本文選題：音頻廣播 + DSP　； 參考：《南京理工大學》2015年碩士論文

【摘要】：如今音頻廣播節(jié)目的來源形式眾多且制作標準差異較大,這使得各節(jié)目源音頻信號的電平等參量高低不定,易造成廣播中心發(fā)射效率降低,播出質(zhì)量參差不齊。針對此種情況,與某廣播設(shè)備公司合作研發(fā)了此套多路廣播源音頻處理系統(tǒng)。系統(tǒng)目標任務是對多路音頻輸入信號的電平和頻譜參量進行實時動態(tài)處理以達到音頻質(zhì)量和收聽響度的完美兼顧。經(jīng)過對目標任務的研究分析,系統(tǒng)音頻處理主體部分通過軟件實現(xiàn),其中使用MATLAB對算法進行仿真設(shè)計,C語言完成所有算法編程,VC++語言編寫主機控制軟件程序。系統(tǒng)解決方案采用DSP+PC,其中核心DSP芯片采用數(shù)據(jù)處理能力優(yōu)秀的TMS320VC5509A處理器。通過高效的TLV320AIC23B編解碼芯片完成對多路音頻信號的采樣轉(zhuǎn)換以及5509A自有的USB模塊作為數(shù)據(jù)傳輸通路,充分保障數(shù)據(jù)處理的實時性。使得系統(tǒng)具有對多路音頻信號參數(shù)均衡調(diào)整、多頻段動態(tài)范圍控制,實時頻率檢測功能。音頻均衡算法以高/低頻shelving濾波器和帶通濾波器組合為基礎(chǔ)實現(xiàn),均衡器各段中心頻率,增益和帶寬均可調(diào)整。采用針對性模塊客觀功能測試及系統(tǒng)聯(lián)調(diào)實際音頻測試,證明均衡器對各頻段的提升或抑制效果良好,音頻改善效果理想。動態(tài)范圍控制算法采用將其四種工作方式組合形式實現(xiàn),同時設(shè)計了基于LR分割器的具有平坦頻響的四頻段分割器,通過幅度與時間雙向控制,組成多頻段可控動態(tài)范圍處理器,經(jīng)過模塊功能測試及整體實際音頻節(jié)目客觀與主觀測試,顯示其對音頻信號動態(tài)范圍控制精準,處理后聲音自然清晰。頻率檢測算法是基于復數(shù)FFT算法及重心頻譜校正算法實現(xiàn)的,可對設(shè)定閾值下噪聲信息實時檢測,進而為噪聲抑制提供標準。經(jīng)仿真及系統(tǒng)實際測試表明,信號頻率及幅值測量準確度及精確度高,符合預期設(shè)計。
[Abstract]:Nowadays, the source forms of audio broadcasting programs are numerous and the production standards are quite different, which makes the level of audio signals of various program sources fluctuate, which can easily cause the transmission efficiency of broadcast centers to be reduced and the broadcasting quality is not uniform. In order to solve this problem, a multi-channel broadcasting source audio processing system was developed in cooperation with a broadcasting equipment company. The target task of the system is to dynamically process the level and spectrum parameters of multi-channel audio input signal in order to achieve the perfect balance of audio quality and listening loudness. Through the research and analysis of the target task, the main part of the system audio processing is realized by software, in which MATLAB is used to simulate the algorithm and C language is used to complete all the arithmetic programming and VC language to write the host computer control software program. The system adopts DSP PC.The core DSP chip is TMS320VC5509A which has excellent data processing ability. Through the efficient TLV320AIC23B codec chip to complete the multi-channel audio signal sampling and conversion, and the 5509A own USB module as the data transmission path, the real-time data processing is fully guaranteed. The system has the function of adjusting the parameters of multi-channel audio signal, controlling the dynamic range of multi-frequency band and detecting the frequency in real time. The audio equalization algorithm is based on the combination of high / low frequency shelving filter and bandpass filter. The central frequency gain and bandwidth of each segment of the equalizer can be adjusted. The objective function test of targeted module and the actual audio test of system combination are used to prove that the equalizer has a good effect on the enhancement or suppression of each frequency band and the effect of audio improvement is ideal. The dynamic range control algorithm is implemented by combining its four working modes. At the same time, a four-band splitter with flat frequency response based on LR splitter is designed, which is controlled by amplitude and time bidirectional. The multiband controllable dynamic range processor is made up of the module function test and the objective and subjective test of the whole actual audio program. It shows that the dynamic range control of audio signal is accurate and the sound is clear after processing. The frequency detection algorithm is based on the complex FFT algorithm and the centroid spectrum correction algorithm. It can detect the noise information under the set threshold in real time and provide the standard for noise suppression. The results of simulation and system test show that the accuracy and accuracy of signal frequency and amplitude measurement are high and accord with the expected design.
【學位授予單位】：南京理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN931

【參考文獻】

相關(guān)期刊論文 前3條

1 邱盛明;多媒體音頻處理技術(shù)[J];電聲技術(shù);1999年10期

2 劉文,王文,劉忠;音頻處理器在電視播出系統(tǒng)中的應用[J];中國傳媒科技;2002年03期

3 姜穎韜;;基于DSP的IIR濾波器設(shè)計與仿真[J];科協(xié)論壇(下半月);2008年06期

相關(guān)碩士學位論文 前4條

1 柳永娟;數(shù)字音頻真實性鑒定的研究[D];大連理工大學;2010年

2 李倩然;網(wǎng)絡化音頻處理器的設(shè)計與實現(xiàn)[D];電子科技大學;2011年

3 李歆遒;網(wǎng)絡數(shù)字音頻處理器的研究[D];浙江大學;2006年

4 葉蓉;數(shù)字電視音頻后處理的研究與實現(xiàn)[D];天津大學;2008年

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本文編號：1994429