ANALISIS KINERJA TEKNIK KOMPRESI ADVANCED VIDEO CODING (AVC)

Teknik kompresi Advanced Video Coding (AVC) adalah standar video coding yang dikembangkan oleh Moving Picture Experts Group (MPEG). Tujuan dari teknik kompresi video adalah untuk memampatkan ukuran datanya. Dibandingkan dengan teknik kompresi sebelumnya MPEG-4, teknik kompresi AVC memiliki kinerja dan efisiensi kompresi yang lebih baik. Pada tugas akhir ini dilakukan analisis kinerja teknik kompresi AVC. Kinerja dan efisiensi kompresi diukur berdasarkan bitrate dan PSNR video hasil kompresi. Untuk menentukan bitrate dan PSNR yang tepat pada video ditentukan berdasarkan kuantisasi parameter yang dipakai. Untuk mengetahui efisiensi kompresi, teknik kompresi AVC dibandingkan dengan teknik kompresi video sebelumnya MPEG-4 Part 2 ASP (Advanced Simple Profile), H.263 HLP (High Latency Profile) dan MPEG-2 Video ML@MP (Main Level at Main Profile). Untuk memenuhi standar kualitas video yang baik yaitu dengan nilai PSNR > 37 dB, kuantisasi parameter yang digunakan yaitu 25, sedangkan bitrate video yaitu 64 – 256 kbps. Efisiensi kompresi teknik kompresi AVC sekitar 50% bila dibandingkan dengan teknik kompresi MPEG-4 Part 2. Kata kunci : AVC, kuantisasi parameter, bitrate, PSNR, kinerja, efisiensi kompresi Advanced Video Coding (AVC) compression technique is a video coding standard developed by the Moving Picture Experts Group (MPEG). The goal of video compression techniques is to compress the size of the data. Compared to previous MPEG-4 compression techniques, AVC compression techniques have better compression performance and efficiency. In this final project, AVC compression technique performance analysis is measured. Compression performance and efficiency are measured based on the compressed bitrate and PSNR of the video. To determine the exact bitrate and PSNR of the video, it is determined based on the parameter quantization used. To find coding efficiency, the AVC compression technique is compared with previous video compression techniques MPEG-4 Part 2 ASP (Advanced Simple Profile), H.263 HLP (High Latency Profile) and MPEG-2 ML@MP Video (Main Level at Main Profile). To find a good video quality standard with a PSNR value > 37 dB, the parameter quantization used is 25. While the video bitrate required is 64 - 256 kbps. AVC compression efficiency up to 50% when compared to the previous standard MPEG-4 Part 2 compression technique. Keywords: AVC, parameter quantization, bitrate, PSNR, performance, compression efficienc

Enhancing the error detection capabilities of DCT based codecs using compressed domain dissimilarity metrics

Video compression standards are implemented in wireless data transmission technologies to provide multimedia services efficiently. These compression standards generally utilize the Discrete Cosine Transform (DCT) in conjunction with variable length codes (VLC) in order to achieve the required high compression ratios. While providing the necessary high data rates, this technique has the disadvantage of making the system more susceptible to transmission errors. The standard decoders do not manage to detect a large number of corrupted macroblocks, 40.54% not detected for H.263+, contributing to a significant reduction in the end-to-end video quality as perceived by the end-user. This paper presents three dissimilarity metrics which contain both color and texture information and that can be extracted directly from the compressed DCT coefficients. These metrics can be used to enhance the error-detection capabilities of standard DCT based codecs. Simulation results show that the proposed algorithm increases the error detection rate by 54.06% with a gain in peak signal-to-noise ratio (PSNR) of 3.21 dB. This improvement in performance is superior to other solutions found in literature.peer-reviewe

Layered Wyner-Ziv video coding: a new approach to video compression and delivery

Following recent theoretical works on successive Wyner-Ziv coding, we propose a practical layered Wyner-Ziv video coder using the DCT, nested scalar quantiza- tion, and irregular LDPC code based Slepian-Wolf coding (or lossless source coding with side information at the decoder). Our main novelty is to use the base layer of a standard scalable video coder (e.g., MPEG-4/H.26L FGS or H.263+) as the decoder side information and perform layered Wyner-Ziv coding for quality enhance- ment. Similar to FGS coding, there is no performance di®erence between layered and monolithic Wyner-Ziv coding when the enhancement bitstream is generated in our proposed coder. Using an H.26L coded version as the base layer, experiments indicate that Wyner-Ziv coding gives slightly worse performance than FGS coding when the channel (for both the base and enhancement layers) is noiseless. However, when the channel is noisy, extensive simulations of video transmission over wireless networks conforming to the CDMA2000 1X standard show that H.26L base layer coding plus Wyner-Ziv enhancement layer coding are more robust against channel errors than H.26L FGS coding. These results demonstrate that layered Wyner-Ziv video coding is a promising new technique for video streaming over wireless networks. For scalable video transmission over the Internet and 3G wireless networks, we propose a system for receiver-driven layered multicast based on layered Wyner-Ziv video coding and digital fountain coding. Digital fountain codes are near-capacity erasure codes that are ideally suited for multicast applications because of their rate- less property. By combining an error-resilient Wyner-Ziv video coder and rateless fountain codes, our system allows reliable multicast of high-quality video to an arbi- trary number of heterogeneous receivers without the requirement of feedback chan- nels. Extending this work on separate source-channel coding, we consider distributed joint source-channel coding by using a single channel code for both video compression (via Slepian-Wolf coding) and packet loss protection. We choose Raptor codes - the best approximation to a digital fountain - and address in detail both encoder and de- coder designs. Simulation results show that, compared to one separate design using Slepian-Wolf compression plus erasure protection and another based on FGS coding plus erasure protection, the proposed joint design provides better video quality at the same number of transmitted packets

Low complexity video compression using moving edge detection based on DCT coefficients

In this paper, we propose a new low complexity video compression method based on detecting blocks containing moving edges us- ing only DCT coe±cients. The detection, whilst being very e±cient, also allows e±cient motion estimation by constraining the search process to moving macro-blocks only. The encoders PSNR is degraded by 2dB com- pared to H.264/AVC inter for such scenarios, whilst requiring only 5% of the execution time. The computational complexity of our approach is comparable to that of the DISCOVER codec which is the state of the art low complexity distributed video coding. The proposed method ¯nds blocks with moving edge blocks and processes only selected blocks. The approach is particularly suited to surveillance type scenarios with a static camera

A low bit-rate video-coding algorithm based upon variable pattern selection

Recent research into pattern representation of moving regions in blocked-based motion estimation and compensation in video sequences, has focused mainly upon using a fixed number of regular shaped patterns. These are used to match the macroblocks in a frame that have two distinct regions involving static background and moving objects. In this paper a new Variable Pattern Selection (VPS) algorithm is presented which selects a preset number of best-matched patterns from a pattern codebook of regular shaped patterns. While more patterns are used than in the previous work, the performance of the VPS algorithm in using variable length coding, by exploiting the frequency of the best-matched patterns, leads to a higher compression ratio, without degrading the overall image quality

Very low bit-rate video coding focusing on moving regions using three-tier arbitrary-shaped pattern selection algorithm

Very low bit-rate video coding using patterns to represent moving regions in macroblocks exhibits good potential for improved coding efficiency. Recently an Arbitrary Shaped Pattern Selection (ASPS) algorithm and its Extended version(EASPS) were presented, that used a dynamically extracted set of patterns, of the two different sizes, based on actual video content. These algorithms, like other pattern matching algorithms failed to capture a large number of active-region macroblocks (RMB) especially when the object moving regions is relatively larger in a video sequence. As the size of the moving object may vary, superior coding performance is achievable by using dynamically extracted patterns of a larger size. This paper, proposes a three-tier Arbitrary Shaped Pattern Selection (ASPS-3) algorithm that uses three different pattern sizes for very low bit ate coding. Experimental results show that ASPS-3 exhibits better performance compared with other pattern matching algorithms, including the low-bit rate video coding standard H.263