This invention relates to the field of edge-cloud
collaboration technology, specifically to an
emergency rescue video call
system and method for people trapped in malfunctioning elevators. The
system includes: a state-aware coding module that calculates the
signal-to-
noise ratio slope to compress macroblocks and construct a video
stream; a keyframe loss assessment module that calculates
packet loss density to obtain truncation
loss rate; an asymmetric error correction scheduling module that stretches the step size to construct a
hybrid stream; a
delay mapping
retransmission module that monitors
delay parameters to obtain detection results; and a cross-
modal time-domain synchronization module that stretches audio and shifts and calibrates time markers. In this invention, spatial redundancy compression is performed based on dynamic image and
signal-to-
noise ratio patterns to adapt to physical channel attenuation. The load missing density is analyzed and the step distance is dynamically stretched to perform asymmetric error correction scheduling. Combined with the
delay detection results, periodic peak search and non-modulation extension are performed on the waveform to drive the
retransmission packet marker shift calibration. In a weak network transmission environment, the audio-visual data is kept aligned in the
time domain and the screen
stuttering and disconnection faults are eliminated.