TIme Shifting Radio without killing your iPod Battery
Listening to your favorite programs on your own
time is great, but if your programs are longer than 15 minutes, your battery
charge doesn't last very long. Here's how to get around that.
I like to listen to NPR programs (oops,
there goes half of my audience) like "Fresh Air", "This American Life" and "A
Prairie Home Companion." Unfortunately, I am not always available to listen to
these programs at the time they are broadcast. For years I have wanted a way to
time shift them, the way I time shift TV programs. Finally, technology is
available to do it. When I started recording the programs off the internet
radio streams, I discovered another problem. My 3rd generation iPod has only(!)
20 minutes or so of skip protection. This means that the whole track can't stay
in memory, so the hard disk has to run quite a lot, leading to a much reduced
battery charge. This article will tell how I get around that. (Sorry, the
code presented here only works for Mac). This stuff is only necessary for hard
disk based iPods. Shuffles and nanos have no problem with long tracks, since
everything is in flash memory
already.
There are many products which can capture internet radio streams. After trying a few, I settled on Audio Hijack. It does a good job of capturing the streams I want. But I am left with the problem of slicing them up. Now, there are stream capture apps that slice up captured streams, but those are oriented to grabbing music, not the kind of continuous programs I am interested in.
So, back to good old AppleScript. iTunes can be told to set the start and stop times of a track, and then to convert that track, creating a new track that is only from the start to the stop time:
There are many products which can capture internet radio streams. After trying a few, I settled on Audio Hijack. It does a good job of capturing the streams I want. But I am left with the problem of slicing them up. Now, there are stream capture apps that slice up captured streams, but those are oriented to grabbing music, not the kind of continuous programs I am interested in.
So, back to good old AppleScript. iTunes can be told to set the start and stop times of a track, and then to convert that track, creating a new track that is only from the start to the stop time:
tell
application
"iTunes"
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
set
newTrack
to
item 1
of
(convert
theTrack)
end
tell
OK, that's a good start, but hardly useful. It would require setting new start and stop times, and a lot of manual work. Let's set up a repeat loop to slice a whole track up into 15 minute segments.
OK, that's a good start, but hardly useful. It would require setting new start and stop times, and a lot of manual work. Let's set up a repeat loop to slice a whole track up into 15 minute segments.
tell
application
"iTunes"
set
trackDuration
to
the
duration
of
theTrack
set
theStart
to
0
set
theFinish
to
15 * minutes
repeat
while
theFinish
< trackDuration
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
with
timeout
of
1200 seconds
set
newTrack
to
item 1
of
(convert
theTrack)
end
timeout
set
theStart
to
theFinish
set
theFinish
to
theFinish
+ 15 * minutes
if
theFinish
>
trackDuration
then
set
theFinish
to
trackDuration
end
if
end
repeat
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
with
timeout
of
1200 seconds
set
newTrack
to
item 1
of
(convert
theTrack)
end
timeout
end
tell
Now we're cooking. The timeout statements make sure that the script doesn't timeout while the conversion is going on (AppleScript has a default timeout which is shorter than most conversions). But we don't have a way to specify the track. Well, how about converting the current selection in iTunes? And as long as we're doing that, how about we make it possible to select a group of tracks to convert all at once?
tell
application
"iTunes"
set
selectedTracks
to
selection
repeat
with
theTrack
in
selectedTracks
set
trackDuration
to
the
duration
of
theTrack
set
theStart
to
0
set
theFinish
to
15 * minutes
repeat
while
theFinish
< trackDuration
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
with
timeout
of
1200 seconds
set
newTrack
to
item 1
of
(convert
theTrack)
end
timeout
set
theStart
to
theFinish
set
theFinish
to
theFinish
+ 15 * minutes
if
theFinish
>
trackDuration
then
set
theFinish
to
trackDuration
end
if
end
repeat
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
with
timeout
of
1200 seconds
set
newTrack
to
item 1
of
(convert
theTrack)
end
timeout
end
repeat
end
tell
Well, that cuts down a lot of the work. But now we're stuck renaming all of the new tracks, and we will probably want to put them into a playlist. As the Perl camel book says, laziness is one of the hallmarks of a good programmer. So back to the code.
tell
application
"iTunes"
set
selectedTracks
to
selection
repeat
with
theTrack
in
selectedTracks
set
trackName
to
name
of
theTrack
set
theDatePos
to
offset
of "20"
in
trackName
set
showName
to
text 1
thru
(theDatePos
- 2)
of
trackName
set
playListName
to
"`" &
showName
& "'"
set
theList
to
playlist
playListName
set
trackDuration
to
the
duration
of
theTrack
set
theStart
to
0
set
theFinish
to
15 * minutes
set
theIndex
to
1
repeat
while
theFinish
< trackDuration
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
with
timeout
of
1200 seconds
set
newTrack
to
item 1
of
(convert
theTrack)
end
timeout
set
newName
to
the
name
of
theTrack
& " " & theIndex
set
name
of
newTrack
to
newName
add
(get
location
of
newTrack)
to
theList
set
theStart
to
theFinish
set
theFinish
to
theFinish
+ 15 * minutes
if
theFinish
>
trackDuration
then
set
theFinish
to
trackDuration
end
if
set
theIndex
to
theIndex +
1
end
repeat
set
start
of
theTrack
to
theStart
set
finish
of
theTrack
to
theFinish
with
timeout
of
1200 seconds
set
newTrack
to
item 1
of
(convert
theTrack)
end
timeout
set
newName
to
the
name
of
theTrack
& " " & theIndex
set
name
of
newTrack
to
newName
add
(get
location
of
newTrack)
to
theList
end
repeat
end
tell
So, what's going on here? Audio Hijack leaves me with tracks that are named like this: "Fresh Air 20051124 1259". So I have created playlists like this: `Fresh Air'. The backtick (`) sorts to the top of an ASXII sorted list, putting these playlists at the top of my iPod list. The first part of the repeat gets the playlist name for the given track. Each sliced track is renamed with an appended index, and then added to that playlist.
One tricky point. Contrary to what the iTunes APpleScript dictionary says, convert does not return a track. it returns the track in a list. Thus, to get the track, you need to ask for the first item of the list.
Well, that does it. Just copy that last script into a new script editor doc, and save it into your Scripts folder. Make the appropriate playlist(s) in iTunes, Select the tracks you want to slice, and choose your script. You will get sliced up shows, named and put into playlists.
One final thing. It occurred to me while I was preparing this entry that perhaps a track converted to an audiobook wouldn't have the battery problem. I can't find anything that ways one way of the other. If you have information about that, put it into the comments.
So, what's going on here? Audio Hijack leaves me with tracks that are named like this: "Fresh Air 20051124 1259". So I have created playlists like this: `Fresh Air'. The backtick (`) sorts to the top of an ASXII sorted list, putting these playlists at the top of my iPod list. The first part of the repeat gets the playlist name for the given track. Each sliced track is renamed with an appended index, and then added to that playlist.
One tricky point. Contrary to what the iTunes APpleScript dictionary says, convert does not return a track. it returns the track in a list. Thus, to get the track, you need to ask for the first item of the list.
Well, that does it. Just copy that last script into a new script editor doc, and save it into your Scripts folder. Make the appropriate playlist(s) in iTunes, Select the tracks you want to slice, and choose your script. You will get sliced up shows, named and put into playlists.
One final thing. It occurred to me while I was preparing this entry that perhaps a track converted to an audiobook wouldn't have the battery problem. I can't find anything that ways one way of the other. If you have information about that, put it into the comments.
Posted: Thu - November 24, 2005 at 11:58 AM
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Published On: Jun 10, 2006 05:40 PM
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Published On: Jun 10, 2006 05:40 PM