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Before you use this command you want to replace everything after the "https:" with the url of the video which you want to download. This string and it's switches will use "youtube-dl" to download the Youtube url into the directory/folder where it is called from. It will output the video using the same name as Youtube uses.
If you're using the experimental vorbis encoder (homebrew version of libffmpeg)
This removes the video and subsequent file size and directly copies the audio.
This encodes it in ogg format.
Does on-the-fly encoding of the incoming stream.
Great for radio streams as they're often flv format.
This *does not change the video encoding*, so it's fast (almost purely I/O-bound) and results in a file of nearly the same size.
However, OSX (and possibly other programs) will more easily play/seek the file when wrapped as MOV. For example, you can QuickLook the resulting file.
This basically does the same as the commercial ClipWrap program, except using the free program ffmpeg.
Note: %~nI expands %I to a file name only (cf. http://technet.microsoft.com/en-us/library/bb490909.aspx)
Take a picture from your webcam and save it to a jpeg.
A very slightly modified version of MarxBro's command.
sox (SOund eXchange) can capture the system audio be it a browser playing youtube or from hardware mic and can pipe it to ffmpeg which encodes it into flv and send it over rtmp.
Tested using Red5 rtmp server.
mp4box is great when working with mp4s
This command takes a 1280x1024 p picture from the webcam.
If prefer it smaller, try changing the -s parameter: qqvga is the tiniest, vga is 640x480, svga is 800x600 and so on.
Get your smile on and press enter! :)
-i sets the source file
-f and -acodec both set the output to be raw audio, PCM signed 16-bit little endian
-i sets the source file
-r sets the output frame rate, set it to the same frame rate as the input to output each frame
-f sets the output format, trough it might be guessed by the extension
Now we can capture only a specific window (we have to chose by clicking on it)
ffmpeg complains about "Frame size must be a multiple of 2" so we calculate the upper even number with (g)awk trickery.
We remove the grep, we are already using (g)awk here ....why losing time with grep !!! ;)
Alternative, imho better, using the concat protocol
Play with the framerate option '-r' to scale back bandwidth usage.
The '-s' option is the captured screan area, not the rescaled size. If you want to rescale add a second '-s' option after '-i :0'. Rescaling smaller will also decrease bandwidth.
A simple command to extract audio from flv/mp4 video file.
Just change extentions...
Takes all the .3gp files in the directory, rotates them by 90 degrees, and saves them in the lossless ffv1 encoding.
If this rotates in the wrong direction, you may want transponse=1
Re-encoding to ffv1 may result in a significant increase in file size, as it is a lossless format. Other applications may not recognize ffv1 if they don't use ffmpeg code. "huffyuv" might be another option for lossless saving of your transformations.
The audio may be re-encoded as well, if the encoding used by your 3gp file doesn't work in a avi container.
ffprobe is specially intended to get video information
Faster thumbnail creation than '-itsoffset'
ffmpeg -itsoffset -4 -i test.avi -vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 test.jpg
sxga ==> 1280x1024
vga ==> 800x600
xwininfo -root | grep geometry