Multiplexed audio data decoding apparatus and receiver apparatus

• US 8,098,695 B2
• Filed: 09/23/2008
• Issued: 01/17/2012
• Est. Priority Date: 11/04/1998
• Status: Expired due to Fees

• Current Assignee: Maxell, Ltd.
• Original Assignee: Hitachi, Ltd., Hitachi Video & Information System Incorporated
• Inventors: Fujii, Yukio, Obata, Shinichi, Shirane, Hiroaki, Yamamoto, Eiji
• Primary Examiner(s): Shah, Chirag
• Assistant Examiner(s): Patel, Jay P
• Application Number:
  US12/235,942
• Publication Number:
  US 20090024400A1
• Time in Patent Office: 1,211 Days
• Field of Search: 370/536, 370/542
• US Class Current: 370/536
• CPC Class Codes: G11B 20/10527 Audio or video recording; Data buffering arrangements G11B20/12 - G11B20/18 take precedence
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/42615 involving specific demultiplexing arrangements
• CPC Class Codes: H04N 21/42692 for reading from or writing on a volatile storage medium, e.g. Random Access Memory [RAM]
• CPC Class Codes: H04N 21/434 Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream demultiplexing of data packets for data networks, e.g. RTP/UDP H04L65/00
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/435 Processing of additional data, e.g. decrypting of additional data, reconstructing software from modules extracted from the transport stream
• CPC Class Codes: H04N 21/4384 involving operations to reduce the access time, e.g. fast-tuning for reducing channel switching latency
• CPC Class Codes: H04N 21/4392 involving audio buffer management
• CPC Class Codes: H04N 5/50 Tuning indicators; Automatic tuning control

Abstract

A multiplexed audio data decoder apparatus is provided in which integration of an audio decoder is easy, and has a high flexibility when the number of the formats to be processed is increased or when the specification is changed. In an external ROM 60 there are accumulated a plurality of decoding program codes corresponding to respective plural methods for compressing and encoding. A controller 50 transfers the decoding program code corresponding to the method for compressing and encoding after changing thereof, from the external ROM 60 to an internal RAM 25. A DSP 22 starts decoding processing by using the decoding program code which is transmitted into the internal RAM 25.

Claims

1. A multiplexed audio data decoder apparatus, for inputting a group of packets, each being formed by packetizing audio data sequences which are compressed and encoded and by multiplexing a plurality of those sequences, and for selectively decoding one audio data sequence which is designated by a user, the multiplexed audio data decoder comprising:

a demultiplexer for extracting the one audio data sequence which is designated by the user from said group of packets depending upon a property or attribute information of each packet, and further for extracting a method of compression and encoding which is applied for compressing the audio data sequence from a header information of each audio data sequence;

a memory in which decoding program codes are accumulated including decoding algorithms corresponding to said method of compression and encoding;

a digital signal processor for decoding the compressed audio data sequence in accordance with said decoding program codes, sequentially; and

a controller for receiving a method of compression and encoding from said demultiplexer, for detecting whether said method of compression and encoding changes to another method of compression and encoding or not, and if said method of compression and encoding changes, for downloading the decoding program code corresponding to said another method of compression and encoding, to said memory from outside of said memory,

wherein said digital signal processor begins decoding processing by using the decoding program code which is downloaded to said memory.

2. A multiplexed audio data decoder apparatus as defined in claim 1, wherein

after downloading the decoding program code corresponding to the changed method of compression and encoding, to said memory from outside of said memory, said digital signal processor conducts a process for deciding a presence of download errors.

3. A multiplexed audio data decoder apparatus as defined in claim 2, wherein

in the process for deciding the presence of download errors which said digital signal processor conducts, a specific audio data sequence is decoded by using the decoding program code, and is compared with an expected value corresponding thereto.

4. A multiplexed audio data decoder apparatus, for inputting a group of packets, each being formed by a packetizing video data sequence and audio data sequences accompanying therewith which are compressed and encoded and by multiplexing a plurality of those sequences, and for selectively decoding one set of a video data sequence and an audio data sequence accompanying therewith, which is designated by a user, comprising:

a demultiplexer for extracting the one audio data sequence which is designated by the user from said group of packets depending upon a property or attribute information of each packet, and further for extracting a method of compression and encoding which is applied for compressing the audio data sequence from a header information of each audio data sequence;

a memory in which decoding program codes are accumulated including decoding algorithms corresponding to said method of compression and encoding;

a digital signal processor for decoding the compressed audio data sequences in accordance with said decoding program codes, sequentially;

a video decoder for decoding said video data sequence which is compressed and encoded; and

a controller for receiving a method of compression and encoding from said demultiplexer, for detecting whether said method of compression and encoding changes to another method of compression and encoding or not, and if said method of compression and encoding changes, for downloading the decoding program code corresponding to said another method of compression and encoding, to said memory from outside said memory,

wherein said digital signal processor begins decoding processing by using the decoding program code which is downloaded to said memory.

5. A multiplexed audio data decoder apparatus as defined in claim 4, wherein

after downloading the decoding program code corresponding to the changed method of compression and encoding, to said memory from outside of said memory, said digital signal processor conducts a process for deciding a presence of download errors.

6. A multiplexed audio data decoder apparatus as defined in claim 5, wherein

in the process for deciding the presence of download errors which said digital signal processor conducts, a specific audio data sequence is decoded by using the decoding program code, and is compared with an expected value corresponding thereto.