Data synchronized playback apparatus

• US 20050220130A1
• Filed: 03/02/2005
• Published: 10/06/2005
• 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
• Granted Patent: US 7,639,706 B2
• Time in Patent Office: Days
• 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 synchronized playback 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 clock generator which generates a clock signal with a frequency that changes according to the measured data quantity; and

wherein the digital/analog converter operates based on the clock signal generated by the clock generator.

2. A data synchronized playback apparatus according to claim 1, further comprising a processor clock generator which generates a clock signal at a frequency separate from the clock signal generated by the clock generator,

wherein the decoder operates based on the clock signal generated by the processor clock generator.

3. A data synchronized playback 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 processor clock generator which supplies a clock signal to the decoder; and

a clock generator which supplies a clock signal to the digital/analog converter at a frequency separate from the clock signal generated by the processor clock generator.

4. A data synchronized playback apparatus according to claim 3, 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.

5. A terminal for playing back 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 measures the quantity of streaming data stored in the buffer, and generates a clock signal with a frequency changed according to the measured data quantity, and

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

6. A terminal according to claim 5 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.