Streaming an incoming MMS stream to the Intranet

[Brahman]

Hi,

when I try to stream an MMS stream, which comes to our intranet through the outside DSL Internet connection to about 40 internal users via the multicast protocol using the streaming wizard, I was not able to get any sound on my first trial.

Then I used these settings:
:sout=#transcode{acodec=mp3,ab=32,channels=1}:duplicate{dst=std{access=udp,mux=ts,dst=239.255.255.255:1234,sap,group="MOU"}}

and got video to be artifact free but now the audio quality is really bad.

The original stream is encoded in wma2 44khz 32kb/s, mono (A/V) 1-pass CBR 16 bits per sample Windows Media Audio 9, video is WMV3, Windows Media Video 9 Res.384x288.

What can I do to improve the audio?

Thank you for your help.

Kind Regards.

Brahman

[Arite]

Well the original audio is already highly compressed - 32kbps WMA. Recompressing into 32kbps MP3 (a very low setting for MP3) will make it a lot worse.

Lossy to lossy transcoding should be avoided if possible, so to retain the full quality you would either want to just duplicate the original stream (so WMA2 - would probably need to use the ASF container for that), or use uncompressed audio or a lossless codec. However, since that is fairly unecessary for audio that is already compressed so much - I would recommend a high MP3 bitrate, such as 192kbps or higher which is considered the point of perceptual transparency by most (where the differences in the lossy version cannot be heard from the original). However, try 64kbps, 128kbps etc. too).

So, for example, you could try this instead (only difference is bitrate):

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:sout=#transcode{acodec=mp3,ab=192,channels=1}:duplicate{dst=std{access=udp,mux=ts,dst=239.255.255.255:1234,sap,group="MOU"}}

Cheers, Arite.

[Brahman]

Thank you very much for your kind help and quick reply.

192 kps will make for a big bandwidth, which as a charitable organization we are always low on (as well as on funds )

How do I multicast into an ASF container? I wanted to duplicate the stream, but was not able to do that. Only the MPEG Transport Stream option was given as an option by VLC for UDP Multicast protocol.

Can I override that somehow?

Thanks for your help.

Oh, one more question: When the user saves the streamed file locally, what extension would he/she give to the file, so that other players won't complain?

Kind Regards,

Brahman

[Arite]

I think it is only possible to stream using MPEG-TS using the UDP protocol. However, that does not mean WMV3/WMA2 won't playback when sent using TS.

You could try not transcoding any of it (may work?) - just send out the same video and audio without transcoding, for example:

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:sout=#duplicate{dst=std{access=udp,mux=ts,dst=239.255.255.255:1234,sap,group="MOU"}}

Then the clients should be able to play the stream locally, or could stream the UDP stream to a file (and select the ASF container). This file should be playable in VLC (may or may not be playable in others though). If ASF is selected, then use the *.asf file extension.

Arite.

[Brahman]

Hi Arite,

thanks again for your help.

That is really what I wanted to do, stream without transcoding.

I followed your suggestion, but again, the result was that the clients had no audio, the video was great though.

VLC showed in the receiving clients media info only a WMV3 stream, but no audio at all and no audio decoding activity at the client.

Somewhere else in this forum I have read, that the plain vanilla builds of VLC 0.86c do not support wma for streaming. Where could I obtain a stable build that would support streaming wma so that this problem could be solved for me?

What is the best extension to save the file too with my old transcode to mp3, duplicate video and MPEG TS way?

I will also try to run the VLC server as an NT service for improved stability (right now it crashes, if the Internet is for some reason not available or the connection is not good, may also have to do with our 6 year old Netgear RP114 router). Can I just add -I ntservice --ntservice-install --ntservice-extraintf=http to my command line or do I need to do it first in a separate step?

Thanks for your continuing support.

Kind Regards,

Brahman

[Arite]

OK, yes - didn't realise WMA2 wouldn't stream via UDP.

I tried the lastest nightly build (0.9.0-svn - from here) however was unable to stream WMA2 well.

You could try, for example, just using 64kbps or 128kbps MP3 audio. Also, if those don't sound very good then try MP4A and then MP2A instead (at same/similar bitrates).

As for the container to stream to, ASF is the only container where a WMV3 video would fit properly, so try that.

I just tested it (using only 0.8.6c) with a video (WMV3 video and WMA2 audio), and it worked when I streamed with the audio transcoded to 128kbps MP3 via UDP (video just duplicated), then streamed (using a second instance of VLC) from the UDP network stream to a file (with no transcoding), encapsulating as an ASF (file with *.asf extension). It played in both VLC and Windows Media Player without a problem.

This method, however, did not work with MP2A or MP4A (just MP3).

Cheers, Arite.

[Brahman]

Hi Arite,

thank you very much for testing this setup for me.

It is working well here too. You are my hero!

Some users complained that the recording ASF file is now larger than when they were directly recording the (now multicast) MMS stream (and bringing our internet connection to a crawl). Therefore I cut down the MP3 bitrate to 96 and audio still seems to be OK.

However I am having difficulties now with the stability of the multicast which should run at leat 14 hours a day and I do not always want to babysit it :

For unexplained reasons the multicast sometimes just stops. The VLC server still shows to be connected, but nothing comes in nor goes out. I have to stop VLC and restart it to reconnect. I assume, that short network or stream outages cause this. Is there any way VLC can automatically reconnect and recover when that happens?

For that reason I was thinking to get the VLC server running as an NT service for improved stability -- before it was also crashing, if the Internet was for some reason not available or the connection was not good. It may have had to do with our 6 year old Netgear RP114 router, but now it seems to be better after I activated IPv2 instead of IPv1 on the router.

Can I just add -I ntservice --ntservice-install --ntservice-extraintf=http to my command line or do I need to do start VLC as a server with these parameters first and then call it again with the multicast instructions?

Kind Regards,

Brahman

[Arite]

I don't think ntservice can be added when the stream is created, since it is an interface you need to start it in it.

You could just use the complete commandline when you start VLC, e.g.:

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vlc -I ntservice --ntservice-install --ntservice-extraintf=http input_file :sout=#transcode{acodec=mp3,ab=96,channels=2}:duplicate{dst=std{access=udp,mux=ts,dst=239.255.255.255:1234,sap,group="MOU"}}

Where input_file is the url of the mms:// stream.

However, ntservice did not seem to work for me. This did, however:

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vlc input_file :sout=#transcode{acodec=mp3,ab=96,channels=2}:duplicate{dst=std{access=udp,mux=ts,dst=239.255.255.255:1234,sap,group="MOU"}}

But that is just a way starting the stream from startup.

Arite.

[Brahman]

Hi Arite,

so I tried the NT service and I can start the service.

But the rest of the command line after http (the mms stream and :sout commands) are not taken.

So I went to the http interface with my browser and there I only found a "stream output" module where I was able to enter the udp numbers. There was no mention if multicast is suported here, but I assume it is.

But I could not find a way to enter the mms stream name which I want to multicast ? Do you have any idea??? In fact I could not find any way to input anything to be streamed??? Very odd. Am I missing something obvious here?

It would be nice to have the NTService thing working in the background, because the machine is used by other people for work and I don't want them to interrupt the streaming.

Kind Regards,

Brahman

[Arite]

I was unable to get the http interface with ntservice running (if it actually was running - did you use "vlc -I ntservice --ntservice-install --ntservice-e
xtraintf=http" since that doesn't seem to work for me?).

However, I managed to stream via UDP using the http interface (enabled using "vlc -I http"). Try the MRL string:

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input_file :sout=#transcode{acodec=mp3,ab=96,channels=2}:duplicate{dst=std{access=udp,mux=ts,dst=239.255.255.255:1234,sap,group="MOU"}}

And press "Play" in the web interface.

Cheers, Arite.