19 Jun
2015
19 Jun
'15
12:39 p.m.
Thanks very much for swift reply Carl and for reassurance about the
encoding errors.
In my opinion, it'd be good for the log to be verbose and include all
FFMPEG output - you never know when it's going to be useful for
debugging. To avoid worrying people with odd messages, each FFMPEG log
line could always be prefixed with "Info only: FFMPEG: ". But you may
disagree and prefer to keep the logs shorter.
I'm guessing that the swscaler messages are because the pixel height of
the input is not divisible by 16 (see
http://superuser.com/questions/728795/new-ffmpeg-swscaler-0xa314080-warning…).
And, yes, the time it takes to scale is probably a drop in the ocean
compared to the JPEG2000 encoding. Roll on that GPU-accelerated encoding!
Many thanks,
Jim
On 19/06/2015 12:33, Carl Hetherington via DCPomatic wrote:
Hi Jim,
On Fri, 19 Jun 2015 09:26:48 +0100
Jim Dummett via DCPomatic <dcpomatic(a)carlh.net> wrote:
[snip]
[swscaler @ 0x103830800] Warning: data is not
aligned! This can lead to
a speedloss
...lots of progress...
[prores @ 0x103811e00] invalid plane data size
[prores @ 0x103811e00] invalid plane data size
[prores @ 0x103811e00] ac tex damaged 3371, 1024
...progress until end
NB I was using dcpomatic_cli, rather than the GUI. The DCP-o-matic
project was created using the GUI, but then I use a script to call
dcpomatic_cli, in order to batch process multiple DCPs.
DCP-o-matic 1.79.0, Mac OS X 10.9.5.
A few questions:
1. These errors/warnings are not included in the log file - they were
just output to the terminal, presumably from FFMPEG. Shouldn't they also
go to the log file? If I'd run the encode from the GUI, the errors would
be silently ignored and there'd be no record of them.
FFmpeg generally gives
quite a lot of output on the console, as
you have observed. I have seen a lot of source files which cause
FFmpeg to raise warnings or "errors" such as these but which play back
perfectly (and hence result in good DCPs).
Any errors that are returned from calls to FFmpeg that DCP-o-matic makes
are handled and reported by DCP-o-matic. At the moment I *believe*
that nothing serious is reported via the console, so I think
putting it into the logs may result in unnecessary concerns when people
read those logs.
2. Should I be worried about the "invalid
plane data size" and "ac tex
damaged" lines? Presumably this indicates corruption in the source file,
but has FFMPEG quietly fixed that, or may the DCP be corrupt too?
I think it is
unlikely that the DCP is corrupt. FFmpeg has probably
quietly ignored or fixed any problems that is perceives.
3. Does "3371" indicate the frame
number which is possibly corrupt?
I doubt it. I would guess that number would only
mean something to an
FFmpeg developer.
4. I've noticed the "swscaler"
warning message a lot before on various
files. Does this have a major impact on encode times?
It does happen a lot.
Encode times are dominated by JPEG2000 encoding,
so I would doubt this message indicates any serious slow-down. That
being said, I will finally get around to investigating its source one
of these days, to be sure!
With best regards,
Carl
_______________________________________________
DCPomatic mailing list
DCPomatic(a)carlh.net
http://main.carlh.net/cgi-bin/mailman/listinfo/dcpomatic