Audio Editing With Cool Edit 2000
The following steps should be done after you capture your video file but before you complete the actions described in my video processing sections.
I'm assuming you've downloaded and installed the demo of Cool
Edit 2000 at my Software page.
1) You must first open your captured video in VirtualDub (usually capture.00.avi). Make sure you open the video file with the "automatically detect and load additional segments" option enabled.
2) Click on File -> Save WAV. Change the file name from *.avi to something like "capture.wav" and hit save. It will take a few minutes to extract the wave file.
Normalizing the Audio
In my Audio Tuning section, I had you set the volume level of your video so that the sound would be as loud as possible without introducing unwanted clipping effects. However, the volume level that you set was merely a rough approximation of the maximum desired level of loudness. Using Cool Edit 2000, you can accurately adjust the volume of your captured video, ensuring that the maximum acceptable loudness level is reached. This will increase the sound quality of your final encoded video.
1) Run Cool Edit 2000. Since the trial version is partially crippled, you will have to select which options you'd like to use. To be able to normalize the audio, you must select the following options at the Cool Edit 2000 startup screen:
2) Open your .wav file in Cool Edit 2000.
3) Click on Edit -> Select Entire Wave.
4) Now click on Transform -> Amplitude -> Normalize. Configure the normalization to 95% as pictured below, making sure to select Normalize L/R Equally if you are working with stereo audio:
Hit OK, and Cool Edit 2000 will begin normalizing your audio.
5) When the normalization is complete, look closely at your .wav file. You should notice that the peaks of your waveform have expanded so they are nearer to the top and bottom of the graph.
6) Using the Play button in the lower left-hand corner of Cool Edit 2000 window, test your wave file to make sure it sounds okay. Then you can save the file and exit Cool Edit 2000.
Removing Background Hiss
1) Run Cool Edit 2000 and select the following options at the startup screen:
2) Open your wave file by going to File -> Open and selecting the .wav file you just created.
3) You should now see a waveform of your audio data. You'll find that if you drag with the left mouse button across the waveform, you can select portions of the audio. Hit the play button to play the current selection. Also, after you have selected a portion, you can use the lower-left yellow button at the bottom of the window to zoom in to your selection. Trying playing around with selecting and zooming until you get the hang of it. You can always zoom out to see the full .wav file by pressing the upper-right yellow button at the bottom of the window.
4) Now we are ready to start the noise reduction process. In order to remove the background hiss, you need to find a portion of the audio where only the hiss and no other sounds are present. Usually you can find a hiss-only portion of the audio at the very beginning of the .wav file. To go there, select the left side of the graph and click on the zoom to selection button. Keep doing this until you are close enough to see where the audio begins. (The audio will usually begin after a hiss-only area near the beginning of the file.) If you cannot find a hiss-only portion of audio at the beginning of your .wav file, you can try looking at the end of your .wav file. Simply press the zoom out full button, and then repeat this step with a selection on the far right side of the graph. Here is a picture of a zoomed-in wave file:
The selected portion, where the graph is almost a straight line, is the hiss. To the left of the selection is the commercial that preceded the show I was recording. To the right of the selection is the beginning of the program.
5) Make a selection extending around the hiss area (the nearly straight line) and zoom in to that selection. Then make a new selection in the middle of the hiss area. This hiss selection must be at least 0.100 seconds in length and should not include any sounds besides the hiss. Making a longer selection of pure hiss will produce better results. See the pictures below:
6) With the hiss still selected, click on Transform -> Noise Reduction -> Noise Reduction. Now enter all the options you see in this screenshot:
Once all the options are entered as pictured above, click on the "Get Profile from Selection" button. Then hit the Close button (not the OK button).
7) Now, using the appropriate yellow icon on the bottom of the screen, zoom out so you can see your entire .wav file. When you are completely zoomed out, double-click anywhere on the graph to select the entire .wav file. Then go back to Transform -> Noise Reduction -> Noise Reduction. This time, you will not be changing any options. Once you have the Noise Reduction dialog box up, just click on the OK button. Cool Edit 2000 will then begin eliminating the hiss from your .wav file. This will take several minutes.
8) When Cool Edit 2000 is done processing the file, make a selection and press play. If everything worked, the hiss should be eliminated. You may now save the file and exit Cool Edit 2000.
Removing Unwanted Audio and Fading In/Out
At times it is useful to silence audio or fade your soundtrack
in or out. For example, sometimes a (TV commercial/introduction/closing sequence) will be played immediately before or
after your captured program. It is possible for the (ad/intro/ending) to be so
close to your program that you will be able to hear a small part of it at the beginning or end of your video file.
Using Cool Edit
2000, you can eliminate (silence) the unwanted snippet of audio and smoothly
fade into your soundtrack.
It is important to mention that you do not want to simply delete the unwanted audio. This would decrease the length of your .wav file and consequently destroy the video/audio synchronization.
1) Run Cool Edit 2000. To be able to fade the audio in and out, you must select the following options at the Cool Edit 2000 startup screen:
2) Open your .wav file in Cool Edit 2000.
1) Use the play and zoom controls to find the segment of audio that you wish to eliminate.
2) Make a selection containing just the audio that you want to silence.
3) Click on Transform -> Silence. The portion of audio you selected should now be replaced with complete silence. You may repeat these 3 steps to silence other sections of audio.
1) Use the play and zoom controls to find the segment of audio that you wish to fade in or out.
2) Make a selection containing just the audio that you want to fade in or out.
3) Click on Transform -> Amplitude -> Amplify and select Fade In or Fade Out from the list of Presets. The Amplify window should look something like this:
Now hit the OK button. The portion of audio you selected should have a fade-in or fade-out. You may repeat these 3 steps elsewhere in the .wav file to fade in/out other segments of the soundtrack.
1) Test your wave file to make sure it sounds okay, save it, and then exit Cool Edit 2000.
If everything went okay, you should have an enhanced, hiss-free .wav file on your computer. You may now go on to the next step, Low Resolution Video Processing or High Resolution Video Processing.