As a monitoring method, telemetry digital video plays an important role in the test flight of large civil aircraft. For telemetry video under H.264 compression, two different PCM coding formats are proposed,which are transport stream coding and asynchronous stream coding. This paper describes the data structure of the two codes, compares and analyzes the characteristics in terms of bandwidth utilization and anti－jamming. At the same time, this paper elaborates on the identification, extraction, analysis and playing of multi－channel embedded HD video data streams under two encoding formats, which successfully guarantees the flight test of some aircraft on important subjects, and lays the technical foundation for ensuring the flight test safety and shorten the flight test period.