Apple's Patent Background on Crossfading Audio

Portable electronic devices are increasingly capable of performing a range of audio operations in addition to simply playing back streams of audio. One such audio operation, crossfading between songs, may take place as one audio stream ends and another begins for a seamless transition between the two audio streams. Typically, an electronic device may crossfade between two audio streams by mixing the two streams over a span of time (e.g., 1-10 seconds), during which the volume level of the first audio stream is slowly decreased while the volume level of the second audio stream is slowly increased.

Some electronic devices may perform a beat-matched, DJ-style crossfade by detecting and matching beats in the audio streams. Conventional techniques for such beat detection in electronic devices may involve complex, resource-intensive processes. These techniques may involve, for example, analyzing a decoded audio stream for certain information indicative of a beat (e.g., energy flux). While such techniques may be accurate, they may consume significant resources and therefore may be unfit for portable electronic devices.

Apple's Proposed Advances to Crossfading Audio

Apple's invention relates to methods and devices for efficient beat-matched, DJ-style crossfading between audio streams. For example, such a method may involve determining beat locations of a first audio stream and a second audio stream and crossfading the first audio stream and the second audio stream such that the beat locations of the first audio stream are substantially aligned with the beat locations of the second audio stream. The beat locations of the first audio stream or the second audio stream may be determined based at least in part on an analysis of frequency data unpacked from one or more compressed audio files.

About Apple's Patent Figures: FIG. 4 is a schematic diagram of two audio streams during the crossfading operation; FIG. 7 is a schematic block diagram representing a manner in which the electronic device may perform a beat-matched crossfading operation; and FIG. 16 is a plot modeling a relationship between time window sizes over a series of frames of frequency data and the likely location of beats therein.

Patent Credits

Apple's patent application 20120046954 was originally filed in Q3 2010 by inventors Aram Lindahl and Richard Powell.

Other Noteworthy Patent Applications Published Today

One: A Composite Microphone Boot

Apple's patent application 20120046780 covers a microphone assembly for the iPhone. The microphone assembly can include a microphone, a microphone boot and a printed circuit board. The microphone boot can be a composite microphone boot that is formed from multiple materials. A hardness of the each of the materials used in the microphone boot can be selected to improve sealing integrity and reduce shock transmission. One of the composite materials is noted as being a softer plastic material, such as a silicone plastic. A patent figure illustrated below provides a perspective view of a microphone assembly which includes a microphone and microphone-boot.

Two: Modular Material Antenna Assembly

Broadly speaking, Apple's patent application 20120044123 describes a modular material antenna assembly that includes an antenna block having a portion with a shape that interlocks with a corresponding portion of an electrically non-conductive frame and secures the antenna block to the electrically non-conductive frame. The electrically non-conductive frame is attached to an interior of an electrically conductive housing so that the electrically non-conductive frame and the electrically conductive housing form an integrated structure. An antenna flex is then mechanically supported by the antenna block, and electrically connected to a circuit board. The frame is designed to support a cover glass for the portable electronic device and may be affixed to the housing.

In one embodiment, the antenna block is made of Cyclo Olefin Polymer (COP), while the frame is made of a glass-filled plastic. The resultant difference in dielectric constant, in conjunction with the interlocking portions of the frame and antenna block, as well as the difference in dielectric loss tangent, improves antenna performance.

Three: A Formed Printed Circuit Board (PCB)

Broadly speaking, Apple's invention describes printed circuit board (PCB) well suited for use in consumer electronic devices, such as laptops, cellphones, netbook computers, portable media players and tablet computers. In particular, PCB designs are described that address packaging issues that can result when a light-weight consumer electronic device with a thin and compact enclosure is used. Methods for designing and forming the PCBs are described in this patent application. Apple's patent FIG. 3A illustrates a view of a bendable printed circuit board.

In a particular embodiment, a relatively thin multi-layered PCB for use in a portable computing device can be provided. The multi-layered PCB can be formed in a planar configuration. During assembly of the portable computing device, the PCB can be bent in certain regions to allow it to be installed in a non-planar configuration. The bending capabilities can be used more efficiently fit the PCB within available spaces remaining in the enclosure after larger components, such as the battery are installed. You could find more details in Apple's patent application 20120044637.

Four: A Dual Image Sensor Image Processing System & Method

Apple is constantly advancing the cameras that are present in their OS X and iOS hardware. Today, Apple reveals their proposed dual image sensor processing system. According to Apple, their new image processing system may include control circuitry configured to determine whether a device is operating in a single sensor mode (one active sensor) or a dual sensor mode (two active sensors).

When operating in the single sensor mode, data may be provided directly to a front-end pixel processing unit from the sensor interface of the active sensor. When operating in a dual sensor mode, the image frames from the first and second sensors are provided to the front-end pixel processing unit in an interleaved manner. For instance, in one embodiment, the image frames from the first and second sensors are written to a memory, and then read out to the front-end pixel processing unit in an interleaved manner.

About Apple's Patent Figures: FIG. 7 is a block diagram illustrating front-end image signal processing (ISP) logic and ISP pipe processing logic that may be implemented in the image processing circuitry; FIG. 8 s a more detailed block diagram showing an embodiment of the ISP front-end logic of FIG. 7; and FIG. 20 is a block diagram that provides a more detailed view of one embodiment of the ISP front-end pixel processing unit, as shown in the ISP front-end logic of FIG. 8.

Apple's patent is a massive work with over 79 patent figures and incredible detail. Those interested in exploring this patent should explore patent application 20120044372.

Five: Motion Plane Correction for Micro-Electro-Mechanical-Based Input Devices

And lastly, Apple is adding a little more to their January 2010 patent application that we covered in a reported titled "Apple Could Advance Gaming & Paint in Magic Mouse Upgrade." In patent application 20120046902, Apple describes a future magic mouse and method for correcting errors in acceleration due to a deviation from a horizontal plane of motion by correcting for gravitational acceleration components due to the deviation in the plane of motion.

Apple states that many existing methods for tracking two-dimensional motion with accelerometer-based devices like a mouse don't adequately take into account variations in three-dimensional orientation. For example, an orientation change of only about 0.5 degrees from the horizontal plane can contribute up to 10 mG acceleration in a plane of motion, which can be significant with respect to human initiated motion. Therefore, there is a need for systems and methods that account for a tilt in a plane of motion so as to provide a result that is more indicative of a user's intended motion of the input device.

Another patent on this subject matter was covered in our February 2010 report titled "Apple Wants the Magic Mouse to Rock'n Roll!" Update 2PM: You could get another view of what Apple is thinking of in our April 2010 report titled "NFC iPhone to Control All of Your In-Home Electronics & More." In that report you'll see one option of the TV remote simply being a future iPhone controlling the same devices listed below. You also get a great visual of what a 3D-Motion remote could do - like turn items on screen. So this isn't about a remote for 3D TV as much as it is a 3D motion related patent. It's technology that could be added as a feature of a next generation HDTV remote.

Today's invention could be, according to Apple, used as a mouse, receiving device or receiver which they translate to being video game consoles, set-top boxes, televisions, personal computers (whether desktop, laptop, or otherwise), digital video recorders, communications equipment, terminals, mobile devices such as the iPhone and display devices. Hmm, a TV Remote with advanced 3D motion; add that to Siri based voice controls and you have a killer TV remote that will rival what Google has up their sleeve.

Notice: Patently Apple presents a detailed summary of patent applications with associated graphics for journalistic news purposes as each such patent application is revealed by the U.S. Patent & Trade Office. Readers are cautioned that the full text of any patent application should be read in its entirety for full and accurate details. Revelations found in patent applications shouldn't be interpreted as rumor or fast-tracked according to rumor timetables. Apple's patent applications have provided the Mac community with a clear heads-up on some of Apple's greatest product trends including the iPod, iPhone, iPad, iOS cameras, LED displays, iCloud services for iTunes and more. About Comments: Patently Apple reserves the right to post, dismiss or edit comments.

Here are a Few Sites covering our Original Report: MacSurfer, Twitter, Facebook, Apple Investor News, Google Reader, Macnews, iPhone World Canada, MarketWatch, MacDailyNews, App Advice, Techmeme, and more.