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orange_juice
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Location: Athens - Greece
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 Posted: Sun Aug 12, 2007 11:13 pm Post subject: Connecting a non-USB camera and achieving qualtiy [solved] |
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Hallo,
I have an HDV Canon HV20 camera and I would like to connect it to my box so I can record directly to the hard disk, or temporarily use it as web cam.
The camera has the following outputs:
HDV/DV terminal (Firewire)
Component out (Only for video. Its wire resembles 4pin firewire from one edge and leads to 3 RCAs to the other edge [Blue Green Red])
HDMI
What components do I need to achieve the connection?
For the moment I use the firewire connection for playing back the tape and grabbing the video. Can I also use it for acquiring "live image" from the camera?
I would appreciate your help.
Kind regards,
orange_juice
Last edited by orange_juice on Tue Aug 14, 2007 9:16 pm; edited 3 times in total |
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barophobia
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| Posted: Mon Aug 13, 2007 12:42 am Post subject: |
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Kino will do that for you through firewire.
http://www.kinodv.org/
Video out stuff and hdmi you need a tv tuner card with the inputs you want.
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orange_juice
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Location: Athens - Greece
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| Posted: Mon Aug 13, 2007 5:50 pm Post subject: |
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Thank you.
That seem to be doing the trick.
The issue is that kino can only capture in DV mode and the quality of the picture is very poor, compared to the capabilities of this camera.
The picture has a lot of grain and motion in the frame is constantly being followed by black lines.
Would this be a matter of hardware or software?
| Code: | 01:00.0 VGA compatible controller: nVidia Corporation G70 [GeForce 7600 GT] (rev a1)
02:0b.0 FireWire (IEEE 1394): Texas Instruments TSB43AB22/A IEEE-1394a-2000 Controller (PHY/Link) |
Kind regards,
orange_juice |
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barophobia
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| Posted: Mon Aug 13, 2007 6:23 pm Post subject: |
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| orange_juice wrote: |
The picture has a lot of grain and motion in the frame is constantly being followed by black lines.
Would this be a matter of hardware or software?
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I don't have a hd dv camcorder but let see what the bandwidth requirements for it will be. I think the firewire link transfers uncompressed video i might be wrong on this.
Uncompressed hdtv at 1080p 1920*1080 pixels at 24bit per pixel at 30fps = 186,624,000 (edit forgot a zero) byte per sec
That needs a really really fat pipe to cram down 177.98 megabyte/sec, but i think still with in the specs of firewire unless firewire is 400 megaBIT/sec if it is then you are screwed. Even if you are not screwed there there is other areas where you can get in trouble. Unless you can compress this stream of data real time there is no way your standard hdd will be able to keepup. Or you have to have a huge storage device than can sustain that stream of data.
I think the firewire dv link falls back on to the poorer quality, dvd quality.
As for the grain... there might be some filters you can run to fix that I haven't messed with kino much.
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orange_juice
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| Posted: Mon Aug 13, 2007 8:29 pm Post subject: |
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| barophobia wrote: | | Uncompressed hdtv at 1080p 1920*1080 pixels at 24bit per pixel at 30fps = 18,662,400 byte per sec |
Thank you!
I did a little research on this issue. I found this post, where at #6 it is stated that | Quote: | | The HV 20 'sees' 1920x1080 resolution, which is then translated by the DSP into 1440x1080 resolution with a PAR of 1.33, still using a 4:2:2 color space. If you export with HDMI at that time in 8 bit, it requires an approximate data stream of around 125 MByte/s. If the signal is recorded to tape, the signal has been compressed to MPEG2 in a 4:2:0 color space. Just like compressing WAV to MP3, during compression 11/12 has been thrown away and is irretrievably lost. When using HDMI after the fact (from tape) it is nothing more than a fire wire similar connection for digital transfer. See the image below: |
I checked that my firewire connection is 400 Mbit/s, which translates to 50 Mbytes/s.
According to the above post 25Mbytes/s are adequate when capturing HDV from the tape whereas 200Mbytes/s are needed when capturing HDV live, as you suggested.
With HDV playback (only being able to be captured from lives) there are not any issues and the picture seems to be of adequate quality.
My issue is that even when I use dvgrab to capture playback from the tape in DV mode, I get this grain and those lines.
This might be an issue of the Canon's DV quality,in one hand ... which is not the best in the market.
I suppose that this can excuse the grain which is present even in the display of the camera. But on the other hand ...
... what about the black lines which follow the subjects of the footage when they move in DV mode only?
Kind regards,
orange_juice |
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barophobia
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| Posted: Mon Aug 13, 2007 9:23 pm Post subject: |
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| orange_juice wrote: |
My issue is that even when I use dvgrab to capture playback from the tape in DV mode, I get this grain and those lines.
This might be an issue of the Canon's DV quality,in one hand ... which is not the best in the market.
I suppose that this can excuse the grain which is present even in the display of the camera. But on the other hand ...
... what about the black lines which follow the subjects of the footage when they move in DV mode only?
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The black lines I am guessing is caused by the computer not being able to keep up with the displaying live capture or an uncompressed stream. Try recording a bit, even go and encode it into something like xvid, and playing back the the video on your computer. But then again I am guessing here, I have no clue why this is happening.
If you capture video on your camcorder then play it back on a hdtv with your camcorder and the gain noise goes away then cannon is doing some noise reduction with their digi2 or some chip on playback. There are some noise reduction algorithms for video you have access to like in mplayer/memcoder kino should have these also.
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orange_juice
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| Posted: Tue Aug 14, 2007 7:59 pm Post subject: |
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I think I have some news...
The above posts were published after using dvgrab with command line -in gentoo- to capture from tape playback the recorded video.
I also used kino to capture live DV format using 64Studio where my video card was not properly configured.
The news are that when I emerged kino in gentoo and performed the above operations, there were almost no lines during live capture or during playing back of the captured scenes using kino.
However, the lines appeared when I played back the files in VLC or Mplayer either in raw format (.dv) or encoded in .avi or .mpeg
How comes and the same file when played in kino, looks almost nice, and when played in another player, the quality diminishes, if not vanishes... (xine performed a little better, but ... why? Is'n it the same file?  )
******** EDIT *********
I exported the file from Kino as .mpg with the deinterlace option set in "YUV Deinterlace film-like", and playing it with other players ... I think I saw a miracle!!!
Therefore, using dvgrab, either from the command line or from kino and capturing in raw format (.dv) everything works fine if the final file is exported in mpg format and deinterlaced.
I am noob, aren't I!!! 
Last week, dvgrab 3.0 has been released which is able to capture HDV format in the same manner as dvgrab works. Great news whatsoever!!! 
**********************
Kind regards,
orange_juice |
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