Data synchronized playback apparatus

• US 7,639,706 B2
• Filed: 03/02/2005
• Issued: 12/29/2009
• Est. Priority Date: 03/30/2004
• Status: Active Grant

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hamada, Koichi, Yamaguchi, Muneaki, Yokoyama, Toru, Akiyama, Yasuhiro, Kageyama, Masahiro
• Primary Examiner(s): Vu; Thong H
• Application Number:
  US11/068,916
• Publication Number:
  US 20050220130A1
• Time in Patent Office: 1,763 Days
• Field of Search: 370/503, 375/373, 375/358, 375/240, 375/372, 369/47, 369/59
• US Class Current: 370/428
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/612 for unicast
• CPC Class Codes: H04L 65/764 at the destination reformatting of additional data in video clients H04N21/4355
• CPC Class Codes: H04L 65/80 Responding to QoS

Abstract

A data synchronized playback apparatus comprises a buffer which stores streaming data, a buffer fill quantity measurement unit which measures the amount of streaming data stored in the buffer, a decoder which decodes the streaming data and sends decoded data to a D/A converter, a D/A converter which converts the decoded data to an analog signal, a clock generator which generates a clock signal with a frequency that changes according to the measured data quantity, and the digital/analog converter operates based on the clock signal generated by the clock generator.

Claims

1. A data outputting or reproducing apparatus comprising:

a buffer which stores streaming data;

a buffer fill quantity measurement unit which measures the amount of streaming data stored in the buffer;

a decoder which decodes the streaming data and sends decoded data to a digital/analog converter;

a digital/analog converter which converts the decoded data to an analog signal;

a first clock generator which generates a clock signal at a first frequency;

a digital/analog converter clock generator which generates a clock signal with a second frequency that is separate from the clock signal generated by the first clock generator and changes according to the measured amount of streaming data stored in the buffer;

wherein;

the decoder operates based on the clock signal generated by the first clock generator,

the digital/analog converter operates based on the clock signal generated by the digital/analog converter clock generator, and

reproduction of streaming data occurs without a PLL circuit.

2. A data outputting or reproducing apparatus comprising:

a decoder which decodes the streaming data and sends decoded data to a digital/analog converter;

a digital/analog converter which converts the decoded data to an analog signal;

a first clock generator which supplies a clock signal to the decoder; and

a digital/analog converter clock generator which supplies a clock signal to the digital/analog converter at a frequency separate from the clock signal generated by the first clock generator, and

wherein reproduction of streaming data occurs without a PLL circuit.

3. A data synchronized playback apparatus according to claim 2, comprising:

a buffer which stores streaming data; and

a buffer fill quantity measurement unit which measures the amount of streaming data stored in the buffer,

wherein the clock generator generates a clock signal with a frequency changed according to the data quantity measured by the buffer fill quantity measurement unit, and supplies the clock signal to the digital/analog converter.

4. A terminal for outputting or reproducing received streaming data comprising:

a data reception unit which receives streaming data;

a buffer which stores the streaming data;

an application processor which executes an application program;

a processor clock generator which supplies a clock signal to the application processor;

a digital/analog converter for converting audio data to analog signals; and

an audio output unit for outputting audio,

wherein the application processor executes an application program based on the clock signal generated by the processor clock generator,

wherein the application processor measures the quantity of streaming data stored in the buffer, and generates a clock signal with a frequency that is separate from the clock signal generated by the processor clock generator and is changed according to the measured amount of streaming data stored in the buffer,

wherein digital/analog converter operates based on the clock signal generated by the application processor, and

wherein reproduction of streaming data occurs without a PLL circuit.

5. A terminal according to claim 4 comprising:

a display unit which displays video; and

a display controller which controls the display unit,

wherein the application processor sends the video data to the display controller so that the video can be displayed on the display in synchronization with the audio outputted by the audio output unit.