Low-complexity field DCT to frame DCT conversion in MPEG-2 to MPEG-4 transcoder

In MPEG-2 to MPEG-4 Simple Profile (SP) transcoder based on the discrete cosine transform (DCT) domain, data conversion from the field DCT to frame DCT must be implemented. We proposed a low-complexity conversion method based on the DCT domain, which does not need performing inverse DCT and DCT. This method exploits the relationship between the filed DCT and the frame DCT on the transform domain to complete the conversion. We presented analysis of performance indicate that the presented method has much lower computational complexity compared to the traditional method based on pixel domain. Experiments show that applying the proposed method, transcoding efficiency can be improved significanly while maintaining the transcoding quality.