in this case i was using the legacy/old quicktime player 7.6.6 (1709) /
quicktime version 7.7.1 (2315).
i don't like that new qt x player. but i just checked with that one,
too. same shift.
i used ffmpeg build N-38292-ga4c22e3. so this is for sure not the newest
build. and yes, that's one of the
annoying things with ffmpeg, that it's basically developed so 'actively'
that there's a fairly high chance that things
break from one build to the next.
Holger
Nathan Rusch wrote:
Are you using whatever the default Quicktime viewer is on OSX these
days, or are you explicitly using Quicktime 7? The two tend to
interpret files differently (which I'm sure some engineer somewhere
has an explanation for), but that might explain why you are seeing a
difference. What version of ffmpeg are you using?
And yeah, the frame rate thing is very strange. Even running the exact
same command as you, I haven't been able to set the frame rate when
using '-vcodec copy' on a .jpg sequence. Perhaps the behavior I'm
seeing is a regressive bug introduced in one of the newer versions...
-Nathan
-----Original Message----- From: Holger Hummel|Celluloid VFX
Sent: Wednesday, May 01, 2013 2:35 PM
To: Nuke user discussion
Subject: Re: [Nuke-users] ffmpeg Photo-JPEG QuickTimes
hey Nathan,
i'm sorry, but i don't understand why that doesn't work for you...
with the command i wrote in my last mail i'm able to generate quicktimes
of all sorts of frame rates - even when using '-vcodec copy'.
i just tested it again before sending the mail.
i was just able to compare the jpg files and the QT on OS X. the gamma
shift is also visible there. but what's also interesting
is that there's much more banding visible in the QT compared to viewing
the jpg. guess i should try an encode process on linux to
see if that works properly....
oh well, this endless pain called QT....
Holger
Nathan Rusch wrote:
Yeah, I normally use the -r flag to set the source and destination
frame rate, but what I'm saying is that when '-vcodec copy' is
passed, the rates are all ignored, and ffmpeg assumes 25 fps for both
the source and destination. This is with ffmpeg 1.2.
As for the lack of gamma shifting, these are being encoded on Linux
and viewed on OSX. In Quicktime 7, there is no difference between the
raw JPEG sequence and the resulting .mov. This matches the behavior
of files exported from Quicktime 7 itself, but files encoded with
Shake on OSX *do* show a gamma shift when viewed in Quicktime 7.
-Nathan
-----Original Message----- From: Holger Hummel|Celluloid VFX
Sent: Wednesday, May 01, 2013 1:37 PM
To: Nuke user discussion
Subject: Re: [Nuke-users] ffmpeg Photo-JPEG QuickTimes
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
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--
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]
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