Perceptually-Driven Video Coding with the Daala Video Codec

The Daala project is a royalty-free video codec that attempts to compete with the best patent-encumbered codecs. Part of our strategy is to replace core tools of traditional video codecs with alternative approaches, many of them designed to take perceptual aspects into account, rather than optimizing for simple metrics like PSNR. This paper documents some of our experiences with these tools, which ones worked and which did not. We evaluate which tools are easy to integrate into a more traditional codec design, and show results in the context of the codec being developed by the Alliance for Open Media.Comment: 19 pages, Proceedings of SPIE Workshop on Applications of Digital Image Processing (ADIP), 201

Combined Source and Channel Coding for Channels with a Power Constraint and Multilevel Signaling

In this paper, a method for optimizing the index map between the output indices of a vector quantizer and the channel symbols for a channel with a power constraint and multilevel signaling is presented. The method is based on simulated annealing and makes use of dynamic scaling of the signal constellation during the optimization procedure in order to optimize for a fixed transmitted power. The method is applied to a memoryless Gaussian source and to the subband samples of a still image subband coder. The resulting system is shown to give a significant gain in terms of channel signal-to-noise ratio when compared to a reference system based on arbitrary index maps. 1. INTRODUCTION Recently, there has been a lot of work in the area of combined source and channel coding. A lot of this work has been focused on the transmission of samples from a Gaussian source over a discrete noisy channel without a power constraint [1,2,3]. In [1] simulated annealing (SA) is used to find a good index map ..

Combined Source and Channel Coding for Channels with a Power Constraint and Multilevel Signaling

In this paper, a method for optimizing the index map between the output indices of a vector quantizer and the channel symbols for a channel with a power constraint and multilevel signaling is presented. The method is based on simulated annealing and makes use of dynamic scaling of the signal constellation during the optimization procedure in order to optimize for a fixed transmitted power. The method is applied to a memoryless Gaussian source and to the subband samples of a still image subband coder. The resulting system is shown to give a significant gain in terms of channel signal-to-noise ratio when compared to a reference system based on arbitrary index maps. 1 Introduction Recently, there has been a lot of work in the area of combined source and channel coding. A lot of this work has been focused on the transmission of samples from a Gaussian source over a discrete noisy channel without a power constraint [1,2,3]. In [1] simulated annealing (SA) is used to find a good index map ..

Combined CELP Speech Coding and Quadrature Amplitude Modulation

. In this paper, a method for optimizing the index map between the output indices of a wideband (7 kHz) CELP speech coder and the channel symbols for a power constrained channel and multilevel signaling is presented. The method is based on simulated annealing and makes use of dynamic scaling of a QAM signal constellation during the optimization procedure in order to optimize for a fixed transmitted power. The resulting system is shown to give a significant gain in terms of channel signal-to-noise ratio when compared to a reference system based on arbitrary index maps. 1. Introduction Recently, there has been a lot of work in the area of combined source and channel coding. Most of this work has focused on the transmission of samples from a discrete source over a binary symmetric channel (BSC) without power constraints [1-4]. In [1] simulated annealing (SA) was used to find a good index map between the output indices from a vector quantizer (VQ) and the binary codewords of a BSC. In thi..

Robust Subband Video Coding with Leaky Prediction

The use of leaky prediction in a video transmission system designed for noisy channels is investigated. For the proposed system, graceful degradation is achieved by finding good index maps between the quantized source coder parameters and the amplitude levels of a QAM signal constellation. The contribution of this paper, however, is to investigate the use of leaky prediction to further increase the robustness to channel noise. It is shown that by using a temporal prediction coefficient slightly less than one, large improvements can be achieved with only a small degradation for the noiseless case. The performance of the proposed system is comparable to a reference system based on the H.263 video coder for high CSNR values, and degrades far more gracefully for low CSNR values. 1. INTRODUCTION Recently, there has been much interest in combined source coding and channel coding /modulation for transmission over noisy channels. In [1], the index assignment problem was addressed by using si..

Robust and Efficient Video Communication Based on Combined Source- and Channel Coding

A video communication system based on combined source- and channel coding is proposed. The proposed system uses a subband video coder structure in combination with powerconstrained channel-optimized vector quantization (PCCOVQ) to achieve efficient and robust transmission of the video signal over a channel with multidimensional PAM signaling. The side information is protected by using a sufficiently large minimum distance of the PAM signal constellation. This ensures error free transmission for the channel-optimized case, and graceful degradation for channel mismatch situations. For the main information, however, PCCOVQ with direct mapping from the source parameter space to the channel (modulation) space is used. A video communication system based on the H.263 video coder is used as a reference. The proposed system compares favorably to the reference system, and offers graceful degradation for channel mismatch situations. 1. INTRODUCTION Combined source and channel coding systems have..

Combined Video Coding And Multilevel Modulation

A video transmission system based on combined source coding and multilevel modulation is proposed. For the proposed system, graceful degradation for noisy channels is obtained by finding good index maps between the quantized source coder parameters and the amplitude levels of a multilevel QAM signal constellation. The index maps are designed both for good neighbor properties and for power efficient transmission by using simulated annealing. The performance of the proposed system is comparable to a reference system based on the H.263 coder for high CSNR values, and degrades far more gracefully for low CSNR values. 1. INTRODUCTION Recently, there has been much interest in combined source coding and channel coding/modulation for transmission over noisy channels. Some of the work has been focused on binary symmetric channels (BSCs) [1, 2], while other studies have considered amplitude continuous channels [3, 4, 5, 6, 7]. In [1], the index assignment problem was addressed by using simulate..

Bandwidth Compression For Continuous Amplitude Channels Based On Vector Approximation To A Continuous Subset Of The Source Signal Space

Two methods for transmission of a continuous amplitude source signal over a continuous amplitude channel with a power constraint are proposed. For both methods, bandwidth reduction is achieved by mapping from a higher dimensional source space to a lower dimensional channel space. In the first system, a source vector is quantized and mapped to a discrete set of points in a multidimensional PAM signal constellation. In the second system the source vector is approximated with a point in a continuous subset of the source space. This operation is followed by mapping the resulting vector to the channel space by a one-to-one continuous mapping resulting in continuous amplitude channel symbols. The proposed methods are evaluated for a memoryless Gaussian source with an additive white Gaussian noise channel, and offer significant gains over previously reported methods. Specifically, in the case of two-dimensional source vectors, and one-dimensional channel vectors, the gap to the optimum perfor..

Channel-Optimized Subband Video Coding For Channels With A Power Constraint

A video communication system based on combined sourcechannel coding is proposed. The proposed system uses a hybrid subband video coder structure in combination with power-constrained channel-optimized vector quantization (PCCOVQ) to achieve efficient and robust transmission of the video signal over a channel with multidimensional PAM signaling. The error-sensitive side information parameters are protected by using traditional channel coding and a sufficiently large minimum distance of the PAM signal constellation. This ensures error free transmission for the channeloptimized case, and graceful degradation for channel mismatch situations. For the main information, PCCOVQ with a direct mapping from the source parameter space to the channel (modulation) space is used. A traditional video communication system based on the H.263 video coder is used as a reference. The proposed system compares favorably to the reference system for high rate applications, and offers graceful degradation for c..