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HW1 HW1Sol HW2 HW2Sol HW3 HW3Sol

Solution to HW#1: Audio Processing

Goal:

Assignment Date: 1/21/2010

Due Date: Part 1: 1/27/2010; Part 2: 2/1/2010

Description:

Related Resources and Logistics:

• For Part 2.3 MP3 Audio Masking and future video compression exercises, we will use Matlab to assist our understanding. The PCs in campus common labs (EAS, SE-A208, El Pomar, Columbine, Dwire) are all installed with Matlab.
• For remote access Matlab from home, you can use RATS.eas.uccs.edu (windows), LATS.eas.uccs.edu (linux), or access the five machines (windows) in SENG A210 lab (SE-A210-01, 02, 03, 04, and 05).
  • Use RDP with uccs ufp account to access RATS.
  • Use RDP with CSNET account to access A210 lab machines. (will cover the steps in class)
  • Use NoMachine NX Client to connect LATS.
• To spread the load, please use your designated host (See the table below). Make sure you logout after you have done your exercise, since six of you are sharing it. Your login is the same as your ufp account or the login part of your uccs email address. The password format was sent to cs525-l@uccs.edu. Please verify you can access the machines. The MATLAB R2009b icon is on the desktop.
  

  Name	Assigned A210 Lab Host
  Ahmed, Mohammed Abdulaziz	se-a210-01.csnet.uccs.edu
  Almurayh, Abdullah Saeed	se-a210-01.csnet.uccs.edu
  Alqahtani, Mohammed Saeed	se-a210-01.csnet.uccs.edu
  Anderson, Christopher Alan	se-a210-01.csnet.uccs.edu
  Badam, Rajya Laxmi	se-a210-01.csnet.uccs.edu
  Bryant, Devon Leno	se-a210-01.csnet.uccs.edu
  Daelli, Edoardo	se-a210-02.csnet.uccs.edu
  Dille, Adam Michael	se-a210-02.csnet.uccs.edu
  Erickson, Derrick Scott	se-a210-02.csnet.uccs.edu
  Garcia, Benjamin James	se-a210-02.csnet.uccs.edu
  Hendricks, Joshua Carl	se-a210-02.csnet.uccs.edu
  Hinson, Jeffrey Scott	se-a210-02.csnet.uccs.edu
  Hutchison, Troy L	se-a210-03.csnet.uccs.edu
  Hutton, Mark-anthony	se-a210-03.csnet.uccs.edu
  Iyer, Vijay Navin	se-a210-03.csnet.uccs.edu
  Kirkbride, Erica Lynn	se-a210-03.csnet.uccs.edu
  Kopps, Michael John	se-a210-03.csnet.uccs.edu
  Lama, Palden	se-a210-03.csnet.uccs.edu
  Last, Justin Charles	se-a210-04.csnet.uccs.edu
  Liptak, Jason Jeffrey	se-a210-04.csnet.uccs.edu
  Logan, James Phillip	se-a210-04.csnet.uccs.edu
  Mcallister, David Bartlett	se-a210-04.csnet.uccs.edu
  Menozzi, Michael Jason	se-a210-04.csnet.uccs.edu
  Mudrak, George Francis	se-a210-04.csnet.uccs.edu
  Namburu, Mounika	se-a210-05.csnet.uccs.edu
  Shuster, Christopher Michael	se-a210-05.csnet.uccs.edu
  Stroud, Benjamin Scott	se-a210-05.csnet.uccs.edu
  Taylor, Joe Bert	se-a210-05.csnet.uccs.edu

• Here are the IP addresses of these machiens:
  se-a210-01.csnet.uccs.edu 128.198.62.11
  se-a210-02.csnet.uccs.edu 128.198.62.12
  se-a210-03.csnet.uccs.edu 128.198.62.13
  se-a210-04.csnet.uccs.edu 128.198.62.14
  se-a210-05.csnet.uccs.edu 128.198.62.15

Part 1:

• Create a class personal web page, <your login>.html, in your public_html/cs525 directory on viva.uccs.edu.
• Put your close up photo image (see the samples in S2008photo album) as <login>.jpg in public_html/cs525/images directory.You can refer the image file using the relative URL format, "images/<login>.jpg in the the <IMG> tag of your personal web page.
• Scan your recent photo with face big enough and save in JPEG format as <your login>.jpg.Here the web page with instructions for scanning photo image.After scanning in your picture, transfer the .jpg file to viva.uccs.edu. In your CS525 web page, include short vita and leaves email address, for privacy reason, you may choose not to give out phone number. Include your  interests and potential semester projects for  CS525. See  web page examples in http://viva.uccs.edu/~achattop/cs525/achattop.html
  Here is the HTML basic tutorial web page.
• Verify the correctness of the web page by entering url "http://viva.uccs.edu/~<login>/cs525/<login>html"

Part 2:

1. Audio Encoding.
   With mono, 16 bits, 22 kHz, PCM encoding, how many bytes of data will be generated by a three minute sound recording?
   
   Ans: 1*16*22000*3*60 bits / 8 bits/byte = 7,920,000 bytes.
2. Embed Audio in a Web Page.
   Use Adobe Soundbooth or any audio editor to record a less than 5 second greeting voice with mono, 16 bit, 22kHz, encoding. Edit out the unnecessary silence portion of the sound track and apply the normalized special effect. Save as .wav and .mp3 file format. scp or sftp your audio files to your public_html/cs525/audio directory and create a hyperlink in your class personal web page. Embeded it in your cs525 web page using <embed src="audio/achattop.mp3" autostart=true hidden=true loop=false></embed> Replacing achattop.mp3 with <yourlogin>.mp3.
   Question 2.2. What are size differences among audio files encoded in .wav, .mp3 and that used pcm encoding (estimated)?
   
   Ans: Here are the list of the audio files with different encoding formats for my web site welcome recording. MP3 compress ratio is about 4.9:1 ratio. AAC compressed ratio is about 9.1. 3GPP mobile multimedia compress ratio is about 12.2.
   

   Fileformat	FileName	Size
   PCM/Wave	chowWebSiteWelcome441k.wav	292kB
   MP3	chowWebSiteWelcome441k.mp3	60kB
   QuickTime/AAC	chowWebSiteWelcome441k.mov	32kB
   3GPP	chowWebSiteWelcome441k.3gp	24kB

3. MP3 Audio Masking Exercise with Matlab.
   Repeat the exercise 3 in audio.html handout, by using 300Hz as masker (sig1). Find out the corresponding masking thresholds for the 300 Hz signal at 200Hz (sigLow) and 420Hz (sigHigh) by generating and evaluating the synthesized signals (sigA, sigB, sigC) with the following formula in Matlab code. You may adjust the signal ratio of the masked signal until you can recognize the masked signal. Save the wave files generated by this exercise in your CS525 web site, and include their urls and the masking thresholds as your submission.
   1. sigA=[sig1 sig1+0.031622777*sigLow] % sigLow is 30dB weaker
   2. sigB=[sig1 sig1+0.1*sigHigh] %sigHigh is 20dB weaker
   3. sigC=[sig1 sig1+0.1*sigLow+0.1*sigHigh]