With cuts-only editing, does OpenShot convert to RGB?

[codemaster]

From OpenShot documentation, I understand that imported clips are decoded with ffmpeg. And when rendering the timeline, encoding is done with ffmpeg.

So, for example, I have clip X. Video is a H.264 stream. Audio is AAC. Container is MP4.

If I give clip X to ffmpeg as input, trim it, encode it with libx264, copy the audio, and mux to mkv, then ffmpeg will not convert to RGB.

Question 1:

If I import clip X into OpenShot, add it to timeline, trim it, and export an mkv file, will OpenShot convert from YUV to RGB to YUV? Or will it just decode YUV and encode YUV, without converting to RGB after decoding and before encoding? If I cut, but don't add transitions, effects, titles, etc, I know Premirere Pro doesn't convert to RGB, but does OpenShot convert to RGB?

Question 2:

If I add clip X to timeline in OpenShot, trim it, add a fade in, add a fade out, then export an mkv file, then which frames will be converted to RGB? All frames in the timeline, or just the frames containing the fade?

Question 3:

Is there a test I can do, that confirms if the output file was converted to RGB before encoding?

[poisondeathray]

Question 3:

Is there a test I can do, that confirms if the output file was converted to RGB before encoding?

You can test it by importing a YUV clip with full range values, and a 2nd YUV test that generates out of gamut RGB values; then export a YUV format. If the YUV export no longer has full range values, or no longer has those YUV values that generate out of gamut RGB values, then likely there was an intermediate RGB step

So you can test if effects, transitions are affected when applied , or if entire clip is affected