Rate Video Codec Research Articles

Frame differencing-based segmentation for low bit rate video codec using H.264

In video sequence coding, a combination of temporal and spatial coding technique is used in order to remove the predictable or redundant image content and encode only the unpredictable information. The objective of video compression technique is to increase the coding efficiency and to increase the data rate savings. A segmentation-based compression method is proposed to achieve this goal. In this paper, static portions are identified using frame differencing method and segmented during the encoding process. This encoded information is passed to the synthesiser. In synthesis, information which is passed during segmentation process is added to reconstruct the video. This method is integrated with the conventional video codec H.264/AVC video codec. Experimental results substantially proved the data rate is reduced by as much as 25%.

ADAPTIVE STREAMING OVER HTTP (DASH) UNTUK APLIKASI VIDEO STREAMING

This paper aims to analyze Internet-based streaming video service in the communication media with variable bit rates. The proposed scheme on Dynamic Adaptive Streaming over HTTP (DASH) using the internet network that adapts to the protocol Hyper Text Transfer Protocol (HTTP). DASH technology allows a video in the video segmentation into several packages that will distreamingkan. DASH initial stage is to compress the video source to lower the bit rate video codec uses H.26. Video compressed further in the segmentation using MP4Box generates streaming packets with the specified duration. These packages are assembled into packets in a streaming media format Presentation Description (MPD) or known as MPEG-DASH. Streaming video format MPEG-DASH run on a platform with the player bitdash teritegrasi bitcoin. With this scheme, the video will have several variants of the bit rates that gave rise to the concept of scalability of streaming video services on the client side. The main target of the mechanism is smooth the MPEG-DASH streaming video display on the client. The simulation results show that the scheme based scalable video streaming MPEG-DASH able to improve the quality of image display on the client side, where the procedure bufering videos can be made constant and fine for the duration of video views

Low Power Design of DCT and IDCT for Low Bit Rate Video Codecs

This paper examines low power design techniques for discrete cosine transform (DCT) and inverse discrete cosine transform (IDCT) circuits applicable for low bit rate wireless video systems. The techniques include skipping DCT computation of low energy macroblocks, skipping IDCT computation of blocks with all coefficients equal to zero, using lower precision constant multipliers, gating the clock, and reducing transitions in the data path. The proposed DCT and IDCT circuits reduce power dissipation by, on average, 94% over baseline reference circuits.

Foveation scalable video coding with automatic fixation selection

Image and video coding is an optimization problem. A successful image and video coding algorithm delivers a good tradeoff between visual quality and other coding performance measures, such as compression, complexity, scalability, robustness, and security. In this paper, we follow two recent trends in image and video coding research. One is to incorporate human visual system (HVS) models to improve the current state-of-the-art of image and video coding algorithms by better exploiting the properties of the intended receiver. The other is to design rate scalable image and video codecs, which allow the extraction of coded visual information at continuously varying bit rates from a single compressed bitstream. Specifically, we propose a foveation scalable video coding (FSVC) algorithm which supplies good quality-compression performance as well as effective rate scalability. The key idea is to organize the encoded bitstream to provide the best decoded video at an arbitrary bit rate in terms of foveated visual quality measurement. A foveation-based HVS model plays an important role in the algorithm. The algorithm is adaptable to different applications, such as knowledge-based video coding and video communications over time-varying, multiuser and interactive networks.

A comparative review of digital image stabilising algorithms for mobile video communications

The paper presents image stabilisation algorithms in combination with low bit rate video codec techniques in a mobile video communication environment by analysing standalone as well as integral processing methods.

A DCT-based embedded image coder using wavelet structure of DCT for very low bit rate video codec

This paper presents an efficient DCT-based embedded image coder designed for I(intra)-frame coding in a very low bit rate video codec. Motivated by the recognition that a DCT (discrete cosine transform) on N/spl times/N blocks of an image can be viewed as a wavelet decomposition with a uniform N/spl times/N-subband decomposition, the proposed coder rearranges the DCT transformed image into a 2-level wavelet pyramid structure and makes use of improved embedded zerotree coding. The proposed rearrangement structure is quite well coupled with a embedded zerotree coding. The resulting DCT-based embedded image coder shows a better rate-distortion performance than conventional H.263 and MPEG4 as well as EZW-style coders. Also, the performance of the proposed new coder is comparable to that of state-of-art still image compression methods. In addition, the embedded feature of the proposed coder makes it possible to encode the I-frame at the exactly chosen bit rate.

Analysis of bandwidth allocation schemes for transmission of VBR video traffic on a FODA satellite network

FODA, an access protocol for satellite networks based on a TDMA technology, is designed to support integrated services. To this end, FODA provides two types of service: synchronous and asynchronous; only the users of the synchronous service have guaranteed bandwidth. In the paper the authors focus on the synchronous service alone and investigate static bandwidth allocation strategies which satisfy the quality of service (QoS) requirements (i.e. a limited transfer delay and a packet loss rate < 10-6) for the transmission of the data generated by a variable bit rate (VBR) video codec. By solving an analytical model it is shown that, due to the stringent QoS constraints, the amount of reserved bandwidth for VBR video applications must be much higher than their throughput. Hence a portion of low-priority traffic (e.g. EDP data) can be transmitted on the FODA synchronous services to utilise the satellite link to the maximum extent. Via simulation, the authors analyse, for the bandwidth allocation schemes which provide an acceptable QoS for high-priority traffic, the QoS available to low-priority users.

A variable bit rate video codec for ATM networks and its robustness against cell losses

AbstractA video codec for ATM (Asynchronous data Transfer Mode), which is the transfer scheme in the era of B‐ISDN (broadband aspects of ISDN) is constructed and the performance is evaluated. The experimental equipment can realize the variable‐rate coded video transmission corresponding to CCIR 601 recommendation, through the experimental switching network. The periodic cyclic refresh, packeting of the coded information, and the interframe prediction DCT layered coding are employed, realizing a robustness against the cell loss which is the cause of a drastic image quality deterioration in ATM.As a result of the subjective evaluation experiment, the image quality of MOS 3.5 or above is obtained for the cell loss ratio of 10−6 using only the cyclic refresh and the packeting of the coded information, and 10−2 to 10−4 of low‐priority order information using the interframe prediction DCT layered coding.

VLSI technology requirements for an ATM variable bit rate video codec : P. Guebelset al. Elect. Commun.65, 140 (1992)

VLSI technology requirements for an ATM variable bit rate video codec : P. Guebelset al. Elect. Commun.65, 140 (1992)

Statistical multiplexing gain for variable bit rate video codecs in ATM networks

AbstractAsynchronous transfer mode (ATM) broadband networks will support variable bit rate video codecs, which are capable of maintaining a constant picture quality. To demonstrate this capability, a prototype hardware video coder has been developed in the Siemens Central Communications Laboratories. The prototype uses interframe coding, combined with a discrete cosine transform, and is able to reproduce the original picture quality, independent of signal sources or picture material used.A gain in transmission efficiency is expected when several video sources share a common ATM channel (‘statistical multiplexing’). This paper reports on a series of measurements that have been performed using this coder for a large variety of video sources to determine the possible gain in transmission efficiency.The main results are: for realistic video phone scenes, up to about three times the number of signals can be transmitted compared to transmision with constant rate and the same picture quality, if the output signal of the coder has been smoothed over a period of one frame. Smoothing over shorter periods reduces the potential gain substantially. The statistical multiplexing gain increases with the duration of the picture sequences due to the criterion of constant picture quality. It varies very little with the acceptable packet loss rate.

Video codec standardization in CCITT study group XV

This paper presents CCITT standardization activities on lower bit rate (primary rate or lower) video codecs mainly for videoconferencing or videophone, covering the previous study period (1981–1984) and the present study period (1985–1988). Codecs for sub-primary rates ( n × 384 and m × 64 kbit/s) have been studied in the Specialists Group on Coding for Visual Telephony in Study Group XV, whose objectives and achievements are detailed. Current status and future study toward making a final Recommendation are also touched upon.