I want to create a gif image from a jpeg image list, everything works fine, but how can I slow the animation?
Here is my code:
<?php
exec('ffmpeg -f image2 -i thumb/%001d.jpg -vf scale=480x240 out.gif');
?>
To slow down an image sequence, lower its framerate
ffmpeg -f image2 -framerate 10 -i thumb/%001d.jpg -vf scale=480x240 out.gif
You want the -r flag to set the frame rate (in frames per second). From the official documentation:
-r[:stream_specifier] fps (input/output,per-stream)
Set frame rate (Hz value, fraction or abbreviation).
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.
As an output option, duplicate or drop input frames to achieve constant output frame rate fps.
For example, setting to 30 fps:
ffmpeg -f image2 -i thumb/%001d.jpg -vf scale=480x240 -r 30 out.gif
Note: The -r argument must appear after the input file if you want it to apply to the output
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 want to use ffmpeg to convert a sequence of images to a video, the images are got in realtime, the interval of getting image is changeable, maybe i get next image in 1 second or even 1 millisecond.
I want the target video in a special fps(like 100), now my implement is creating a loop, which fade ffmpeg last image then sleep(like 10ms).
Do you guys know some options could let ffmpeg fill frames automatically?
If that option do exist, i wonder is that possible to make video real fps is half of it is claimed.
My ffmpeg command likes follow:
ffmpeg -f image2pipe -r 100 -i pipe:0 -f flv -r 100 pipe:1
You can use
ffmpeg -f image2pipe -use_wallclock_as_timestamps 1 -i pipe:0 -f flv -vsync cfr -r 100 pipe:1
FFmpeg will set each incoming frame's timestamp to the time it is received. SInce the output rate is set and mode is constant frame rate, ffmpeg will duplicate the last frame till next input frame is received, or drop if two frames are less than 10ms apart. Change -r to 1000 to keep frames only a millisecond apart.
I would like to use ffmpeg on Ubuntu with the following command:
ffmpeg -i input_video -vf scale=w=320:h=-1 -y -vcodec libx264 -preset ultrafast -r 60 output_video
For the -r option the documentation says:
-r[:stream_specifier] fps (input/output,per-stream)
Set frame rate (Hz value, fraction or abbreviation).
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.
As an output option, duplicate or drop input frames to achieve
constant output frame rate fps.
I would like to use the output option. How can I do this? What is the per-stream option doing (it is not written above)?
Second, is it correct that the -vf scale=w=320:h=-1 option scaled the video to width 320 and keeping the aspect ratio?
I would like to use the -r output option. How can I do this?
Your command is using it as an output option. The location of options is important as it determines what is applied to the input or the output:
ffmpeg [input options] -i input [output options] output
What is the per-stream option doing (it is not written above)?
"per-stream" means that this option can be declared several times to apply to different streams using stream specifiers. Since you have only one video stream in your output you can ignore this.
Second, is it correct that the -vf scale=w=320:h=-1 option scaled the video to width 320 and keeping the aspect ratio?
Yes, but when encoding with libx264 consider using -2 instead of -1. It does the same thing but makes sure the result is divisible by 2 which is required for this encoder (there are exceptions).
trying to get my head around ffmpeg to create a slideshow where each image is displayed for ~5 seconds with some audio. created a bat file to run the following so far:
ffmpeg -f image2 -i image-%%03d.jpg -i music.mp3 output.mpg
It gets the images and displayes them all very fast in the first second of the video, it then plays out the rest of the audio while showing the last image.
I want to make the images stay up longer (about 5 seconds), and stop the video after the last frame (not playing the rest of the song), are either of these things possible? i could hack the frame rate thing i guess by having hundreds of the same image in order to keep it up longer, but this is far from ideal!
Thanks
The default encoder for mpg output, mpeg1video, is strict about the allowed frame rates, so an input and an output -r are required:
ffmpeg -r 1/5 -i image-%03d.jpg -i music.mp3 -r 25 -qscale:v 2 -shortest -codec:a copy output.mpg
The input images will have a frame rate of 1 frame every 5 seconds and the output will duplicate frames to reach 25 frames per second.
-f image2 is generally not required.
-qscale:v can control output quality. A sane range is 2-5.
-shortest will make the output duration the same as the shortest input duration.
-codec:a copy copy your MP3 audio instead of re-encoding.
MPEG-1 video has more modern alternatives. See the FFmpeg and x264 Encoding Guide for more info.
Also see:
* FFmpeg FAQ: How do I encode single pictures into movies?
* FFmpeg Wiki: Create a video slideshow from images
You could use the filter fps instead of output framerate
ffmpeg -r 1/5 -i img%03d.png -i musicfile -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4
This however skips the last image for me strangely.
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.