Apple files patent for an advanced graphic equalizer for iPod and more
Posted by Dennis Sellers 
Sep 21, 2005 at 2:10am
On September 15, 2005, the US Patent & Trademark Office revealed Apple’s patent application 20050201572 entitled Method and system for approximating graphic equalizers using dynamic filter order reduction. The inventors listed on the patent are Aram Lindahl, Joseph Mark Williams for serial number 799526, originally filed on March 11, 2004.
Broad overview
Broadly speaking, the invention relates to improved approaches to flexibly implement graphic equalizers on certain iPod models and/or small form factor media players in general, that store and present/display music, videos/movies or images.
Today, iTunes can display a graphic equalizer on various types of home computers. To a limited extent, equalizer settings for media items can be transferred from iTunes to an iPod, which typically has limited computational resources due to its small form factor. Consequently there are difficulties with implementing a graphics equalizer on an iPod (or media players in general). Within the patent application, Apple presents a number of proposed solutions that are uniquely presented as Advantages of the Invention, as follows:
Advantage # 1: is that an equalizer characterization process can reduce the computational complexity of implementing a graphic equalizer without significantly changing its perceived effect to the listener.
Example 1: the equalizer characterization process can convert a 10-band graphic equalizer to a single shelf filter. Since each filter type requires the same number of operations, it would be about ten times faster to execute after conversion to a single shelf filter.
Example 2: the equalizer characterization process can convert a 10-band graphic equalizer to three filters, namely, one shelf filter and two parametric filters. Since each filter type requires the same number of operations, it would be more than three times faster to execute after conversion.
An iPod or other embedded platform may not be able to run more than a few bands of a many band equalizer. Hence, another advantage of the invention allows a high computational load equalizer to be represented and run on lower performance hardware. The reduced computational load also helps the portable computing device conserve power, which is particularly beneficial for battery powered device.
Example 3: an iPod or other embedded platform can perform an equalizer characterization process at run time when a file is downloaded to the device or when loaded for playback. Further, the equalizer characterization process can also be performed in real-time so as to enable a user to dynamically alter equalizer settings during playback.
Advantage # 2: is that an equalizer characterization process does not require any complex optimization problems to be solved.
Example: implementations of the invention can avoid math intensive frequency response calculations. No curve-fitting operations, which have unknown or hard to bound solution times, need be performed. Auto-regressive models that are very difficult to optimize are also avoided. The use of costly trigonometric functions (sin, cos, sin h) to determine filter coefficients can also be avoided. Hence, by avoiding complex optimization problems, computation time for the equalizer characterization process can be substantially faster, guaranteed to happen and bounded.
Advantage # 3: is that an equalizer characterization process can be flexible.
Example: any M-band graphic equalizer to be converted to an N-band parametric filter representation, where N is less than M and determined by the target complexity of the equalizer implementation.
Advantage # 4: is that an equalizer characterization process can include the concept of tolerance bands based on human JND (just noticeable differences).
This tolerance can serve to ignore or group gain changes that are not perceptually distinct, thereby saving additional computation resources that would otherwise be wasted. In one implementation, the host/home computer can interact with the portable computing device.
Example: the host/home computer can transfer media items and associated equalizer information (e.g., equalizer values or one or more equalizer codes) to an iPod. The host/home computer can utilize an application resident on the host computer to perform the transfer of the media items and their attributes between the host/home computer and the iPod. One such application is iTunes.
Extras for detail junkies
The invention can be implemented in numerous ways, including as a method, system, device, apparatus, or computer readable medium. Several embodiments of the invention are discussed below.
As a computer-implemented method – for approximating n-band graphic equalizer settings:
… for a media player using not more than m bands
… for a media player using less than n filters, one embodiment of the invention includes at least the acts of: examining the equalizer setting values for approximate correlation to at least a portion of a frequency response of a shelf type filter; selecting the shelf type filter if a first set of the equalizer setting values approximately correlate; examining the equalizer setting values other than the first set for approximate correlation to at least a portion of a frequency response of a parametric type filter; selecting the parametric type filter if a second set of the equalizer settings approximately correlate; and determining parameters for the shelf type filter and the parametric type filter, wherein at least the shelf type filter and the parametric type filter are used to approximate the n-band graphic equalizer settings for the media player.
As a computer readable medium:
As a computer readable medium including at least computer program code for approximating n-band graphic equalizer settings for a computing device player using less than n bands, one embodiment of the invention includes at least: computer program code for classifying at least a plurality of the equalizer setting values with respect to characteristics of at least a portion of a frequency response shape of at least one of a plurality of predetermined filter types; and computer program code for determining parameters for one or more filters of the at least one of the plurality of predetermined filter types used in classifying the equalizer settings.
As a system:
As a system for approximating an n-band graphic equalizer for use on a device having limited computational resources or computational time, one embodiment of the invention includes at least: means for classifying at least a plurality of equalizer setting values of the n-band graphic equalizer with respect to characteristics of at least a portion of a frequency response shape of at least one of a plurality of predetermined filter types; and means for determining parameters for one or more filters of the at least one of the plurality of predetermined filter types used in classifying the equalizer settings.
As a media device:
One embodiment of the invention includes at least: a data store for storing media data received from a host computer, the media data include media content and equalizer setting information for at least one media item; and a processor operatively connected to the data store, the processor operates to acquire equalizer setting values based on the equalizer setting information, to approximate the equalizer setting values with a reduced filter order approximation, and to present the media content at the media player in accordance with the reduced filter order approximation.
Macsimum Notes
The patent application also notes the following: Although the media items of emphasis in several aspects of the application relate to audio items (e.g., audio files or songs), the media items are not limited to audio items. For example, the media item can alternatively pertain to videos (e.g., movies) or images (e.g., photos). In addition, that various aspects, embodiments, implementations or features of the invention can be used separately or in any combination. Furthermore, that while the invention is preferably implemented by software, it could also be implemented in hardware or a combination of hardware and software. The invention can also be embodied as computer readable code on a computer readable medium.
Off topic – humorous note
On a humorous note, it was interesting to see ZDNet’s September 19/05 report following Macsimum’s report filed on September 16/05 about “Apple files patent for a unique camera built into laptop.” Too bad that they didn’t have the professional courtesy of referencing our report as a source. Sorry, but ZDNet doesn’t cover Apple patents (at least no others popped up in their site search), their timing clearly three days late – and without adding a single original thought on the matter. Oh, but they did add this line:
An Apple spokesperson declined to say whether the company is planning to include the feature in any forthcoming products, explaining that the company doesn’t comment on “rumor and speculation.”
Wow, I should add that line to more reports, being that Apple never comments on “rumor and speculation” when asked the question “are you planning”— anything. Nice twist though to make it look like they actually researched the matter! My opinion, of course.
neo@macsimumnews.com
Sebhelyesfarku Says:
“Consequently there are difficulties with implementing a graphics equalizer on an iPod (or media players in general).”
What a BS. Rio Karma has parametric graphic equaliser since 2004. (And gapless playback, also missed from iPoo.)
Posted on September 21, 2005
Ralph Says:
I took a look at some of the details of this patent, and the point made Sebhelyesfaku, is that there’s a cost associated with other remedies, and that by having it included for a future iPod would benefit users. Apple’s remedy also goes further in dealing with battery life etc.
You could usally find alternatives to Apple’s solutions, so I don’t know what your point is. It’s not up to Apple’s patent filing to list products available from third party developers. So don’t be so freaked out by it.
Posted on September 21, 2005
Can't Wait Says:
I was thinking parametric EQ, but only at the beginning as more of a descriptor of the end result as opposed to how it will function and be operated by the end user.
Posted on September 21, 2005
News2Me Says:
Hey Sebhelyesfarku, so how’s life in Hungry?
Thanks for dropping by. Cheers!
Posted on September 21, 2005
Sebhelyesfarku Says:
It’s Hungary, not Hungry you dumbass.
Posted on December 17, 2005
Jack Says:
Duh. The simple solution is for Apple to enable iTunes to export equalized music to iPod. That way advantage can be taken of iTunes multiple choice of equalizer settings. Managing an equalizer on iPod sounds clumsy and distracting. After all, it’s just a playback machine.
Posted on May 23, 2006
Article Information
Comment on this Article Print this Article Email this Article Apple’s patent application 20050201572 entitled Method and system for approximating graphic equalizers using dynamic filter order reduction. The inventors listed on the patent are Aram Lindahl, Joseph Mark Williams for serial number 799526, originally filed on March 11, 2004.
Broad overview
Broadly speaking, the invention relates to improved approaches to flexibly implement graphic equalizers on certain iPod models and/or small form factor media players in general, that store and present/display music, videos/movies or images.
Today, iTunes can display a graphic equalizer on various types of home computers. To a limited extent, equalizer settings for media items can be transferred from iTunes to an iPod, which typically has limited computational resources due to its small form factor. Consequently there are difficulties with implementing a graphics equalizer on an iPod (or media players in general). Within the patent application, Apple presents a number of proposed solutions that are uniquely presented as Advantages of the Invention, as follows:
Advantage # 1: is that an equalizer characterization process can reduce the computational complexity of implementing a graphic equalizer without significantly changing its perceived effect to the listener.
Example 1: the equalizer characterization process can convert a 10-band graphic equalizer to a single shelf filter. Since each filter type requires the same number of operations, it would be about ten times faster to execute after conversion to a single shelf filter.
Example 2: the equalizer characterization process can convert a 10-band graphic equalizer to three filters, namely, one shelf filter and two parametric filters. Since each filter type requires the same number of operations, it would be more than three times faster to execute after conversion.
An iPod or other embedded platform may not be able to run more than a few bands of a many band equalizer. Hence, another advantage of the invention allows a high computational load equalizer to be represented and run on lower performance hardware. The reduced computational load also helps the portable computing device conserve power, which is particularly beneficial for battery powered device.
Example 3: an iPod or other embedded platform can perform an equalizer characterization process at run time when a file is downloaded to the device or when loaded for playback. Further, the equalizer characterization process can also be performed in real-time so as to enable a user to dynamically alter equalizer settings during playback.
Advantage # 2: is that an equalizer characterization process does not require any complex optimization problems to be solved.
Example: implementations of the invention can avoid math intensive frequency response calculations. No curve-fitting operations, which have unknown or hard to bound solution times, need be performed. Auto-regressive models that are very difficult to optimize are also avoided. The use of costly trigonometric functions (sin, cos, sin h) to determine filter coefficients can also be avoided. Hence, by avoiding complex optimization problems, computation time for the equalizer characterization process can be substantially faster, guaranteed to happen and bounded.
Advantage # 3: is that an equalizer characterization process can be flexible.
Example: any M-band graphic equalizer to be converted to an N-band parametric filter representation, where N is less than M and determined by the target complexity of the equalizer implementation.
Advantage # 4: is that an equalizer characterization process can include the concept of tolerance bands based on human JND (just noticeable differences).
This tolerance can serve to ignore or group gain changes that are not perceptually distinct, thereby saving additional computation resources that would otherwise be wasted. In one implementation, the host/home computer can interact with the portable computing device.
Example: the host/home computer can transfer media items and associated equalizer information (e.g., equalizer values or one or more equalizer codes) to an iPod. The host/home computer can utilize an application resident on the host computer to perform the transfer of the media items and their attributes between the host/home computer and the iPod. One such application is iTunes.
Extras for detail junkies
The invention can be implemented in numerous ways, including as a method, system, device, apparatus, or computer readable medium. Several embodiments of the invention are discussed below.
As a computer-implemented method – for approximating n-band graphic equalizer settings:
… for a media player using not more than m bands
… for a media player using less than n filters, one embodiment of the invention includes at least the acts of: examining the equalizer setting values for approximate correlation to at least a portion of a frequency response of a shelf type filter; selecting the shelf type filter if a first set of the equalizer setting values approximately correlate; examining the equalizer setting values other than the first set for approximate correlation to at least a portion of a frequency response of a parametric type filter; selecting the parametric type filter if a second set of the equalizer settings approximately correlate; and determining parameters for the shelf type filter and the parametric type filter, wherein at least the shelf type filter and the parametric type filter are used to approximate the n-band graphic equalizer settings for the media player.
As a computer readable medium:
As a computer readable medium including at least computer program code for approximating n-band graphic equalizer settings for a computing device player using less than n bands, one embodiment of the invention includes at least: computer program code for classifying at least a plurality of the equalizer setting values with respect to characteristics of at least a portion of a frequency response shape of at least one of a plurality of predetermined filter types; and computer program code for determining parameters for one or more filters of the at least one of the plurality of predetermined filter types used in classifying the equalizer settings.
As a system:
As a system for approximating an n-band graphic equalizer for use on a device having limited computational resources or computational time, one embodiment of the invention includes at least: means for classifying at least a plurality of equalizer setting values of the n-band graphic equalizer with respect to characteristics of at least a portion of a frequency response shape of at least one of a plurality of predetermined filter types; and means for determining parameters for one or more filters of the at least one of the plurality of predetermined filter types used in classifying the equalizer settings.
As a media device:
One embodiment of the invention includes at least: a data store for storing media data received from a host computer, the media data include media content and equalizer setting information for at least one media item; and a processor operatively connected to the data store, the processor operates to acquire equalizer setting values based on the equalizer setting information, to approximate the equalizer setting values with a reduced filter order approximation, and to present the media content at the media player in accordance with the reduced filter order approximation.
Macsimum Notes
The patent application also notes the following: Although the media items of emphasis in several aspects of the application relate to audio items (e.g., audio files or songs), the media items are not limited to audio items. For example, the media item can alternatively pertain to videos (e.g., movies) or images (e.g., photos). In addition, that various aspects, embodiments, implementations or features of the invention can be used separately or in any combination. Furthermore, that while the invention is preferably implemented by software, it could also be implemented in hardware or a combination of hardware and software. The invention can also be embodied as computer readable code on a computer readable medium.
Off topic – humorous note
On a humorous note, it was interesting to see ZDNet’s September 19/05 report following Macsimum’s report filed on September 16/05 about “Apple files patent for a unique camera built into laptop.” Too bad that they didn’t have the professional courtesy of referencing our report as a source. Sorry,…&topic=tech_news&phase=2" id="digg">Digg This
Contributor
Dennis Sellers
Dennis has been a newspaper editor/reporter (seven years) and teacher (seven years). He has over 4,000 magazine, newspaper and online articles to his credit. He has also covered the Mac and tech industries for over a decade for such online publications as MacCentral, MacMinute and now MacsimumNews.
Cats Says:
Anything they could add to the iPod to stay ahead of the competition the better. At my age, a graphic equalizer doesn’t do much, but for younger users who spend more time on the iPod, it could be fun.
Posted on September 21, 2005