Subsonic Forum

by **hgelpke** » Fri May 20, 2011 12:03 am

I run Subsonic on an MSI Wind Desktop 1.6ghz atom processor and 2gb of RAM running Windows 7.

I'm connecting over Sprint 3g and I'm trying to get smaller file sizes for better streaming. I'm not sure if I'm hitting a bottleneck in the streaming or the transcoding.

I'm on a 20mbps down/1mbps up line.

Any help would be appreciated.

by **GJ51** » Fri May 20, 2011 3:09 am

1mbps up isn't the strongest up speed, but it should be ebough for music. Transcoding on an atom isn't the ideal either, but I haven't yet heard anyone complain about transcoding music, just video.

I usually try to isolate the cause of the problem by isolating each factor and changing each variable until I can tell where the bottleneck is. Take one track and fromat it into the different formats you're testing to see how it affects performance.

You also mention connecting over Sprint 3g. That can be an issue in and of itself as connection speeds on 3g are extremely variable and unreliable - especially Sprint - I know, I have Sprint and the 3g speeds have been terrible lately.

Do you see the same problems when you connect within the lan, wifi, or on another computer over a good internet connection? If so, then it's your 3g speed that's killing you. I'd look there first.

by **hgelpke** » Fri May 20, 2011 11:51 pm

As somebody with Sprint, what settings are you using as far as transcoding goes?

by **GJ51** » Sat May 21, 2011 12:05 am

ffmpeg -i %s -v 0 -f wav -
lame -b %b --tt %t --ta %a --tl %l -S --resample 44.1 - -

If you go to my site I have a couple albums that I formatted to 64kbps ogg for testing. Feel free to give them a test run. Site is listed at the bottom.

by **hgelpke** » Sat May 21, 2011 12:08 am

I'll give it a shot. Are you transcoding to 64kbps files for your own personal setup?

by **hgelpke** » Sat May 21, 2011 12:18 am

Sorry about the multiple posts.

Is the first line for the downsample command and the second line the transcoding command?

by **GJ51** » Sat May 21, 2011 12:32 am

Settings/Transcoding

Step 1: ffmpeg -i %s -v 0 -f wav -

Step 2: lame -b %b --tt %t --ta %a --tl %l -S --resample 44.1 - -

I just did some testing with ogg a while back for some others that were having issues. The OGG Music on my site is 64kbps ogg being transcoded to mp3.

I don't really need to go this route with my gear, but it would be helpful to anyone who has metered bandwidth. It is surprising how nice the sound quality is from the 64kbps ogg.

Downsample command: lame -S -h --resample 44.1 -b %b --tt %t --ta %a --tl %l %s -

by **hgelpke** » Sat May 21, 2011 12:36 am

Can I use these settings to transcode from mp3 to ogg?

Right now my setup is:

Step 1: ffmpeg -loglevel error -v 0 -i %s -f ogg -vn -acodec libvorbis -ar 44100 -ab 64k -ac 2 -map_meta_data 0:0 -

No step 2.

by **GJ51** » Sat May 21, 2011 12:42 am

Don't know, never tried it.

http://www.longtailvideo.com/support/jw ... io-formats

by **hgelpke** » Sat May 21, 2011 12:55 am

What transcoding are you doing then? Are you transcoding from wav to mp3?

by **GJ51** » Sat May 21, 2011 12:59 am

I am transcoding 64kbps ogg to mp3.

I'm not sure, but I think you'd need to upgrade to the latest JW version to go the other way. I've never gotten an ogg to play directly to JW 5.4.1492 which is the current ver installed with SS 4.4. I've done manual updates of JW before, but it's a pain.

by **yourlord** » Mon May 23, 2011 10:36 pm

I'll agree that the quality of ogg vorbis at low bitrates will shock you when you hear it.

I have my subsonic server set up to transcode my library (largely FLAC) to q2 vorbis (~96Kbps) when listening on android, and when using external players such as VLC. That's a very low bitrate for streaming, and can be a challenge to ABX it with the original. You can do it, but I've found it a challenge to do so consistently, and I can usually ABX lame at 160Kbps easier than I've found vorbis at q2.

Even my old mid to high bitrate mp3's are decent when transcoded to q2 vorbis, though the artifacting is a little more pronounced there.

I serve my streams from an ADSL connection with 512Kbps upstream, traffic shaped to limit any one connection from exceeding 420Kbps. There is never a bandwidth problem with streaming from my server, even when I'm serving 2-3 clients.

My subsonic server is a P4 2.2GHz with 512MB of RAM and has no trouble with transcoding multiple streams at once.

The FLAC to OGG transcode command I use is:
oggenc -q2 -o - %s

It's a single stage conversion since oggenc can natively read FLAC. No need to pass the metadata on the command line because oggenc will get it from the FLAC file. Each transcode process averages about 10-15% cpu.

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System requirements for transcoding to 64kbps OGG?

System requirements for transcoding to 64kbps OGG?

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