I have been trying to extract keyframes from video using ffmpeg 0.11.1 . So far all the commands I have tried do not extract keyframes but return all the frames ie 25fps*total time number of frames in the output.
I tried setting the keyint_min as 25 to make sure there is a amximum of 1 keyframe per second.
ffmpeg -vf select="eq(pict_type\,PICT_TYPE_I)" -g 250 -keyint_min 25 -i C:\test.mp4 -vsync 2 -f image2 C:\testTemp\thumbnails-%02d.jpeg
But still all the frames are returned.
Then i tried, to separate the keyframes by 20 seconds.
ffmpeg -i C:\test.mp4 -vf select='eq(pict_type\,I)*(isnan(prev_selected_t)+gte(t-prev_selected_t\,20))' -vsync 0 -f image2 C:\testTemp\%09d.jpg
Again same result, all the frames are returned.
What should I do?
In your first command you are using the filter as an input option. I don't know how ffmpeg will interpret that.
Try this:
ffmpeg -i C:\test.mp4 -vf select='eq(pict_type\,I)',setpts='N/(25*TB)' C:\testTemp\%09d.jpg
Change 25 to the frame rate of your source: 30000/1001 for NTSC video, 24000/1001 for NTSC film, 25 for PAL, etc.
Control output quality with the -q:v or -qscale:v option (just called -qscale in old ffmpeg). Range for mpeg* is 1-31 where 31 is the worst quality.
Next time remember that ffmpeg usage questions are to be asked at superuser.com since stackoverflow is specifically for programming.
Related
I have a folder of exactly 300 images in png format (labelled 1.png, 2.png, ..., 300.png), which I'm trying to convert to a video. I would like the video to be in the webm format, but there seems to be an issue:
using the following command:
ffmpeg -start_number 1 -i ./frames/%d.png -frames:v 300 -r 30 out.webm
does generate an out.webm file, and, according to ffprobe -select_streams v -count_frames -show_entries stream=nb_read_frames,r_frame_rate out.webm (which is presumably quite an inefficient way to get that information, but that's besides the point), it does contain 300 frames and has a framerate of exactly 30/1, however, instead of the expected exactly 10 seconds (from 300 frames being played at 30 fps), the video lasts slightly longer (about 12 seconds).
This discrepancy does seem to scale up with video length; 900 frames being converted to a video the same way and with the same frame rate yield a 36 (instead of 30) second video.
For testing, I also tried generating an mp4 file instead of a webm one, with the following command (exact same as above, but out.mp4 instead of out.webm), and that worked exactly as expected, out.mp4 was a 10-second long video.
ffmpeg -start_number 1 -i ./frames/%d.png -frames:v 100 -r 30 out.mp4
How do I fix this? is my ffmpeg command off or is this a bug within the tool?
The documentation ( https://www.ffmpeg.org/ffmpeg.html ) has an example:
For creating a video from many images: ffmpeg -f image2 -framerate 12
-i foo-%03d.jpeg -s WxH foo.avi
and
To force the frame rate of the input file (valid for raw formats only)
to 1 fps and the frame rate of the output file to 24 fps: ffmpeg -r 1
-i input.m2v -r 24 output.avi
and also
As an input option, ignore any timestamps stored in the file and
instead generate timestamps assuming constant frame rate fps. This is
not the same as the -framerate option used for some input formats like
image2 or v4l2 (it used to be the same in older versions of FFmpeg).
If in doubt use -framerate instead of the input option -r.
For your case result:
ffmpeg -framerate 30 -i ./frames/%d.png output.webm
I have more than a thousand images that I want to transform into a 3 minutes video. I tried using this line ffmpeg -r 30 -i "E:/White-box-Cartoonization/test_code/cartoonized_images/$flower%03d.bmp" -c:v libx264 -pix_fmt yuv420p out.mp4 it worked but creates only a 5 seconds video. What do I need to do to turn it into a full length 3 minutes video?
If you have 1250 images and want an output duration of 180 seconds:
ffmpeg -framerate 1250/180 -i input%03d.bmp -c:v libx264 -vf format=yuv420p output.mp4
This example results in a frame rate of 6.94. Some players can't handle such low frame rates. If your player does not like it then add the -r output option to make a normal output frame rate. ffmpeg will duplicate the frames but the output will look the same.
ffmpeg -framerate 1250/180 -i input%03d.bmp -c:v libx264 -vf format=yuv420p -r 25 output.mp4
For 3 minutes of video at 30 frames per second (-r parameter) you'd need 30*60*3 images: 5400 images.
Your source parameter specifies there would be only 3 digits, so you have a maximum of 1000 source images:
$flower%03d.bmp => $flower000.bmp .. $flower999.bmp
1000 images at 30 frames per second should give about 30 seconds of video ... if you actually have $flowerxxx.bmp files.
You might need a 4th digit in there somewhere.
$flower%04d.bmp
Using avconv (or even ffmpeg, so I can use as a reference), how can I create a time lapse video by taking only anchor/reference frames from another video? Most information I find is on how to create a time lapse video by combining images, and I'd like to do it by extracting frames from a video. Say, if a video is 30 seconds long at 30 FPS, I'd like to take 60 out of those 900 frames (900/60 = every 15 seconds) to produce a 2 second video.
To take every 15th frame, use
ffmpeg -i in.mp4 -vf select='not(mod(n,15))',setpts=N/FRAME_RATE/TB out.mp4
Another method is to use the framestep filter
ffmpeg -i in.mp4 -vf framestep=15,setpts=N/FRAME_RATE/TB out.mp4
I had a H264 video from a camera and after lots of attempts found following command that produce 16x faster video with good result and 60 FPS (option -r) that is good for the YouTube timelapse
ffmpeg -i video.avi -r 60 -filter:v "setpts=0.0625*PTS" -vcodec libx264 -an timelapse.avi
You can check the result here https://www.youtube.com/watch?v=azhRqKQ7kCU
Since you are asking for 1/15 frame it will be 1/15 ~= 0.06667 with 30 FPS result video you will need command
ffmpeg -i video.avi -r 30 -filter:v "setpts=0.06667*PTS" -vcodec libx264 -an timelapse.avi
I have a directory that contains 2001 PNG files. I can convert all of the frames to an mp4 video using ffmpeg and the following command:
ffmpeg -framerate 60 -start_number 0 \
-i pic.comp2.%07d.png -c:v libx264 -r 30 \
-pix_fmt yuv420p input1ia.mp4
This works fine. However, I am creating a more complicated application that needs to read only the first 1020 files in the directory (specifically 0 thru 1019). Some googling around led me to the -vframes option. My problem is -- it seems to get ignored or at least interpreted differently than I expect.
My modified command looks like:
ffmpeg -framerate 60 -start_number 0 \
-i pic.comp2.%07d.png -vframes 1020 -c:v libx264
-r 30 -pix_fmt yuv420p input1.mp4
It seems like many other people doing the same thing as me do not encounter this issue. So I did some more digging. I tried changing vframes from 1020 to -vframes 20, and this seemed to work properly. So now I am thinking it might be some kind of mismatch between -framerate and -r?
The full resultant video is 33 sec long... which makes sense mathematically.
1 sec
--------- x 2001 frames = 33.35 seconds
60 frames
That's why I thought that specifying ~1/2 of the PNGs as the 'end point' would result in a video of the first ~16-17 seconds. But I always get the full length video from using the -vframes option.
I assume my input to -vframes must be incorrect mathematically, since a small number of frames seems to work. However, I do not understand why.
The most educated guess I can seem to make is that it is reading the PNGs as 60fps (-framerate), but the -r makes the output video 30fps or something? However, then I would assume that the full output video would not be 33 seconds long.
When the input and output rates don't match, ffmpeg drops or duplicate frames as per a regular scheme to achieve the output rate. So, for an input rate of 60 and an output rate of 30, half the frames are dropped. With the vframes option, 1020 frames at a output rate of 30 should produce a video of duration 1020/30 = 34 seconds.
To achieve what you want, use the t option
ffmpeg -framerate 60 -start_number 0 -t 17 \
-i pic.comp2.%07d.png -c:v libx264 -r 30 \
-pix_fmt yuv420p input1ia.mp4
where 17 is number of frames to be used / input rate
I have a GIF image. I am trying to convert it to MP4.
ffmpeg -f image2 -r {delay_time_of_gif_between_each_frame}/1 -i temp/%05d.png -vcodec libx264 video.mp4
This MP4 is not running at the same speed when compared to the original GIF. How do I make it to run with the same speed?
It seems I am making mistakes with the -r property. I played with it but don't get anything useful. I even removed it. Still it isn't working.
If you already know the time of delay between subsequent frames, then you need to take the inverse of it to convert it to a frame rate. For example, if the time between each frame is 40ms (or 0.04s), then the inverse would be 1 divided by 0.04, thus 25 fps.
You can not simply divide the time between frames by 1, since division by 1 will give you the same result as before.
So, try either of these again:
ffmpeg -f image2 -r 1/0.04 -i temp/%05d.png -c:v libx264 out.mp4
ffmpeg -f image2 -r 25 -i temp/%05d.png -c:v libx264 out.mp4
Note that the default input frame rate for image2 is 25 anyway, but this was just for illustration.
Also, you can change the frame rate of the output video as well, by putting -r after the input file, which should make a difference.
ffmpeg -f images -i temp/%05d.png -c:v libx264 -r 25 out.mp4
Although this question is somewhat older:
Current versions of ffmpeg automatically determine the delays between the frames according to the information in the gif images, so no need to set the frame rate in the command.