Elton One

Using the BASH shell in OS X I wanted to examine the EXIF data of my JPG files for a script I am writing. Unfortunately, the exif command in BASH does not work, despite there being a man page for it. I’m solving this problem by using ExifTool by Phil Harvey, but it leaves me asking the question “Why does the BASH exif command work with Linux but not with OS X?” I had a similar problem using the uniq command that works fine with Linux but only partially with OS X:
uniq -w 32
That is because in OS X there is no -w flag. Most of the scripts and examples I find to learn from are written in BASH with Linux and I’m having a really hard time understanding why BASH is not the same with OS X. It makes no sense.

Anyone?

UPDATE 10/07/08

In fact, you don’t get exif on Linux so what am I talking about (and there isn’t even a man page for it like on OS X). Use exiv2 or exiftool. Still confusing why it’s there in OS X though..

After several years of using a multitude of applications under OS X to play videos locally and over a network, I have come to the following conclusions:

• Quicktime is a nice application but has limited support for a large number of file types (avi, divx, flv) and despite the availability of additional codecs (such as FlipForMac for Flash) I have never been able to consistently play all the file types I have. Network playback is also very hit and miss, and without the ability to change the cache size playback that does work is often very jittery. Not being Open Source and with the newest versions supporting DRM really puts the nail in the coffin, although Quicktime is a powerful application.
• VLC is also a nice application with good support for all the file types I use and a great deal of options but it is hard to find what you are looking for in the preferences and documentation. Local playback is great but network playback is not so good and despite playing around with the cache size, playback is almost always jittery and I get the following error:
  

  

  
  On checking the forums it seems a large amount of OS X users have similar problems and the developers, despite VLC’s awesome cross-platform support, are not so interested in developing further to solve this problem (see here).

• MPlayer has consistently proven to be very effective for both playing files locally and over a network, and with simple visual preference options backed up by advanced command line
  functionality and good online documentation it is a powerful application. Cache size can be altered in Preferences/Miscellaneous by ticking Additional Parameters and entering
  -cache 10000
  with the value representing kilobytes. 10000 works great for me with minimal load time and no jittering. This will load the specified amount before playback commences and continue to stay that far ahead as playback continues unlike VLC which loads the amount specified in the cache but after this amount has been played the jittering kicks in (the cache seems to be a one time pre-load).

  

  N.B. It is important to note that for this to take effect in MPlayer “Use cache (slow media)” needs to be ticked in Preferences/Miscellaneous, otherwise you get jittery playback regardless of specifying the cache size in Additional Parameters.
  
  

Conclusion

If you want to play local and network video using OS X with no jittering or other playback errors, MPlayer with the additional cache parameter is your best bet.

I have been using MPlayer Version 1.0 rc1 with OS X 10.4.8 on an Intel machine and MPlayer OS X Version 2.0b9r5 on OS X 10.4 & OS X 10.4.11 on a PPC machine.

Intel machine is great, PPC machine plays back with no jittering but audio is half speed and through the left channel only. I will endeavour to solve this problem.

Conclusion:

Check out http://dougscripts.com/itunes/ and using the Apple Script Editor (installed by default at Applications/AppleScript/Script Editor) you can create scripts, use the built in documentation and get to grips with making iTunes do what you want, or indeed any other Apple application.


I have a few ideas I want to impliment into iTunes to add various functionalities so I had a look on http://developer.apple.com to see how to develop plugins for iTunes. I know it is possible as I have seen various different plugins a bout for a while now, for example Qloud.

What ever I searched for and what ever page I went to I could not find a relevant SDK or even any information on developing iTunes other than those listed on this page (http://developer.apple.com/sdk/), none of which are what I am looking for.

• iTunes COM for Windows SDK
• iTunes Visual Plug-ins SDK for Windows
• iTunes Visual Plug-ins SDK for Mac

So I sent Apple an email:

Where can I download the iTunes SDK or anything that will enable me to develop plugins for iTunes 4.7+ under OS X 10.4?

The only reference to iTunes I can find on http://developer.apple.com/sdk/ is https://connect.apple.com/cgi-bin/WebObjects/MemberSite.woa/wa/getSoftware?bundleID=19923

Surely there must be information available - why is it so hard to get to?

Awaiting your reply
Eltonone

From http://developer.apple.com/sdk/ there are no links to any pages that discuss iTunes development. Infact, navigating to http://developer.apple.com/mac/ (The Mac Development Centre) everything is about Leopard with nothing on previous Os’s. What happened to all the people using pre-10.5 Apple Operating Systems? Back date compatibility is essential and in the past has been important to Apple, what a shame iFad sales are now more so.

I found this (http://developer.apple.com/referencelibrary/GettingStarted/GS_AppleApplications/index.html) which pretty concisely dashes my hopes of developing anything for iTunes without frist fully understanding how iTunes was built and how it functions. Why no API? GRRRRRRR Apple.

Getting Started with Apple Applications

Technology Overview

Apple publishes a variety of applications for the Macintosh platform, many of which are distributed free with Macintosh computers.

If you are a plug-in developer, you can create a visual effect plug-in for either the Macintosh or the Windows version of iTunes, Apple’s music management software, that presents visual effects while music is playing. Plug-ins for iTunes are written in C.

If you are a content developer, you can create new widgets for Dashboard, an environment designed to keep useful information at your fingertips. Dashboard widgets are built using standard web technologies, like HTML, CSS, and JavaScript.

If you are a hardware developer, you can build XML printing preset files for iPhoto, Apple’s still photo management software, to enhance its compatibility with your printer. Preset files for iPhoto are written in XML.

If you are an application developer, your application can:

• Access the data in AddressBook, Apple’s centralized database for the user’s contact and other personal information
• Import and export projects to and from Final Cut Pro, Apple’s professional video editing software, using the Final Cut Pro XML Interchange Format
• Exchange documents with Keynote, Apple’s presentation software, using the Keynote XML File Format (APXL)

All I want is the information on the currently playing or most recently played song, including physical location. Last.FM can get this information; how is it doing it? iTunes writes the currently playing track to a file for history, so I can get that information.

I want to be able to control when I excecute my function, either by adding a button to iTunes (which seems impossible without a lot more learning) or maybe with a system wide keyboard shortcut.

Hmm, a work around is beginning to take shape…

Seems that AppleScript is what I need to use (check out some of the stuff you can do with it http://dougscripts.com/itunes/). It would have been useful to see some information at some point while searching http://developer.apple.com that made it clear what you can do and what you need to do it in terms of both creating new applications and adding additional functionality to existing ones under OS X. I’ve been aware of AppleScript for some time, I just didn’t realize that it was the best solution for what I want to do and some pointers on all this on the Apple site would have been a great help and made the learning process a great deal less illusive.