US 6,119,091 A · DVD audio decoder having a direct access PCM FIFO

Abstract

An audio decoder is described which supports simple sound-effect generation. The audio decoder includes a direct access pulse code modulation (PCM) first-in-first-out buffer (FIFO) to support simple sound effect generation. In one embodiment, the audio decoder additionally includes an input buffer, a decoding module, and an output interface. The input buffer buffers incoming data frames for the decoding module to retrieve and convert to a sequence of decoded audio samples. The FIFO is configured to receive and buffer audio sound effect samples from a control component external to the audio decoder. The output interface is configurable to retrieve decoded audio samples from the decoding module and audio sound effect samples from the FIFO. Any retrieved audio sound effect samples are included in a digital audio output signal provided by the output interface. The digital audio output signal may be provided directly to a digital-to-analog converter for sound reproduction. The availability of the FIFO for direct writing of audio samples by control components of the system provides desirable system features at negligible cost. A control component of the system is provided with the ability to easily generate test tones, to produce audio feedback to assist in user-control manipulation, and to support new system features such as alarm clocks and timers.

Claims18

Dependent claims

An audio decoder which supports generation of simple sound effects, wherein the audio decoder comprises:

an input buffer configured to receive and buffer audio data frames;
a decoding module coupled to retrieve the audio data frames from the input buffer and configured to convert the audio data frames into a sequence of decoded audio samples;
a first-in first-out buffer (FIFO) configured to receive sound effect audio samples generated by an external control component;
a host interface coupled to the external control component to receive the sound effect samples and to receive decoding module configuration information, wherein the host interface is coupled to provide the sound effect samples to the FIFO, and coupled to provide the configuration information to the decoding module;
and
an output interface coupled to retrieve decoded audio samples from the decoding module and sound effect audio samples from the FIFO in response to an audio sample request clock, wherein the output interface is configurable to provide the retrieved sound effect audio samples to a digital-to-analog converter for conversion to an analog audio signal.

3 more elements

A multimedia decoder which supports generation of simple sound effects by a control component, wherein the multimedia decoder includes:

an interface configured to receive a multimedia bitstream;
a pre-parser coupled to the interface to receive the multimedia bitstream and configured to extract an audio bitstream and a video bitstream from the multimedia bitstream;
a memory configured to include an audio bitstream buffer and a video bitstream buffer, wherein the pre-parser is configured to provide the audio bitstream and the video bitstream to their respective buffers;
a video decoder configured to receive the video bitstream and to convert the video bitstream into a sequence of video frames;
a display controller configured to retrieve the sequence of video frames and convert each video frame into a digital video signal;
an audio decoder configured to receive the audio bitstream and to convert the audio bitstream into a sequence of digital audio samples, wherein the audio decoder includes:
an output interface configured to retrieve the sequence of digital audio samples in response to a sample request clock, and to provide the digital audio samples as a digital audio output signal;
a FIFO configured to buffer sound effect samples provided by a control component and coupled to provide the sound effect samples to the output interface, wherein the output interface is configurable to include the sound effect samples in the digital audio output signal;
and
a host interface coupled to the control component to receive the sound effect samples and to receive audio decoder configuration information, wherein the host interface is coupled to provide the sound effect samples to the FIFO, and configured to set parameters for the conversion of the audio bitstream into digital audio samples.

7 more elements

Dependencies are inferred from the claim text.

DVD audio decoder having a direct access PCM FIFO

Life of this patent

DVD audio decoder having a direct access PCM FIFO

Life of this patent

Abstract

Claims18