[MENTION=279296]jcaino[/MENTION] thanks for posting the video. I have a ton of GoPro that I haven't posted because they are real-time speed. Mind sharing what program you used to speed up the video?
From the warmth and safety (and comfort of knowing there's a real bathroom nearby) of my home that video looks like it shouldn't have been so bad to try going down the "technical" side of Flagpole rather than the packed-snow-ice side we ended up voting for and doing :fear::fear:
I actually used ffmpeg from the command line to both join the auto-split gopro files and to speed it up - this avoids a full-on re-encode (and reduction in quality) that you would get by using editing software.
To join the files together, I put the file names (in order that I want them joined) into a text file, we'll call it 'list.txt' and then run ffmpeg.
Example:
contents of list.txt:
file 'GOPR3046.MP4'
file 'GP013046.MP4'
file 'GP023046.MP4'
file 'GP033046.MP4'
file 'GP043046.MP4'
file 'GP053046.MP4'
command to join the files using this list:
fmpeg -f concat -safe 0 -i list.txt -c copy dunkle_whole.mp4
where dunkle_whole.mp4 is the output file. this is the way to go if all the files are in the same format. if you are dealing with input files that are from different format, then you'll need to use some other options.
As for speeding up or slowing down video, that command looks like this:
ffmpeg -i GOPR3046.MP4 -r 120 -filter:v "setpts=0.0625*PTS" -an pre_edit/GOPR3046.MP4-fast.MP4
This basically tells ffmpeg to:
-r 120 = create a 120fps video - it drops frames to do the speed-up - the original is 60fps, so this helps retain more frames than keeping it at 60fps
-filter:v = just concerned with the video, do not process audio, output file will not have an audio track
"setpts=0.0625*PTS" = this is how much we're speeding things up
-an = again telling it to skip audio
First answer here gives a good (more succinct than ffmpeg's official docs) info on joining the audo files:
h.264 - How to concatenate two MP4 files using FFmpeg? - Stack Overflow
officlal docs:
Concatenate – FFmpeg
official docs on changing playback speed:
How to speed up / slow down a video – FFmpeg
Once I had video files joined and sped up, then I threw that into OpenShot (
OpenShot Video Editor | Free, Open, and Award-Winning Video Editor for Linux, Mac, and Windows!) and adding the beginning title, the end fade, and the audio track. I originally export it to 720p, 60fps video....which looks great, but YouTube absolutely murdered the quality with compression artifacts. Seems that YouTube re-encodes 4k differently than 1080p and under, so I ended up re-running the video export to upsample to 4k and then uploaded to YouTube - after ~24 hours of them processing the HD feed, the quality is....meh, acceptable.
I very nearly said heck with it and just posted/hosted the video out of my house.....I'm on a 1gb connect with a dedicated media server, so probably would have been fine lol.
Actually, I'll just go ahead and post it anyway.....if you are curious to see the difference between the original 720p version I created vs. the up-sampled one that YouTube (still mangled a bit) processed:
https://home.jcaino.com/dunkle_edit.html
-Jon
