Re: [Debconf-video] MiniDebConf Prishtina video
On 08/10/17 21:14, Wouter Verhelst wrote:
> Hi Daniel,
>
> On Sun, Oct 08, 2017 at 08:09:23PM +0200, Daniel Pocock wrote:
>> Hi,
>>
>> Where can I store the raw video and audio files from the MiniDebConf in
>> Prishtina?
>>
>> Is there a workflow I can suggest for volunteers to process these into a
>> format suitable for the web?
>>
>> We have about 30GB of data, including video files from a DSLR and audio
>> recorded with a lapel microphone.
> Whoa.
>
> I hope you used a clapperboard or something along those lines, otherwise
> getting them back into sync might be complicated. The human mind is
Given that over half the talks are in Albanian and they are all
concatenated in 3 large WAV files, it will be complicated++.
Fortunately we have two very competent Albanian speaking communities
keen to help out.
> *extremely* good at detecting when A/V desync has happened; the only way
> to reliably get things back into sync well enough is by using a
> visualisation of the audio and to line that up with a visual cue that
> can be easily related to part of the audio visualisation (like would be
> the case with a clapperboard and the spike that its clap would produce).
I've done this before with Blender so I understand what you are getting
at. Somebody will need to identify the start points in the big WAV
files and potentially cut them into smaller files and normalize them
with sox.
If we can create a basic wiki page for this situation then one of the
hackerspace communities (Prishtina or Tirana) might have a go at it.
The DSLR also had a Rode VideoMic Pro and it probably has reasonable
quality audio from the audience questions, this source can be muted for
the talks and enabled for the questions. As it also picks up the
speakers very well it is very useful for the sync process.
I've previously patched the Diktofon app to disable AGC and add high bit
rates. Would anybody have any suggestions for further enhancements to
Diktofon that could make it easier to sync with DSLR and mobile phone
videos?
> Most nonlinear editors will support doing so. One nonlinear editor that
> exists in Debian is "kdenlive". Not sure whether it supports that --
> haven't tried yet.
Blender is also in Debian and it is useful for this, although some
people feel kdenlive is easier. I've read elsewhere that the Blender
keystrokes are "wrong" for people who do this type of work regularly.
https://packages.qa.debian.org/b/blender.html
https://danielpocock.com/quick-start-blender-video-editing
> Alternatively, sreview (https://sreview.debian.net) is capable of
> processing A/V desync correction values, but it doesn't have any way to
> help you line up the audio and video yet.
>
> If you want to do the former, you'll probably have to do more work
> yourself, and afterwards one of us will have to do the upload into the
> meetings archive.
>
> If you want to do the latter, we'll have to get the raw files uploaded
> to vittoria.debian.org, I'll have to add code to sreview so that audio
> from alternate sources is supported (shouldn't be too hard, can probably
> get that done next weekend or maybe a little earlier), you'll have to
> give me the schedule, and then you and any volunteers you want to share
> the load with can do review through the sreview webinterface.
>
> Let me know what you decide ;)
>
The schedule is on the wiki:
https://wiki.debian.org/DebianEvents/ks/2017/MiniDebConfPrishtina#Schedule
but from what you describe, it doesn't seem like sreview is the right
solution for this type of raw data.
However, I would really like to upload the raw data somewhere for backup
purposes at the very least, can I still put it on vittoria.debian.org
and if so, under which directory?
One other issue: I notice the DSLR doesn't always keep the speaker in
focus when autofocus is enabled. It is a Nikon D800. Can anybody with
more experience comment on this? Is there anything I can do to get the
autofocus working well? Do I need to have the camera closer to the
speaker for good autofocus? Or should I just put it in manual focus
mode in future? Are any other DSLR models better for this? In this
case, the camera was about 5- 6 meters from the speaker.
Regards,
Daniel
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