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More => Old Versions => Media Center 15 (Development Ended) => Topic started by: HiFiTubes on August 23, 2010, 10:23:47 pm

Title: Library Server transcoding on server 1/2 works
Post by: HiFiTubes on August 23, 2010, 10:23:47 pm
So I'm hoping we can hear more about getting the server to "Always Convert" and have transcoding done on the fly on the server. Assuming not many people have tried this option?
Title: Re: Library Server transcoding on server 1/2 works
Post by: Qythyx on August 25, 2010, 09:29:56 pm
I do this and it works fine. Perhaps I don't understand your question.
Title: Re: Library Server transcoding on server 1/2 works
Post by: HiFiTubes on August 25, 2010, 10:31:06 pm
The default is Never Convert.

For any format, Always Convert, does not work for me.
Title: Re: Library Server transcoding on server 1/2 works
Post by: HiFiTubes on August 31, 2010, 02:19:14 pm
Can someone else test this? I've never been able to get this to work, and have tried for the last 20 builds.
Title: Re: Library Server transcoding on server 1/2 works
Post by: Matt on August 31, 2010, 02:21:55 pm
It's a known issue that converting to WAV doesn't work with a library server client.  It will be addressed in a future build.

However, we recommend not converting to WAV for a library server client.  The CPU usage and bandwidth needed to move the increased data will more than offset any savings in decoding.
Title: Re: Library Server transcoding on server 1/2 works
Post by: HiFiTubes on August 31, 2010, 02:30:51 pm
Thanks Matt.
Title: Re: Library Server transcoding on server 1/2 works
Post by: HiFiTubes on August 31, 2010, 11:29:13 pm
Quick question, when resampling on the client and using Never Convert>Uncompressed, the resampling is done on the client right?

Title: Re: Library Server transcoding on server 1/2 works
Post by: justsomeguy on September 01, 2010, 12:14:30 am
Unless I'm wrong you can't resample without decoding first if it's something like mp3.  So if you say Never Convert then I don't think it will resample.  Same thing with the volume leveling feature.  It has to be converted to do either, which is why I'm waiting for the uncompressed issue to be fixed.  Only way around the problem is to have it convert the lossy mp3 to wav then recompress back to mp3.  So you are losing audio quality.
Title: Re: Library Server transcoding on server 1/2 works
Post by: HiFiTubes on September 01, 2010, 04:55:17 am
Unless I'm wrong you can't resample without decoding first if it's something like mp3.  So if you say Never Convert then I don't think it will resample.  Same thing with the volume leveling feature.  It has to be converted to do either, which is why I'm waiting for the uncompressed issue to be fixed.  Only way around the problem is to have it convert the lossy mp3 to wav then recompress back to mp3.  So you are losing audio quality.

Why wouldn't the server simply send the FLAC or mp3 to the client, where it is then decoded and resampled? It seems like resampling is occurring in the client; just my feeling based on cpu usage if testing 192kHz.

I'm using a word clock so I have to pick one sample rate (unless I want to get up and manually change the clock every time), and I'd like to upsample to 96kHz any non-native 96kHz material.

Matt's earlier point implies about the increased bitrate was something I hadn't thought would make an impact; partially because I thought the server WAS decoding already.
Title: Re: Library Server transcoding on server 1/2 works
Post by: Matt on September 01, 2010, 09:55:38 am
The server sends a file.

The client reads, decodes, and does any DSP like resampling.

The server can optionally convert the file before sending, but conceptually this just means the server is sending a different file.  The client still reads, decodes, and does any DSP on the converted file.
Title: Re: Library Server transcoding on server 1/2 works
Post by: justsomeguy on September 01, 2010, 02:08:30 pm
I'm sorry, I miss read the question.  The dsp of the client can do the resamplin, however the client won't do any replaygain because that tag is not sent with the file.  There is an option server side however to do the resampling there, along with volume leveling.  Both of which require the mp3 to be decoded server side first then re-encoded by the server before sent.
Title: Re: Library Server transcoding on server 1/2 works
Post by: Matt on September 01, 2010, 02:13:58 pm
I'm sorry, I miss read the question.  The dsp of the client can do the resamplin, however the client won't do any replaygain because that tag is not sent with the file.  There is an option server side however to do the resampling there, along with volume leveling.  Both of which require the mp3 to be decoded server side first then re-encoded by the server before sent.

I think you know this, but for others, I want to make sure it is clear:

If you're connecting from a Media Center to a Library Server, the client fully supports Replay Gain.  There is no need to transcode.

If you're connecting from a DLNA device or using DLNA instead of Library Server, then transcoding by the server (which applies Replay Gain for DLNA) is needed for Replay Gain.
Title: Re: Library Server transcoding on server 1/2 works
Post by: justsomeguy on September 01, 2010, 02:22:53 pm
Well crap I feel dumb now.  I guess yet again I miss read the original question too.  The OP was asking about a library server not DLNA.  It was late when I replied the first time and got it stuck in my head I guess as to what I thought the question was.

I don't want to cause any confusion.  Thanks for clearing it up and correcting me.