may be assigned a certain number, or a scene that requires a large bit rate may not have enough bit rate, so the image quality and sound quality for the file size. Cospa is bad
\nVBR (variable bit rate)
\nVBR (variable bit rate) is<\/p>\n
A video whose bit rate varies depending on the scene.<\/p>\n
VBR_figure<\/p>\n
for instance,<\/p>\n
Scenes with intense movement
\nScenes with complex audio
\nIn “scenes that require many bit rates”, such as assigning many bit rates and<\/p>\n
Motionless scene
\nScene without audio
\nFor “scenes that do not require a lot of bit rate”, assign a lower bit rate.<\/p>\n
In this way, a video that assigns only the required bitrate according to the scene, “You need this bitrate, don’t you?” It’s called VBR (Variable Bit Rate) video.<\/p>\n
The following are the characteristics of VBR.<\/p>\n
(\u25cb) Image quality (sound quality) by file size is the best
\nCompared to CBR and ABR, the image quality (sound quality) by file size is the best.
\n(\u25b3) Unpredictable file size after encoding
\nThe file size cannot be predicted because the bit rate fluctuates extremely depending on the content of the material to be encoded. (However with the x264 encoder etc it is possible to predict because it puts an upper limit on the file size and allocates the maximum bit rate within that range)
\n(X) Old MP3 players may not play well
\nIf you have an old MP3 player, the playing time display may be strange, the bit rate display may be strange, or you may not be able to play from beginning to end.
\n(X) When used as video editing material, it may cause sound drift.
\nFor more information, see the following article
\nReference: Causes and countermeasures for sound deviation [Encoding]
\nIf you want to encode video with high image quality and low capacity, VBR is your choice.<\/p>\n
By the way, in VBR, it is common to determine video quality by “quality standard” (CRF value in x264 encoder) rather than by “bit rate standard”.<\/p>\n
For example, instead of saying “Encode at 192bps!”, Specify something like “Encode at<\/p>\n","protected":false},"excerpt":{"rendered":"