Audio Codecs : Audio Compression Codec, Codecs De Audio, mpeg 4 Audio Codec

HE-AAC Decoder

2009-08-12T23:11:00.000-07:00

HE-AAC decoder on ARM9E and TI C64x+

AAC is a popular audio coding technique recommended by MPEG committee. SBR is a tool used in combination with the AAC general audio codec resulting in HE-AAC (also known as aacPlus). It provides significant increase in coding gain. In SBR, the high-band, i.e. the high frequency part of the spectrum is replicated using the low-band.

The bit-rate is by far below the bit-rate required when using conventional AAC coding. This translates into better quality at lower bit-rates.It can be used in consumer applications like mobile streaming and download, digital terrestrial, cable & satellite television broadcasting and Internet Video on demand service.

For more information contact us at: http://www.ipsupermarket.com/Multimedia-Codecs/Audio-Codecs/AAC+/dynamic/ipname/6.htm

Latest AAC Audio Codecs at IPSupermarket

2009-07-08T22:32:00.000-07:00

IP Title	:	AAC Decoder

Ref	:	4619A1B6BE

IP Title	:	AAC BSAC Decoder On TI 64x

Ref	:	0A5EC4E2AE

IP Title	:	AAC LC Decoder TI 54xx, DM 27x

Ref	:	B6ECEB245F

IP Title	:	AAC LC Decoder On ARM7

Ref	:	571CC49830

IP Title	:	VAAC VINJEY MPEG 2/4 AAC Decoder

Ref	:	D3B32474D4

IPsupermarket is listed on Global Semiconductor Alliance WebSite

2009-04-29T03:14:00.000-07:00

GSA decision to list the IPsupermarket website on their resource page will increase the traffic & alliance of both the GSAGlobal & IPsupermarket.This partnership creates marketing synergies for both the companies to target the wide need for IPs in numerous application types.

GSA listed the IPSupermarket in their reference material of the IP catalog resources. IPsupermarket IP catalog provides GSA members with direct access to IPsupermarket's comprehensive catalog of Software IP & IP core, which serves as a valuable resource for SOC designers, Design House, Semicon & Services Companies, OEM and Freelancers.

IPSupermarket is offering free membership for the Buyers who are looking about the information on IPs and also offering Free Membership to the sellers who are looking to sell their IPs.

For more information about the GSA Listing please visit at: http://www.gsaglobal.org/resources/ipcatalog/index.asp or Browse www.ipsupermarket.com

Audio codecs : Pros & Cons

2008-04-24T22:48:00.000-07:00

The audio codecs is a method of compression/decompression of audio file, audio data or streaming audio format. The codecs stands for Coders / Decoders.

There are various kinds of audio codecs available. Since these codecs have been implemented by different algorithms by number of companies; they have different specification and application in various fields. These audio codecs generally complies Industry standards.

The various software audio codecs are:

AAC
AAC+ / AAC+ Enhanced
AC3 or Digital Dolby
Digital Dolby Plus
Speex
FLAC
MIDI
MP3
MP3 Pro
Monkey’s audio
Ogg Vorbis
QCELP
Real Audio
SMPTE VC-1
Sony: ATRAC
WMA
Melody
HVAC
Wavepack etc

These various Audio codecs are technically differentiated from each other based on various factors which includes compression technology / algorithm, platform supported, sampling, OS supported etc

One can easily compare the various audio codecs on wikipedia. But still there is confusion over to which codec is the best? So let’s try to see what are the pros and cons of some codecs, which gives us the better idea about these codecs.

AAC

Pros

An international standard approved by the ISO
Flexible: supports several sampling rates (8000–96000 Hz), bit depths, and multichannel (up to 48 channels)
Several implementations, including free and high quality ones (iTunes or Nero Digital)
Reaches transparency in most samples and for most users at around 150 kbps
Part of MPEG-4 specs
Anyone can create its own implementation (specifications and demo sources available)

Cons

Problem cases that trip out all transform codecs
Heavily patented
Increased complexity
AAC comes in different "flavors" (object types: AAC LC, AAC HE, AAC PS etc.).
Many (especially portable) players only support LC (at the moment) so you can have files that are valid but your player won't play them.

AAC+ / Enhanced AAC

AACplus (AAC+) is a variant of AAC which is optimized for low bit rates developed by Coding Technologies. It uses techniques including SBR (Spectral Band Replication) and PS (Parametric Stereo).
Multi-channel support for 5.1, 7.1 and beyond (48 channels total)
Optimized speech, mixed speech/music down to 8 kbps mono

AC3 / Digital Dolby / Digital Dolby plus

Pros

Digital Dolby or AC3 decoder is the industry standard for DTV and DVD media. Nearly all new DVD movies come with a DD soundtrack program
AC-3 provides only full range channels, its sound is really much better in terms of quality. And it is also backward compatible.
Digital Dolby plus also supports 7.1 channel

Cons

Max support for 5.1 channel audio CDs, limited to 448 kbps maximum for Digital Dolby

SPEEX

Pros

Speex is an Open Source/Free Software patent-free audio compression format
Speex is based on CELP and is designed to compress voice at bitrates ranging from 2 to 44 kbps
Speex has a number of features that aren’t in other codecs such as Intensity stereo encoding, integration of multiple sampling rates in the same bitstream, and a VBR mode

Cons:

Speex is mainly designed for only three different sampling rates: 8 kHz, 16 KHz & 32 KHz

FLAC

Pros

FLAC is portable to many systems
Open source and freely licensed
The encoding of audio data incurs no loss of information.
Hardware support & Streaming support
Extremely fast decoding
Supports multi channel and high resolution streams
Supports Replay Gain & cue-sheet (with some limitations)
Gaining wide use as successor to Shorten

Cons:

Compresses less efficiently than other popular modern compressors (Monkey's Audio, OptimFROG)
Higher compression modes slow, for little gain over the default setting.

MP3

Pros

Widespread acceptance, support in nearly all hardware audio players and devices
An ISO standard, part of MPEG specs
Fast decoding, lower complexity than AAC or Vorbis
Anyone can create their own implementation (Specs and demo sources available)
Relaxed licensing schedule

Cons

Lower performance/efficiency than modern codecs.
Problem cases that trip out all transform codecs.
Sometimes, maximum bitrate (320kbps) isn't enough.
No multichannel implementations.
Unusable for high definition audio (sampling rates higher than 48kHz).

OGG VORBIS

Pros

(Ogg) Vorbis specification is in the public domain; it is free for commercial or noncommercial use, under both (LGPL and BSD licenes)
Easy to use high-level API (Application Programming Interface)
Good all-round performance (>48 kbps – a leading codec at 128 kbps)
Well written specs
Supported by most portable (Ogg) DAPs
Suitable for internet-streaming (via Icecast and other methods)
Fully gapless playback
High potential for further tuning
Structured to allow the design for a hybrid filterbank

Cons

Limited official development (third-party developement is always encouraged)
Current implementations are more computationally intensive to decode than MP3

To commercialize these audio codecs couples of sites are available such as design-reuse, chipestimates, IPsupermarket.com which allows you to buy/sell or license these codecs.