Topic
Audio codec
About: Audio codec is a research topic. Over the lifetime, 1039 publications have been published within this topic receiving 8493 citations.
Papers published on a yearly basis
Papers
TL;DR: An inverter-based SC circuit and its application to low-voltage, low-power delta-sigma (DeltaSigma) modulators is proposed and the prototype DeltaSigma modulators achieved high power efficiency maintaining sufficient performances for practical applications.
Abstract: An operational transconductance amplifier (OTA) is a major building block and consumes most of the power in switched-capacitor (SC) circuits, but it is difficult to design low-voltage OTAs in scaled CMOS technologies. Instead of using an OTA, this paper proposes an inverter-based SC circuit and its application to low-voltage, low-power delta-sigma (DeltaSigma) modulators. Detailed analysis and design optimizations are also provided. Three inverter-based DeltaSigma modulators are implemented for an implantable pacemaker, a CMOS image sensor, and an audio codec. The modulator-I for an implantable pacemaker achieves 65-dB peak-SNDR for 120-Hz bandwidth consuming 0.73 muW with 1.5 V supply. The modulator-II for a CMOS image sensor implemented with 320-channel parallel ADC architecture achieves 63-dB peak-SNDR for 8-kHz bandwidth consuming 5.6 muW for each channel with 1.2-V supply. The modulator-III for an audio codec achieves 81-dB peak-SNDR with 20-kHz bandwidth consuming 36 muW with 0.7-V supply. The prototype DeltaSigma modulators achieved high power efficiency maintaining sufficient performances for practical applications.
324 citations
1 Sep 2012
TL;DR: This document describes the Opus codec, designed for interactive speech and audio transmission over the Internet.
Abstract: This document describes the Opus codec, designed for interactive
speech and audio transmission over the Internet.
262 citations
Patent•
19 Oct 2000
TL;DR: In this article, a portable audio player (10) that includes a removable media drive (30) and audio playback components (20) to play audio data stored on the removable media (12).
Abstract: A portable audio player (10) that includes a removable media drive (30) and audio playback components (20) to play audio data stored on the removable media (12). The audio playback components (20) include an audio decoder, an audio Codec (24), and a digital to analog converter (25) which receives outputs analog audio signals to headphones (50). A memory (23) within the audio player (10) stores an operating system and a plurality of software Codecs. A suitable software Codec is selected from the plurality of Codecs to decompress the audio data file prior to conversion to analog signals. If the suitable Codec is not stored in memory, it may be read from the removable media (12) such that the portable audio player (10) may properly play the audio content. The portable audio player (10) may also be operated as a removable data storage device for a personal computer.
176 citations
TL;DR: In this article, a method and apparatus for compression and decompression of audio signals using a novel boundary analysis and synthesis framework to substantially reduce quantization-induced frame or block discontinuity is presented.
Abstract: A method and system for reduction of quantization-induced block-discontinuities arising from lossy compression and decompression of continuous signals, especially audio signals. One embodiment encompasses a general purpose, ultra-low latency, efficient audio codec algorithm. More particularly, the invention includes a method and apparatus for compression and decompression of audio signals using a novel boundary analysis and synthesis framework to substantially reduce quantization-induced frame or block discontinuity; a novel adaptive cosine packet transform (ACPT) as the transform of choice to effectively capture the input audio characteristics; a signal-residue classifier to separate the strong signal clusters from the noise and weak signal components (collectively called residue); an adaptive sparse vector quantization (ASVQ) algorithm for signal components; a stochastic noise model for the residue; and an associated rate control algorithm. The invention further includes corresponding computer program implementations of these and other algorithms.
154 citations
18 Mar 2005
TL;DR: The requirements imposed by mobile audio services are discussed and a technology overview of AMR-WB+ as a codec matching these requirements while providing outstanding audio quality is given.
Abstract: Highly efficient low-rate audio coding methods are required for new compelling and commercially interesting applications of streaming, messaging and broadcasting services using audio media in 3rd generation mobile communication systems. After an audio codec selection phase, 3GPP has standardized the extended AMR-WB (AMR-WB+) codec that provides a unique performance at very low bit rates from below 10 kbps up to 24 kbps. This paper discusses the requirements imposed by mobile audio services and gives a technology overview of AMR-WB+ as a codec matching these requirements while providing outstanding audio quality.
141 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 20 |
| 2020 | 32 |
| 2019 | 34 |
| 2018 | 21 |
| 2017 | 32 |
| 2016 | 38 |