Low Complexity Real-Time Video Transcoders for Video Upload and Retrieval Applications

This paper proposes low complexity real-time video transcoders for video upload and retrieval applications. The proposed transcoders consist of both picture type conversion and syntax conversion in the compressed domain, and can highly reduce the computation amount in comparison with that of the conventional tandem transcoding method, in which decoding and re-encoding are necessary. The proposed syntax conversion can provide loss-less conversion, while the conventional tandem method is lossy conversion. Timestamp adjustment method is also proposed to avoid audio visual de-synchronization problem due to picture type conversion, when the stream is transmitted via constant bandwidth network. Complexity evaluation results based on DSP implementation confirm that the complexity of the proposed transcoders is very low and is less than 1/3 of that of the conventional tandem transcoder.