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IDProjectCategoryView StatusDate SubmittedLast Update
0000335KdenliveRenderingpublic2008-11-10 10:592010-01-24 01:07
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PlatformOSOS Version
Product VersionRecent git 
Target Versionfuture versionFixed in Version 
Summary0000335: Print/Render/write to Tape/Firewire from Kdenlive GUI
DescriptionYou have firware capture for DV and HDV.

You should have a "Print to Tape" function where you can send out the sequence as it would get rendered back to tape in DV or HDV format (directly via Camera or Tape Deck.. should be the same I think).

Perhaps not call it "Print to Tape" as thats what its called in Apple's Final Cut Pro.

Pehrpas "Render to Tape" or include it in a Render dialogue as a destination option.
Additional InformationAs Dan has explained in note 1164, this requires a two stage process where kdenlive in the first stage renders to a (set of) file(s) that represents the data that needs to be transferred to the firewire unit, then in the second stage, writes this (set of) file(s) to the camera.

Kino can do this directly because kino uses a model where all effects are rendered as they are applied. However, Kdenlive uses a better model for edits, that has the drawback that rendering time is not predictable, not even to DV/HDV.
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-  Notes
madsdyd (administrator)
2008-11-10 16:30

Do people really use this? :-)

Can we have some more "votes" on this one, please - some discussion. :-)
cinephiliac (updater)
2008-11-10 20:55

Some definitely do. I would say that it's probably only 10% or so though. I'd say it would be useful, but quite a low priority. Anyone else?
Athiril (reporter)
2008-11-10 21:59

We use this at SAE as a backup of final project/render to tape
ddennedy (developer)
2008-11-11 06:02

We can not reliably render to tape in real time, as required by FireWire. Instead you have to render to a DV file and then export that using Kino for now. Maybe we can make a standalone wizard that does this and then eventually integrate it as a post-render option.
madsdyd (administrator)
2008-11-12 11:01

Dan, I am curious. When you say that we can not do it, is that because of the conversion that has to take place during rendering? Much like in the old days, when you had to create an iso image before you could burn it to a CD? Or, is there something else in kdenlive that disallows this feature from beeing implemented?
ddennedy (developer)
2008-11-12 18:40

Well, MLT has this real_time=1 feature where it will drop video frames to "keep up" like when using SDL preview. However, if you have done any AVCHD editing or have used really heavy filters, you will have noticed that apparently it is not good enough because the sound breaks up. However, let's say I fixed that, then this FireWire output could only be used as a preview with a high risk of many frames dropping and perhaps even entirely skipping over short transitions. If you need a FireWire output with full integrity, then the amount of rendering is non-deterministic and not governed to guarantee real time - don't forget that real time DV or MPEG-2 encoding is required as well. Therefore, you would have to render in real time.

MLT has an adjustable render-ahead buffer that can be quite large but limited by RAM, and the buffer can absorb short periods that take longer than real time. However, this only works in highly controlled, predictable environments like the video server I just wrote for a customer with fixed, preset effects and known hardware.
madsdyd (administrator)
2008-11-12 21:56

Thanks Dan for clearing this up.
madsdyd (administrator)
2008-11-12 22:01

Acknowledged as a feature for 0.7.1, but I do not think it will be done for 0.7.1 as it requires too much effort.
IngeSv (reporter)
2009-02-07 16:46
edited on: 2009-02-07 17:00

The reason I bought I tape cam was to be able to write the edited film back to tape for backup. I know to little to understand everything in this discussion, but I wonder if it would be possible to write the rendered HDV file back to tape from the hard disk? Do I get it right that the HD quality will be lost by rendering it to a DV file and the writing it to tape with Kino?

ddennedy (developer)
2009-02-08 02:39

You do not need to try to understand everything in this issue.
Basically, all that exists today for sending MPEG-2 over FireWire is a little example program called test-mpeg2 in the libiec61883 tarball - not installed as part of a package typically as it is just an example. It lacks a lot features to make it usable and robust. Also, it has very little testing for HDV. So, right now if you render to DV and export using Kino, you will lose the HD resolution.

There is no decent command line utility for sending DV or HDV over FireWire. No, dvconnect is not any good because it uses deprecated and known unreliable APIs. Really, what needs to happen, is that kdenlive needs to design a post-render workflow system. This would cover sending to tape, uploading to YouTube, burning to DVD, etc. Then, there would be workflow actions implemented using the libiec61883 library for sending to tape.
IngeSv (reporter)
2009-02-08 10:12
edited on: 2009-02-08 10:17

Thank you for your clarifying answer. I've tested "test-mpeg2 -t 0 Untitled.m2t", but it says Starting to transmit and the camera says Check your HDV/DV input after I've started it. Maybe I'm doing something wrong.
If I could do this right maybe I could help in testing test-mpeg2 with HDV.

ddennedy (developer)
2009-02-09 01:44

Try it without -t 0.
IngeSv (reporter)
2009-02-09 09:32

As far as I can see it gives the same result.
ddennedy (developer)
2009-02-09 18:23

We need to separate encoding, mux, and FireWire I/O issues. Please test this first with a file that you _captured_ instead of one that you rendered - both with and without the -t option. Finally, you need to be sure that you use the correct node-id when using the -t option. Run 'plugreport' in a terminal window, and the node that has plugs - more than likely there is only one - is the one to use. Thank you.
IngeSv (reporter)
2009-02-09 19:09

Now I get:
inge@svensson:~> test-mpeg2 capture002.m2t
couldn't find a PCR within 20000 packets; giving up
couldn't find a PCR within 20000 packets; giving up
Starting to transmit

plugreport gives:
inge@svensson:~> plugreport
Host Adapter 0

Node 0 GUID 0x0000850001a28bfc
oMPR n_plugs=1, data_rate=0, bcast_channel=63
oPCR[0] online=0, bcast_connection=0, n_p2p_connections=0
        channel=63, data_rate=0, overhead_id=0, payload=146
iMPR n_plugs=1, data_rate=0
iPCR[0] online=1, bcast_connection=1, n_p2p_connections=0

Node 1 GUID 0x00e0180000a81f3f
libiec61883 error: error reading oMPR
libiec61883 error: error reading iMPR

The same as above with test-mpeg2 -t 0 capture002.m2t
ddennedy (developer)
2009-02-09 19:19

OK, obviously libiec61883 is not prepared to support HDV transmission. I do not have a HDV camera yet to look into this. Sorry, I am not willing to log into a remote box to work on it either. I have a lot of things to tend to that can be done without owning the equipment, and these will get priority. A friend has offered the sale of a used HV20 that I might get, but do not count on it because I owe taxes for 2008. Feel free to work on this yourself if you can.
IngeSv (reporter)
2009-09-28 10:06

What I don't understand is that I can't print DV files to my Canon HV-30 with test-mpeg2. I don't know if I'm doing something wrong with test-mpeg2 or the cam. When I start Kino from command line it works to print a video (DV) from inside Kino. It uses iec61883Writer port 0 channel 63. Is it using iec61883? In that case how? Could I use some command from it?
IngeSv (reporter)
2009-09-29 18:09

It seems that people are having this problem with other programs with this camera. The camera says something like "Check HDV/DV input"
ddennedy (developer)
2009-09-29 18:23

I have an HV20 now, so I can take a look at this. I am quite busy, but at the very least, in the near time, I can run some tests and record my results here. Thanks for trying.
IngeSv (reporter)
2010-01-14 19:32

With libiec61883 1.2.0 I at least get starting to transmit and after some time done, but nothing is printed to the tape.
ddennedy (developer)
2010-01-14 19:44

"get starting to transmit" means nothing to me. Do you mean that you see the video you are trying to send in the viewfinder.
"printed to the tape" sounds silly and is not entirely clear. Do you mean that the camera did not _record_ to tape the video you sent? If so, that is entirely expected. All that test-mpeg2 does is send. You have to use 'dvcont record' or some control on the camera itself to tell it to record.
IngeSv (reporter)
2010-01-14 19:54

starting to transmit is written in the konsole window. Yes, the camera didn't record to tape. I try to give the camera the command by pressing buttons that I found out. I tried both before and after I gave the command test-mpeg2 with parameters.
ddennedy (developer)
2010-01-14 20:13

I am fairly certain the video should appear in the viewfinder when it is working, do not worry about recording yet. In any case, these updates serve as my reminder to do a test on my own camera.
IngeSv (reporter)
2010-01-17 19:20

I think you are right about the video appearing in the viewfinder. I did when I tried with a Windows program.
ddennedy (developer)
2010-01-24 01:07

I tested test-mpeg2 with my Canon HV20, and it does not work. When it was developed, I was only able to test against a DTV settop box, where I got it working, and the other developer got it to work with DVHS. It is highly non-trivial to get it working with a lot of devices (or just HDV in general), and I do not plan on doing it.

- Issue History
Date Modified Username Field Change
2008-11-10 10:59 Athiril New Issue
2008-11-10 16:30 madsdyd Note Added: 0001043
2008-11-10 16:30 madsdyd Status new => feedback
2008-11-10 20:55 cinephiliac Note Added: 0001065
2008-11-10 21:59 Athiril Note Added: 0001077
2008-11-11 06:02 ddennedy Note Added: 0001089
2008-11-12 11:01 madsdyd Note Added: 0001143
2008-11-12 18:40 ddennedy Note Added: 0001164
2008-11-12 21:56 madsdyd Note Added: 0001166
2008-11-12 22:01 madsdyd Note Added: 0001167
2008-11-12 22:01 madsdyd Priority normal => low
2008-11-12 22:01 madsdyd Status feedback => acknowledged
2008-11-12 22:01 madsdyd Projection none => major rework
2008-11-12 22:01 madsdyd Target Version => 0.7.1
2008-11-12 22:01 madsdyd Summary Print to Tape => Print/Render/write to Tape/Firewire from Kdenlive GUI
2008-11-12 22:01 madsdyd Additional Information Updated
2008-11-17 20:54 madsdyd Target Version 0.7.1 => future version
2009-02-07 16:46 IngeSv Note Added: 0002372
2009-02-07 16:52 IngeSv Note Edited: 0002372
2009-02-07 16:53 IngeSv Note Edited: 0002372
2009-02-07 17:00 IngeSv Note Edited: 0002372
2009-02-08 02:39 ddennedy Note Added: 0002375
2009-02-08 10:12 IngeSv Note Added: 0002376
2009-02-08 10:14 IngeSv Note Edited: 0002376
2009-02-08 10:14 IngeSv Note Edited: 0002376
2009-02-08 10:15 IngeSv Note Edited: 0002376
2009-02-08 10:17 IngeSv Note Edited: 0002376
2009-02-09 01:44 ddennedy Note Added: 0002378
2009-02-09 09:32 IngeSv Note Added: 0002380
2009-02-09 18:23 ddennedy Note Added: 0002389
2009-02-09 19:09 IngeSv Note Added: 0002391
2009-02-09 19:19 ddennedy Note Added: 0002392
2009-09-28 10:06 IngeSv Note Added: 0004022
2009-09-29 18:09 IngeSv Note Added: 0004043
2009-09-29 18:23 ddennedy Note Added: 0004047
2010-01-14 19:32 IngeSv Note Added: 0004515
2010-01-14 19:44 ddennedy Note Added: 0004516
2010-01-14 19:54 IngeSv Note Added: 0004517
2010-01-14 20:13 ddennedy Note Added: 0004518
2010-01-17 19:20 IngeSv Note Added: 0004520
2010-01-24 01:07 ddennedy Note Added: 0004572

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