Debian Multimedia :: VLC Stream Capture Audio Out Of Sync
Oct 20, 2015
So I got myself a USB capture card (EasyCap) to use for capturing gaming, digitizing my kids' old VHS movies, etc. It works fine, I've been using VLC to view and record stuff from it, but I've noticed one issue. When recording streams via VLC, even with no other programs running to give VLC as much CPU time as it wants, the audio slowly falls out of sync. I've tried the MP4 (H264/MP3) container and the OGG (Vorbis/Theora) container.
Early on you can't hardly tell, but the further into a movie you get the more out of sync the audio gets, so that by the end of the movie the audio is a good 1-2 seconds off. It's not a set amount either so I can't just split the audio to a separate file then shift it one direction or the other to make up for the difference, because like I said, the offset starts out at nothing and gets progressively larger as the movie goes on. When I select "display locally", the video/audio that is displayed stays in sync, only the video/audio that gets committed to the output file falls out of sync, and it doesn't matter if I play the file with Totem or VLC.
I am fed up of listening to my (Windows XP) gaming computer through headphones so I want to get it hooked to the stereo.
Rather than use a heck of a lot of wire, I can sit my Ubuntu 9.10 netbook on top of the stereo and stream the audio across WiFi.
So, ideally what I am after is something to capture the outgoing audio on the Windows computer, stream it across the wifi to the Ubuntu netbook and finally play it through the speakers.
This plays fine in VLC, and there's a "Record" button there but I'm never prompted to save the recording anywhere. I wandered through preferences but didn't see any default capture directory fields.Where/how do I capture the stream for playback later? The docs that I've stumbled across so far are pretty outdated (but I'm still googling).
im creatind dvd's from others hd movies and ive seen theres an option to adjust framerate in audio, but ive never using that and i dont see the difference, when i play the video i see audio is syncronized with the video.for example, for a movie with 23,97 fps i converted to PAL (25fps) and i dont do anything to the audio, and it plays sicnronized then ¿Its neccesary to sync audio, and how its done with ffmpeg?
i do somethin like this: ffmpeg -i source.mkv -target pal-dvd -acodec copy mydvd.mpg (is audio fps syncronized because of the target?)if i dont use target, should is use sb like this?.: ffmpeg - i source.mkv -r 25 -vcodec mpeg2video -acodec ac3 -r 25 output.mpg
I try to record video with my Win TV capture card with avconv. The exact same lines worked fine with Ubuntu 12 and with SUSE, but with Ubuntu 14, the audio is out of sync.
I have a problem with avconv. Most of the use cases work spledidly, but when I need to crop a segment and then splice multiple segments together, I get problems.
The process I use is this:
1. Raw recording of short segments in high-quality AVI, These are produced by avconv, some as screencast and some by combining a PNG file with flac audio from audacity.
3. Splicing of the segments using MP4Box or oggCat. (I used to do this in ffmpeg, but I have not figured out how to do it in avconv.) This works.
In some cases I need to crop the segments, using the copy codecs and the -ss and/or =t options.
If I crop the AVI segments (between 1 and 2) the sound is clipping (this also generates a spree of error messages `Non-monotonous DTS'). If I crop mp4/ogv segments, (between 2 and 3) the remaining video, after the cropped segment are out of sync. I get the same problems with both OGV and MP4 playing them in vlc. Playing the mp4 directly in iceweasel works as it should.
Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps, the parameter is the maximum samples per second by which the audio is changed. -async 1 is a special case where only the start of the audio stream is corrected without any later correction.Searching the net makes one believe that this command is just some sort of magic.People just put it in the line and it just works. Isn't that nice?
It says nothing about how to change the TIME the audio starts syncing. Like do I want it to start 5 seconds delayed? Or what about 5 seconds sooner?What if the audio gets more out of sync as the video goes on? Can I slip it a little at a time? What? No magic?No one mentions a file that already has badly synced audio.So what -async 1 really does is simply start the audio at the beginning of the file. LIKE AS IF THAT ISN'T STANDARD PROCEDURE?So what is the exact solution to syncing a messed up video? And why can't it just do the proper "timestamp" sync in the first place?No docs, no info and you are left out in the cold.
SOUND from analog Capture is out of sync in Pinnacle Studio 14.
[code]...
This problem can occur during capture from an analog capture card if CPU utilization exceeds 95 percent. To avoid this problem, configure virtual memory to be "System managed" by following these steps:
1. Choose Start -> Control Panel. 2. Open the System control panel. 3. Click the Advanced tab. 4. Click the Advanced tab. 5. In the Virtual memory box, click Change. 6. Select System managed size, and click Set. 7. Click OK.
I've used VLC for years, in both windows and linux. In windows streaming, you can select "NONE" for a Video Input, and just stream audio. This is not the case for Ubuntu's version.What can I do to stream just audio in VLC?
I need to capture from my webcam. It has a mic too.I can specify video input device as /dev/video0.I specified input audio device as /dev/dsp2 ( OSS device, corresponding to USB Webcam), Now VLC throws an error, "VLC is unable to open the MRL 'alsa:///dev/dsp2'. Check the log for details".Thinking it wants an alsa device, I specify device as /dev/snd/pcmC2D0c. (got it from kinfocenter and dolphin). Now again an error, "VLC is unable to open the MRL 'alsa:///dev/snd/pcmC2D0c'. Check the log for details.".I try with any device, the same error. I have added myself to audio device so that I can read/write to the mentioned devices.I see no way of switching VLC to use OSS. And I see no information (documentation on net) on it's expected device listing for audio.
I recently installed openSUSE 11.4-64bit on my Gateway desktop, and I can't seem to get my mic work at all. The mic is built into my Microsoft LifeCam Cinema webcam and works fine when I boot into Windows. The mic will not record sound in krecord or lame and doesn't work during Skype sessions.
According to the literature for the device driver my the mic should be supported, and that is evidenced by the fact that the mic shows up as a capture device in in kmix. I have made this mic the master channel under capture devices and I have given it highest preference amongst my capture devices in both the Communications and Accessibility categories of kmix's Settings/Audio Setup.
There was a very similar case solved in January:
How I got my Sound Input working
I've done my best to implement these fixes, but half of it looks like gibberish to me. All I was really able to do was update my alsa software and generate this comprehensive alsa.conf (its long, so I'll wait to post it until asked).
I've had since updating to 11.4, and I gotta say: I've been really impressed so far.
I have two networked Ubuntu 10.40 machines and I am trying to stream audio from one machine to the other. I find on the surface everything works - I simply installed padevchooser and set the pulseaudio sink to the other machine. Now here comes the problem - whenever I do anything else involving network activity the sound crackles and hangs and it becomes hopeless. I've seen people elsewhere online complaining about crackling in relation to CPU usage but I can't find anyone talking about network usage.
In particular I often work on my office computers over VNC. I try to fire up VNC and it starts to load the remote desktop and the sound completely fails. I assume this is some kind of latency issue? Another good example is trying to watch a video on ..... - the sound plays at first but then as the video is being downloading in the background the stream starts to mess up. Listening to an mp3 in totem with no other network activity works fine.
I have an old computer that I have put Ubuntu on. I would like to connect it to my stereo and stream audio to it from my laptop, so that it plays through the stereo.
I'm hoping to find some software to put onto this old computer to make it work similarly to an airport express. Anyone know of any software like this?
I'm trying to capture my desktop screen and audio , before I used xvidcap but after upgrading my system I can not use it and also recordmydesktop anymore these APPs hanged when I try to use them.Now I try to use recorditnow via ffmpeg recorder interface , it work properly in recording the desktop but it does not record the sound , so I tried to add below options to its command -f alsa -ac 2 -i hw:0,0 but it just record sound at the beginning and just for 1 second. Also when I try to capture my desktop with ffmpeg directly from command line with below command I face with same problem!!! ffmpeg -f x11grab -s 1024X768 -r 30 -i :0.0 -f alsa -ac 2 -i hw:0,0 ~/out.mpg
I want to record some streaming internet radio talk shows and music performances on NPR, and I'm wondering what my options are in Ubuntu. I'm looking for something that can output high quality lossless files in several formats, hopefully including mp3 and ogg.
I'm looking for configuring a Ubuntu box, we need to capture alsa output into ffmpeg with jack or OSS but not pulseaudio, as that tends to glitch badly. We have things working, but we are sort of hacking around in the dark, we play music, but as we aren't linux audio experts ourselves.
my problem is regarding .asx live streams. Up till 2-3 weeks ago I was able to listen to [URL] perfectly well with Totem under Ubuntu 9.10.
Since then whenever I want to start the stream, Totem darkens and nothing happens. I've tried Mplayer and VLC as well but neither of them work (but that's not news because they didn't work when Totem did either).
I had a look at the recent package updates in Synaptic to see if any audio-related ones had been changed and I have downgraded libaudiofile0 (to version 0.2.6-7ubuntu2) and gstreamer0.10-plugins-bad (to version 0.10.14-4ubuntu1). The problem still remained, so I updated them again.
The radio chanel works perfectly under Windows, and other .asx streams (for example [URL]) are working fine with Totem in Ubuntu.
I would like to know how to demux the audio from a flash video file (copied from /tmp while browsing a video site). I would prefer to avoid re encoding if possible.
I was wondering is somebody could look at this simple script that I am working on. I cannot get it to output to my home directory. I noticed the message "bad input or output format" in the VLC verbose terminal.
We have a Jetway JBC600C99-52W-B (Mini-top) with Xubuntu 10.10 and Logitech Z-205 USB Speakers but I have no sound. EDIT: fixed after installing gnome-volume-control and selecting my output device. Now i have a other problem, when i stream a video it plays sound for 1 second and when i click the play button it works fine for a while but after a few minutes the audio stops again. the video plays fine.
I'm trying to figure out the hidden stream URL for the following local radio station here in Tulsa, OK. [URL] I'd like to be able to play it in Rhythmbox.
I have been using the streaming audio feature in Firefox for years, and have upgraded Ubuntu with each new release. I've never had a problem with streaming from my favorite radio stations until I upgraded to Natty. If I know the IP and use Audacious or another client, I can still stream through them-- but not from my browser any more. Flash-based content works OK too.I have upgraded two computers from 10.10 to Natty (desktop and laptop) and it has happened with both. the desktop is the 64-bit system (AMD), and the laptop runs the 32-bit OS (Intel). We have two other computers still running 10.10, and they're both still OK. I have uninstalled and reinstalled the xine plugin (which seems to do most of the streaming), VLC, and a couple of others. No luck. I don't think I see any gaps between the codecs installed for the 10.10 computers and the ones running Natty.I tried Chrome -- same result.
I'm using it on a small IBM machine in my closed ( ) which is my multimedia center, file sharing, router, http server & others. To escape the cable paradox, lately I came up with an idea to stream music from my mobile phone (LG GD880) via bluetooth to my SUSE box (which has it's audio output linked to my HIFI Sound system). This means pairing the devices and of course set the SUSE box as reciever. I found how to accomplish this here and here .
The problem: While trying to complete the above tutorial(s), I found that in /etc/bluetooth there is no ' audio.conf ' file, only ' main.conf '. If I insert the option: Enable=Source in main.conf, it has no effect what so ever. This means that org.bluez.AudioSource will not show up in D-Feet, thus I cannot take the next steps. What can I do? Is there another way to accomplish the audio streaming?
I just had a quick question. I would like to burn a DVD to disc. The VOBs in the Video_TS folder have 3 Audio tracks: Stereo, Surround, Mono. By default it plays the Stereo track. Is there any way to change this? ffmpeg -i [insert_video_location] in the terminal gives me:
Will 0x80 always be the default? Normally this wouldn't be a problem, but I'm going to be playing these discs on a DVD Player without a remote (can't help it), so I won't be able to switch the audio on the fly, and they have no menus. You put it in, and it goes straight to the movie.
How's the quality of the sound that gets to your loudspeakers? What components do you have - brand, specs, mode and distance of computer to amplifier?[URL].. Mid and bass sound good.
I am looking at ripping the audio from a very old episode of 'In Our Time'. The episode is so old that it predates the podcast (which of course, would solve all my problems). I would like to use something like icecream or VLC to rip the audio from the 'Listen Now' link on this page. Unfortunately I am having a hard time finding the actual URL. The player itself is a Flash widget, so it is something more complicated than looking for OGG, mp3 or RAM file extensions in the page source. If there are some nifty command flags I should add when invoking icecream on the command line, I am all ears.
I have an Asus EEPC that I use in my classroom whenever I want to show a movie. I normally keep all of my educational videos as ISOs, and then simply move one over to the netbook when needed. I normally use VLC for playback. With the latest upgrade, however, I'm having a few difficulties. No matter what DVD I choose to show with VLC, the audio stream will randomly drop every 10 minutes or so whenever I am using KDE as my desktop environment. In order to re-enable the audio stream, I have to either completely stop playback OR reconfigure the audio output in VLC.
(It does not matter if I change it right back to what it was, I will get audio for another 10 minutes or so). I've also noticed that if I pause playback, sometimes the audio will not re-enable when unpaused. Strangely, however, I do not have this behavior at all when I'm using Gnome as the desktop environment. I get seamless audiovisual playback and never have to fiddle with the audio. Is this a documented problem in Phonon somewhere? How I might better backtrace what's going on?
