Libav is a fork of the popular FFmpeg multimedia tool, best known for appearing in the Ubuntu packages. Include the full, uncut console output when asking for help with a command.

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Encoding multiple video streams with a single avconv invocation

I played with avconv on Ubuntu and I'm now able to e.g. record the desktop with sound from a soundcard. One thing I wanted to do was recording two video inputs at the same time, for instance the ...
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Debian: Version number of installed package differ from those in repository causing dependency issues

I can't install libav-dbg due to dependency issues with version numbers of installed packages, that do not correspond to those in the repository. How is this possible, and how can i resolve the issue? ...
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How do I merge a folder of PNG images to a mp4 movie using avconv?

I have a folder containing many time stamped PNG images which I'd like to merge to a short movie. The contents of that directory looks like this: └── images ├── img_20130421_115547.png ├── ...
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Libav, slow internet, the golden median

Some time ago I was to configure a streaming service, unfortunately there were surprises at every corner... (awesome official bugs, delays on deliveries and etc.) After tweaking around a lot I found ...
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Why would I choose Libav over FFmpeg, or is there even a difference?

From what I've seen it looks to me like Libav's avconv is thought to become a successor of ffmpeg — is that correct? If that's true, why is that so? What exactly is libav doing better and why would ...
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Ubuntu Screencasting: Libavdevice segmentation fault

I'm trying to stream to twitch a screencast of a remote desktop, but I meet some segmentation fault. The OS is: Xubuntu 14.04 , xfce, x2go I tried with Ubuntu 14.04, Ubuntu 12.04, ffmpeg and avconv, ...
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User Generated Chroma Key Composite Videos with FFMPEG / AVCONV

I want to create a system where a user can upload two videos to a website, one of which has blue screen in the background, and the website uses AVCONV (or similar) to create a composite video of the ...
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Converting RAW Blackmagic Intensity Card frames

I am trying to convert raw video frames that I have captured using a Blackmagic Design Intensity card. The output frames are of the format: YCbCr 4:2:2 packed 8 Bit UYVY Abekas How can I convert ...
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30 views

How can I save an avconv/ffmpeg command for later?

I'd like to save my entire avconv command with options so that I can reuse it without typing it in every time. I would still need to specify the input and output filenames. How do I do this? I'm on ...
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Using avconv to convert an animated gif to mp4 with sound

I want to convert an animated gif and a midi (music) file into a mp4 video. Is it possible? I saw a lot of topics on documentation, foruns and stackexchange sites, but I didn't find. It works with 1 ...
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How do I capture my second monitor using avconv?

With this command: avconv -f x11grab -s 2560x1440 -i :0.0 I can stream video from my main monitor. I also have a second, 1080p monitor on which I do my gaming. I want to stream from that monitor. ...
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Install latest libav/avconv on OSX? [closed]

How can I install avconv on OS X?
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119 views

speed up video using avconv without quality loss

After having read this page, I'm using avconv (which in this case is apparently same as ffmpeg, and which I need to use instead since I'm on Ubuntu trusty) to speed up a .swf video. I don't want a ...
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Why can't I seem to get the framerate right when using avconv to convert a sequence of images to a gif?

I need to convert a series of images to gifs. I found three broad ways to do this. One involving ImageMagick, One involving gifsicle and another involving avconv. I can't use Imagemagick because ...
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489 views

How to use avconv or ffmpeg to convert any video to an exact size and shape

We have a system that supports streaming video, but we support multiple players. I have multiple systems that I COULD use for this. Currently, I've been using the media server that we use to stream ...
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FFmpeg/Avconv: Scaling Filter “Error when evaluating the expression”

I'm trying to scale a video with FFmpeg with the following command: ffmpeg -i input.jpg -vf scale="'if(gt(a,4/3),320,-1)':'if(gt(a,4/3),-1,240)'" output_320x240_boxed.png This is taken verbatim ...
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209 views

Video concatenating, with overlay

I have a video recorded from a gopro which is split into 3 parts as the maximum filesize is reached after about 17 minutes and the gopro automatically splits it into multiple parts. I also have a ...
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127 views

Reducing video size with avconv… why does the size increase?

i have an android video: $ mediainfo 20140324_192544.mp4 General Complete name : 20140324_192544.mp4 Format : MPEG-4 Format profile ...
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avconv option -c:a copy

I am converting a bunch of videos from FLV to MP4 (for iphone compatibility) and using AAC codec it kept throwing out "invalid audio bitrate" or similar errors. I tried -c:a copy option and it works, ...
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Burn-in subtitles with avconv?

I have a mkv file and want to convert it to an DVD compatible mpg file with avconv. How can I also burn-in one subtitle stream from the same mkv file? avconv -i input.mkv -map 0:0 -map 0:1 -target ...
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149 views

How to make avi (MJPEG codec) by avconv for iphone?

I try to make video from pack of jpg by avconv and open it on iphone. I make avi file using MJPEG by command: avconv -r 10 -i %06d.jpg -r 10 -vcodec mjpeg -qscale 1 out.avi Eveything is ok on my ...
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Piping images to avconv at unknown fps

I am currently reading images from a camera "as fast as possible" (>50fps), outputting them as JPEGs, and piping them to avconv using the image2pipe input. What is a good approach to getting the ...
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112 views

How to convert any video to .avi with wmv1 codec using ffmpeg/avconv?

I have installed ffmpeg to convert a video. I am trying to convert a .mp4 to a .avi video with the codec wmv1. How to do this? I am using the command avconv in a Kubuntu terminal. Last attempt I did ...
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Automated avconv recordings script

I'm currently recording video from my IP camera to disk by making use of avconv (ffmpeg). avconv -i rtsp://192.168.1.1/stream -c copy pool.mp4 This works great as my feeds are already h264, I ...
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Read frames into Matlab with avconv

I have a very large video file (5.9 GB - 120fps at 1.3 megapixel for 2h) from which I want to extract a few hundred frames at known, sparse time points, and send via the shortest path to Matlab. ...
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Converting with avconv without trying to increase quality

This might just be a quick question or a matter of a specific flag, but I have a standard format that I use for storing videos on my computer. The idea is to cut down on storage requirements while ...
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181 views

avconv recording pulseaudio output monitor stretches audio

Recording audio from pulseaudio output monitor results in stretched audio: The audio falls out of sync as it moves slower than the video I've checked, the video is in sync, it's the audio that's ...
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What is the difference beetween ffmpeg and libav, and how to chech which one is used for application? [duplicate]

I am working with some gstreamer based application and some other streaming stuff and I came to some confusion: What is difference between libav and ffmpeg? I found no explanation what are they and ...
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31 views

How can I make the output format of a video the same as the input format?

How can I make the output format of a video the same as the input format for general case? avconv -i source -vcodec copy -acodec copy -movflags empty_moov -f ??? output I would not like to use -f ...
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ffmpeg/avconv async is not working - unsync audio

I have a javascript that records video from a webcam as webm and audio from microphone as wav together. I am encoding these webm and wave files to generate a mp4 file using ffmpeg/avconv. But i've ...
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Understanding avconv console output

I'm using avconv to broadcast a video on justin.tv from my Raspberry Pi. I get it (weakly) working a very few times. Most of the times justin.tv is not being updated and says "disconnected". The ...
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using avconv to convert rbga image sequence into video while preserving alpha chanel

Is there any way to use "avconv" to convert a sequence of png images with alpha channel into a video and preserving the alpha channel? $ avconv -f image2 -framerate 60 -i img_%5d.png -r 29 foo.mp4 ...
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350 views

avconv gets killed if mkv has subtitles

What I'm trying to do is to take a movie (in an Matroska container), convert all audio tracks to AC3 and don't touch anything else. I'm using this line: avconv -i infile.mkv -map 0 -vcodec copy ...
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Human insensitive video compression

I have an AVI video file recorded by my laptop web-cam. It's only 10 minutes but it has so large size, 3.9 GB! I'm not expert in multimedia but I've seen really good quality long movies in only 4 GB. ...
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Messed up ffmpeg/libav configuration (ubuntu)

I tried to update my ffmpeg version from the default deprecated version to the latest one. I'm now trying to revert my system back. I removed the PPA I used, but I can't seem to revert the packages. ...
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513 views

Resizing with avconv causes pixellation in output

I am trying to resize a video from 1920x1800 to 1280x720 for phone viewing. This is the command I used: avconv -i input.mkv \ -map 0:v -map 0:a:1 -map 0:s:0 \ # map video, 2nd audio stream, and ...
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Codec choice for non CPU-intensive video transcoding

I am trying to achieve real-time transcoding of mkv / H264 videos on a low-end (slow CPU) platform. Using the following command line as a testing harness: avconv -i test.mkv -c:v mjpeg -q:v 3 -c:a ...
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Simplest video grab from webcam: how to

On Raspbery Pi's Raspbian (based on Debian Wheezy) I'm trying to make a simplest video grab from a Logitech C910 webcam to a video file via ffmpeg/avconv. I say: $ avconv -t 5 -f video4linux2 -s ...
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reduce size of mp4 using avconv

I'm looking at this question Reduce size of MP4 and I want to do it using avconv, however, I'd also like to shrink the frame size by about half. My problem is when I do avconv -i "$file" -s 640x480 ...
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avconv can't convert stream to MP4 file, fails with “Unable to set encoding parameters”

I'm trying to script some testing of Wowza Media Server. Basically, I'm attempting to just beat the living bejeepers out of the thing. I have 5 slightly older computers, originally XP boxes, which I ...
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OUTPUT webcam video over rtp

I'm currently trying to stream webcam video from beagleboard black to my laptop and am using this line of code: avconv -f video4linux2 -i /dev/video0 -debug -vcodec mpeg2video -r 25 -pix_fmt yuv420p ...
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Where in FFmpeg is the DTS decoder located?

Where is the actual DTS decoder located? When I search through the FFmpeg folders, dtsdec.c and dtshddec.c show up, but they're only 2–4 kB, and don't have any actual decoding code anywhere within ...
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341 views

How can I record a video signal in Linux from the command line?

I have a Linux machine with a Pinnacle video card. I wanna record a video signal from my TV connected to the S-Video input in my Pinnacle card. I could record using VLC GUI, but I wanna cron it, so I ...
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Resizing videos with ffmpeg/avconv to fit into static sized player

I have a html 5 video player which is 700px wide, 400px high. I'm trying to use avconv to use ffmpeg to resize (while retaining the aspect ratio) and making sure it fits into my player. Input can be ...
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Use avconv to convert iMovie DV streams to other formats

I have a bunch of DV streams that were imported from a DV camcorder using iMovie. Unfortunately, neither avconv nor VLC seem to be capable of converting these files correctly, whereas QuickTime ...
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avconv mkv to mkv with audio compression bug

In order to make quality tests, I would like to compress the audio part (to a low bitrate) of a matroska file without damaging video. Audio codec is AAC and video codec is H264. I am using avconv on ...
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668 views

How do I merge two videos and increase sound volume using Avconv?

I'm trying to merge two cd-s into 1 file and also boost sound volume 200%, I tried this using avconv tool, but I only got cd1 and without an boost in sound: nohup avconv -i cd1.avi -i cd2.avi -vcodec ...
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avconv and ffmpeg - drawtext filter text_w evaluates as 0 in Ubuntu Precise

I'm attempting to draw text onto a video using either the avconv or ffmpeg commands. When specifying x= for where on the final video to place the text, the 'text_w' value is evaluating to 0, rather ...
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797 views

H264 decompression/decomposition into JPG - quality issues

I'm trying to decode a 1920x1080 30fps h264 stream. Individual frames look outstanding in VLC media player (pausing the playback), but when I decode using avconv (ffmpeg has been deprecated and ...
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312 views

Encode mp3 to playback at 1.5x speed in avconv (libav)

I would like to take an mp3 file and re-encode it to play faster (perhaps at 1.5x speed). I primarily use avconv in debian linux, but can use any other program if recommended. I can use any operating ...