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Both avconv and ffmpeg suffer from the poorly chosen defaults for each container and codec. Therefore you should not simply give the command in the format as you have presented, but also tell it what to do. I use avconv, but if you are still using ffmpeg then the format is rather similar, so you should be able to follow. You will need to specify the audio ...


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I have already changed to avconv, so i apologise if the answer may be a little different in the classic ffmpeg, but i believe that not much difference should be there. You can have a moving crop if you can create some sort of formula between the frame number and the position of the crop; but there are no analytic tools available to do that. This means that ...


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After Effects should be able to do this. It allows you to track a selected object as it moves around the screen. Set the speaker's head as the selected object. Have the virtual "camera" track him as he moves around. It will appear as though the original camera was tracking him perfectly as he moved. You can then apply a stationary mask around that area ...


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The trick was to use amix=inputs=2 My error was thinking that I wanted to add another output stream to the track and the solution was to mix down the two tracks into one function stream { ffmpeg -r 10 -threads 2 \ -f x11grab -video_size 1600x900 -framerate 10 -i :0.0 \ -f v4l2 -video_size 320x240 -framerate 10 -i /dev/video0 \ -f alsa -ac 2 -i pulse ...


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I've reported the issue on Debian bug tracker here, as well as upstream here. Really the only available reference implementation can be found here.


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Got it. The error is cuased by the font location in the command is of a Linux computer. The font location need to be different for windows. The error caused by this line in the command: drawtext=fontfile=/usr/share/fonts/truetype/DroidSans.ttf The above line does not work in Windows. For windows change to: drawtext=fontfile=/Windows/Fonts/arial.ttf


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There shouldn't be anything special about making a video for HTML5 video, so just look for any video encoding guide to learn about choosing how to trade off CPU time vs. bitrate vs. quality. Hint: encode once, display many is a use case where it makes sense to spend as much CPU time as possible on the encode, to get the quality you want in as small a ...


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Looks like ffmpeg needs to see the quotes around the parens, so you need to protect them from the shell with another layer of quotes. ffmpeg -i ~/Downloads/in.mov -vcodec copy -af "volume=enable='between(t,0,3)':volume=0" ~/Downloads/out2.mov Also, don't forget to specify something about the audio codec. ffmpeg's default AAC encoder is bad compared to ...


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If you want to mute the first 3 seconds of each audio stream then you have to filter each one: ffmpeg -i input.mov -filter_complex \ "[0:a:0]volume=enable='between(t,0,3)':volume=0[a0]; \ [0:a:0]volume=enable='between(t,0,3)':volume=0[a1]; \ [0:a:0]volume=enable='between(t,0,3)':volume=0[a2]; \ [0:a:0]volume=enable='between(t,0,3)':volume=0[a3]; \ ...


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The solution seems to be to use both a different video and audio encoder. This line works: FFmpeg/ffmpeg -video_size 1024x768 -framerate 25 -f x11grab -i :0.0+0,0 -f alsa -ac 2 -i pulse -acodec aac -strict experimental output.flv I couldn't get it to work without -acodec aac -strict experimental, contrary to the HOWTO on ffmpeg wiki. The error message ...


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LordNeckbeard explained in his answer, why the given ffmpeg command line does not provide any known advantage. But what - in general - could be reasons to transcode? Available input codecs/containers of your NLE (video editing software) There are hundreds of codec/container combinations out there, and maybe your NLE has just problems with the one that ...


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On this page author reencodes MP4 from GoPro to MOV for "easy post processing". Why the processing becomes easier after that? The author provides no explanation and does not go into any detail of what he means by "post processing". What we know: The author's ffmpeg command is using the encoder mpeg4 which will output MPEG-4 Part 2 video (like the old ...



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