Archive for November, 2016

How to use ffmpeg to avoid having to open cinelerra to do simple video tasks, also I am starting a new channel on Youtube

November 14, 2016

I wanted to save the “workflow” I used for my last video.

Video? Oh yeah, I started a new Youtube channel. It’s just for practice. I want to get a cam-audio guitar practice vid up as close to daily as possible.

The channel is here:

I also have an old channel that I still upload to, in case you were wondering:

The first video I put up I used my full-featured nonlinear video-editing software of choice, cinelerra. But all I even *used* it for was to crop the beginning and end!

That first video is here:

I’m practicing an acoustic version of “The Suburbs” by Arcade Fire. I feel like the world is going to come to an end in a few days or weeks or months or years and in that mindset I am beginning to reinterpret some of the lyrics to this song in new ways.

For the second video, I was smarter, and did everything in the command line.

The second video is here:

I’m practicing “Suzanne” by Leonard Cohen. I’m pretty torn up about his passing and I want to learn his songs because I respect him so much.

Walker’s instructions for how to make simple videos:

  1. Record the video on your Flip cam.
  2. Get the file into a linux or mac computer with ffmpeg installed.
  3. Use the following command to take the audio out of the video:
    ffmpeg -i videofile.MP4 audiofile.wav
  4. Open the audio file in audacity. Apply noise reduction, then very light compression, then very light equalization (roll off extreme lows). Export to newaudio.wav
  5. Use the following command to remux the old video with the new audio AND trim the video:
    ffmpeg -i videofile.MP4 -i newaudio.wav -map 0:v -map 1:a -codec copy -ss 00:00:00 -t 00:04:00 remuxedvid.mkv
    Take note that one should replace “00:00:00” with the intended start time. Everything before that will be trimmed. “00:04:00” should be replaced with the total time. Everything after [start + total] time will be trimmed as well.

Compared to the first time around, I avoided 15 minutes of rendering and 15 minutes of reencoding. So using ffmpeg as much as possible and cinelerra as little as possible is usually the most time-optimal solution.

Also, by being sneaky I did all of this using the flip cam’s space. No need to delete temp files from two¬†locations.

Walker’s new rule for doing video work: Do you need to composit something? Then use cinelerra. If you do not, then do not use cinelerra.