Low complexity H.264 list decoder for enhanced quality real-time video over IP

Abstract

This paper presents a novel list decoding approach exploiting the receiver side user datagram protocol (UDP) checksum. The proposed method identifies the possible locations of errors in the packet by analyzing the calculated UDP checksum value at the receiver side. This makes it possible to considerably reduce the number of candidate bitstreams in comparison to conventional list decoding approaches. When a packet composed of N bits contains a single bit in error, instead of considering N candidate bitstreams, as is the case in conventional list decoding approaches, the proposed approach considers N/32 candidate bitstreams, leading to a 97% reduction in the number of candidates. Our simulation results on H.264 compressed sequences reveal that, on average, the error is corrected perfectly 80% of the time, and thus, the original bitstream is fully recovered when the first valid candidate is considered as the best candidate. In addition, the proposed approach provides, on average, a 2.78 dB gain over the error concealment approach used by the H.264 reference software, as well as 1.31 dB and 1.51 dB gains over the state-of-the-art error concealment and HO-MLD approaches, respectively.

Table-Free Multiple Bit-Error Correction Using the CRC Syndrome

“…In order to further increase the proposed method's error correction performance, it can be jointly used with other methods providing a list of potential error patterns as their output. For example, the work on UDP checksum proposed in [9], [26], [27] can be combined with our algorithm. Crosschecking both candidate lists would generate a matching list with a reduced number of entries.…”

International Journal of Electronics and Telecommunications

“…One of the most important video coding standards, video coding standard called H.264/AVC. This standard remarkably has better coding efficiency than its predecessors, and has attracted considerable interest from the academic and developer communities [2,3].…”

Checksum-Filtered List Decoding Applied to H.264 and H.265 Video Error Correction

“…a fixed or floating point log-likelihood ratio (LLR) value for each bit of the packet, throughout the protocol stack (from the physical up to the application layer), is complex to implement and deploy in practice. In our previous work [29], we studied the checksum bit pattern for the case of a single-bit error, and showed that it could be exploited to eliminate 97% of the candidate bitstreams considered by list decoding approaches. The proposed method was tested on H.264 CAVLC coded sequences.…”