Audio/Video

Using gphoto2 to Automate Taking Pictures

Shawn Powers — Sat, 27 Jan 2018 15:04:01 +0000

Introducing an app that allows DSLR cameras to function as an image or video capture device in Linux.

With my obsession—er, I mean hobby—regarding BirdCam, I've explored a great number of camera options. Whether that means trying to get Raspberry Pi cameras to focus for a macro shot of a feeder or adjusting depth of field to blur out the neighbor's shed, I've fiddled with just about every webcam setting there is. Unfortunately, when it comes to lens options, nothing beats a DSLR for quality. Thankfully, there's an app for that.

The gphoto2 suite of drivers and apps allows a huge list of DSLR cameras to function as image or video capture devices inside Linux. There's a compatibility list at the gphoto site, and even if your camera isn't listed, it's likely you'll be able to use it in some manner. For example, my Nikon Coolpix P610 isn't officially supported, but I'm able to get some images from it regardless. In fact, it even supports previewing a photo in ASCII art. That might not be a useful feature, but I found it incredibly fun to play with.

In all reality, if you want to automate taking pictures while using a real DSLR camera, gphoto2 is probably the tool you want. Whether it's a short-term setup on a tripod or a future super-high-def BirdCam (send me a link!), be sure to check it out. And if I can get my wife to loan me her Canon DSLR with the 50mm prime lens, BirdCam might rise to a whole new level!

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Building Your Own Audible

Shawn Powers — Sat, 20 Jan 2018 14:35:41 +0000

by Shawn Powers

A quick look at some options for streaming audio books.

I have audiobooks from a variety of sources, which I've purchased in a variety of ways. I have some graphic audio books in MP3 format, a bunch of Audible books in their DRM'd format and ripped CDs varying from m4b (Apple format for books) to MP3 and even some OGG. That diversity makes choosing a listening platform difficult. In order to meet my idea of perfection, I need:

A system that plays any audio format.
A way to play books on multiple platforms, iOS Android and web browsers.
Current location stored and honored across platforms.
The ability to play audiobooks at different speeds.
An easy way to access my entire library remotely.

Several options come close. My favorite Android audiobook app, for instance, is "Listen", available in the Play Store. But, it falls short on the multi-platform front and also on accessing books remotely. Audible itself will do most of what I need, but it doesn't allow importing remote books. And, traditional music players are out.

Honestly, Plex seems like the perfect platform for audiobooks. And although some people do use it, they're just kludging things. Plex doesn't natively support the concepts behind audiobooks, so the process isn't smooth at all. I'm honestly hoping that changes in the future, because it would be a perfect addition to an already amazing system. Thankfully, in the meantime, there's BookSonic.

You've probably heard of SubSonic, which is a music streaming server that allows you to do pretty much what I'm looking for with audiobooks, but it's strictly for music. Patrik Johansson has forked SubSonic and created BookSonic, specifically modified to handle audiobooks. It even handles tagging and book art. Currently, the system isn't perfect, but it's closer than any other projects come to book nirvana, and if you use Docker, it's dead simple to get installed. A simple:


docker -d create \
  --name booksonic \
  -p 8080:8080 \
  -v :/audiobooks \
  -v :/var/booksonic \
  ironicbadger/booksonic

will get BookSonic running on your Docker host. Once it's installed, just head over to http://docker_host:8080 and log in as admin/admin. You can start the book scan, and fairly soon, your books will show up for you to start playing!

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Creating an Internet Radio Station with Icecast and Liquidsoap

Bill Dengler — Mon, 15 Jan 2018 14:34:13 +0000

by Bill Dengler

Ever wanted to stream prerecorded music or a live event, such as a lecture or concert for an internet audience? With Icecast and Liquidsoap, you can set up a full-featured, flexible internet radio station using free software and open standards.

Icecast is "a streaming media (audio/video) server that currently supports Ogg (Vorbis and Theora), Opus, WebM and MP3 streams. It can be used to create an internet radio station or a privately running jukebox and many things in between. It is very versatile in that new formats can be added relatively easily and supports open standards for communication and interaction."

Liquidsoap is "a powerful and flexible language for describing your streams. It offers a rich collection of operators that you can combine at will, giving you more power than you need for creating or transforming streams. But Liquidsoap is still very light and easy to use, in the UNIX tradition of simple strong components working together."

When combined, Icecast and Liquidsoap can create a flexible, feature-rich internet radio station. In this article, I describe how to configure Icecast to host an internet radio station. Then, I explain how to install and configure Liquidsoap to connect to Icecast, adding random (or sequential) music playback with smart cross-fading, prerecorded randomly inserted announcements and jingles, a song request system and support for live streams, with automated recording and seamless switching between live and automated programming. I also show how to configure the server to serve your stream in MP3, Ogg and Opus formats for maximum player compatibility.

Icecast, Vorbis and related projects are maintained by Xiph.Org, a nonprofit organization that develops open multimedia standards and software. To ensure that you are running the latest version of Icecast, with all (or most) features, you should install from an official Xiph.Org repository. Visit the list of official repositories here, and follow the instructions on that page to add the Icecast repository for your distribution. Then, install using your system's package manager. On Debian-based systems (such as Ubuntu), you may be asked to "configure Icecast" during package installation; select "no" as you will configure the server manually if you are following along with this article.

Open the Icecast configuration file using your preferred text editor. On Debian-based systems, the file is located at /etc/icecast2/icecast.xml. The location on other systems may differ; check your package's documentation for the correct path. The configuration file is in XML format and is divided into several sections. First, enter your server's location and email into the location and admin fields, respectively—for example:

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Live Stream Your Pets with Linux and YouTube!

Shawn Powers — Thu, 26 Oct 2017 11:53:25 +0000

by Shawn Powers

Anyone who reads Linux Journal knows about my fascination with birdwatching. I've created my own weatherproof video cameras with a Raspberry Pi. I've posted instructions on how to create your own automatically updating camera image page with JavaScript. Heck, I even learned CSS so I could make a mobile-friendly version of BirdCam that filled the screen in landscape mode.

Recently, however, I've finally been able to create an automated system that streams my BirdCam live over YouTube. It starts when the sun comes up and stops when the sun goes down. And thanks to some powerful open-source software, I never have to touch the system!

Some of the tools I describe here have been covered in other articles, but this is the first time I've been able to create a stream that anyone can see utilizing bandwidth Google pays for!

Figure 1. Birds are always camera-shy. If you watch long enough, however, they come and steal peanuts!

My List of Ingredients

First off, I want to be clear about what sort of hardware and software is required in order to accomplish something similar to what I'm doing:

A Linux computer: if you plan to use USB cameras, this needs to be a physical computer. If your video source is network-based, this can be a virtual machine on your network. A Raspberry Pi isn't really powerful enough for the video work that has to be done, unless maybe it's low-resolution. I have an old i5 CPU running at 1.6GHz, and it's more than enough.
A video source: this can be pretty much any video source you have at hand. If you plan to use a USB webcam, you'll need to be sure you are using a physical Linux computer as noted above. I've used USB, MJPEG over http (see my old BirdCam articles), cheap wireless security cameras that have an RTSP stream, and most recently, I started using UniFi video cameras. In fact, if you are considering purchasing outdoor video cameras for a project like this, I can't recommend UniFi cameras enough. They are PoE, HD and the free software handles recording and provides RTSP streams that have both HD video and top-notch audio.
A YouTube account with Live Streaming enabled: you'll need to verify your account, and then enable live streaming here. It's not a difficult process, but without following those steps, you won't be able to use the free service.

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Working with YouTube and Extracting Audio

Dave Taylor — Tue, 10 Oct 2017 11:48:21 +0000

by Dave Taylor

In my last few articles, I've been exploring the capabilities of ImageMagick, showing that just because you're working on a command line doesn't mean you're stuck processing only text. As I explained, ImageMagick makes it easy to work with images, adding watermarks and analyzing content far more accurately than with the standard Linux file command, and much, much more.

Continuing in a similar vein, I want to look at audio and video in this article. Well, maybe "listen" to audio and "look" at video, but again, I'm still focusing on the command line, so in both instances, player/viewer apps are required.

YouTube to MP3 Audio

As someone who watches a lot of lectures online, I'm also intrigued by the online services that can extract just the audio portion of a YouTube or Vimeo video and save it as an MP3. Listening to a lecture while driving is far safer than trying not to watch a video on the move, for example.

Since there are so many live concert performances online, many people also like to use a video-to-MP3 service to add those songs to their music libraries.

Note: be leery of copyright issues with any download and conversion of content. Just because it's on Vimeo, YouTube or other online service, doesn't mean you have permission to extract the audio or even download it and save it on your computer.

Let's start with the most basic functionality: downloading a video from YouTube so you can watch it on your Linux system. There are a lot of browser plugins and even websites devoted to this task, but who wants to risk malware or be plagued by porn site ads? Yech.

Fortunately, there's a terrific public domain program called youtube-dl on GitHub that covers all your needs. At its most basic, it lets you download video content from YouTube and a variety of other online video repositories, but as you'll learn, it can do quite a bit more.

You can grab a copy for your system here.

Let's start by downloading a copy of one of my own YouTube videos. It's a review of the splendid 1More quad-driver headphones, and its URL is https://www.youtube.com/watch?v=BFL1E77hTHQ.

As an aside: I have a YouTube channel where I review consumer electronics and gadgets. You should subscribe! Find all my videos at http://youtube.com/askdavetaylor.

YouTube has a bunch of ways it can assemble a URL, however, including using its URL-shortener youtu.be, but fortunately, youtube-dl can handle the variations.

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YouTube on the Big Screen

Shawn Powers — Wed, 20 Sep 2017 15:32:58 +0000

by Shawn Powers

For years I've been jealous of folks with iOS devices who could just send their phone screens to their Apple TV devices. It seems like the Android screen-mirroring protocols never work right for me. My Sony Xperia has multiple types of screen mirroring, and none of them seem to work on my smart TVs or Roku devices.

YouTube is a completely different story. It doesn't matter if I'm on a laptop, iPhone, Android device or Chromebook, I can "cast" the video to any of my Roku devices or smart TVs without any problems at all. It works and works well. The great part about casting is you can shut off the connection from the sending device, and it keeps playing! Because 95% of the stuff I want to display on the TV from my phone is YouTube videos, I couldn't be happier. Plus, I can check email on my phone while the family watches the latest "Bad Lip Reading" video on the big screen! Take that Apple TV!

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Nativ Vita

James Gray — Mon, 21 Aug 2017 13:38:01 +0000

by James Gray

The motto "open to anything" underpins Nativ's development philosophy on all of its audio solutions, including its new Nativ Vita, "the world's first High-Resolution Music Player" and touchscreen control center that is designed to function as the central access point for one's entire music collection.

This philosophy is evident in Nativ Vita's Linux and open-source internals, offering advantages like support for virtually any music service—even lesser-known and regional services like Jango Radio, KKBox and Paradise Radio—and extensibility far beyond pure audio applications. Naturally, Nativ Vita supports mainstream music services like Apple Music, SoundCloud, Vevo, Spotify, TIDAL, Pandora and Amazon Music, among others.

Nativ Vita can store up to 4TB of music on its internal hard disk drives or SSDs and can access remote files on a PC, NAS or smartphone. Wireless streaming to multi-room speaker systems is achieved utilizing popular solutions like SONOS and Bluesound and to high-end headphones via Bluetooth aptX. A high-end digital output stage with myriad outputs ranging from AES/EBU to USB Audio Class 2.0 connect the Vita to an amplifier or USB DAC for best-in-class sound performance.

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The Post-TV Age?

Shawn Powers — Tue, 15 Aug 2017 14:33:57 +0000

by Shawn Powers

The most basic cable package from Charter (Spectrum?) costs me more than $70 per month, and that's without any equipment other than a single cable card. It's very clear why people have been cutting the cord with cable TV companies. But, what options exist? Do the alternatives actually cost less? Are the alternatives as good? I've been trying to figure that out for a few months now, and the results? It depends.

The idea of cord cutting isn't new. For years, people have been severing their ties with cable companies in order to save money. The ever-persistent question is this: how do the options compare?

Real Time or On Demand?

When replacing cable TV, there are two main types of media in question. Services like Netflix, Amazon Prime and Hulu are great, but they don't provide live television. In fact, depending on the show and service, you might need to wait until the next day or even the end of a season before your desired shows are available. You usually get the advantage of no commercials, but the waiting often is unbearable if you're into television shows that end with cliffhangers.

It is interesting though, now that Netflix and Amazon have been so successful with their streaming services, they're beginning to get their own exclusive shows. This means that not only are the shows not delayed, but they're also actually not available at all via cable TV! Admittedly that phenomenon is fairly new (only the last few years), but it makes the case for streaming far stronger. Why pay $70 per month and still not get to watch Jessica Jones?

Also, many individual stations are starting to offer their own streaming options, so the days of paying for cable so you can see a particular HBO show are over. Broadcast networks are starting to offer streaming options too, so if you're just looking for the ability to watch particular television shows, even paying for multiple online accounts is cheaper than paying for cable—usually.

All Those Cable Channels...

Some of the biggest hurdles for cord-cutters are cable-only channels. I have a relative who watches only shows on the History Channel. And my mother-in-law couldn't live without watching movies on the Hallmark Channel. And everyone I know in real life is addicted to HGTV and its tiny house program. Those channels aren't big enough to support a full streaming platform (or are owned by actual cable companies, so they won't offer a non-cable alternative). So what's a cord-cutter to do?

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Analyzing Videos for Fun and Profit

Joey Bernard — Wed, 05 Jul 2017 10:46:26 +0000

by Joey Bernard

People's phones and all of the various sensors that may be built in to them is a source of scientific data logging that almost everyone carries around. Although the selection of sensors varies from phone to phone, they almost all have a camera. In this article, I take a look at a piece of software called Tracker that can be used to analyze videos you take of experiments.

You can download Tracker directly from the project page. A lot of good documentation is available at the main website, including examples of how you might be able to use it from the community of other users. Tracker is written in Java, however, so you also need to have a JVM installed on your system before you can use it. For example, on a Debian-based system, you can install a very good JVM with the command:


sudo apt-get install openjdk-8-jre

You then can download the relevant installer for your system and run it from a terminal window. You probably will need to make the installer executable with a command like this:


chmod +x Tracker-4.95-linux-64bit-installer.run

Don't forget to use the sudo command so that you have the correct permissions to do the installation.

Once it's installed, you should have a new entry in your applications menu system. Starting Tracker will give you a new empty project for beginning your video analysis.

Figure 1. When you start Tracker, you get a new empty project.

Although you could start analyzing your own videos immediately, you may want to use simpler videos while learning how Tracker works. When you ran the initial installer for Tracker, it should have asked you whether you also wanted to install example files. Assuming you said yes, you now can load one of those within Tracker. When you click on the menu item File→Open File, you'll see a new window where you can select either a movie file or a Tracker file.

Figure 2. The open file dialog box allows you to open movie files or Tracker files.

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Android Candy: the Verbification of Video Chat

Shawn Powers — Wed, 14 Jun 2017 15:45:33 +0000

by Shawn Powers

People who study the history of languages probably will look back at our current time and scratch their heads. We keep inventing verbs! First, Google became the verb we use for searching. Then, "Facebooking" someone became a viable way to contact them. Heck, I forgot about "texting" someone. It seems we just keep taking perfectly good nouns and making them verbs. We keep verbing all our nouns! But I digress.

Unfortunately, I've noticed a trend where people who want to do video chat are starting to say, "Facetime me." The problem isn't with the terminology, it's with the proprietary technology. If you're an Android user, you can't "Facetime" someone. Google Hangouts sort of solves that problem, but it's not as user-friendly as Facetime on iOS is.

Google hopes to change that with its new Duo app. It's designed very much like Facetime, but it has native iOS and Android apps. In my trials, the video quality is fine, so it's really only adoption that needs to happen in order to become the standard across platforms. It's worth a try, but you'll have to convince your Apple friends to install a new app for video chatting. Also, "duo" doesn't really lend itself to verbification, so I'm a little worried Google has a non-starter on that note alone!

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