Music player with adjustable pitch controller

• US 7,430,158 B1
• Filed: 12/13/2004
• Issued: 09/30/2008
• Est. Priority Date: 12/13/2004
• Status: Expired due to Fees

• Current Assignee: Chris Tanner
• Original Assignee: Chris Tanner
• Inventors: Tanner, Chris
• Primary Examiner(s): Edun; Muhammad N.
• Application Number:
  US11/009,746
• Time in Patent Office: 1,387 Days
• Field of Search: None
• US Class Current: 369/59.19
• CPC Class Codes: G11B 2220/2545 CDs
• CPC Class Codes: G11B 27/005 Reproducing at a different information rate from the information rate of recording for television signals H04N5/783

Abstract

A media player having variable pitch is disclosed. The player incorporates a memory buffer that is responsive to a user-designated pitch adjustment. The result is that a user can manually control and adjust the pitch of prerecorded CDs and MP3s or other digital media in an “on-the-fly” environment.

Claims

1. A media player having user-selectable variable pitch, comprising:

a reproduction mechanism; and

a logic module comprising a data extractor and associated memory buffer that can extract tonal data from said media through said reproduction mechanism, and then operate to adjust said tonal data up or down in pitch according to a pitch signal responsive to user input;

wherein said logic module further comprises;

a frame synchronizer, connected to said data extractor;

wherein said data extractor extracts said tonal data by digitizing the tonal data into binary values, detecting bit clocks inscribed therein, and then transmitting said bit clocks to said frame synchronizer, which works in conjunction with a clock divider, a demodulator, and a signal processor to effectuate an audible playback of said tonal data.

2. The player of claim 1, further comprising:

a user console having a plurality of manually operatable pitch control buttons.

3. The player of claim 2, wherein said console further comprises:

visual and button options that allow a user to change tunings, such as up or down one half-step, one whole-step, or one octave.

4. The player of claim 1, wherein said logic module further comprises:

a system controller such as a microprocessor or CPU.

5. The player of claim 1, wherein said frame synchronizer detects a frame synchronization signal from the data extractor and outputs the data being cut off at every frame to the demodulator, using a detected frame signal.

6. The player of claim 1, wherein said data extractor obtains said bit clock information using a PLL.

7. The player of claim 6, wherein said PLL further comprises:

a reference clock input, for receiving a clock signal having a desired frequency;

a data input connected to a phase comparator, which is in turn connected to a voltage controlled oscillator for converting voltage into a frequency, which is in turn connected to a loop filter for removing unwanted phase-shifted portions of an input signal;

wherein said loop filter is in turn connected to an output, wherein said output is re-routed back into said input resulting in an output signal which has the desired frequency of the reference clock input.

8. The player of claim 6, wherein said PLL further comprises:

a reference clock input, for receiving a clock signal having a desired frequency;

a data input connected to a high-speed phase comparator, which in turn is connected to a charge pump to act as an amplifier;

a filter for removing signal noise, connected to the output of said charge pump;

a voltage controlled oscillator connected to the output of said charge pump, for converting voltage into a frequency;

a feedback divider connected between said input and an output;

wherein said phase comparator compares said input signal to a feedback signal from the feedback divider, wherein depending on the phase difference between the input and reference clocks, the phase comparator drives the charge pump, the output of which is used to drive the voltage controlled oscillator;

wherein said voltage controlled oscillator receives a voltage and then outputs a signal with a frequency proportional to that voltage, wherein the output of said voltage controlled oscillator is fed back through a feedback divider to the phase comparator;

wherein said voltage controlled oscillator is in turn connected to an output, wherein said output is re-routed back into said input through said feedback divider resulting in an output signal which has the desired frequency of the reference clock input.

9. The player of claim 6, wherein said PLL further comprises:

a reference clock input, for receiving a clock signal having a desired frequency;

a data input connected to a phase compare for detecting a phase difference between a reference clock and the clock of a signal received at said input, wherein said phase compare outputs a phase difference signal representative of the phase difference between these reference and input clocks;

a charge pump and low pass filter block, connected to said phase compare and which receive said phase difference and convert the digital phase difference signal into an analog phase difference signal through a digital/analog converter and is then fed through a low pass filter to filter out high frequency noise; and

a voltage controlled oscillator, connected to the output of said filter, for converting a voltage into a frequency.

10. The player of claim 9, wherein said PLL further comprises:

a self-sweeping autolock sub-circuit, connected at the input and output of said low pass filter,

wherein a filtered analog phase difference signal is output from the charge pump and low pass filter in a feed-back loop to said voltage-controlled oscillator;

and further wherein if a phase difference signal is lost or unrecoverable, the self-sweeping autolock sub-circuit can scan a wide spectrum of frequencies and thereby assist said PLL in re-establishing an output frequency.

11. The player of claim 1, wherein said media comprises CDs.

12. The player of claim 1, wherein said media comprises .MP3 files.

13. The player of claim 1, wherein said logic module is implemented entirely in software.

14. The player of claim 13, further comprising:

a software PLL comprising a summation counter which has a read module to periodically read a value from a plurality of phase counters, and a comparison module to compare a current summation counter value to a most recent of a plurality of previously-stored summation counter values.

15. The player of claim 14, wherein said software PLL further comprises:

an error detector connected to said summation counter to disable further summation counter reading if the reference clock signal is lost; and

a fallback register for storing said most recent summation counter value.

16. A method of operating a software PLL employed within a media player which permits user-selectable pitch control, comprising:

receiving a input clock signal;

splitting said input clock signal into a plurality of phases;

counting the rising and the falling edges of each of the phases;

storing each of said counts within its own counter;

latching a reference clock at a predetermined interval;

latching counter information summation counter;

summing said latched counter information thereby indicating the number of edges in a predetermined time period between latches of the reference clock;

reading said number of edges in a predetermined time period by a CPU;

comparing a newest counter value from said summation counter with a secondmost recent counter value; and

if the newest counter value is greater than the secondmost recent counter value, slowing an output clock;

or

if the newest counter value is less than the secondmost recent counter value, speeding an output clock.