I am trying to cut a part of a mp4 to make a shorter clip via ffmpeg however when I do I get no sound
ffmpeg -ss 00:06:51 -i truth.mp4 -c:a aac -c:v copy -t 8 true-30sec.mp4
The original clip has sound.
ffmpeg -ss 00:06:51 -i truth.mp4 -t 8 true-8sec.mp4
if you want 30 seconds video from 00:06:51 time, try
ffmpeg -ss 00:06:51 -i truth.mp4 -t 30 true-30sec.mp4
Related
I want to use FFMPEG (the latest version) to cut a 24 fps matroska file. So I am using -ss and -t, but I noticed with VLC that the very first frame is ALWAYS duplicated one time, no matter the file or the duration I choose. While it is not a really serious issue, but I wanted to know if there was a way to prevent that.
Here is the command I am using:
ffmpeg -ss 00:01:26.086 -i file.mkv -t 00:00:02.000 -c:v libx264 -crf 18 output.mp4
add -vsync vfr in your cmd may be helpful
ffmpeg -ss 00:01:26.086 -i file.mkv -vsync vfr -t 00:00:02.000 -c:v libx264 -crf 18 output.mp4
Hi I am trying to speed up and trim clips with FFMPEG version 4.2.2. Is there a limit to how fast you can speed up a clip? If I try to speed up a clip over a certain then the output file cannot be opened.
I have tried two methods without any luck: 1. using the setPTS filter and 2. inputing the file at a faster frame rate.
1.
ffmpeg -i GH012088.MP4 -y -ss 18 -t 0.48 -an -filter:v "setpts=0.096*PTS" -r 25 output.MP4
2.
ffmpeg -r 312.1875 -i GH012088.MP4 -y -ss 18 -t 0.48 -r 25 -an output.MP4
I am trying to create a clip from the input that starts at 1 second in the original clip, plays at 10.4166 x speed and lasts for 0.48 seconds
What am I doing wrong?
Thanks
Use
ffmpeg -ss 1 -i GH012088.MP4 -y -t 0.48 -an -filter:v "setpts=0.096*PTS" -r 25 output.MP4
The seek has to be on the input side, before frames are retimed. The -t has to be on output side, after frames are retimed.
Does the movie have sound?
If yes, than we have to sync speed up audio and video by combine filter:
ffmpeg -i video.avi -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]" -map "[v]" -map "[a]" -f avi video1.avi
Let's say I have a video called Concert.mp4. I want to extract a performance from it quickly with minimal reencoding. I want to do the equivalent of this, but faster:
ffmpeg -i "Concert.mp4" -ss 00:11:45 -to 00:18:15 -preset veryfast -y artist.mp4
This takes 17 seconds, which is way too long for our needs.
Now, it turns out that 11:45 and 18:15 don't fall on iframes, so if you try this you will get a 3 second delay at the beginning before the video shows:
ffmpeg -i "Concert.mp4" -ss 00:11:45 -to 00:18:15 -c copy -y artist.mp4
Running this command, we can see where we need to cut:
ffprobe -read_intervals "11:00%19:00" -v error -skip_frame nokey -show_entries frame=pkt_pts_time -select_streams v -of csv=p=0 "Concert.mp4" > frames.txt
So what we need to do is encode the first 3.708 seconds, copy the middle, and then encode the last 5.912 seconds.
I can get the 3 segments to all look perfect (by themselves) like this:
ffmpeg -ss 698.698 -i "Concert.mp4" -ss 6.302 -t 3.708 -c:v libx264 -c:a copy -c:s copy -y clipbegin.mp4
ffmpeg -ss 708.708 -to 1089.088 -i "Concert.mp4" -c copy -y clipmiddle.mp4
ffmpeg -ss 1089.088 -i "Concert.mp4" -t 5.912 -c:v libx264 -c:a copy -c:s copy -y clipend.mp4
ffmpeg -f concat -i segments.txt -c copy -y artist.mp4
segments.txt of course contains the following:
file 'clipbegin.mkv'
file 'clipmiddle.mkv'
file 'clipend.mkv'
I saw this solution presented here, but no amount of tweaking gets it to work for me:
https://superuser.com/a/1039134/73272
As far as I can tell, this method doesn't work at all. It crashes VLC pretty hard no matter what I try.
The combined video keeps glitching after the 3 seconds, probably because the PTS times are different or something (using some options, I have seen warning messages to this effect). Is there anything I can add to the commands above to get this to work? The only requirement is that the middle command must not re-encode the video, but must do a fast copy.
Thanks in advance.
OK, so the answer was just that the latest VLC seems to be buggy. What I did above plays just fine with a very slight pause at the cut point in ffplay, mplayer and PotPlayer.
Following #Gyan's advice, I set the profile and level to match the original (using -profile:v main -level:v 4) and even the slight pause went away.
ffmpeg -ss 698.698 -i "Concert.mp4" -ss 6.302 -t 3.708 -c:v libx264 -c:a copy -c:s copy -profile:v main -level:v 4 -y clipbegin.mp4
ffmpeg -ss 708.708 -to 1089.088 -i "Concert.mp4" -c copy -y clipmiddle.mp4
ffmpeg -ss 1089.088 -i "Concert.mp4" -t 5.912 -c:v libx264 -c:a copy -c:s copy -profile:v main -level:v 4 -y clipend.mp4
ffmpeg -f concat -i segments.txt -c copy -y artist.mp4
I want to convert video to gif with audio. The two should match when played at the same time.
The command I use somehow generates results that's a bit off.
To create gif:
ffmpeg -ss 00:00:10 -i input.mp4 -t 4 -pix_fmt rgb24 -r 10 -filter:v "scale=-1:300" out.gif
To create mp3:
ffmpeg -ss 00:00:10 -i input.mp4 -t 4 out.mp3
I'm guessing this has something to do with the slicing.
Untested: You could try one of these two options below. If still not working then please provide a short clip (MP4 link) that can be tested to give you required solution...
Option 1) Try using -itsoffset instead of -t...
ffmpeg -ss 00:00:10 -itsoffset 4 -i input.mp4 -pix_fmt rgb24 -r 10 -filter:v "scale=-1:300" out.gif
ffmpeg -ss 00:00:10 -itsoffset 4 -i input.mp4 out.mp3
Option 2) Avoid issue of non-matching times for keyframes (of video track vs audio track)...
First trim the video (get's whatever audio is available at nearest video keyframe to your time):
ffmpeg -ss 00:00:10 -i input.mp4 -t 4 trimmed.mp4
Then use trimmed MP4 (will have synced audio) as source for your output GIF and MP3.
ffmpeg -i trimmed.mp4 -pix_fmt rgb24 -r 10 -filter:v "scale=-1:300" out.mp4
ffmpeg -i trimmed.mp4 out.mp3
With FFmpeg you have the option -t which will set the duration of the output. However I do not see a way to limit the duration of the input. Take this command
ffmpeg -i video.mp4 -c copy -t 60 out.mp4
This simply creates a 60 second clip of the original video. However if I wanted to clip the audio while keeping the full video stream, FFmpeg does not seem to have an option for this.
I have tried simply clipping the audio first, then combining the clipped audio with the video file, but this causes video/audio sync issues for me.
‘-aframes number (output)’
Set the number of audio frames to record. This is an alias for -frames:a.
§ Audio Options
ffmpeg -i video.mp4 -c copy -aframes 100 out.mp4
Use the "-itsoffset" option.
This makes the first 10 seconds mute.
ffmpeg -i video.mp4 -vn -acodec copy -ss 10.0 out_audio.mp4
ffmpeg -itsoffset 10.0 -i out_audio.mp4 -i video.mp4 -vcodec copy -acodec copy out.mp4