17 Oct
2014
17 Oct
'14
7:56 p.m.
I just did a test with separate video/audio clips. Imported them, video source is 24fps.
DCP-o-matic reports source and DCP will have same frame rate. No mention of audio. I then
adjust the DCP frame rate to 25 fps. DCP-o-matic tells me that the frame rate will be
adjusted to 25 fps. However, there is no indication what it will now do anything with the
audio? I think we discussed this before shortly, but didn't come to a proper
conclusion. With separate audio files, will DCP-o-matic simply assume that the separate
audio has to be in sync to the chosen DCP frame rate? Because with a different frame rate
for video, it could just as well resample the audio to 25 fps as well - but it needs to be
instructed to do so - which includes that there is a frame rate/sampling rate relation
established before and a change being notified.
The question is - with separate audio, how/where do you establish it's frame rate
reference at first so that DCP-o-matic knows to what framerate the audio is referenced?
With interleaved audio, this is clear, upon loading it, the audio/video timing reference
is established, but with separate video and audio files?
Did I make my issue clear?
- Carsten
17 Oct
17 Oct
8:59 p.m.
Good question. If I get them separately, I master my picture and audio together first. But
yes on other DCP software there has to be a frame accurate correlation between picture and
audio to make that adjustment. But I sometimes get audio that starts at 2 beep, and
picture starting at Picture Start. How would it handle that? Even at the same frame rate?
Is there an adjustment for delaying audio for sync purposes, then keeping it in sync once
a frame rate adjustment has been made?
Tom Rovak - Executive Producer / Sr. Colorist / Post Production Supervisor
ROVAK COLORIST SERVICES
A Division Of The Annex Studios
Commercials, Feature Films, Music Videos, Long Form
Color Correction, Dailies, Editorial, Finish/VFX
trovak(a)comcast.net
(815)690-8323
Website / Commercial Reel: http://colorist-rovak.com/
----- Original Message -----
From: "Carsten Kurz" <audiovisual(a)t-online.de>
To: "DCP-o-matic net carlh" <DCPomatic(a)carlh.net>
Sent: Friday, October 17, 2014 2:56:08 PM
Subject: [DCP-o-matic] audio subsampling when adjusting frame rate
I just did a test with separate video/audio clips. Imported them, video source is 24fps.
DCP-o-matic reports source and DCP will have same frame rate. No mention of audio. I then
adjust the DCP frame rate to 25 fps. DCP-o-matic tells me that the frame rate will be
adjusted to 25 fps. However, there is no indication what it will now do anything with the
audio? I think we discussed this before shortly, but didn't come to a proper
conclusion. With separate audio files, will DCP-o-matic simply assume that the separate
audio has to be in sync to the chosen DCP frame rate? Because with a different frame rate
for video, it could just as well resample the audio to 25 fps as well - but it needs to be
instructed to do so - which includes that there is a frame rate/sampling rate relation
established before and a change being notified.
The question is - with separate audio, how/where do you establish it's frame rate
reference at first so that DCP-o-matic knows to what framerate the audio is referenced?
With interleaved audio, this is clear, upon loading it, the audio/video timing reference
is established, but with separate video and audio files?
Did I make my issue clear?
- Carsten
_______________________________________________
DCPomatic mailing list
DCPomatic(a)carlh.net
http://main.carlh.net/cgi-bin/mailman/listinfo/dcpomatic
9:09 p.m.
Am 17.10.2014 um 22:59 schrieb Tom Rovak:
Good question. If I get them separately, I master my
picture and audio together first. But yes on other DCP software there has to be a frame
accurate correlation between picture and audio to make that adjustment. But I sometimes
get audio that starts at 2 beep, and picture starting at Picture Start. How would it
handle that? Even at the same frame rate? Is there an adjustment for delaying audio for
sync purposes, then keeping it in sync once a frame rate adjustment has been made?
Sync delay or offset is possible with the controls under audio and Trimming/Position. But
then again, what happens when the frame rate is changed?
Of course, normally you would assume that with separate audio and video imported they have
been aligned externally and will be used like this.
But still, you could import separate audio and video with a common 25 fps reference, then
change the video framerate to 24 fps in DCP-o-matic. In that case, audio resampling should
be applied accordingly.
Maybe DCP-o-matic even does that now - but it seems currently it is not indicating it the
way it's doing it with interleaved video/audio?!
- Carsten
18 Nov
18 Nov
12:05 p.m.
On Fri, 17 Oct 2014 23:09:50 +0200
Carsten Kurz <audiovisual(a)t-online.de> wrote:
Am 17.10.2014 um 22:59 schrieb Tom Rovak:
What might change with delay when the frame rate changes? It is
expressed in milliseconds, so independent of frame rate.
Good question. If I get them separately, I master
my picture and
audio together first. But yes on other DCP software there has to be
a frame accurate correlation between picture and audio to make that
adjustment. But I sometimes get audio that starts at 2 beep, and
picture starting at Picture Start. How would it handle that? Even
at the same frame rate? Is there an adjustment for delaying audio
for sync purposes, then keeping it in sync once a frame rate
adjustment has been made?
Sync delay or offset is possible with the controls under audio and
Trimming/Position. But then again, what happens when the frame rate
is changed? Of course, normally you would assume that with
separate audio and
video imported they have been aligned externally and will be used
like this.
But still, you could import separate audio and video with a common 25
fps reference, then change the video framerate to 24 fps in
DCP-o-matic. In that case, audio resampling should be applied
accordingly. Maybe DCP-o-matic even does that now - but it seems
currently it is not indicating it the way it's doing it with
interleaved video/audio?!
If I understand right, this lack of indication is fixed in 1.76.x
(there is now a note in the Audio tab about what resampling will be
done).
Best regards,
Carl
12:16 p.m.
Am 18.11.2014 um 13:05 schrieb Carl Hetherington:
If I understand right, this lack of indication is fixed in 1.76.x
(there is now a note in the Audio tab about what resampling will be
done).
Oops, that was an old one, yes, the resampling notification is now there under the audio
tab.
- Carsten
14 Jan
14 Jan
10:09 a.m.
Hi all,
Digging this out from the depths of my inbox...
If you have audio and video that are not in sync, the "delay" setting
in the Audio tab can be used to put it in. This is independent of any
frame rate adjustment.
Let me know if it's not clear.
Best regards,
Carl
On Fri, 17 Oct 2014 20:59:12 +0000 (UTC)
Tom Rovak <trovak(a)comcast.net> wrote:
Good question. If I get them separately, I master my
picture and audio together first. But yes on other DCP software there has to be a frame
accurate correlation between picture and audio to make that adjustment. But I sometimes
get audio that starts at 2 beep, and picture starting at Picture Start. How would it
handle that? Even at the same frame rate? Is there an adjustment for delaying audio for
sync purposes, then keeping it in sync once a frame rate adjustment has been made?
Tom Rovak - Executive Producer / Sr. Colorist / Post Production Supervisor
ROVAK COLORIST SERVICES
A Division Of The Annex Studios
Commercials, Feature Films, Music Videos, Long Form
Color Correction, Dailies, Editorial, Finish/VFX
trovak(a)comcast.net
(815)690-8323
Website / Commercial Reel: http://colorist-rovak.com/
----- Original Message -----
From: "Carsten Kurz" <audiovisual(a)t-online.de>
To: "DCP-o-matic net carlh" <DCPomatic(a)carlh.net>
Sent: Friday, October 17, 2014 2:56:08 PM
Subject: [DCP-o-matic] audio subsampling when adjusting frame rate
I just did a test with separate video/audio clips. Imported them, video source is 24fps.
DCP-o-matic reports source and DCP will have same frame rate. No mention of audio. I then
adjust the DCP frame rate to 25 fps. DCP-o-matic tells me that the frame rate will be
adjusted to 25 fps. However, there is no indication what it will now do anything with the
audio? I think we discussed this before shortly, but didn't come to a proper
conclusion. With separate audio files, will DCP-o-matic simply assume that the separate
audio has to be in sync to the chosen DCP frame rate? Because with a different frame rate
for video, it could just as well resample the audio to 25 fps as well - but it needs to be
instructed to do so - which includes that there is a frame rate/sampling rate relation
established before and a change being notified.
The question is - with separate audio, how/where do you establish it's frame rate
reference at first so that DCP-o-matic knows to what framerate the audio is referenced?
With interleaved audio, this is clear, upon loading it, the audio/video timing reference
is established, but with separate video and audio files?
Did I make my issue clear?
- Carsten
_______________________________________________
DCPomatic mailing list
DCPomatic(a)carlh.net
http://main.carlh.net/cgi-bin/mailman/listinfo/dcpomatic
19 Oct
19 Oct
4:05 p.m.
On Fri, 17 Oct 2014, Carsten Kurz wrote:
I just did a test with separate video/audio clips.
Imported them, video
source is 24fps. DCP-o-matic reports source and DCP will have same frame
rate. No mention of audio. I then adjust the DCP frame rate to 25 fps.
DCP-o-matic tells me that the frame rate will be adjusted to 25 fps.
However, there is no indication what it will now do anything with the
audio? I think we discussed this before shortly, but didn't come to a
proper conclusion. With separate audio files, will DCP-o-matic simply
assume that the separate audio has to be in sync to the chosen DCP frame
rate? Because with a different frame rate for video, it could just as
well resample the audio to 25 fps as well - but it needs to be
instructed to do so - which includes that there is a frame rate/sampling
rate relation established before and a change being notified.
The question is - with separate audio, how/where do you establish it's
frame rate reference at first so that DCP-o-matic knows to what
framerate the audio is referenced? With interleaved audio, this is
clear, upon loading it, the audio/video timing reference is established,
but with separate video and audio files?
Hi Carsten,
At the moment, DCP-o-matic looks for the video content which is active at
the audio content's start point and uses that *video* content to decide
what to do with the audio.
If, for example, you have a 24fps video file and an audio file at position
0 on the timeline and you are generating a 25fps DCP, DCP-o-matic will see
that the video is being run fast and resample the audio to cope with that.
Hence it assumes that the sound file has been prepared to be in sync with
the video file as imported.
Does that answer your question?
Regards,
Carl
7:49 p.m.
Am 19.10.2014 um 18:05 schrieb Carl Hetherington:
If, for example, you have a 24fps video file and an
audio file at position
0 on the timeline and you are generating a 25fps DCP, DCP-o-matic will see
that the video is being run fast and resample the audio to cope with that.
Alright, I'll do some testing around it. I brought this up again because I did a quick
test under exactly these conditions, and, unlike with single file interleaved video/audio,
DCP-o-matic did indicate the change in video framerate in the GUI, but not the audio
resampling. So maybe only the audio resampling notification under the content tab is
missing under these conditions?
- Carsten
22 Oct
22 Oct
10:57 a.m.
On Sun, 19 Oct 2014, Carsten Kurz wrote:
Am 19.10.2014 um 18:05 schrieb Carl Hetherington:
Hi Carsten,
1.76.2 has a small note in the audio tab about resampling. Is that enough
to clarify things?
Best,
Carl
If, for example, you have a 24fps video file and
an audio file at position
0 on the timeline and you are generating a 25fps DCP, DCP-o-matic will see
that the video is being run fast and resample the audio to cope with that.
Alright, I'll do some testing around it. I brought this up again because
I did a quick test under exactly these conditions, and, unlike with
single file interleaved video/audio, DCP-o-matic did indicate the change
in video framerate in the GUI, but not the audio resampling. So maybe
only the audio resampling notification under the content tab is missing
under these conditions?
11:23 a.m.
Hi Carsten,
1.76.2 has a small note in the audio tab about resampling. Is that enough
to clarify things?
Just noticed it in 1.76.3
Actually I was missing it below the image content tab, where the general processing chain
- cropping, scaling, etc. is explained as well. You are of course right that a resampling
notification has it's own place under the audio tab.
I'm so into this specific aspect probably because that notification - frame rate
change, audio resampling, was the first thing I noticed when trying DVD-o-matic the first
time - a one-stop-solution for DCP conversion that precisely says which processing steps
are applied. I was always against using 'simple software' for video conversions
because most of them take short-cuts and sacrifice quality, so I really liked the way
DVD-o-matic documented it's processing.
That's why I like to have that information at one point for a quick glance over all
the processing applied. One could as well add information about the padding of channels,
and how many channels will be created, etc.
Of course that full overview wouldn't need to be where it is now. It could as well go
near the job progress bar on the right so that you can always see it when doing changes on
the left.
So, my main concern is to get a quick indication about what is happening during the
conversion. Adding it somewhere around the progress bar could also mean you can look up
the parameters of previous conversion jobs if they stay there.
- Carsten
Am 22.10.2014 um 12:57 schrieb Carl Hetherington:
> On Sun, 19 Oct 2014, Carsten Kurz wrote:
>
>>
>> Am 19.10.2014 um 18:05 schrieb Carl Hetherington:
>>
>>> If, for example, you have a 24fps video file and an audio file at position
>>> 0 on the timeline and you are generating a 25fps DCP, DCP-o-matic will see
>>> that the video is being run fast and resample the audio to cope with that.
>>
>>
>> Alright, I'll do some testing around it. I brought this up again because
>> I did a quick test under exactly these conditions, and, unlike with
>> single file interleaved video/audio, DCP-o-matic did indicate the change
>> in video framerate in the GUI, but not the audio resampling. So maybe
>> only the audio resampling notification under the content tab is missing
>> under these conditions?
>
Hi Carsten,
1.76.2 has a small note in the audio tab about resampling. Is that enough
to clarify things?
>
> Best,
> Carl
>
> _______________________________________________
> DCPomatic mailing list
> DCPomatic(a)carlh.net
> http://main.carlh.net/cgi-bin/mailman/listinfo/dcpomatic
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9 comments
3 participants
participants (3)
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Carl Hetherington -
Carsten Kurz -
Tom Rovak