In my previous column, I described the success I've had with using VP8 for compressing the video for the Lib-Ray main feature multimedia file. At the end of that process, though, I still have a silent film. We also need to get the audio, and make a decision about the format. WebM calls for Vorbis sound, which probably makes sense for internet downloads, but this is where we part ways -- for my application, bit-perfect audio with FLAC seems to make more sense, at least for the main audio tracks (Vorbis is still in the picture for things like commentaries).
Airtime is the GPLv3 broadcast software for scheduling and remote station management. It supports both soundcard output to a transmitter, and direct streaming to an Icecast or SHOUTcast server. Web browser access to the station's media archive, multi-file upload and automatic metadata import features are coupled with a collaborative on-line scheduling calendar and playlist management. The scheduling calendar is managed through an easy-to-use interface and triggers playout with sub-second precision.
Not so much a software book as a book on theory and technique of sound processing, "Sound Effects, Tips and Tricks" is a concise look at what can be done with good signal processing software. I found the book interesting, occasionally frustrating, and enlightening. In the end, it mostly taught me to have a better understanding of what I didn't know -- but that's useful.
A few years ago, I discovered a site called "FreeSound.org" which sounded quite exciting, but turned out to be rather disappointing because the content was released under the Creative Commons "Sampling+" license, which is not a free license. This made all of the content incompatible with use on free software or free culture projects, and was very frustrating, especially given the name. Last month, though, Creative Commons decided to retire the Sampling+ licenses, and FreeSound.org is rolling out a new site with a license chooser that favors the "CC 0" public domain declaration and the "CC By" attribution licenses -- both compatible with free projects. This will be a big help for free-culture multimedia projects.
Home recording is not that hard or expensive to do, and Audacity provides a great tool for recording and editing dialog. I recently got the equipment together to do decent voice recording for our "Lunatics" video project. Total cost was under $150.00 for a condenser USB microphone system, and the sound is a tremendous improvement over my previous attempts. Now our biggest challenge is the room acoustics. So far, we're having a lot of fun recording dialog.
Audacity is one of my favorite free software applications, and it has really improved over the years. This book covers the latest features in the 1.3.x series, which is expected to lead directly to the version 2.x Audacity. The book covers more than just Audacity, though. In the process of covering several different uses, it also discusses everything from hardware equipment selection to copyright and business problems that may come up in a project. Overall, it's a good read and a good introduction to Audacity, audio recording, and audio processing.
You might think that a good program is all about good programming. But for a number of applications, the barrier to success isn't programming at all. Some of the most interesting projects nowadays -- speech recognition, for example -- rely on machine-learning from databases of information. It's not enough to write free software for these applications, we have to also provide that software with the right data. Contributing to these projects is needed from a much larger group of people, but it also can be very easy to do.
I found a useful sound effect in an online video from NASA which replaces an earlier temporary sound I used in a scene soundtrack for the Lunatics pilot, "No Children in Space." I'm going to extract the sound from the video (with VLC), cut out the sound I need, clean it up, and insert it into an existing sound mix (all with Audacity). This should give you some insight into using Audacity and a VLC on a real project.
As I was working on a sound track project for a science-fiction film I've been working on, I remembered reading an article in Free Software Magazine, by Gianluca Pignalberi, in which he described filtering using Gimp and a command-line program then called "ARSE" (version 0.1). The program is now called "The Analysis & Resynthesis Sound Spectrograph" ("ARSS", now version 0.2.3). Combined with an image editor of your choice (I also chose Gimp), it also turns out to be a very interesting way to make original sound effects -- by painting the sound spectrum.
For me there is nothing quite as relaxing as the sounds of the beach. The slow crashing of waves and the gentle lapping of water in the tide pools really helps me find my inner calm. Of course, I could do without the smell of rotting fish carcasses, the constantly screeching gulls and the looming threat of melanoma. So I decided to create my own virtual beach experience using some free sound clips from the internet and the free software package called Audacity. I’ve got all the relaxation without the annoying dead fish, dive bombing birds and sunburn.
Mylatest blog entry began with this paragraph:
Messing with MP3 files is, for some people, a synonym for illegal use of copyrighted music. Well, actually it's not.
The reason I wrote that incipit remained unclear to many, that didn't seeany link between this first phrase and the rest of the article. I therefore decided towrite a few blog entries on the subject. This time I'll talk about theMP3 format in itself.