Sound Cards

Ubuntu supports a wide variety of sound hardware and software. Two models of sound card drivers compete for prominence in today’s market:

▸ ALSA, the Advanced Linux Sound Architecture, which is entirely open source

▸ OSS, the Open Sound System, which offers free and commercial drivers

Ubuntu uses ALSA because ALSA is the sound architecture for the Linux kernel, starting with the 2.6 series, all the way to the current 5.x series. OSS might still be found here and there, but it is no longer in widespread use and should be considered deprecated.

ALSA supports a long list of sound cards. You can review the list at www.alsa-project.org/main/index.php/Main_Page if you are interested, but Ubuntu detects most sound cards during the original installation and should detect any new additions to the system during boot. To configure the sound card at any other time, use the sound preferences graphical tool by searching the Dash for “sound.”

In addition, Ubuntu uses an additional layer of software called PulseAudio. PulseAudio, which is a sound server, acts as a mediator between the various multimedia programs that have sound output and the ALSA kernel drivers. Over the years, many different sound servers have been used in Linux, each with different strengths, usability issues, and levels of documentation. These various sound servers have often been forced to run side by side on the same computer, causing all sorts of confusion and issues. PulseAudio aims to replace all of them and work as a single handler to accept output from applications that use the APIs for any of the major sound servers already in use, such as ESD, OSS, GStreamer, and aRts, and route the various output streams together through one handler. This provides several advantages, including the ability to control the output volume of various programs individually.

PulseAudio has matured over the past several releases and is better and more powerful than ever before. Although there were stability issues and complaints early on, they don’t seem to be problematic anymore except in unusual hardware combinations and special cases, and more and more features have been implemented. For more information about PulseAudio, see www.pulseaudio.org.

Sound Formats

A number of formats exist for storing sound recordings. Some of these formats are associated with specific technologies, and others are used strictly for proprietary reasons. Ubuntu supports all the most popular sound formats, including the following:

▸ RAW (.raw)—RAW is more properly known as headerless format, and audio files using this format contain an amorphous variety of specific settings and encodings. All other sound files contain a short section of code at the beginning—a header—that identifies the format type.

▸ MP3 and MP4 (.mp3,.mp4)—These popular commercially licensed formats for the digital encoding are used by many Linux and Windows applications.

▸ WAV (.wav)—This popular uncompressed Windows audiovisual sound format is often used as an intermediate file format when encoding audio.

▸ Ogg-Vorbis (.ogg)—Ogg is the free software community’s preferred audio encoding format. You enjoy better compression and audio playback and freedom from proprietary licensing concerns when you use this open source encoding format for your audio files.

▸ FLAC (.flac)—This lossless format is popular with audiophiles. The name stands for Free Lossless Audio Format, and it is a compressed format, like MP3, but does not suffer from any loss of quality.

Ubuntu also includes software in the repositories (such as the sox command, used to convert between sound formats) so that you can more easily listen to audio files provided in a wide variety of formats, such as AU (from NeXT and Sun), AIFF (from Apple and SGI), IFF (originally from Commodore’s Amiga), RA (from Real Audio), and VOC (from Creative Labs).

Ubuntu also offers several utilities for converting sound files from one format to another. Conversion utilities come in handy when you want to use a sound in a format not accepted by your current application of choice. The easiest one to use is also the easiest to install. Install the soundconverter package and then search for Sound Converter. It has a clear graphical interface and easy-to-understand configuration options.

Listening to Music

If you’re anything like us, you might be a huge music fan. Beyond using your web browser with your favorite sites, which is simple and common, you can also play music without an Internet connection.

The GNU Image Manipulation Program

One of the best graphics clients available is the GNU Image Manipulation Program (GIMP). GIMP is a free, GPL-licensed image editor with sophisticated capabilities that can import and export more than 30 different graphics formats, including files created with Adobe Photoshop. It is often compared with Photoshop, and GIMP represents one of the first significant successes of GNU Project. Many images in Linux were prepared using GIMP.

GIMP is not installed by default, but you can easily install it from the Ubuntu software repositories.

You see an installation dialog box when GIMP is started for the first time, followed by a series of dialog boxes that display information regarding the creation and contents of a local GIMP directory. This directory can contain personal settings, preferences, external application resource files, temporary files, and symbolic links to external software tools used by the editor.

Using Scanners in Ubuntu

With the rise of digital photography, there has been an equal decline in the need for image scanners. However, there are still times when you want to use a scanner, and Ubuntu makes it easy with a program installed by default called Simple Scan. Simple Scan is designed to do one thing: scan photos or documents easily. It has few settings or options but does all the things most people would want or need.

You can also use many types of image scanners with GIMP, which is likely to be the choice of people who like to tinker with settings and options or who need greater flexibility than is offered by Simple Scan. If it wasn’t installed when you installed GIMP, install the xsane package. Then, when you scan from GIMP, you will have an abundance of settings and options that you can use. You can also use XSane by itself.

Working with Graphics Formats

Image file formats are developed to serve a specific technical purpose (lossless compression, for example, where the file size is reduced without sacrificing image quality) or to meet a need for a proprietary format for competitive reasons. Many file formats are covered by one or more patents. For example, at one time the GIF format fell into disfavor with the open source crowd because the patent holder waited a while before deciding to enforce his patent rights rather than being up front with requests for patent royalties. The GIF format is no longer patented, however.

If you want to view or manipulate an image, you need to identify the file format so you can choose the proper tool for working with the image. The file’s extension is your first indicator of the file’s format. The graphics image formats supported by the applications included with Ubuntu include the following:

▸ BMP (.bmp)—Bitmapped graphics, commonly used in Microsoft Windows

▸ GIF (.gif)—CompuServe Graphics Interchange Format

▸ JPG (.jpg)—Joint Photographic Experts Group

▸ PCX (.pcx)—IBM Paintbrush

▸ PNG (.png)—Portable Network Graphics

▸ SVG (.svg)—Scalable Vector Graphics

▸ TIF (.tif)—Tagged Image File format

You can find an extensive list of image file extensions in the man page for ImageMagick, an excellent application included with Ubuntu, which you read more about in upcoming sections of this chapter.

Sometimes, a file you want to manipulate in some way is in a format that cannot be used by either your graphics application or the final application. The solution is to convert the image file—sometimes through several formats. The convert utility from ImageMagick is useful, as is the netpbm family of utilities. If it is not already installed, you can easily install ImageMagick from the Ubuntu repositories; the netpbm tools are always installed by default.

convert is super simple to use from the command line. Here is an example:

Click here to view code image

matthew@seymour~:$ convert image.gif image.png

The convert utility converts between image formats recognized by ImageMagick. You can also manipulate color depth and size during the conversion process. You can use ImageMagick to append images, surround them with borders, add labels, rotate and shade them, and perform other manipulations well suited to scripting. Other commands associated with ImageMagick include display, animate, identify, and import. The application supports more than 130 different image formats (all listed in the man page for ImageMagick).

The netpbm tools are installed by default because they compose the underpinnings of graphics format manipulation. The man page for each image format lists related conversion utilities; the number of those utilities gives you some indication of the way each format is used and shows how one is built on another:

▸ ppm—The man page for .ppm, the portable pixmap file format, lists 47 conversion utilities related to .ppm. This makes sense because ppm is considered the lowest common denominator for color image files. It is therefore often used as an intermediate format.

▸ pgm—The man page for .pgm, the portable graymap file format, lists 22 conversion utilities. This makes sense because .pgm is the lowest common denominator for grayscale image files.

▸ pnm—The man page for .pnm, the portable anymap file format, lists 31 conversion utilities related to it. However, there is no format associated with .pnm because it operates in concert with .ppm, .pgm, and .pbm.

▸ pbm—An examination of the man page for .pbm, the portable bitmap file format, reveals no conversion utilities. It’s a monochrome format and serves as the foundation of the other related formats.

The easiest way to resize or rotate image files is to install the nautilus-image-converter package from the repositories. This enables you to right-click an image when you are viewing files in the File Browser (for example, from Places, Pictures) and choose menu options to resize or rotate one or multiple images without opening another program.

Capturing Screen Images

You can use graphics-manipulation tools to capture images that are displayed on your computer screen. Although this technique was used for the production of this book, it has broader uses; there is truth to the cliché that a picture is worth a thousand words. Sometimes showing an example is easier than describing it.

You can use a captured screen image (also called a screen grab or a screenshot) to illustrate an error in the display of an application (a font problem, for example) or an error message that is too complex to copy down by hand. You might just want to share an image of your beautifully crafted custom desktop configuration with your friends or illustrate your written documents.

When using the default desktop, you can take advantage of the built-in screenshot mechanism (gnome-screenshot). You can use this tool by pressing the Print Screen key. (Alt+Print Screen takes a screenshot of only the window that has focus on a desktop.) Captured images are saved in PNG format.

Other Graphics Manipulation Options

If you have very specific requirements for working with graphics, you may find one of the following options better suits your needs than the preceding general options and comments. Some, but not all, of these are in the Ubuntu repositories:

▸ Blender—A 3-D image and animation editor that you can find at www.blender.org

▸ CinePaint—A powerful and complex tool used by many Hollywood studios that you can find at www.cinepaint.org

▸ darktable—A RAW editor that can be found at www.darktable.org

▸ digiKam—Photo management software that can be found at www.digikam.org

▸ Hugin—A panoramic photo stitcher that can be found at https://hugin.sourceforge.net

▸ Inkscape—A vector graphics creation and editing tool that you can find at https://inkscape.org

▸ Krita—A raster graphics creation and editing tool that you can find at https://krita.org

▸ POV-Ray—A powerful and complex 3D graphics program that uses ray tracing and can be found at www.povray.org

▸ Radiance—Intended for the analysis and visualization of lighting in design and can be found at www.radiance-online.org

▸ Xara Xtreme—A general-purpose graphics editor that you can find at www.xaraxtreme.org

Handheld Digital Cameras

Because of the good development carried out in the Linux world, you can plug almost any digital camera or camera phone in to your computer through a USB interface, and Ubuntu automatically recognizes the camera as a USB mass storage device. You can even set Ubuntu to recognize when a camera is plugged in so that it automatically imports your photographs for you.

Using Shotwell Photo Manager

Shotwell Photo Manager, mentioned earlier in this chapter, includes simple adjustment tools. You can import your photos into Shotwell, assign tags to them, sort and arrange them, and even upload them to your favorite Internet photo-hosting sites such as Instagram.

Creating CDs and DVDs with Brasero

Although adequate for quick burns and use in shell scripting, the command-line technique for burning CDs and DVDs is an awkward choice for many people (but we still cover it later in this chapter because others find it useful and desirable). Fortunately, Ubuntu provides several graphical clients; the most useful is Brasero.

Brasero is an easy-to-use graphical CD and DVD burning application that is installed by default. Brasero takes a project-based approach to disc burning, opening up with a wizard that offers four different tasks that people commonly want to do. Brasero also remembers previous “projects,” enabling you to quickly create several copies of a disc, which is ideal if you’re planning to pass on copies of Ubuntu to your friends and family.

Burning a data CD or DVD is as easy as selecting the option in the opening screen and dragging and dropping the files you want to include from the directory tree on the left to the drop area on the right. If you insert a blank CD or DVD in your writer, Brasero keeps an eye on the disc size and tells you when you reach or exceed the limits. It also creates ISO files, which are disc images that contain everything that would exist on the medium if you burned a real CD or DVD in one file that can be mounted by computer file systems, which is useful if you want to create multiple copies of the same disc or if you want to share a disc image, perhaps using a USB thumb drive or over the Internet.

Finally, click the Burn button, input a label for the disc, and Brasero starts creating your new CD or DVD or image file. How long it takes to create a CD or DVD depends on the amount of data you are writing and the speed of your drive.

Creating CDs from the Command Line

In Linux, creating a CD at the command line is a two-step process. You first create the ISO9660-formatted image, and then you burn or write the image onto the CD. The ISO9660 is the default file system for CD-ROMs.

Use the mkisofs command to create the ISO image. The mkisofs command has many options (see the man page for a full listing), and you use the following for quick burns:

Click here to view code image

matthew@seymour~:$ mkisofs -r -v -J -l -o /tmp/our_special_cd.iso /
source_directory

The options used in this example are as follows:

▸ -r—Sets the permission of the files to more useful values. UID and GID (individual and group user ID requirements) are set to 0, all files are globally readable and searchable, and all files are set as executable (for Windows systems).

▸ -v—Displays verbose messages (rather than terse messages) so that you can see what is occurring during the process; these messages can help you resolve any problems that occur.

▸ -J—Uses the Joliet extensions to ISO9660 so that your Windows-using buddies can more easily read the CD. The Joliet (for Windows), Rock Ridge (for UNIX), and HSF (for Mac) extensions to the ISO9660 standard are used to accommodate long filenames rather than the eight-character DOS filenames that the ISO9660 standard supports.

▸ -l—Allows 31-character filenames; DOS does not like it, but everyone else does.

▸ -o—Defines the directory where the image will be written (that is, the output) and its name. The /tmp directory is convenient for this purpose, but the image could go anywhere you have write permissions.

▸ /source_directory—Indicates the path to the source directory—that is, the directory containing the files you want to include. There are ways to append additional paths and exclude directories (and files) under the specified path; it is all explained in the man page, so check there if you need that level of complexity. The simple solution is to construct a new directory tree and populate it with the files you want to copy and then make the image using that directory as the source.

Many more options are available, including options to make the CD bootable.

After you have created the ISO image, you can write it to the CD with the cdrecord command:

Click here to view code image

matthew@seymour~:$ sudo cdrecord -eject -v speed=12 dev=0,0,0 /tmp/
our_special_cd.iso

The options used in this example are as follows:

▸ -eject—Ejects the CD when the write operation is finished.

▸ -v—Displays verbose messages.

▸ speed=—Sets the speed; the rate depends on the individual drive’s capabilities. If the drive or the recordable medium is poor, you can use lower speeds to get a good burn.

▸ dev=—Specifies the device number of the CD writer.

Creating DVDs from the Command Line

There are several competing formats for DVD, as follows:

▸ DVD+R

▸ DVD-R

▸ DVD+RW

▸ DVD-RW

Differences in the + and - formats mostly have to do with how the data is modulated onto the DVD itself, with the + format having an edge in buffer underrun recovery. How this is achieved affects the playability of the newly created DVD on any DVD player. The DVD+ format also has some advantages in recording on scratched or dirty media. Most drives support the DVD+ format. As with any other technology, your mileage may vary.

We focus on the DVD+RW drives because most drives support that standard. The software supplied with Ubuntu has support for writing to DVD-R/W (rewritable) media, as well. It will be useful for you to review the DVD+RW/+R/-R[W] for Linux HOWTO at https://fy.chalmers.se/~appro/linux/DVD+RW/ before you attempt to use dvd+rw-tools, which you need to install to enable DVD creation (also known as mastering) and the cdrtools package. You can ignore the discussion in the HOWTO about kernel patches and compiling the tools.

You need to have the dvd+rw-tools package installed, as well as the cdrtools package. The dvd+rw-tools package contains the growisofs application (which acts as a front end to mkisofs) and the DVD formatting utility.

You can use DVD media to record data in two ways. The first way is much the same as that used to record CDs in a session, and the second way is to record the data as a true file system, using packet writing.

matthew@seymour~:$ sudo your_application | growisofs -Z /dev/scd0=/dev/fd/0

matthew@seymour~:$ sudo growisofs -Z /dev/scd0=image

Video Formats

Ubuntu recognizes a variety of video formats. The formats created by the MPEG group, Apple, and Microsoft dominate, however. At the heart of video formats are the codecs—the encoders and decoders of video and audio information. Codecs are typically proprietary, but free codecs do exist. Here is a list of the most common video formats and their associated file extensions, although many more exist:

▸ AVI (.avi)—The Windows audiovisual format

▸ FLV (.flv)—Used in Adobe Flash; supports H.264 and others

▸ MPEG (.mpeg)—The MPEG video format; also known as .mpg

▸ MOV (.mov)—A QuickTime video format

▸ OGV/OGG (.ogv/.ogg)—The Ogg Theora freely licensed video format

▸ QT (.qt)—The QuickTime video format from Apple

▸ WEBM (.webm)—Google’s royalty-free container for audio and video (such as in VP8 format) designed for HTML5

Viewing Video in Linux

Out of the box, Ubuntu does not support any of the proprietary video codecs due to licensing restrictions. However, this functionality can be acquired if you install the ubuntu-restricted-extras package from the Ubuntu software repositories. You can learn more about it at https://help.ubuntu.com/community/RestrictedFormats.

You can watch video files and video DVDs with Totem Movie Player, which is installed by default. This may also be used with several other file formats and for both video and audio and is especially well suited for almost anything you are likely to want to use after you install the ubuntu-restricted-extras package.

A more powerful video viewer application is VLC, which is available in the software repositories and also for other operating systems, like Windows and macOS. VLC uses its own set of audio and video codecs and supports a wider range of video formats than any other media player we have encountered. If VLC can’t play it, it probably can’t be played.