user17632: "Is it possible to speed up a video using handbrake?"
In the above link, Mulvya show us how to speed up a video, but I want to know, if possible, how can I speed the video joining two or more videos and increasing the frame rate, for example:
I have 2 video files, which I need to join. Both are at 30fps and I want to speed up to 5 times and increase the frame rate to 60fps.
How can I do it?

user1871: Assuming audio's not a concern,
ffmpeg -i in1.mov -i in2.mov -filter_complex
       "[0]setpts=(PTS-STARTPTS)/5[a];[1]setpts=(PTS-STARTPTS)/5[b];[a][b]concat[v]"
       -map "[v]" -r 60 -crf 18 output.mov


17632: <p><a href="https://video.stackexchange.com/questions/18469/is-it-possible-to-speed-up-a-video-using-handbrake">"Is it possible to speed up a video using handbrake?"</a></p>

<p>In the above link, Mulvya show us how to speed up a video, but I want to know, if possible, how can I speed the video joining two or more videos and increasing the frame rate, for example:</p>

<p>I have 2 video files, which I need to join. Both are at 30fps and I want to speed up to 5 times and increase the frame rate to 60fps.</p>

<p>How can I do it?</p>
 1871: <p>Assuming audio's not a concern,</p>

<pre><code>ffmpeg -i in1.mov -i in2.mov -filter_complex
       "[0]setpts=(PTS-STARTPTS)/5[a];[1]setpts=(PTS-STARTPTS)/5[b];[a][b]concat[v]"
       -map "[v]" -r 60 -crf 18 output.mov
</code></pre>
