hey Nathan,
regarding the frame rate:
you need to specifiy the '-r 24' parameter before the input file '-i
inputfile.%04d.jpg' then it does set the frame rate
correctly:
ffmpeg -r 24 -i inputfiles.%04d.jpg -vcodec copy output.mov
what OS do you see that same gamma/brightness of the jpg files as well
as the resulting QT?
i'm on windows here so that might be once more the reason for the
problem i'm having...
cheers,
Holger
Nathan Rusch wrote:
The '-vcodec copy' option is nice, but I've had issues using it in
conjunction with trying to set the frame rate for the output media;
any combination of flags attempting to set either the source or
destination frame rates seem to be ignored, and you always end up with
a 25 fps output file.
Also, for what it's worth, using ffmpeg to re-encode a JPEG sequence
doesn't introduce a gamma shift in any scenario I've encountered.
-Nathan
-----Original Message----- From: Holger Hummel|Celluloid VFX
Sent: Wednesday, May 01, 2013 7:50 AM
To: Nuke user discussion
Subject: Re: [Nuke-users] ffmpeg Photo-JPEG QuickTimes
unfortunately, i don't know how to get around that nasty
gamma/brightness shift either. i'd be more than happy to find the
solution for this.
but there's another option that you can also use to get a Photo-JPEG
Quicktme with the exact jpg quality you want.
you just render out a jpg sequence with the esact setting as you want
from within Nuke and then use ffmpeg's '-vcodec copy' option.
this will just copy/wrap the jpg files into a Quicktime file without
re-encoding - unfortunately including that nasty gamma shift.
Holger
Nathan Rusch wrote:
I ended up writing an movWriter for Linux for this exact reason. I’m
not exactly sure how to translate Quicktime’s “90%” setting into
quantizer and bitrate parameters, but this should at least give you a
bitrate and quality level somewhere in the same neighborhood.
ffmpeg -r 24 -start_number 1001 -i /path/to/input_sequence.%04d.jpg
-pix_fmt yuvj420p -vcodec mjpeg -f mov -qmin 0 -qmax 1
/path/to/output/file.mov
You need the '-start_number' flag if your sequence starts at a frame
other than 1 or if you only want to use a subset of a sequence. The
'-r' flag sets the frame rate of the source, and since no target rate
is specified, the same will be used for the output. You can also use
'yuvj422p' for the output '-pix_fmt' value if you want 4:2:2 chroma
subsampling.
Hope this helps.
-Nathan
*From:* Dan Rosen <mailto:[email protected]>
*Sent:* Tuesday, April 30, 2013 4:49 PM
*To:* Foundry <mailto:[email protected]>
*Subject:* [Nuke-users] ffmpeg Photo-JPEG QuickTimes
Hello,
Sorry to use this forum, but hopefully someone can point me in the
right direction to use ffmpeg (given that Nuke cannot properly write
out a Photo-JPEG QuickTime with correct color nor with 90% quality).
I am trying to write out frames from Nuke, with the lut applied in
Nuke, and then compile them into Photo-JPEG QuickTime with 90%
quality. There's a brightness shift that appears to be the pesky gama
atom, but the file does not actually contain the atom so there's no
solid way to remove the shift. I am still testing so the shift maybe
something else. Fwiw, I have found good results with the ProRes codec
(no shift).
I have read up on the it online, but all results list "mpeg" as the
format in the Inspector window of QuickTime, but maybe it's correct
since it lists "Photo-Jpeg" in the format int the Properties window.
Any help would be much appreciated. Thanks!
-Dan
------------------------------------------------------------------------
_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
------------------------------------------------------------------------
_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
--
Holger Hummel - [email protected]
Celluloid Visual Effects GmbH & Co. KG
Paul-Lincke-Ufer 39/40, 10999 Berlin
phone +49 (0)30 / 54 735 220 - [email protected]
_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
