System and method for realizing DSD audio hardware decoding

Abstract

The invention discloses a system and a method for realizing DSD audio hardware decoding. The system comprises an application processor module, wherein the application processor module is used for acquiring and analyzing original audio data, and transmitting a data bus address as well as data parameters and audio data in an analysis result to an audio processing module by means of a data bus; the data parameters comprises a data sampling rate, a bit number, a code stream, whether or not it is a DSD format, the DSD format, and modes that a back-end digital-to-analog conversion module needs to support; the audio processing module reads the data parameters and the audio data according to the data bus address, decodes the audio data according to the data parameters, and transmits the decoded audio data to a digital-to-analog conversion module; the digital-to-analog conversion module is used for converting the decoded audio data into an analog audio signal for output; and an asynchronous dual-crystal-oscillator clock is used for outputting a clock signal to the audio processing module. The system and the method realize the effect of supporting the playing of DSD audio of all specifications, realize precise playing of a full sampling rate and achieve good sound effect.

Description

technical field [0001] The invention relates to the technical field of audio decoding, in particular to a system and method for realizing DSD audio hard decoding. Background technique [0002] With the rapid development of electronic information technology, music is inseparable in people's life, and people's requirements for sound quality are getting higher and higher. The current commonly used music playback method is to decode various audio formats into PCM (Pulse-Code Modulation, Pulse Code Modulation) for playback, but in order to obtain better sound quality, Sony and Philips developed DSD (Direct Stream Digital, Direct Stream Digital) in 1996. The audio in direct bit stream digital) format is based on PDM (pulse-density modulation) pulse density modulation, and the analog audio signal is represented by density, and the accuracy of each sampling of PDM is 1 bit, so it can provide better sound effects , DSD has extremely small quantization noise and super high signal-to-...

AI Technical Summary

Problems solved by technology

[0003] There are three ways to realize DSD audio in the prior art: one is to realize the playback of DSD audio through USB xmos, but xmos has large power consumption, large volume and high cost, which is not suitable for portable HiFi players, and needs to be used through USB The interface realizes DSD transmission, but many MCUs have few USB interfaces and are not very versatile; the second uses the standard I2S (Inter-IC Sound) bus (also known as the integrated circuit built-in audio bus) to transmit audio data, which converts DSD audio The PCM data is decoded by the processor and sent to the digital-to-analog converter for playback. Because it is converted into PCM data, it cannot take advantage of the direct bit stream digital data, and the MCU is used for decoding, which requires high MCU performance and is generally the highest. It can only support the decoding of DSD128 format, DSD256 and DSD512 cannot decode, and cannot play native DSD audio; the third is to use DoP (DSD over PCM) method to package DSD data in MCU and disguise it as I2S standard PCM data transmission, and then the back-end DAC decodes the DSD data for playback, although this method does not undergo format conversion from DSD to PCM, but because the MCU does not support data transmission of DSD audio streams higher than the sampling rate (2.8224MHz), therefore It can only support DSD64, the sampling rate is 2.8224MHz and DSD128, the sampling rate is 2.8224MHz 32bit DSD audio stream transmission, it cannot support DSD256 sampling rate of 11.2896MHz and DSD512 sampling rate of 22.5792MHz higher DSD music playback, and can not Support DSD native (Native DSD) mode, it can be seen that this method supports incomplete DSD format, and cannot support higher-standard DSD audio playback and Native DSD mode

Images