[FFmpeg-user] FFmpeg Architecture

Mark Filipak markfilipak.imdb at gmail.com
Wed Feb 14 04:10:57 EET 2024

On 13/02/2024 20.27, amindfv--- via ffmpeg-user wrote:
>>> params *before* "-i" are *input params*
>>> params *after* "-i" are *output params*
>>> that has *always* been the case at least for 15 years and so it's
>>> logical that you can't place a param at a random position by common
>>> sense and expect the same result
>> Thank you, Harald. I knew that but your gentle reminder is welcome. It has
>> helped me to better see the problem.
> This is documented in the first 2 sections here: https://trac.ffmpeg.org/wiki/Seeking

Yes, Tom, and it essentially says they are very different in execution time but identical in result, 
which they're not, not even close.

Also, '-i'-before-'-ss' is ignoring '-copyts'.
Also, 'too-early' video packets are being output instead of cut.
Also, 'too-early' audio packets are being output instead of cut.
Also, the first audio packet that is erroneously passed is much smaller and has a different CRC than 
it should have even though this is a remuxing operation.
The evidence of bugs throughout is overwhelming.

Contrary to what's written, '-i this.m2ts -ss 20 -to 60' outputs 40 seconds, not 60.

Shall I go on?

My question once again, in this thread's first post:

Why are these different?
ffmpeg -ss 20.061708333 -copyts -i %SOURCE% -map 0 -c copy -sn -dn -muxdelay 0 %TARGET%
ffmpeg -copyts -i %SOURCE% -map 0 -ss 20.061708333 -c copy -sn -dn -muxdelay 0 %TARGET%

Note that "20.061708333" is a time, not a PTS.

Why are they hundreds of frames different?

We are over 35 posts in this thread (not counting 2 other threads of related stuff) and no one has 
even said whether they should or should not be the same.

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