The VideoLAN Forums

Hi all,

I'm using VLC to stream video over the internet. I can record to mpeg using the standard ivtv tools and then stream the resulting mpeg over - and it works beautifully. I just can't seem to do it directly from /dev/video0 - it gets to the part about 'main private debug: pre buffering' and then sits there forever. I have tried both 0.8.2 and the snapshot from 20050729 with the same results.

It works great when I do something like this:
..and then in another console a second or so later..
This is almost ideal except for creating a huge tv.mpg that I would have to erase and reset every once in a while, and being a little bit behind (however long it takes me to switch consoles and type the vlc command).

Below is the command that fails and the output - does anyon have any idea why it is stopping at the prebuffering message?
..and then it just sits there until I hit ^C repeatedly.

I am running this on Ubuntu with a 2.6 kernel and whatever the latest ivtv drivers were a week and a half ago. I compiled VLC and all of its required libraries except for zlib and libxml2 from sources. Capturing using the perl tools works fine. Streaming the captured mpegs works fine as shown above. The tuner frequency is the correct one for channel 1 used in the perl script. If I try to record a channel at a bad frequency, I can actually stream the snow live to myself without the buffering problem.

I've noticed that it says 0 for the framerate above - not sure why.

Anyone have any idea how to fix my problem? Any help will be very much appreciated as I have been hacking on this (well, and a few other problems I have already overcome) for days. Once I can get this part working, I can start the fun programming parts for my web interface.

Thanks in advance!

VLC isn't receiving any data from it's input. so the input settings you have specified don't do the trick. Reason unknown. You should try to get local playback running before doing things like streaming, transcoding etc. (1 step at a time approach)

VLC isn't receiving any data from it's input. so the input settings you have specified don't do the trick. Reason unknown. You should try to get local playback running before doing things like streaming, transcoding etc. (1 step at a time approach)

Sounds logical and that's certainly what it looks like is happening with the 0fps etc. At the moment though the box is several thousands of miles away and we are parted for a good year or so yet. I'll try messing around with libcaca or aalib a bit to see if I can get something useful over the console. I'm still not sure what to look for - in theory, the instructions here should work with the current versions right? I read a couple posts to the effect that there were problems with the pvr access module 0.8.1.

By the way, I'm not sure if it will help, but this is what happens when I try to tune to and stream a dead channel (97250/ch2 instead of 91250/ch1):
And then it just keeps going with the late and synchro warnings forever. When I load the mmsh stream in a local VLC, I get the snow, plus a little bar of video at the bottom - though not live video - it's about 2 seconds that plays a couple frames then goes back. At least it gets past the buffering part, though I'm still seeing 0fps in the output I guess.

Anyhow, thanks for the tip. I will certainly try to tweak the settings some more on a local output device without sout first. I'm also open to other suggestions if anyone can find a clue in either of the two outputs.

Thanks!

By the way, should I be worried about the warnings like this?:

[00000342] main decoder warning: cannot load module `/usr/local/lib/vlc/codec/liblibmpeg2_plugin.so' (libmpeg2.so.0: cannot open shared object file: No such file or directory)
...
[00000347] main private warning: cannot load module `/usr/local/lib/vlc/audio_filter/liba52tofloat32_plugin.so' (liba52-0.7.4.so: cannot open shared object file: No such file or directory)

They seem to still come up when I stream a regular mpeg file and seem to be harmless, I can stream the file over the network just fine. I don't want to spam the forums any more than I already have, so the output of playing a regular mpeg file successfully over the stream is located here: http://maetel.makenai.net/out3.txt. Thanks again!

Well these are errors from 2 decoder plugins of VLC. Basically you are unable to decode mpeg video and a52 (dolby) audio. But since you are streaming it, you don't decode, so it won't matter.

Well these are errors from 2 decoder plugins of VLC. Basically you are unable to decode mpeg video and a52 (dolby) audio. But since you are streaming it, you don't decode, so it won't matter.

I know I'm getting a little bit off of my own topic now but.. I've recompiled both libmpeg2 and a52 with --enable-shared. In the case of mpeg2, I'm no longer getting the error - however in the case of a52:

[00000323] main private warning: cannot load module `/usr/local/lib/vlc/audio_filter/liba52tofloat32_plugin.so' (liba52-0.7.4.so: cannot open shared object file: No such file or directory)

Why is it looking for liba52-0.7.4.so anyway? Shouldn't it just be liba52.so?

<EDIT> Making the link manuall fixed the error message. (sudo ln -s liba52.so.0.0.0 liba52-0.7.4.so liba52-0.7.4.so.0). I still wish I knew why it was looking for the one with the version in it.</EDIT>

Also, I am getting a skins2 error even though I am compiling with skins2 support specifically disabled:

[00000262] skins2 interface error: Cannot open display
[00000262] skins2 interface error: Cannot initialize OSFactory

Finally, I updated mpeg2 and libdvbpsi to the newest versions (were a little outdated last time). I am now trying to play directory to aalib with the same problem - an infinite delay at 'pre buffering'. Please feel free to thwack me hard in the head with a cluestick if you have one available for any of the issues above.

Thanks again!

Oops - I also meant to ask.. since I am transcoding the video on the fly prior to streaming, rather than streaming the input directly, don't I need to be able to decode?

well to transcode a video you first need to decode it. Else you won't have anything to encode ... which might be a problem.

well to transcode a video you first need to decode it. Else you won't have anything to encode ... which might be a problem.

Ok. I thought so - was just making sure as I might have misunderstood. At any rate - I've fixed those .so errors now, but still can't seem to play things from /dev/video0 yet. The only other suspicious looking thing I see now is this:

[00000283] main demuxer warning: no access_demux module matched "pvr"

Is this something that could be causing a problem? I think I've seen it in other peoples' dumps before who could stream video but were having other problems (with a 3 second delay or something), so I'm not sure.

it looks like you might need to compile VLC yourself with the pvr module (i don't know if its compiled in the default builds).

it looks like you might need to compile VLC yourself with the pvr module (i don't know if its compiled in the default builds).

I was compiling stuff for most of the day yesterday after I decided I couldn't rely on the default builds. I did make sure to include --enable-pvr.

To sort of answer my own question - it looks like that message isn't important as I am now able to stream from the PVR just fine.

As some nice guys on the #videolan irc channel pointed out to me, I was trying to access the wrong resolution to NTSC (copied line from the howto and forgot to adjust the resolution to NTSC).

This line buffers forever:
..this line works fine:
Thanks E-bola and Trax - also everyone here who helped!

If you are not getting past 'pre buffering', you might be setting the wrong resolutions!