In the H.264 video codec, which type of video frame is sent when the remote side requests a fast picture update?

An I-frame (Intra-coded frame) contains complete image data and does not depend on any other frame for decoding, making it the appropriate response to a fast picture update request. When packet loss causes video artifacts, the receiving endpoint sends an FPU request, and the encoder immediately transmits a new I-frame to refresh the video stream. This allows the decoder to re-synchronize without waiting for the next scheduled intra-refresh interval.

A P-frame (Predictive frame) encodes only the differences from a previous reference frame and cannot independently refresh a corrupted video stream.

A B-frame (Bidirectional Predictive frame) depends on both preceding and following frames for decoding and cannot serve as a standalone reference point to recover from packet loss.

There is no C-frame type defined in the H.264 video codec standard.