The 'concat' format that you use requires the input file to be a text file with a list of file paths to concatenate, one per line.

ffmpeg -i audio.opus -i vid.webm -c:v copy -c:a opus -strict experimental output6.webm replace aac with opus and the two files around with opus being in front(i think), it should work.Ī few points to check: Are you sure all webm files have the exact same codecs ? WebM is just a format and supports various codecs. ffmpeg concat webmįfmpeg -i video.webm -i audio.opus -c:v copy -c:a aac -strict experimental output.mp4 it should look something like this. The image file demuxer uses -framerate, while the output frame rate is set using -r. The console output will tell you if frames are being dropped or duplicated. Lower values may increase CPU usage.įfmpeg -framerate 10 -i input -r 25 output.mp4 In this example frames will be duplicated to go from 10 to 25. Set maximal partition size used for convolution. Lower values decreases latency at cost of higher CPU usage. Set minimal partition size used for convolution. This option is used only when response is enabled. times contains a list of comma separated duration specifications, in increasing order.

The output duration of the video will stay the same.įor constant frame rate videos a value of 1/(2*frame_rate) should address the worst case mismatch between the specified time and the time set by force_key_frames.

There is a Bash script called mmcat which was useful for older versions of ffmpeg that did not include the concat filter.įfmpeg can be used to change the frame rate of an existing video, such that the output frame rate is lower or higher than the input frame rate. This tells ffmpeg to use the results of the concat filter rather than the streams directly from the input files.

Ffmpeg concat different frame rates