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Interface for Playing Back Recorded Audio Data

IP.com Disclosure Number: IPCOM000061300D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 13K

Publishing Venue

IBM

Related People

Hoegh, BT: AUTHOR [+3]

Abstract

An interface for playing back a previously recorded audio digital data stream to a signal processing Personal Computer (PC) adapter card is described. Each recording algorithm provides speech data in fixed-length records. It cannot be assumed that all algorithms use the same record length, but the structure of each record is the same. Some implementations will allow the record length for a particular algorithm to be configured. The interface supplies a buffer via which speech data is transferred. This buffer is made up of a number of blocks, and each block of a number of records.

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Interface for Playing Back Recorded Audio Data

An interface for playing back a previously recorded audio digital data stream to a signal processing Personal Computer (PC) adapter card is described. Each recording algorithm provides speech data in fixed-length records. It cannot be assumed that all algorithms use the same record length, but the structure of each record is the same. Some implementations will allow the record length for a particular algorithm to be configured. The interface supplies a buffer via which speech data is transferred. This buffer is made up of a number of blocks, and each block of a number of records. In principle, the size of a block is a function of the I/O performance of the storage medium relative to the processor, and the size of the buffer is a function of the amount of processing power available to the application (allowing for multi-tasking, time-slicing, I/O wait, etc.). The buffer acts as a ring buffer. The buffer is primed by the application with speech data records from the recording file. When playback is started, the function set proceeds to use records from the beginning of the buffer, and to convert the compressed digital data into audio signals to the port. It continues to use records from the buffer until it reaches the end; at which point it will start from the beginning again, as long as it knows that the block at the beginning of the buffer contains new audio records. During this cyclic process of playing the speech buffer, the application is using the SPEAK function to obtain the address of the oldest complete block of speech records that has already been played back. If there is no such block, a "Busy" code is returned; if there is, the address (NEXT@) is returned, together with the number of empty blocks (BLKS) available from that point. The application reads the next set of records from the recording file and puts them into the...