Trimming video triples the file size

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William Jones

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Trimming video triples the file size

PostSun May 09, 2021 1:43 am

I start with a 100 minute MP4 video (1920x1080-30) that is 2 gb in size. I can trim the original by trimming the beginning and the end and have a 40 minute video that is 6.5 gb in size.
1) Am I doing something wrong?
2) How can I end up with a video of the same file size or smaller?
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capthook

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Re: Trimming video triples the file size

PostSun May 09, 2021 5:47 am

Sounds like your are using 'automatic/best' (the default) for kbps on export.
Try changing the Kb/s and restrict it to the rate of the original, or something other than auto as it can crank up the Kb/s and cause large file sizes.
kbps.jpg
kbps.jpg (52.95 KiB) Viewed 185 times
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peterjackson

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Re: Trimming video triples the file size

PostSun May 09, 2021 10:26 am

If trimming is all you usually do using a lossless cutter might be more appropriate.

TMPGEnc Smart Render
Machete
Lossless Cut
Video Redo
Etc
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Andrew Kolakowski

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Re: Trimming video triples the file size

PostSun May 09, 2021 10:33 am

Your original file has only about 2.6Mbit average bitrate, so you have to keep it the same to get relatively same file size.

If you want to just trim file or do hard cuts the best solution is one of the mentioned tools, which will keep original data.
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William Jones

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Re: Trimming video triples the file size

PostSun May 09, 2021 10:05 pm

capthook wrote: restrict it to the rate of the original


Where do I find what the rate of the original is?
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Uli Plank

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Re: Trimming video triples the file size

PostMon May 10, 2021 1:20 am

MediaInfo is free. But you may not like the quality at the same bitrate.
Why don't you try the Media Manager with the Trim option? It'll leave your encoding untouched, if it can handle the codec.
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