Understanding Interframe in Video Compression

Interframe refers to the time interval between two successive frames in a video stream. In other words, it is the amount of time that elapses between the start of one frame and the start of the next frame. Interframe is typically measured in milliseconds (ms) or microseconds (us).

In video compression, interframe is an important concept because it affects the efficiency of the compression process. By exploiting the temporal redundancy between successive frames, video compression algorithms can achieve better compression ratios and improve the overall quality of the video stream.

There are several types of interframe, including:

1. Inter-picture interval (IPI): This is the time interval between two successive I-frames in a video stream. I-frames are intra-coded frames that contain complete information about the picture, and they are used as references for the other frames in the stream.
2. Inter-frame interval (IFI): This is the time interval between two successive P-frames or B-frames in a video stream. P-frames and B-frames are predictive-coded frames that rely on the information contained in previous frames to achieve better compression.
3. Inter-slice interval (ISI): This is the time interval between two successive slices in a video stream. Slices are groups of pixels that are encoded together as a single unit.

In general, a shorter interframe leads to better compression efficiency and improved video quality, but it can also increase the complexity of the encoding process. A longer interframe can provide more time for the encoding process to complete, but it may result in lower compression efficiency and reduced video quality. The optimal interframe value depends on various factors, such as the type of video content, the bit rate, and the target platform.