Serviio

My QNAP NAS has an optional Serviio armv5tel package that I use. With that, ffmpeg comes pre-compiled and works great! However, it has been suggested that compiling a fixed-point ffmpeg would greatly improve the performance of e.g live streaming.

For live HD streaming, with transcoding turned off in serviio-console, my processor serves ffmpeg with around 30-40% of CPU time. Is this normal or could I expect better performance with a re-compiled fix-point ffmpeg? I find that the streams all start lagging as soon as the NAS processes something in parallel.

NAS hardware specs:


I'm on a hardwire TP between my Samsung (D-series) TV and my NAS. And my connection to the internet is 100/10 Mbit. I never go above 4 Mbit for streaming according to my NAS logging.

I'd ask on FFmpeg mailing list or IRC channel

Actually, what I meant (I understand that now ) is; how do I specify ac3_fixed as audio codec? I understand that you haven't implemented that option as of yet. But is there some option to allow changing targetACodec="ac3" to targetACodec="ac3_fixed" without Serviio complaining over which codecs that are available to choose from?

I.e is there some file that holds the available codecs that I can edit?

I think it is in the source code. However, you can always write an ffmpeg wrapper than replaces references to ac3 with ac3_fixed before passing the commandline args to the real ffmpeg. To do this, set the -Dffmpeg.location property in your serviio.sh to point to a bash script that uses something like sed to make the change and then call ffmpeg. Also make sure you capture the return code from ffmpeg and pass it back to serviio.

Here is the one I use to get you started, it adds an extra param, rather than replacing one, but it should give you an idea, If you need help adapting it then post back and I'll do it for you, but I'll assume you can use sed and work out the correct options on your own. Once it is done and working, it would be nice if you could put together a short guide which can then be put on the wiki for future users.

Thanks!

Here's my code.



Haven't gotten it to work properly. The streams are indexed and shows up on the tv. But nothing will play.

Does it work on normal video files? What happens when you run the ffmpeg commands on their own.

As for your script, I would recomend looking for "-acodec ac3", as ac3 on its own might turn up in things like authentication tokens for some online sources.

Normal files work. But they don't seem to call on ffmpeg (since I disabled transcoding I presume).

As a test, I have the following code.


What's weird is that I manage to get some streams working. But far from all.

works, but since it's -vcodec mpeg2video is struggles at 99 % and lags behind.

does not, and it usually always work.

I get errors when I test the rtmp stream directly on my Mac. How can I test a rtmp stream with ffmpeg properly?
[NULL @ 0x7ff5c9115800] Unable to find a suitable output format for 'pageUrl=http://www.tvsector.com/'

I reverted back to the default call on ffmpeg directly and I'm still having issues. So something I did is still hanging in there.

This is a successful play of BBC News


This is an unsuccessful play of Comedy Central HD

Ok, I seem to have found the issue. On my Mac, I have ffmpeg 0.7.11 and thus I can't debug properly as I can't get it to play nicely with rtmp streams. On my NAS, it only works if I enclose the stream parameters with quotes " ". E.g:


Why isn't this done by default? Can I force it somehow? Feels like a workaround if I start messing with sed to do it.

EDIT: Here's my fix.


There's one issue though. Calling on ffmpeg through the terminal totally works. Calling on it via the script only yields


Calling ffmpeg directly (with parsed output) works.


EDIT 2: Ok, fixed it. It was all in the script. A simple 'eval' prevented it from inserting ' ' around my parsed " ".


ac3_fixed definately improves performance. I'm down from 30 % to a mere 15 % decoding HD streams.

Sorry I missed your post, you seam to have got it working on your own. As for the "" around the -i param, they aren't present in the log, but do get based to ffmpeg by serviio, so if you run your script with the "" in the correct place, you shouldn't need to add them. It might be worth having a little more of a play with the script, because some urls won't end in live=1, so if you are dependent on adding the " back in, it will break in those cases. Anyway, you got it working, and nice to see it has a performance improvement.

No worries. I have been refactoring my script to be more generic.



By extracting argument by argument, I can extract the URL in one piece. The complexity of the script is from accounting for arguments before -i. E.g "-ss 120" which sometimes happen to come before -i 'URL'.

The ac3_fixed definitely lowers CPU usage. I'm suffering from stream lag on and off though. Don't believe it's from my script, but something else.

Ticket exists for this as well https://bitbucket.org/xnejp03/serviio/i ... r-encoding

I saw this before I began working on my script. In the meantime, my script works as a workaround.

Fixed the faulty HD streams too. Apparently <Matches container="flv" vCodec="h264" /> was missing under online transcoding. Not sure if I saw any real difference in the ffmpeg calls though. Shouldn't they differ?

Anyways, my Serviio package (.qpkg for Qnap NAS) came with an outdated profile.xml it seems. I downloaded the Linux gzip from the website and copied the proper profile.xml and it did the trick. No fuzz no nothing. Just works

Good find. This will be useful for the Synology NAS Serviio package for ARM systems.

Some info about the encoder (apparently there is a quality trade-off):
http://libav.org/ffmpeg.html#ac3-and-ac3_005ffixed

From what I remember reading on some page explaining about ARM compilers, a decent soft-float implementation at compile time isn't actually as bad as you might expect - though I guess it's mainly provided to allow compatibility for software that expects an FPU. Hmm, according to this:
http://www.avrfreaks.net/index.php?name ... 98&start=0
not many of these codecs even technically need to use floating-point maths.

For completeness - here's a link to an earlier thread about this topic, with some more info:
viewtopic.php?f=7&t=5596

I have updated the Serviio package for Synology NAS with ARM CPU to use this ac3_fixed encoder.

I found that the script won't work properly unless the filename is surrounded by escaped double quotes. Using single quotes (as in cshomq's example script) will cause the wrapper script to fail when the file or folder name contains a single quote (apostrophe).

added the switch for 1.0

Awesome, thanks for that. Are there any other fixed-point encoders in FFmpeg apart from the ac3 one at the moment?

I see there's also a system property for defining the plugins folder. This will be useful on Synology NAS since the normal appstore folders are not browsable unless by SSH session, which makes adding plugins tricky for non power users.

Tested out the -Dserviio.fixedPointEncoders and it's working like a charm!



As you can see, the audio decoder is set to ac3_fixed. For most of my internet resources, the CPU load went down from 100% to around 15%. A dramatic effect!

To answer your question, I have found:

• Fixed point DTS encoder
• Fixed point MP2 decoder
• fixed point MP3 decoder
• Fixed point WMA decoder
• Fixed point Cook decoder