[FFmpeg-user] How can I get ffmpeg to honor 'analyzeduration' and 'probesize'?

Mark Filipak markfilipak.imdb at gmail.com
Tue Dec 26 01:37:18 EET 2023

Hey Paul, Happy Holidays and Happy New Year to you.
On 12/25/23 16:48, Paul B Mahol wrote:
> On Mon, Dec 25, 2023 at 10:32 PM Mark Filipak <markfilipak.imdb at gmail.com>
> wrote:
>> How can I get ffmpeg to honor 'analyzeduration' and 'probesize'?
>> The terminal output is below.
>> C:\Windows\System32>ffmpeg -report -analyzeduration 5772725000 -probesize 15091101696 -r 24000/1001 -f concat -safe 0 -i c:\00305+00306.txt -map 0 -c copy -dn c:\00305+00306.mkv
> For concat demuxer inputs you probably need to put those options with
> values inside that .txt file.

Yes, I thought so, too. But I couldn't see how to do it.

> Because ffmpeg is not used directly with concat demuxer, as concat demuxer
> is doing many stuff at once.

Yes. It's a sorta macro.

> Consult concat demuxer documention for more info.

Aha! In the line
"option key value
"    Option to access, open and probe the file. Can be present multiple times."
I guess that "option" is the word "option", so I changed c:\00305+00306.txt to read
ffconcat version 1.0
file e:\\00305.mkv
duration 1:32:51.432
option analyzeduration 5772725000
option probesize 15091101696
file e:\\00306.mkv
duration 1:15:04.029
option analyzeduration 5772725000
option probesize 15091101696
# set PREP=-analyzeduration 5772725000 -probesize 15091101696 -r 24000/1001
# set FORMAT=-f concat -safe 0
# set SOURCE=c:\00305+00306.txt
# set CODERS=-c:v libx265 -x265-params crf=16 -c:a copy -c:s copy -dn
# set TARGET=c:\00305+00306.mkv
# ffmpeg %PREP% %FORMAT% -i %SOURCE% -map 0 -c copy -dn %TARGET%
and it worked.

Thanks so much, Paul!

Now I can continue with the more difficult problems. They will be the subject of a different thread. 
I've been working on this for weeks.

Regarding the documentation, if I had the power, I'd replace this:

<samp><code>option <var>key</var> <var>value</var></code></samp>

by this:

<samp>The word "option" followed by <var>key</var> <var>value</var> words (e.g., <code>option 
analyzeduration 2400000000</code>)</samp>

I used TBird's Inspect tool to make the replacement and it looks great. It doesn't add any lines and 
it's correct English usage, too. I wish I could work on the documentation.

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