I have recorded a 2 hour piano recital with a mobile phone (OnePlus 5) as MP4 in 1080p. I am pretty happy with the result, except for the audio. I had a separate audio-only set up with a pair of decent Røde condenser microphones feeding a Tascam DR-44WL at 24Bit/96kHz. Beautiful audio.

I loaded both the video and audio clip into kdenlive, muted the audio from the video file, did some playing with sliding the better audio track and finally got it completely synchronized. I then rendered it as high quality MP4, which took 6,5 hours on a Lenovo X1.

The original video file:

Code: Select all

(+) Video --vid=1 (*) (h264 1920x1080 30.037fps)
 (+) Audio --aid=1 --alang=eng (*) (aac 2ch 48000Hz)

is 18GB in size and the resulting rendered file is:

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 (+) Video --vid=1 (*) (h264 1920x1080 25.000fps)
 (+) Audio --aid=1 (*) (aac 2ch 48000Hz)

and the size is a whopping 96GB. While I like the result in terms of synchronization, the file is so big, and obviously with a really high video bitrate, mpv has trouble playing the file without stutter or dropped frames. As the rendering profile I chose Lossless/HQ (libx264+aac). Obviously I was overdoing it.

Q: Is there away to

a) leave the video as it is without re-encoding and
b) leave the audio in 24/96 as in the original?

Other than that, what are my options in order to at least keep the audio track in 24/96 and transcode the video into something of comparable size to the original?

It make no sense to render a MP4 to a lossless version. Render the video and audio with MP4. Change the audio settings to 192.