How can i concat properly?

Questions that occur when trying to compile FFmpeg.
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Posts: 1
Joined: Mon May 14, 2018 7:38 am

How can i concat properly?

Post by nirmitlamed » Mon May 14, 2018 7:52 am

Hello everyone,
I am hoping i am in the right forum.

I have one video file which i made from it 2 trim new video files using the -ss -t and -c copy commands.
Then i wanted to merge these 2 trim files using -f concat and -c copy commands. It did manage to create new video file however it doesn't have a picture and only sound when using preview option on my Mac OSX but it did played OK in Movist (player) app. However when i tried to upload it to twitter it gave me an error.

The solution i have found was to let ffmpeg to re encode each video files and then concat them. The problem is of course it takes time and thats why i am asking for your help how can i make this process faster and not to re encode.

Why i have this problem although those two video files are from the same original video and was using the same original codec (-c copy)?

Posts: 30
Joined: Thu Nov 02, 2017 7:41 pm

Re: How can i concat properly?

Post by therube » Tue May 15, 2018 3:23 am

Do the individual pieces play as expected?

What are the full command lines you are using for your concat?

I use something like this:

Code: Select all

ffmpeg -f concat -safe 0 -i %OUT%\CONCAT3.TXT -c copy "%OFILE%"
Where CONCAT3.TXT is something like:

Code: Select all

file 'H:\Blue Angels Flight 1.mp4'
file 'H:\Blue Angels Flight 2.mp4'
file 'H:\Blue Angels Flight 3.mp4'

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