Bit rate and control method
The code stream (bit rate) control method in video encoding is mainly divided into: VBR (dynamic bit rate) and CBR (static bit rate). The size of the bit rate determines the size of the video file. We can calculate the size of the video file by the bit rate, see article-How to calculate the file size of security video.
VBR
Variable Bitrate, that is, dynamic bit rate. That is, there is no fixed bit rate, and the compression software instantly determines what bit rate to use according to the audio and video data during compression. This is a way of taking into account the file size on the premise of quality.
VBR is also known as dynamic bit rate encoding. When using this method, you can choose various transition stages from the worst audio and video quality/maximum compression ratio to the best audio and video quality/lowest compression ratio. When encoding a video file, the program will try to maintain the quality of the entire selected file, and will select a bit rate suitable for different parts of the audio and video file for encoding. The main advantage is that the audio and video can roughly meet our quality requirements, but the disadvantage is that the compressed file size cannot be accurately estimated during encoding.
CBR
Constants Bit Rate, or fixed bit rate, means static (constant) bit rate. CBR is a compression method with a fixed sampling rate. The advantage is that it compresses quickly and can be supported by most software and equipment. The disadvantage is that it takes up relatively large space and the effect is not very satisfactory. It has been gradually replaced by VBR.
Other stream control methods
In H.265 encoding, Huawei HiSilicon introduced the AVBR concept, A is advanced, which can save 30% of the code stream compared to the ordinary VBR method.
Some manufacturers have combined the advantages of VBR and CBR to put forward the concept of CVBR code stream control. When the image content is still, bandwidth is saved, and when Motion occurs, the bandwidth saved in the previous period is used to improve the image quality as much as possible, so as to achieve the purpose of taking into account both bandwidth and image quality. This method usually allows the user to enter the maximum code rate and the minimum code rate. When it is stationary, the code rate is stable at the minimum code rate. When in motion, the code rate is greater than the minimum code rate, but does not exceed the maximum code rate.
The code stream (bit rate) control method in video encoding is mainly divided into: VBR (dynamic bit rate) and CBR (static bit rate). The size of the bit rate determines the size of the video file. We can calculate the size of the video file by the bit rate, see article-How to calculate the file size of security video.
VBR
Variable Bitrate, that is, dynamic bit rate. That is, there is no fixed bit rate, and the compression software instantly determines what bit rate to use according to the audio and video data during compression. This is a way of taking into account the file size on the premise of quality.
VBR is also known as dynamic bit rate encoding. When using this method, you can choose various transition stages from the worst audio and video quality/maximum compression ratio to the best audio and video quality/lowest compression ratio. When encoding a video file, the program will try to maintain the quality of the entire selected file, and will select a bit rate suitable for different parts of the audio and video file for encoding. The main advantage is that the audio and video can roughly meet our quality requirements, but the disadvantage is that the compressed file size cannot be accurately estimated during encoding.
CBR
Constants Bit Rate, or fixed bit rate, means static (constant) bit rate. CBR is a compression method with a fixed sampling rate. The advantage is that it compresses quickly and can be supported by most software and equipment. The disadvantage is that it takes up relatively large space and the effect is not very satisfactory. It has been gradually replaced by VBR.
Other stream control methods
In H.265 encoding, Huawei HiSilicon introduced the AVBR concept, A is advanced, which can save 30% of the code stream compared to the ordinary VBR method.
Some manufacturers have combined the advantages of VBR and CBR to put forward the concept of CVBR code stream control. When the image content is still, bandwidth is saved, and when Motion occurs, the bandwidth saved in the previous period is used to improve the image quality as much as possible, so as to achieve the purpose of taking into account both bandwidth and image quality. This method usually allows the user to enter the maximum code rate and the minimum code rate. When it is stationary, the code rate is stable at the minimum code rate. When in motion, the code rate is greater than the minimum code rate, but does not exceed the maximum code rate.