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View Full Version : AAC dropout issues on OSX server with Squeezebox



Michael Robinson
2004-01-03, 03:08
I have exactly the same problem with a Squeezebox, SlimServer 5.0.1 and Mac
OS 10.3.2.

After restarting the Mac, MP3 files play OK but AAC files donąt. The
Squeezebox skips through various songs but no music comes out.

On my system Slimserver is set to start when the system boots. If I then
manually stop and start Slimserver after restarting, AAC files then play
OK.

Going to the pre-release Slimserver (5.0.3) doesnąt improve things much *
AAC files do play but I get cut-offs every 5 seconds or so.

This may have something to do with interactions between the Slimserver and
LAME. I installed the Mike Solomon LAME package as I donąt understand the
installation instructions for iTunes-LAME.

I would try to see if the version of LAME made a difference except I donąt
know how to install iTunes-LAME or find out what version of LAME is being
used as I have already installed the Mike Solomons package.

Collecting debug information before and after manually stopping and starting
Slimserver shows the following. There is a łend of file or error on socket˛
then it skips to the next song.

2004-01-03 09:56:06 22004-01-03 09:56:06 00:04:20:05:04:d6: Switching to
mode play
2004-01-03 09:56:06 openSong on:
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/07%20Day%20One.m4a
2004-01-03 09:56:06 openSong: getting duration 334.50425, size 5352068, and
offset 0 for
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/07%20Day%20One.m4a
2004-01-03 09:56:06 checking formats for:
mov-aif-squeezebox-00:04:20:05:04:d6
2004-01-03 09:56:06 checking formats for:
mov-wav-squeezebox-00:04:20:05:04:d6
2004-01-03 09:56:06 checking formats for:
mov-mp3-squeezebox-00:04:20:05:04:d6
2004-01-03 09:56:06 openSong: this is an mov file:
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/07%20Day%20One.m4a
2004-01-03 09:56:06 file type: mov format: mp3
2004-01-03 09:56:06 command: $mov123$ $FILE$ | $lame$ --silent -b
$BITRATE$ -r $-x$ - -
2004-01-03 09:56:06 Using command for conversion:
"/Library/PreferencePanes/SlimServer.prefPane/Contents/server/bin/darwin/mov
123" "/Users/michaelrobinson/Music/iTunes/iTunes Music/Deadly Avenger/Deep
Red/07 Day One.m4a" | "/usr/local/bin/lame" --silent -b 320 -r - - & |
2004-01-03 09:56:06 Streaming with format: mp3
2004-01-03 09:56:06 New play mode: play
2004-01-03 09:56:07 00:04:20:05:04:d6: Current playmode: play
2004-01-03 09:56:07 realpos 0 calcuated from bytes received: 0 minus buffer
fullness: 0
2004-01-03 09:56:07 songTime: 0 = (0(realpos) / 13380170(size) *
334.50425(duration) * 1(rate)) + 0(time offset of started stream)
2004-01-03 09:56:07 Read to end of file or pipe
2004-01-03 09:56:07 end of file or error on socket, opening next song, (song
pos: 0(tell says: . -1), totalbytes: 13380170)
2004-01-03 09:56:07 opening next song...
2004-01-03 09:56:07 the next song is number 1, was 0
2004-01-03 09:56:07 checking formats for:
mov-aif-squeezebox-00:04:20:05:04:d6
2004-01-03 09:56:07 checking formats for:
mov-wav-squeezebox-00:04:20:05:04:d6
2004-01-03 09:56:07 checking formats for:
mov-mp3-squeezebox-00:04:20:05:04:d6
2004-01-03 09:56:07 openSong on:
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/01%20We%20Took%20Pelham.m4a

Simpserver stopped and started. AAC files now play ok. Successful debug
trace below.


2004-01-03 10:02:15 22004-01-03 10:02:15 00:04:20:05:04:d6: Switching to
mode play
2004-01-03 10:02:15 openSong on:
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/07%20Day%20One.m4a
2004-01-03 10:02:15 openSong: getting duration 334.50425, size 5352068, and
offset for
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/07%20Day%20One.m4a
2004-01-03 10:02:15 checking formats for:
mov-aif-squeezebox-00:04:20:05:04:d6
2004-01-03 10:02:15 checking formats for:
mov-wav-squeezebox-00:04:20:05:04:d6
2004-01-03 10:02:15 checking formats for:
mov-mp3-squeezebox-00:04:20:05:04:d6
2004-01-03 10:02:15 openSong: this is an mov file:
file://localhost/Users/michaelrobinson/Music/iTunes/iTunes%20Music/Deadly%20
Avenger/Deep%20Red/07%20Day%20One.m4a
2004-01-03 10:02:15 file type: mov format: mp3
2004-01-03 10:02:15 command: $mov123$ $FILE$ | $lame$ --silent -b
$BITRATE$ -r $-x$ - -
2004-01-03 10:02:15 Using command for conversion:
"/Library/PreferencePanes/SlimServer.prefPane/Contents/server/bin/darwin/mov
123" "/Users/michaelrobinson/Music/iTunes/iTunes Music/Deadly Avenger/Deep
Red/07 Day One.m4a" | "/usr/local/bin/lame" --silent -b 320 -r - - & |
2004-01-03 10:02:15 Streaming with format: mp3
2004-01-03 10:02:15 New play mode: play
2004-01-03 10:02:15 00:04:20:05:04:d6: Current playmode: play
2004-01-03 10:02:16 realpos 0 calcuated from bytes received: 0 minus buffer
fullness: 0
2004-01-03 10:02:16 songTime: 0 = (0(realpos) / 13380170(size) *
334.50425(duration) * 1(rate)) + 0(time offset of started stream)
2004-01-03 10:02:17 read a chunk of 8192 length
2004-01-03 10:02:17 metadata now: 0
2004-01-03 10:02:17 read a chunk of 8192 length
2004-01-03 10:02:17 metadata now: 0
2004-01-03 10:02:18 read a chunk of 8192 length




>
>
> I had the same problem as Tony. I recently received a SqueezeBox. I had no
> problems connecting it to my network and having it shake hands with SlimServer
> 5.01 on my Mac G4 (OS 10.3.2). I also had no problems seeing all my tunes and
> playlists in iTunes 4.2 on my SqueezeBox. However, when I go to play a tune,
> SqueezeBox appears to be getting ready to play it but after about a minute it
> ends up in "stopped mode" (without playing anything). I've tried changing
> and then changing back the directory location for my music files in iTunes
> preferences as the SlimDevices FAQ suggests in the troubleshooting area on its
> web page (regarding the closest problem to mine) but I have had no success. If
> I try playing all tunes in a playlist SqueezeBox appears to randomly scan
> through (not play) all titles in the playlist.
>
> I tried emailing SlimDevices support but my email got bounced because the
> email address given by SlimDevices for support was seen as a nonexistent mail
> server
> (The original message was received at Fri, 2 Jan 2004 21:29:31 -0500
> from pcp904700pcs.cnorth01.va.comcast.net [68.57.53.27]
>
> ----- The following addresses had permanent fatal errors -----
> <support (AT) slimdevices (DOT) co>
> (reason: 550 Host unknown)
>
> All my tunes are AAC. Regarding AAC, I was also dismayed at reading the
> instruction manual for the SqueezeBox indicating that AAC tunes may be played
> back with deteriorated sound and MP3 should be used. I need to get my problems
> corrected or I'll have to return it. Any suggestions for a fix out there?
>
>

Craig Brannan
2004-01-04, 09:39
In case anyone's interested - I've been able to reproduce problems
similar to those reported by others using slimserver 5.0x with AAC i.e.
transcoded data. I've included details of the testing and results below
in case anyone want's to verify or debunk the findings.

This isn't an exact emulation of what's been reported since I'm
starting with MP3's instead of AAC and I have a slim instead of a
squeeze so I couldn't transcode to a pcm based format. But I think the
testing indicates that there are some problems with lame transcoding
via slimserver in general - at least on OS X.

Testing was done with slimserver 5.03 Jan 2 build on a PMG4 dual 450
with 768 MB RAM with a fresh 10.3.2 install. Nothing else is running or
has even been installed on this system other than the OS, slimserver,
Lame, and my music files. Lame is 3.90 installed into /usr/local/bin.

Test 1: setup convert.conf to transcode MP3 data to MP3 at 96K CBR the
following lines in convert.conf accomplish this:

mp3 mp3 slimp3 *
$lame$ --silent --mp3input -b 96 $FILE$ -

RESULT - slimserver basically became braindead... wouldn't play any
audio - althought the display would show the song playing and the timer
would decrement through the song as if something was happening. Hitting
FF to skip to the next song would cause the display on the slim to flip
through a number of songs in the playlist - displaying the title of
each for a second or so then would settle on one - but again nothing
would play.

Test 2 - setup convert.conf back to the normal mp3 passthrough setting
i.e. don't invoke lame when client is a real Slim - but set
convert.conf to transcode streams played to software clients. The
following lines in convert.conf accomplish this:

mp3 mp3 http *
$lame$ --silent --mp3input -b 96 $FILE$ -

RESULT - the behavior on the slim was (almost) back to normal as
expected - AND a software stream to iTunes on a TiBook also played
fine!
I say playback on the slim almost was normal since I noted that the
stream to the slim would drop off each time I paused and restarted the
stream to iTunes. I had the slim display set to show the data buffer,
and i could watch the buffer drain over the few second after restarting
the iTunes stream. As soon as the buffer display showed no bars, the
sound on the slim would stutter a few times, then stop. after a few
second of silence the buffer would start to fill again and audio would
return. The buffer would stay full as long as I didn't pause and
restart the software stream.

Test 3 - so I thought from the above that maybe the problems might be
due to the processor load imposed by Lame. Maybe the slim server was
being starved for cpu time. To test this I changed convert.conf back to
it's original configuration - i.e. no Lame transcoding for any MP3
stream. I then activated lame from the command line to trancode a few
files with the same settings that had been used above. With Lame
happily transcoding seperately I setup the same http stream to iTunes,
and started playing songs on the Slim as well.

RESULT - There was NO degradation at all on the slimserver performance
with lame running seperately. Pausing/restarting the iTunes stream
didn't cause any buffer problems on the slim I could navigate to and
play any song in the library with the slim with no negative effect from
the cpu load imposed by Lame running separately.

CONCLUSIONS -
I know this isn't exactly scientific - but it looks to me like the root
of the problem is in channeling data from lame into the slimserver for
delivery to a player. I have no idea why it's so much worse with a real
Slim than with a software stream to iTunes, but clearly something is
different there and is causing most of the problems.

The buffer problems on the Slim as a result of the software player
restarting after a pause seem to indicate that the slim server is
giving the HTTP stream all of it's attention while the Slim device is
being starved for new data until the software player stream has
resumed.

The observation that a separate lame process can run without causing
any ill effects on the slimserver indicates (to me anyway) that this
isn't a cpu bottleneck.

Anyway - hope this helps someone.

Craig.



> I have exactly the same problem with a Squeezebox, SlimServer 5.0.1
> and Mac OS 10.3.2.
>
>
> I had the same problem as Tony. I recently received a SqueezeBox. I
> had no problems connecting it to my network and having it shake hands