Basics of Embedded Audio Processing
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A Multidimensional Companding Scheme for Source Coding Witha Perceptually Relevant Distortion Measure
A MULTIDIMENSIONAL COMPANDING SCHEME FOR SOURCE CODING WITHA PERCEPTUALLY RELEVANT DISTORTION MEASURE J. Crespo, P. Aguiar R. Heusdens Department of Electrical and Computer Engineering Department of Mediamatics Instituto Superior Técnico Technische Universiteit Delft Lisboa, Portugal Delft, The Netherlands ABSTRACT coding mechanisms based on quantization, where less percep- tually important information is quantized more roughly and In this paper, we develop a multidimensional companding vice-versa, and lossless coding of the symbols emitted by the scheme for the preceptual distortion measure by S. van de Par quantizer to reduce statistical redundancy. In the quantization [1]. The scheme is asymptotically optimal in the sense that process of the (en)coder, it is desirable to quantize the infor- it has a vanishing rate-loss with increasing vector dimension. mation extracted from the signal in a rate-distortion optimal The compressor operates in the frequency domain: in its sim- sense, i.e., in a way that minimizes the perceptual distortion plest form, it pointwise multiplies the Discrete Fourier Trans- experienced by the user subject to the constraint of a certain form (DFT) of the windowed input signal by the square-root available bitrate. of the inverse of the masking threshold, and then goes back into the time domain with the inverse DFT. The expander is Due to its mathematical tractability, the Mean Square based on numerical methods: we do one iteration in a fixed- Error (MSE) is the elected choice for the distortion measure point equation, and then we fine-tune the result using Broy- in many coding applications. In audio coding, however, the den’s method. -
Recommended Formats Statement 2019-2020
Library of Congress Recommended Formats Statement 2019-2020 For online version, see https://www.loc.gov/preservation/resources/rfs/index.html Introduction to the 2019-2020 revision ....................................................................... 2 I. Textual Works and Musical Compositions ............................................................ 4 i. Textual Works – Print .................................................................................................... 4 ii. Textual Works – Digital ................................................................................................ 6 iii. Textual Works – Electronic serials .............................................................................. 8 iv. Digital Musical Compositions (score-based representations) .................................. 11 II. Still Image Works ............................................................................................... 13 i. Photographs – Print .................................................................................................... 13 ii. Photographs – Digital ................................................................................................. 14 iii. Other Graphic Images – Print .................................................................................... 15 iv. Other Graphic Images – Digital ................................................................................. 16 v. Microforms ................................................................................................................ -
Space Application Development Board
Space Application Development Board The Space Application Development Board (SADB-C6727B) enables developers to implement systems using standard and custom algorithms on processor hardware similar to what would be deployed for space in a fully radiation hardened (rad-hard) design. The SADB-C6727B is devised to be similar to a space qualified rad-hardened system design using the TI SMV320C6727B-SP DSP and high-rel memories (SRAM, SDRAM, NOR FLASH) from Cobham. The VOCAL SADB- C6727B development board does not use these high reliability space qualified components but rather implements various common bus widths and memory types/speeds for algorithm development and performance evaluation. VOCAL Technologies, Ltd. www.vocal.com 520 Lee Entrance, Suite 202 Tel: (716) 688-4675 Buffalo, New York 14228 Fax: (716) 639-0713 Audio inputs are handled by a TI ADS1278 high speed multichannel analog-to-digital converter (ADC) which has a variant qualified for space operation. Audio outputs may be generated from digital signal Pulse Density Modulation (PDM) or Pulse Width Modulation (PWM) signals to avoid the need for a space qualified digital-to-analog converter (DAC) hardware or a traditional audio codec circuit. A commercial grade AIC3106 audio codec is provided for algorithm development and for comparison of audio performance to PDM/PWM generated audio signals. Digital microphones (PDM or I2S formats) can be sampled by the processor directly or by the AIC3106 audio codec (PDM format only). Digital audio inputs/outputs can also be connected to other processors (using the McASP signals directly). Both SRAM and SDRAM memories are supported via configuration resistors to allow for developing and benchmarking algorithms using either 16-bit wide or 32-bit wide busses (also via configuration resistors). -
Concatenation of Compression Codecs – the Need for Objective Evaluations
Concatenation of compression codecs – The need for objective evaluations C.J. Dalton (UKIB) In this article the Author considers, firstly, a hypothetical broadcast network in which compression equipments have replaced several existing functions – resulting in multiple-cascading. Secondly, he describes a similar network that has been optimized for compression technology. Picture-quality assessment methods – both conventional and new, fied for still-picture applications in the printing in- subjective and objective – are dustry and was adapted to motion video applica- discussed with the aim of providing tions, by encoding on a picture-by-picture basis. background information. Some Various proprietary versions of JPEG, with higher proposals are put forward for compression ratios, were introduced to reduce the objective evaluation together with storage requirements, and alternative systems based on Wavelets and Fractals have been imple- initial observations when concaten- mented. Due to the availability of integrated hard- ating (cascading) codecs of similar ware, motion JPEG is now widely used for off- and different types. and on-line editing, disc servers, slow-motion sys- tems, etc., but there is little standardization and few interfaces at the compressed level. The MPEG-1 compression standard was aimed at 1. Introduction progressively-scanned moving images and has been widely adopted for CD-ROM and similar ap- Bit-rate reduction (BRR) techniques – commonly plications; it has also found limited application for referred to as compression – are now firmly estab- broadcast video. The MPEG-2 system is specifi- lished in the latest generation of broadcast televi- cally targeted at the complete gamut of video sys- sion equipments. tems; for standard-definition television, the MP@ML codec – with compression ratios of 20:1 Original language: English Manuscript received 15/1/97. -
Decimal Layouts for IEEE 754 Strawman3
IEEE 754-2008 ECMA TC39/TG1 – 25 September 2008 Mike Cowlishaw IBM Fellow Overview • Summary of the new standard • Binary and decimal specifics • Support in hardware, standards, etc. • Questions? 2 Copyright © IBM Corporation 2008. All rights reserved. IEEE 754 revision • Started in December 2000 – 7.7 years – 5.8 years in committee (92 participants + e-mail) – 1.9 years in ballot (101 voters, 8 ballots, 1200+ comments) • Removes many ambiguities from 754-1985 • Incorporates IEEE 854 (radix-independent) • Recommends or requires more operations (functions) and more language support 3 Formats • Separates sets of floating-point numbers (and the arithmetic on them) from their encodings (‘interchange formats’) • Includes the 754-1985 basic formats: – binary32, 24 bits (‘single’) – binary64, 53 bits (‘double’) • Adds three new basic formats: – binary128, 113 bits (‘quad’) – decimal64, 16-digit (‘double’) – decimal128, 34-digit (‘quad’) 4 Why decimal? A web page… • Parking at Manchester airport… • £4.20 per day … … for 10 days … … calculated on-page using ECMAScript Answer shown: 5 Why decimal? A web page… • Parking at Manchester airport… • £4.20 per day … … for 10 days … … calculated on-page using ECMAScript Answer shown: £41.99 (Programmer must have truncated to two places.) 6 Where it costs real money… • Add 5% sales tax to a $ 0.70 telephone call, rounded to the nearest cent • 1.05 x 0.70 using binary double is exactly 0.734999999999999986677323704 49812151491641998291015625 (should have been 0.735) • rounds to $ 0.73, instead of $ 0.74 -
Marantz Guide to Pc Audio
White paper MARANTZ GUIDE TO PCAUDIO Contents: Introduction • Introduction As you know, in recent years the way to listen to music has changed. There has been a progression from the use of physical • Digital Connections media to a more digital approach, allowing access to unlimited digital entertainment content via the internet or from the library • Audio Formats and TAGs stored on a computer. It can be iTunes, Windows Media Player or streaming music or watching YouTube and many more. The com- • System requirements puter is a centre piece to all this entertainment. • System Setup for PC and MAC The computer is just a simple player and in a standard setup the performance is just average or even less. • Tips and Tricks But there is also a way to lift the experience to a complete new level of enjoyment, making the computer a good player, by giving the • High Resolution audio download responsibility for the audio to an external component, for example a “USB-DAC”. A DAC is a Digital to Analogue Converter and the USB • Audio transmission modes terminal is connected to the USB output of the computer. Doing so we won’t be only able to enjoy the above mentioned standard audio, but gain access to high resolution audio too, exceeding the CD quality of 16-bit / 44.1kHz. It is possible to enjoy studio master quality as 24-bit/192kHz recordings or even the SACD format DSD with a bitstream at 2.8MHz and even 5.6MHz. However to reach the above, some equipment is needed which needs to be set up and adjusted. -
Acoustica-Mp3-Audio-Mixer-Manual.Pdf
Acoustica Registration Overview Quick Start Version History Using MP3 Audio Mixer Working with Sounds Working with Sound Groups Main Window Exporting to MP3, WMA, WAV, or Realaudio™ Preferences Troubleshooting Menu Reference File Edit Sound Group Sound Menu Toolbar Copyright and Ownership Notices MP3 Audio Mixer © Copyright 1998-2002 Acoustica. All Rights Reserved. Includes Xaudio software Copyright © 1996-2002 Xaudio Corporation. All Rights Reserved. RealAudio® encoding components © 1996-2002 by Real Networks, Inc. Windows Media Format © 2000-2002 Microsoft Corporation. All rights reserved. Quick Start So you want to get started in a hurry? Follow "SoundWarrior" through the steps to MP3 Audio Mixer mastery! 1. Start MP3 Audio Mixer SoundWarrior double clicks the MP3 Audio Mixer icon on his desktop. Okay, we could have left this step out. J 2. Drag in some sounds. SoundWarrior has a good sound of a cave-woman scream called arghhh1.wav. The sound is located in "c:\cavescreams\", which he finds, and then drags the sound’s icon onto the MP3 Audio Mixer window. See working with sounds. 3. Drag in some more sounds. SoundWarrior also drags in stampede.wav, the sound of a herd of Mastodons stampeding by his cave. Finally, he drags in an MP3 called "rockrolls.mp3", some of the latest music from "The Stoners" 4. Make a recording if you want. SoundWarrior hits the record button and the record dialog comes up. He punches the record button on the dialog and screams into his microphone "You make fire now! I make fire yesterday!" He then hits the stop button, previews the sound and saves it as "me_talk1.wav". -
PXC 550 Wireless Headphones
PXC 550 Wireless headphones Instruction Manual 2 | PXC 550 Contents Contents Important safety instructions ...................................................................................2 The PXC 550 Wireless headphones ...........................................................................4 Package includes ..........................................................................................................6 Product overview .........................................................................................................7 Overview of the headphones .................................................................................... 7 Overview of LED indicators ........................................................................................ 9 Overview of buttons and switches ........................................................................10 Overview of gesture controls ..................................................................................11 Overview of CapTune ................................................................................................12 Getting started ......................................................................................................... 14 Charging basics ..........................................................................................................14 Installing CapTune .....................................................................................................16 Pairing the headphones ...........................................................................................17 -
Audio Coding for Digital Broadcasting
Recommendation ITU-R BS.1196-7 (01/2019) Audio coding for digital broadcasting BS Series Broadcasting service (sound) ii Rec. ITU-R BS.1196-7 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio- frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http://www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http://www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. -
Realaudio and Realvideo Content Creation Guide
RealAudioâ and RealVideoâ Content Creation Guide Version 5.0 RealNetworks, Inc. Contents Contents Introduction......................................................................................................................... 1 Streaming and Real-Time Delivery................................................................................... 1 Performance Range .......................................................................................................... 1 Content Sources ............................................................................................................... 2 Web Page Creation and Publishing................................................................................... 2 Basic Steps to Adding Streaming Media to Your Web Site ............................................... 3 Using this Guide .............................................................................................................. 4 Overview ............................................................................................................................. 6 RealAudio and RealVideo Clips ....................................................................................... 6 Components of RealSystem 5.0 ........................................................................................ 6 RealAudio and RealVideo Files and Metafiles .................................................................. 8 Delivering a RealAudio or RealVideo Clip ...................................................................... -
(A/V Codecs) REDCODE RAW (.R3D) ARRIRAW
What is a Codec? Codec is a portmanteau of either "Compressor-Decompressor" or "Coder-Decoder," which describes a device or program capable of performing transformations on a data stream or signal. Codecs encode a stream or signal for transmission, storage or encryption and decode it for viewing or editing. Codecs are often used in videoconferencing and streaming media solutions. A video codec converts analog video signals from a video camera into digital signals for transmission. It then converts the digital signals back to analog for display. An audio codec converts analog audio signals from a microphone into digital signals for transmission. It then converts the digital signals back to analog for playing. The raw encoded form of audio and video data is often called essence, to distinguish it from the metadata information that together make up the information content of the stream and any "wrapper" data that is then added to aid access to or improve the robustness of the stream. Most codecs are lossy, in order to get a reasonably small file size. There are lossless codecs as well, but for most purposes the almost imperceptible increase in quality is not worth the considerable increase in data size. The main exception is if the data will undergo more processing in the future, in which case the repeated lossy encoding would damage the eventual quality too much. Many multimedia data streams need to contain both audio and video data, and often some form of metadata that permits synchronization of the audio and video. Each of these three streams may be handled by different programs, processes, or hardware; but for the multimedia data stream to be useful in stored or transmitted form, they must be encapsulated together in a container format. -
Floating Point Representation (Unsigned) Fixed-Point Representation
Floating point representation (Unsigned) Fixed-point representation The numbers are stored with a fixed number of bits for the integer part and a fixed number of bits for the fractional part. Suppose we have 8 bits to store a real number, where 5 bits store the integer part and 3 bits store the fractional part: 1 0 1 1 1.0 1 1 $ 2& 2% 2$ 2# 2" 2'# 2'$ 2'% Smallest number: Largest number: (Unsigned) Fixed-point representation Suppose we have 64 bits to store a real number, where 32 bits store the integer part and 32 bits store the fractional part: "# "% + /+ !"# … !%!#!&. (#(%(" … ("% % = * !+ 2 + * (+ 2 +,& +,# "# "& & /# % /"% = !"#× 2 +!"&× 2 + ⋯ + !&× 2 +(#× 2 +(%× 2 + ⋯ + ("%× 2 0 ∞ (Unsigned) Fixed-point representation Range: difference between the largest and smallest numbers possible. More bits for the integer part ⟶ increase range Precision: smallest possible difference between any two numbers More bits for the fractional part ⟶ increase precision "#"$"%. '$'#'( # OR "$"%. '$'#'(') # Wherever we put the binary point, there is a trade-off between the amount of range and precision. It can be hard to decide how much you need of each! Scientific Notation In scientific notation, a number can be expressed in the form ! = ± $ × 10( where $ is a coefficient in the range 1 ≤ $ < 10 and + is the exponent. 1165.7 = 0.0004728 = Floating-point numbers A floating-point number can represent numbers of different order of magnitude (very large and very small) with the same number of fixed bits. In general, in the binary system, a floating number can be expressed as ! = ± $ × 2' $ is the significand, normally a fractional value in the range [1.0,2.0) .