发明授权
US08175525B2 Conversion from note-based audio format to PCM-based audio format
有权
从基于音频的音频格式转换为基于PCM的音频格式
- 专利标题: Conversion from note-based audio format to PCM-based audio format
- 专利标题(中): 从基于音频的音频格式转换为基于PCM的音频格式
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申请号: US12943139申请日: 2010-11-10
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公开(公告)号: US08175525B2公开(公告)日: 2012-05-08
- 发明人: Rodney Bylsma
- 申请人: Rodney Bylsma
- 申请人地址: CA Waterloo
- 专利权人: Research In Motion Limited
- 当前专利权人: Research In Motion Limited
- 当前专利权人地址: CA Waterloo
- 代理机构: Novak Druce + Quigg LLP
- 主分类号: H04Q7/32
- IPC分类号: H04Q7/32
摘要:
A system and method for converting a note-based audio object to a Pulse Code Modulated (PCM) audio format is disclosed. An electronic computer device includes a memory containing a note-based audio object and a lookup table, the note-based audio object containing note frequency information. A processor is configured for converting the note-based audio object to a Pulse Code Modulated (PCM) stream having a plurality of sample points, the converting including: generating a PCM value for each sample point based upon the note frequency and the trigonometric function evaluations, selecting an entry from the look-up table based upon the note frequency information, a sampling frequency, and a sample point number, and determining a step size within the look-up table based upon a ratio between the note frequency information and the sampling frequency.
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