Posts tagged: audio

Dynamic phonetic chart application

I’ve just completed a new Flash learning application aimed at EFL/ESL learners and teachers which I believe is a good solution to many of the problems facing those who want to use phonetics in teaching English as a foreign or second language.

What does it do?

It can display any number of phonetic symbols which appear in groups as coloured buttons (see illustration).  When users click on one of the symbol buttons, a list of example words appears with the phonetic spelling and a play button next to each one so that they can listen to audio recordings of the example words.

The example on my Moodle deploys the symbols in a typical arrangement. They’re in columns of corresponding short and long vowels, dipthongs, corresponding voiced and unvoiced consonants and finally the remaining consonants.  By editing an external XML file, you can arrange and group the set or subsets of the phonetic symbols any way you like. For example, the past simple of regular verbs ending in /-id/, /-d/ and /-t/.

Why is it an advantage to make it dynamic?

Traditional phonetic charts (also known as phonemic charts) are fixed, static items that you cannot change. In most English courses, learners are presented with a single, very general, one-size-fits-all chart for the entire course. Such charts typically have a small, fixed set of vocabulary for learners to view and listen to and, more often than not, it bears no or little relation to the vocabulary being studied at any particular moment in the course. See this example on Oxford University Press’  New English File site or this example on the British Council’s BBC Teaching English site.

Making any Flash web application dynamic gives one very important advantage. Anyone can edit it without having to buy expensive software. In fact, all you need is a text editor and a little familiarity with XML  which is human readable and relatively easy to learn. Any teacher or course content developer can create any number of vocabulary sets and deploy them in Moodle along with the related course materials, giving learners specific pronunciation support for the target language in a particular module, unit or activity. Did I mention that it’s also very easy to correct any typos that you find?

Secondly (the technical bit), the Flash learning application contains no text or audio itself, all of that is loaded externally, making it only 12Kb in size which is less than half the size of the containing Moodle web page (a similar sized photo would be around 50 – 200Kb). This means that it appears almost instantly. The application then loads the words and phonetics as an XML file (XML is the de facto file format for dynamic learning content). The audio files are loaded as and when users play them. Typically, audio files tend to be quite large and so only loading them as required means that the application starts faster and only uses the internet bandwidth that is absolutely necessary – ideal for users with slow or intermittent connections.

How is using Flash an advantage over normal web page based phonetic charts?

Phonetic symbols have always been a bit of a problem on the internet, well actually, text and fonts in general. In order for a web page to be displayed with the correct font, e.g. Times New Roman, that font must be installed on users’ computers. If it isn’t, a substitute font is found automatically. The trouble is that not all fonts contain phonetic characters, in fact very few do, so what works perfectly well on one computer may be unreadable on another if it hasn’t got the correct font installed.

Flash resolves this issue by allowing developers to embed (include) fonts within their Flash applications. This means that the application carries the required fonts with it and will work on any computer regardless of whether it has any fonts installed or not. This is especially important with phonetic characters since so few fonts contain them. Problem solved!

Try the demo:

As always, I’ve deployed a demo of the chart, with 445 example words, on my Moodle demo course (Login as a guest). (Currently not available)

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My Flash MP3 player to be included in Moodle 2.0

In my last post, I described a project I had just started which was a Flash MP3 player that can be used for tests since teachers can determine exactly how many times a learner can listen to an audio file. Here’s an update on the latest developments…

MP3 Player for Tests

Part of Moodle 2.0

I’m pleased to announce that Gordon Bateson, a core Moodle developer and author of the very popular Hot Potatoes module for Moodle, has chosen to include my MP3 Player for Tests in the next major release of Moodle, Moodle 2.0. It will be part of the QuizPort module which is the successor to Hot Potatoes. Over the last few days, I’ve been working closely with Gordon on the exact specifications and functions of the player to optimise it for learners to take listening tests in Moodle.  The announcement came today on Moodle.org forums. You can login as a guest if you are not already a member of Moodle.org.

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Moodle FLV Player module update

In February 2009, I released the first beta version of the FLV Player plugin activity module for Moodle. It leverages the ubiquitous JW FLV Player and has been very popular among teachers and course content developers working with Moodle. I’m working on a substantial update for the module and in this article I’m going to write about some of the improvements and new features in it.

What has changed?

The most significant changes in the module will be:

  • Support for alternative HD video streams.
  • Support for audio descriptions.
  • Uses simpler SWFObject 2.2 embed method.

Alternative HD video streams

The current FLV Player module can play any video format supported by Flash Player, which includes FLV, F4V, MOV,  MP4 and Youtube.com videos as well as MP3 and AAC audio files, and JPEG, PNG and GIF images (animation is not supported) and Flash animation files. See here for a full list of supported formats.

The new version of the player now supports an alternative HD video stream. This means that users can switch between normal and high definition video at the click of a mouse. All you need to do is provide two video files, one normal and one HD for the player to switch between. This is particularly useful for providing an alternative low definition stream to users with slow or intermittent internet connections.

Audio descriptions

This one’s still a bit buggy and doesn’t allow full control over the audio file. An audio description is a second, separate MP3 audio file that can be deployed alongside a video. It is synchronised with the video so that if you seek through it to a new point in time, the audio file plays at that point respectively. Users can switch the extra audio on and off as they like.

Audio descriptions are typically used for accessibility support for the visually impaired but can also be used for multi-language support, optional narrator’s voice overs, director’s commentaries, etc. I’m sure instructional designers, teachers and course content developers can come up with some creative applications for this feature.

SWFObject 2.2 embedding

Previous versions of the FLV Player module were a little “inconsistent” across different browsers and some suffered from bugs when it was necessary to perform Flash Player upgrades for users who don’t have Flash Player 9.0.115 or later installed. I’ve upgraded the module to SWFObject 2.2 and used a static embed method so that even with Javascript disabled, the video player will work, as well as detecting users’ Flash Player versions and informing them if they need to perform a Flash Player upgrade in order to view the video content, instead of automatically deploying Express Install, giving users more control. The new embed method has been successfully tested on Internet Explorer, Firefox, Safari and Google Chrome.

Prompt to upgrade the Flash Player version

A prompt to upgrade to the required Flash Player version.

Other features still supported

As well as these new features, the new version of the FLV Player will continue to support:

  • HTML notes under the video playback window so you can put lecture notes, diagrams, graphs, tables, photos, links to files or pages, etc. on the same page.
  • TimedText, RealText, ASX, ATOM, RSS and XSPF video caption formats (Users can now switch captions on and off).
  • XML Playlists.
  • Skins to change the visual appearance of the player (also includes support for XML based skins).
  • Definable player control colours.
  • Video poster images before playback commences.
  • A variety of other JW FLV Player plugins (as a CSV list).
  • Player configuration via an externally loaded XML file so that course-wide player policies can be established.

When will the new version be ready?

Many thanks to the brilliant developers at LongtailVideo.com for all their ideas and hard work. I’m still testing and trying to “iron out” the bugs in the FLV Player module but this should be finished in the next week or so. Unfortunately, there’s a bug in the Audio Description plugin, which is beyond my control and I’m waiting for the respective developer to resolve the issue. Hopefully, this will be soon.

Update…

After spending some time going over the various requirements for supporting the new plugins, the changes to the module code and the database table structure, I’ve realised that a number of the changes would “break” older instances on Moodle courses and lead to a lot of extra work for teachers and course content developers. With this in mind, I’ve decided to leave the FLV Player as it is for people who don’t need a feature-rich media player.

I’m now developing a very feature-rich “Media Player” module that will support most of the plugins currently available for the JW FLV Player as well as playlists and all the other features that we expect of a good web video application for e-learning. The module editing page will also be better organised to make it easier to use. The JW FLV Player plugins that I’m experimenting with at the moment are as follows:

Please note that the Live Stream and Snapshot plugins require a server-side script and will not be enabled as standard for security reasons. The search Seach Bar plugin can use custom search scripts but only YouTube.com search will be enabled by default.

Here’s the Google Code project home page: http://code.google.com/p/moodle-mplayer/

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Flash MP3 player for tests

GNU GPL Open Source ProjectEver wanted to control the number of times a learner can listen to a recording in a listening test? Well, I’ve seen this request a number of times on Moodle.org’s forums recently and not so recently. So I’ve decided to develop and share this Flash MP3 player for tests.

What does it do?

It streams (progressive download) and plays a single MP3 (or AAC) audio file once. It has no play back controls whatsoever so there is no way for a learner to listen to the recording again except by refreshing the web page in the browser. There is an optional parameter that sets the number of times the MP3 file plays.

What is it for?

It’s for deploying in listening tests or activities where it’s necessary or desirable to limit the number of times a learner can listen to an audio recording. For example, Cambridge ESOL (English for Speakers of Other Languages) listening tests require that the learner only listen to each recording twice so it’s particularly useful in practice exercises for learners who are preparing to take one of these exams.

How can I use it?

Detailed instructions are included in the download package as well as some example embed code. Unfortunately, I can’t provide any easy to use plugins or modules for LMSs (Learning Management Systems) – It’s too complicated to explain here and now. For now, this Flash application can only be deployed by manually inserting the necessary embed code and editing some of the parameters. I’ve included some code examples and explanations for how to embed it in Moodle from the course files directory (moodledata).  This should present no problems at all for an experienced web designer or web developer and an IT savvy teacher or course content designer could probably deploy it successfully by copying and editing the embed code examples provided.

Do I need to buy a licence to use it?

No, this project is open source and completely free. You can copy it, change it and redistribute it in any way you like. The only condition is that you must leave my name and copyright on it and distribute a copy of the GPL open source licence with it. The Flash CS4 FLA and ActionScript 3.0 source files and full details are included in the download package.

How secure is it?

It’s worth noting that this MP3 player for tests is not secure. An IT savvy learner could easily look at the source code for the web page and see the URL of the MP3 file being played and download it directly. The very popular Firefox web browser also has a number of plugins that makes it very easy to download media files from virtually any source no matter how well they are protected, even streams from media servers that are supposed to be very secure. The easiest way to make it more difficult to cheat is to put a time limit on the listening test itself. That way, there isn’t enough time to listen more than once.

Update:

I’ve moved the MP3 Player for Tests to Google Code to make it more accessible to developers and easier to find and download. You can find the project page here.

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Good quality video

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The Red One from Red

This article is a follow-up to my post, “Good quality audio”. Here, I’ll give a few tips aimed at new-comers to recording video for the web and how to get the best results. I’m assuming that, as a new-comer, you have very basic, low-budget equipment or are about to buy or borrow some. Obviously, something like the industry standard “Red One” from Red, starting at $17,500 for the body alone (not including lenses or recorder, although I’m sure they’ll give you a free t-shirt), is out of our budget.

A little personal video history

My introduction to recording video came when I was very young and my American uncle came to visit us in the UK. He brought an enormous VHS camcorder with him to record his visit for posterity and gave me, aged 13, the responsibility of being his documentary cameraman. Later, I went on to use the (enormous) old industry standard U-Matic video tape recorders, had some basic video recording and production training at art college, and eventually moved on to digital video with 8mm MiniDV recorders. The jump in picture quality from VHS, Betamax and U-Matic to MiniDV was astonishing. I’ve tried other formats since but, for the moment at least, I find that this format offers the best results for the money.

Why do I recommend MiniDV?

It’s an old format and surely the newer SD-Card or HDD video cameras are better, aren’t they?

In my opinion, it depends what you mean by “better”. The newer consumer camcorders are cheaper (sometimes), smaller, lighter, more robust and often, you can take video shot on them and upload it directly onto video sharing websites like YouTube, with no editing or conversion software necessary. It’s wonderful to be able to do that. The downside is that these camcorders use an extremely high rate of digital video compression so while the footage shot on them looks good in its original format, once you start to edit it and, necessarily, recode it, it degrades rapidly. The end result is often unwatchable. MiniDV, on the other hand, uses a low rate of compression (MPEG-2) so that it’s possible to do more editing, recoding and adding special effects and still maintain reasonably good picture quality. Apparently, the BBC still use MiniDV for a lot of its mobile “rough ‘n’ ready” video.  Be warned though, when you come to download video footage onto your computer, you’ll quickly fill up a good few Gigabytes of hard-disk space. You may want to consider installing bigger, faster (7,200 RPM minimum) hard-discs on your computer if you intend to do a lot of editing.

Some of the new hard disk drive and SD card camcorders now include higher bit rate recording in the newer H.264/AVC (Advanced Video Compression) format currently being promoted by Sony and Panasonic. It promises double the rate of compression for the same olour depth and image quality. Although it’s popularly being hailed as the new de facto CODEC, most professionals are still using the older MPEG-2 CODEC simply because it’s more mature, there’s much better software support for it and it takes much less time to render edited videos into a final master copy. For example, most of the Blue-Ray disc movies available today are MPEG-2 not H.264/AVC.

What should I look for in a video camera?

A budget 3CCD MiniDV camcorder

A budget 3CCD MiniDV camcorder

Since we’re on a low budget, my advice is to get the best MiniDV camcorder you can. Something that surprises me about a lot of consumer camcorders, even quite expensive ones, is the lack of microphone inputs so that you can use external microphones to record sound. Some consumer camcorders come with the label “semi-pro” and they usually have microphone inputs and sometimes a “shoe” on which you can attach specialised microphones. Sound is one of the most important parts of the video recording as it contains the speech and the sounds that objects might make. It often carries the “story” of a presentation. Of course, it is possible to record audio separately and manually synchronise the sound and video streams while editing but this is a time consuming extra task that you could really do without. Ideally, you want a stereo input jack so that you can use a stereo microphone or a pair of mono mics. See my article on good quality audio for more details about this.

Another important point with video cameras is the quality of the CCD (charged coupled device) chip. This is the light sensor that converts the light coming in through the camera lens into a digital video image. Needless to say, if the CCD chip is poor quality or has low light sensitivity, no amount of extra features or professional editing software can give you good quality video. The best quality chips use 3 CCD devices which give the best image quality and the best sensitivity, which is useful for shooting in low light conditions such as indoors.

You can find a number of suitable MiniDV 3CCD camcorders of various ages, conditions and prices on shopping sites such as Amazon and eBay. I’ve seen good cameras on eBay for as little as £40.

Update (19th July 2009): Now it looks like HDD camcorders are coming onto the second-hand market at an affordable price. I looked on eBay.co.uk and found quite a few good cameras selling at around the £200 (€230 or $330 US) price range. Before buying any camera, check with the camera manufacturer about what video compression settings the camera has and if they’re suitable for high-quality editing.

Don’t forget to budget for lighting

Even the best of video cameras can only work with the light you give them. Low light conditions give you poor, flat, grainy image quality so it’s well worth investing in at least three good lights. I say three lights because subjects lit with only one or two lights tend to look rather flat and lifeless. Most people who work in photography understand the three-point lighting system. It’s effective and with a little experimentation and trial and error, you can bring your video footage (and studio photography) to life. The principles are simple. You have three lights: a fill light, a key light and a back light. This arrangement ensures that every area of the subject is lit and not in shadow and also gives a 3D effect, making the subject look more life-like. It’s an advantage if the lights give off a broad spectrum of light (i.e. fluorescent lamps or something similar) and even better if you can control their luminosity (i.e you can dim them). You may even want to consider setting up something similar for your webcam if you do a lot of VoIP and video conferencing.

Three-point lighting

Three-point lighting

What about video editing?

When choosing the best video editing software, I think there’s a trade-off between usability and editing features. Professional video editing software allows you to do just about anything you like with your video rushes to get some really impressive results. You usually have the option of using “keying”, also known as “green screen”, to remove the background. Even things like good-looking custom titling can only be achieved with professional software but the problem is that it’s difficult for a novice to use. If you’re new to video editing or have only ever used software packages such as Windows Movie Maker (included with Windows) or iMovie (included with most Macs), professional editing suites like Adobe Premiere Pro (Windows and Mac), Sony Vegas Pro (Windows only) or Final Cut Studio (Mac only) can be daunting and can take weeks or even months to get to grips with. Luckily, they all do consumer versions with intuitive, easy to use features that allow you to start creating your mini epics within hours, if not minutes. The trade-off is that most of the features are set up as pre-set combinations, for ease of use, and are either difficult or impossible to adjust individual feature settings in them to get the specific results you might want. If you’re technically minded and willing to spend the time and money and you want complete control over your editing features, then the pro options are the ones to go for. For fast and not bad looking results, go for the cheaper consumer options. Almost all video editing software has a convenient option for producing video for the web. Even Quicktime pro*, currently at $29.99, can convert a number of compatible formats to MP4 (H.264) for web deployment on Flash Player or the Quicktime browser plugin. By the way, I don’t recommend publishing your videos to the WMV (Windows Media Video) format used by Windows Movie Maker. It’s very difficult to deploy on the web reliably and a lot of people using Mac or Linux operating systems won’t be able to view it at all. I’ll write another article on video formats and media containers soon.

* If you have Quicktime installed on your computer, you already have Quicktime Pro. All you need to do is buy a serial key from Apple to activate the media converter functions on it.

Plan and storyboard your presentation

I think getting physically good results in video is somewhat easier than in audio recording. Most camcorders today capture pretty good quality video so I think the most important thing to concentrate on is the storyline or how you storyboard your video presentation. It’s important to establish a context before going into detail. For example, if you’re doing an interview with a representative of an organisation, start with a short clip of the outside of their headquarters or something with their logo on before showing the interview. Also, don’t forget to introduce the representative and give a little background information about them before launching into the interview questions. All this is setting the context and it makes it much easier for your audience to follow who the person is and what is going on.

Your video clips, no matter how short, should also have a beginning, middle and end. I think it’s best to think of it as taking your viewers on a journey. Whether it’s a visual journey or a spoken one, it’s still a good idea to let your audience know where they’re going to go, then where they’re going and then where they’ve been. Try to maintain a sense of continuity and a logical progression from one scene to the next.

If possible, I recommend attending some kind of introductory course to video recording and editing. An experience professional can get you started, give you hands-on practice, teach you how to storyboard and edit, teach you the finer points of video technique, answer your questions and guide you toward producing some high quality and captivating videos.

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