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.
avconv -f video4linux2 -channel 1 -s 640x480 -i /dev/video0 -deinterlace -f alsa -i plughw:1,0 -ar 22050 -ab 64k -acodec ac3_fixed -vcodec mpeg4 -vb 2000k -y test.mp4
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.
2. Conversion segment by segment into mp4 and ogv
Options A: -acodec aac -strict experimental -ab 128k -ac 2 -vcodec libx264 -s 640x480 -pix_fmt yuv420p -movflags +faststart -crf 22
Options B: -acodec libvorbis -ab 128k -ac 2 -vcodec libtheora -s 640x480 -b 500k
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.
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.
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.
I just converted a movie from mp4 to avi format and was away from the computer during the conversion. When I came back, the file had been properly converted but the computer was at the login prompt. I assume that it rebooted when the conversion was complete. Is this normal behavior? I don't see any avconv 'switches' to prevent that from happening.
View 7 Replies View RelatedI have recently began to use libav and had an issue I was running into.. Not exactly how to word it so I will simply state the symptoms..
Goal: Create a screencast demo on linux, play it back on a windows machine.
I am running this command to record the screen, installed libav:
avconv -f x11grab -r 25 -s 1600x900 -i :0.0 -vcodec libx264 -threads 4 /home/sysadmin/Desktop/output.avi
The issue I am running into is, when I try to play this file in Windows Media Player or even VLC on the linux host, the default size of the video results in the text in the terminal to be unreadable..
When I re-size the video, as in blow it up to full screen, I can see the text clearly..
The playback device is running something like 1280x1020 resolution. Is there a way to make it so that the text will also be readable?
I am trying to perform a 2-pass encoding of a video from .mov to .webm, but it looks like that the 2-pass encoding is much worse than doing a single pass encoding. Here are the two commands I use:
Code: Select allavconv -y -i input.mov -r:v 25/1 -c:v libvpx -minrate 400k -maxrate 600k -b:v 400k -s 640x360 -force_fps -b:a 80k -pass 1 output.webm
avconv -y -i input.mov -r:v 25/1 -c:v libvpx -minrate 400k -maxrate 600k -b:v 400k -s 640x360 -force_fps -b:a 80k -pass 2 output.webm
I've upgraded Ubuntu 10.04 to Ubuntu 10.10 yesterday and I'm experiencing some issues now.
Audio is out of sync for all videos I'm trying to watch in VLC (sync was 100% fine in Ubuntu 10.04).
I watch alot of news videos and within 1 - 2 minutes the video and audio become out of sync. The video is lagging the audio. I'm using 10.10 32 bit with Shock Flash 10.1 r102 on Firefox. Will the 10.2 beta flash fix this problem?
View 2 Replies View RelatedI put all my dvds on my "media center" by converting them to .MP4 with handbrake.
Recently I saw that with a MKV file you could do soft subtitles. I tested a part of a movie, and the audio and video are very out of sync.
With MP4/burned in audio everything is ok...
Edit: Ow yes I'm using XBMC for playing it. MP4 + MKV files are both H.264, they have the exact same settings except for subtitles...
Weirdly Enough: I tried another video and at this one the audio is in sync....
After upgrading to 11.04, video and audio are out of sync by about one second when playing movies in VLC, or opening a clip on the web. Reinstalling does nothing.
View 9 Replies View RelatedI am burning DVD iso's and they seem to work great I have video output and sound output however as the film goes on the audio gradually becomes more out of sync but if I hit the rewind button on my remote and then play the sound is in sync again for a few minuets. I am using DeVeDe and Gnome Baker to create and burn my iso images to disc and they work great on the computer but not so great on my dvd players I am burning onto Verbatim DVD-R using Ubuntu 10.04 lucid lynx.
View 3 Replies View RelatedI am attempting to backup DVDs that I own to .iso format so that I'm able to watch them using xbox media center. I've simply been copying the entire DVD to my HD in .iso using brasero.When I watch the .iso file in XBMC, the audio is a fraction of a second ahead of the video. The gap between the audio and video doesn't seem to change over the duration of the clip.
What are the likely causes of this issue? I've read that it could be a slow processor, little ram, or inadequate video card. If it's indeed a hardware issue, I suppose I'm SOL with my current laptop: a 2006 dell with a core 2 duo processor, 2GB ram, and a middle of the road video card at that time.Is there any software tweak I can explore to get the .iso file to sync properly?Also, I know it's customary for posters to list their system specifications, but I don't know how to call up my software or hardware setups.
I have a couple of .avi clips in which the sound plays 2 seconds before the video, so I need a software that can re-sync the sound correctly with the video with affecting the video/audio quality, what program can I use? What is the name of this feature in video editing programs? I am using Ubuntu 10.04. I noted that the Multimedia & video forum have only threads about problems in playing videos & cards drivers problems.
View 3 Replies View Relatedmy goal is to record video using a canon powershot camera, edit the avi file on my ubuntu 10.04 computer, then upload the rendered file to videos.
problem is that when i cut the video, the audio is no longer in sync with the video, it's off by about 1-2 seconds. this happens with both openshot and pitivi, so i suspect that it's caused by a bug with the codec. (files are avi with mjpeg codec). after searching launchpad, this is apparently a "known issue". that's great but for now i need a workaround.
i do have an old g4 powerbook with imovie hd v6 on it that i can use, but i'd prefer not to because:
1. the powerpc mac is much slower than my new dual core laptop
2. imovie compresses my videos too much so the rendered file is lower quality
3. i simply prefer openshot to imovie
i was thinking of preprocessing my avi files by converting them to another format with a non-buggy codec on linux. i downloaded ffmpeg, but not sure how to use it and what format to use. would mpeg2 be a safe one to use?
My old Palm is on the way out. Which modern phone / PDA works these days - like sync contacts etc Which application ? Thunderbird , evolution, web based?
View 2 Replies View RelatedI have found that if I change the FPS of a video, the audio is out of sync.
Is there a way in mencoder to have it correct this, and maintain the correct sync?
I don't think it is just a matter of audio/video delay. I have tried many times to correct this via that method, and it doesn't come close. Although, if I encode the video to another format, but with the original fps, the audio is sync'd.
V.L.C. and all others - but Totem - video players that I have installed have audio out of sync. This occurs in both D.V.D. and .mkv & .avi. I had this problem with V.L.C. 1.1.10 & now with 1.1.11. I do not think that this is a problem with V.L.C. since I have had the same issue occur with gnome-mplayer. I tried to downgrade gstreamer*, and that did not correct my problem. It shouldn't be a problem with libdvd* since the problem still occurs with files on my drive. Handbrake doesn't fail to rip D.V.D correctly.
Because of all of this I figure that it must be a system library that Totem and HandBrake don't use ( or bundle most likely in the case of HandBrake ).I am using Fedora 15 x86_64 with all updates to date.
Majority of the videos I play with VLC the audo is out of sync, I have to delay it about 400ms to sync it. This only started happening after I upgraded to 10.04 64bit ( from 32bit ). Could it be a bug in the version of VLC I'm using (1.1.10)?
View 2 Replies View RelatedHow to sync audio and video which is captured from a aeperate camera device and a microphone,how to relate timestamps to audio and video to syncing.I m capturinfg video at 30fps and audio 160 samples everytime so how these 2 should be related to sync and playback at a time
View 1 Replies View RelatedI've been trying to use cheese to record greeting from my kids to grand parents etc. But every time I record a video, the video is choppy and the audio sync is off. I've used the one in the (F11) repos and built it from source. It behaves the same using other distros as well. Is this par for the course with cheese, or is it my hardware?[URL]... Any other applications/methods to record audio & video while providing a video.
View 2 Replies View RelatedHow can one adjust/sync audio and video in gnome-mplayer while watching video
The following is my configuration :-
OS : Opensuse 11.2
Media Player : gnome-mplayer 0.9.9
I am trying to use ffmpeg and mencoder to slice a portion of my video out but the audio is always 2 seconds out of sync.
ffmpeg -i bird.avs.MP4 -acodec copy -vcodec copy -ss 00:08:40 -t 00:01:00 test.mp4
mencoder -ss 00:08:40 -endpos 00:01:00 -oac copy -ovc copy bird.avs.MP4 -o test.mp4
mencoder -ss 00:08:40 -endpos 00:01:00 -oac copy -ovc copy -noskip bird.avs.MP4 -o test.mp4
[Code]....
I am running Debian testing with XFCE desktop and a Logitech C920 webcam. I have installed skype but can not get the microphone to work with Skype (I know the webcam works OK as I have tested it on another PC running windows).
I have Pulseaudio installed, I have installed pavucontrol to check the settings and the microphone is enabled. I have checked alsamixer and the microphone is enabled. All I get when I do the Skype audio test is a low hiss in the background no audio or any distortion to suggest that it is capturing my voice
What do I have to do (i.e. which package do I have to install) to activate the 'Audio' tab in Nautilus? With Debian Lenny, as with Fedora Goddard, it is possible to see ID3 tags when right-clicking on a audio file in Nautilus, but oddly this feature is gone with a fresh Debian Squeeze installation. However, it is still possible to view EXIF informations when right-clicking an image file.
View 4 Replies View RelatedBrasero is broken ([URL] .... - "impossible to link plugin pads") and neither Devede nor CD/DVD Creator offer me the classical Audio CD format.
What is a simple and fast way to get Debian/GNOME to burn an Audio CD. Blimey, that can't be that difficult??
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
Error in mplayer is Cannot find codec for audio format 0x706C6351
View 1 Replies View RelatedOn a fresh install of squeeze (with the exception of some installed video firmware and the latest updates from the repos) from the kde cd.
System is running an ASUS Sk8V motherboard with onboard sound, also a SB Audigy 2 ZS sound card. Speakers are plugged into the sound card.
Sound worked fine before in Lenny except I had to create /etc/modprobe.d/sound with the following to get the system to prioritize the SB card over the onboard audio
options snd-emu10k1 index=0
options snd-via82xx index=1
I've done the same with the new install, and still no audio.
I followed the troubleshooting steps from the FAQ forum, but am stuck on the end, which suggests doing the following:
The following string needs to be added to the /etc/modprobe.d/alsa-base.conf file
options snd-hda-intel model=YOUR_MODEL
After hours of googleing I'm stumped.When MPD is playing audio, I cannot play audio in another app (ie Totem/VLC).MPD runs under the mpd user. Alsa config is default (as far as I can tell, it configures itself automatically now). System is squeeze, up to date.
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