Dubbing DV to P2

Mark Donnell · November 2nd, 2006, 10:17 PM

I've been doing some experiments with the HVX-200 with interesting results. The goal is to dub DV which was recorded in the past on a mini-DV camcorder to a P2 card in the HVX-200, then to play it back off of the P2 card onto a high-quality TV. I apologize in advance - this is a bit complicated with a number of variables. The TV in use is a 37" Sony HD CRT TV with multiple inputs. The source tape is a mini-DV recording of a live event recorded on a Sony GL-2 in 30F mode. In the past, I have obtained best playback quality from mini-DV tapes by using the S-video output into the TV. When I tried to dub this tape to P2 by playing the tape on a DVX-100A, outputting the signal via firewire to the HVX-200, and recording onto P2 in the 480i DV mode, it looked fairly good while in play mode, but on inspection of individual frames played back from the P2 card via the component output, a lot of staircase artifact was seen. Disconnecting the component cable and using a S-video cable to the TV, the same results were seen (staircasing on individual frames). Turning off the HVX-200, switching to tape mode, and playing the source tape on the HVX-200 with output via the S-video cable revealed an excellent picture with no staircasing on individual frames. More experiments are pending. Any ideas ?

Mark Donnell · November 5th, 2006, 10:47 AM

I've learned a bit more about this problem. Even when recording DV with the HVX-200 onto P2 cards, the playback shows the same staircase artifacts. This is also present when recording DV with the HVX to tape and playing it back via the S-video connection. The artifacts are much more noticable than recordings made with the DVX-100A onto tape and played back via the S-video connector. In checking the specs of both cameras, the DVX-100A lists the recording system as 525i (NTSC), while the HVX-200 calls it 480i. Is this a true difference between the two cameras ? As a separate observation, I discovered that you cannot input an S-video signal into the HVX and have it converted to DV which can be recorded onto P2 cards. It will convert it to DV, but only for output via the firewire port. My next move is going to be to record DV at 30p on one tape, first with the HVX, then with the DVX, then with a Canon GL-2 in 30F mode. My impression at this point is that the HVX is wonderful for 720p and 1080i, but not as good as other cameras for 480i. I haven't played with the DVCPRO 50 mode, so I can't comment on that.

Ash Greyson · November 5th, 2006, 11:10 PM

This is a known issue. The HVX has 960X540 sensors but uses pixel shift to get the rez higher in EVERY mode. In the non-1080p modes, you get a down conversion and due to an unknown factor, when it gets down converted to 480i, it looks terrible. If you need 60i, it is not the camera for you...

ash =o)

Barry Green · November 6th, 2006, 12:02 AM

This issue appears to affect 480/60i. If you're shooting 480/30p or 480/24p it looks great, but the downconversion to 480/60i leaves a lot of aliasing and staircasing. I find that you can get rid of some of it ("tame it", if you will) by setting the v-detail-level and the detail level to both -7, but that has its own set of drawbacks.

November 2nd, 2006, 10:17 PM	#1
Mark Donnell Major Player Join Date: Nov 2005 Location: Silver City, NM Posts: 385	Dubbing DV to P2 - quality problems I've been doing some experiments with the HVX-200 with interesting results. The goal is to dub DV which was recorded in the past on a mini-DV camcorder to a P2 card in the HVX-200, then to play it back off of the P2 card onto a high-quality TV. I apologize in advance - this is a bit complicated with a number of variables. The TV in use is a 37" Sony HD CRT TV with multiple inputs. The source tape is a mini-DV recording of a live event recorded on a Sony GL-2 in 30F mode. In the past, I have obtained best playback quality from mini-DV tapes by using the S-video output into the TV. When I tried to dub this tape to P2 by playing the tape on a DVX-100A, outputting the signal via firewire to the HVX-200, and recording onto P2 in the 480i DV mode, it looked fairly good while in play mode, but on inspection of individual frames played back from the P2 card via the component output, a lot of staircase artifact was seen. Disconnecting the component cable and using a S-video cable to the TV, the same results were seen (staircasing on individual frames). Turning off the HVX-200, switching to tape mode, and playing the source tape on the HVX-200 with output via the S-video cable revealed an excellent picture with no staircasing on individual frames. More experiments are pending. Any ideas ?

November 5th, 2006, 10:47 AM	#2
Mark Donnell Major Player Join Date: Nov 2005 Location: Silver City, NM Posts: 385	I've learned a bit more about this problem. Even when recording DV with the HVX-200 onto P2 cards, the playback shows the same staircase artifacts. This is also present when recording DV with the HVX to tape and playing it back via the S-video connection. The artifacts are much more noticable than recordings made with the DVX-100A onto tape and played back via the S-video connector. In checking the specs of both cameras, the DVX-100A lists the recording system as 525i (NTSC), while the HVX-200 calls it 480i. Is this a true difference between the two cameras ? As a separate observation, I discovered that you cannot input an S-video signal into the HVX and have it converted to DV which can be recorded onto P2 cards. It will convert it to DV, but only for output via the firewire port. My next move is going to be to record DV at 30p on one tape, first with the HVX, then with the DVX, then with a Canon GL-2 in 30F mode. My impression at this point is that the HVX is wonderful for 720p and 1080i, but not as good as other cameras for 480i. I haven't played with the DVCPRO 50 mode, so I can't comment on that.

November 5th, 2006, 11:10 PM	#3
Ash Greyson Trustee Join Date: May 2003 Location: Tulsa, OK Posts: 1,689	This is a known issue. The HVX has 960X540 sensors but uses pixel shift to get the rez higher in EVERY mode. In the non-1080p modes, you get a down conversion and due to an unknown factor, when it gets down converted to 480i, it looks terrible. If you need 60i, it is not the camera for you... ash =o)

November 6th, 2006, 12:02 AM	#4
Barry Green Barry Wan Kenobi Join Date: Jul 2003 Location: North Carolina Posts: 3,863	This issue appears to affect 480/60i. If you're shooting 480/30p or 480/24p it looks great, but the downconversion to 480/60i leaves a lot of aliasing and staircasing. I find that you can get rid of some of it ("tame it", if you will) by setting the v-detail-level and the detail level to both -7, but that has its own set of drawbacks.