In this tutorial you are going to learn how to view .chm files and convert them to both html and pdf documents. This tutorial will be using the Ubuntu distribution, but this task can be tackled with just about any distribution available.

View chm files

Before we get into converting these files, let’s see how to simply view them in Linux. Luckily there is a single, user-friendly tool for this task. The tool – Xchm. Xchm does one thing – view compiled html documents. This tool can display the contents tree (if one exists), allows you to navigate the document, change the fonts, and search the text.

To install this tool issue the following command:

sudo apt-get install xchm

Figure 1

Once installed, you can start the tool from the Office sub-menu of the Applications menu. When you start the tool up you should instantly notice how simple the interface is.

In Figure 1 Xchm is opened with a Microsoft TechNet document. As you can see, you can navigate around using any link included in the document as well as with the contents tree in the left pane.

But what if you want to edit that document or convert it to a pdf document? Simple – install two more applications.

Editing chm documents

In order to edit these documents you are going to need to convert them to html documents. This conversion is done with the CHMLIB tool. To install this issue the command:

sudo apt-get install libchm-bin

After this tool is installed you can make the conversions with a command like this:

extract_chmLib file.chm output_dir

Where file.chm is the chm file you want to convert and output_dir is the name of the directory you want to output the file to. Understand that the output_dir does not (nor should) already exist, because the command will create it for you.

When the command is issued all of the contents of the chm file will be extracted into the output_dir. From there you can go into the newly created directory and edit to your hearts content.

Converting to pdf

The next task is to convert the file to a pdf document. This is done with the help of the htmldoc application. First, install this with the command:

sudo apt-get install htmldoc

Figure 2

The html tool is a graphical tool that allows you to add as many html documents that you want and convert them all into a single pdf file. The user interface (see Figure 2) is very simple to use.

1. Click the Add Files button.
2. Navigate to the directory containing your html files.
3. Select the file(s) you want to add.
4. Check Web Page as the document type.
5. Click on the Output tab.
6. Check File and then give the file a name in the output path.
7. Check PDF as the output format.
8. Click the Generate button.

You can also deal with the various options in the other tabs, but generating a basic PDF from your html documents is fairly straight forward.

Final thoughts

No longer do you have to miss out on reading those pesky chm files. Although most people have no need for such tasks, there are those of us who do need access to these documents, but don’t (or can’t) read them in their original format. Now you have the means to read them in either html or pdf format.

YouTube isn’t just for watching videos. A lot of times you can find great music in the form of old songs that aren’t available anywhere else online. Or you come across a fascinating audio track and get tempted to use it elsewhere.

Extracting audio from a YouTube video usually requires you to download the video to your hard drive, convert it to another format and then extract the audio track from it. Well, I’ve been doing a little experimenting and discovered that you can extract audio directly without downloading the video from YouTube. The secret of my success: MediaCoder.

As far as transcoders go, Mediacoder is one of the best out there. It requires a bit of a learning curve but it’s capable of a lot of stuff. I’ve been using it almost exclusively whenever I need to convert a video or any media files.

To extract the audio directly from a YouTube video, navigate to the video in question and copy the link in the address bar. Then, open up Mediacoder, click on the Add button and select Add Url. Paste the link of the video in the box that pops up.

Now, you need to adjust the settings of the converted file. On the lower left-hand side of the GUI are the different transcoding parameters. Click on the Audio tab and select the encoder format. For example, if you want an MP3 file, you would select the Lame MP3 encoder. Then, click the Video tab and uncheck the box ‘Enable Video’. This ensures that only the audio is transcoded.

Once your transcoded settings are in place, click the Start button to begin converting your file. It only takes a few minutes or so. After transcoding is finished, play back the transcoded file and check if it’s complete.

I’ve done a lot of testing and this method works for most YouTube videos but not all of them. I think that has something to do with the format used in the original file upload. Still, this is a nice trick to try out whenever you want to quickly extract an audio track from online video.

Have you used Mediacoder to extract audio before? What do you think of this tip? What software do you use to extract audio from a video clip? Let me know in the comments.