P-frames, also known as Predictive frames, are a type of video compression technique used in digital video compression standards such as H.264, H.265, and MPEG-4. The basic idea behind P-frames is that instead of encoding the full video picture for each frame, P-frames only encode the differences between the current frame and the previous one.
The first frame in a sequence of P-frames is called an I-frame (Intra-coded frame) which contains a full image. Subsequent P-frames only contain the differences from the previous frame. This means that P-frames require fewer bits to encode the same information, leading to a more efficient use of bandwidth and storage space.
In a video stream, P-frames are interspersed with I-frames, which provide a full reference image. This allows the decoder to recreate the video stream with high accuracy even in the event of errors or lost data.
Overall, P-frames play an important role in the compression and transmission of digital video, allowing for the efficient storage and transmission of high-quality video content.
Here are some useful links that you may find helpful to learn more about P-frames and video compression:
Video Compression Basics: https://www.techopedia.com/definition/13043/video-compression-basics
P-frames in H.264 Video Compression: https://www.streamingmedia.com/Articles/Editorial/Featured-Articles/P-Frames-in-H.264-Video-Compression-114563.aspx
How P-Frames and I-Frames work in Video Compression: https://www.digitalmediahub.co.uk/knowledge-base/video-compression-p-frames-i-frames/
Overview of H.264 Video Compression: https://www.electronics-tutorials.ws/video/video_compression/video_compression_3.html
Video Compression and Streaming Fundamentals: https://www.pluralsight.com/blog/it-ops/video-compression-streaming-fundamentals
These links provide an in-depth understanding of the concepts of P-frames and video compression, including the technical aspects, the benefits and the application areas.