JVC DR-M10 video recording test

[gshelley61]

If you send the JVC DVD recorder a 7.5 IRE black level video signal (which would be the case with analog NTSC outputs on a 8mm camcorder and probably even a TIVO), then you will wind up with a DVD that has a 7.5 IRE black level, too. That is too light for DVD's, which are supposed to be at 0 IRE. So, when it is played back it is going to look too light. NTSC video sources that are 7.5 IRE should be adjusted (the black level reduced) to 0 IRE with a proc amp prior to conversion to DVD. Some DVD recorders may have an black level input adjustment that does this (Panasonic E50 "darker" input setting, for example). If recording from a DV source (like MiniDV), black level is already at 0 IRE in most cases, and no adjustment should be necessary.

When using a proc amp to set the black level to 0 IRE from a 7.5 IRE source, a small increase in the luma may also be appropriate. This enhances the contrast and makes the image look a bit more vibrant.

Bottom line is, the only way to know for sure what the source black level is and what the peak luma levels are is to use a luminance meter.

[zorankarapancev]

Just a thought, without any intention to inflame the discussion:

Isn’t better value to buy a Sony DVD recorder (with its powerful integrated TBC, the latest 12 bit/108Mhz AD converter and all the necessary optional adjustments that the ordinary user will ever need) instead of JVC + several hundreds of dollars for TBC’s and video correction electronics?

Just a thought…

[gshelley61]

Just a thought, without any intention to inflame the discussion:

Isn’t better value to buy a Sony DVD recorder (with its powerful integrated TBC, the latest 12 bit/108Mhz AD converter and all the necessary optional adjustments that the ordinary user will ever need) instead of JVC + several hundreds of dollars for TBC’s and video correction electronics?

Just a thought…

Not a bad idea, but still no luminance meter or continuously variable adjustments. The SignVideo Proc Amp gives you total image control and very accurate, instantaneuos luma and black level information.

With a unit like the Sony, I suppose you could hook up a luminance meter to one of the recorder outputs, though. That would allow you to see the effect of the adjustments made on the input side.

[zorankarapancev]

gshelley61,

I understand your position, but I was talking about the ordinary users that will never have the need, opportunity or the knowledge to adjust everything up to the broadcast levels of quality. Most of them will never use, or even never learn how to use the FR mode of recording.

I think that for the majority of the people who want to have the best possible quality without meddling with the electronics, that they don’t understand anyway, the Sony will be probably one of the best options to buy (if they can afford it).

[gshelley61]

Sure, I see your point. It is tough to make a consumer-proof DVD recorder, though. One philosophy (in the case of the JVC) is to have image processing and I/O levels be a fixed, non-adjustable feature set precisely to make it easier for the average person to use. Lots of adjustable features and I/O settings may be confusing or even overwhelming for some.

Since this is essentially a video hobbyist forum, I wouldn't expect anyone here to have any major problems using this type of equipment, whether it is simple or complex to operate.

[ejai]

I agree, most of us would love to get our hands on a dvd recorder that will allow us the flexibility to control our own video enhancements.

By default they could set the unit for the best overall quality that the recorder can create. Then allow those who wish to change brightness, color and sharpness to do so. I know it is coming, and I for one will be very happy to finally see that day.

If the JVC had that ability I would no longer need to hunt down a suitable dvd recorder. Just like in most software packages we are given control options that most of us never even use. Yet we are happy to know that they exsist in case we feel a need to use them.

[samijubal]

One of the JVCs biggest advantages, noise reduction, is also one of it's biggest flaws, not being able to turn it off. Noise reduction isn't perfect. To filter out the unwanted (bad) part of the signal, it also has to take some of the quality (good) part with it. If set up right the ratio of bag to good is high, but no matter what the ratio, it will take some good with the bad, that's how it is no getting around it. So for poor quality sources it's a good thing, for good quality sources it's a bad thing. When using noise reduction on a good quality source that doesn't need it, the signal won't be improved any, it will be degraded unnecessarily. Noise reduction doesn't only work when it's needed, if applied to the source it will always degrade the quality some wheather it's needed or not. Anyone that has high quality satellite recordings in SP can see the difference if you use a machine that the noise reduction can be turned on and off on, watch part of the recording with it off, then watch it with it on, the quality will be worse with it on than off.

[Marvingj]

The pictures you posted, they seem to have been a bit darker? Also , the JVC still looks a "tab" softer, does anyone sees that?

[samijubal]

It is definitely softer, I see the difference in brightness/color too.

[gshelley61]

I repeat, some (perhaps most) of the differences you see are due to the inevitable image degradation that results from the DVD player converting a digitally encoded MPEG2 file into analog video. You are looking at a comparison of the original unaltered test pattern digital images from the THX DVD with a copy made from a Digital --> Analog Out --> Analog In --> Digital Sampling --> MPEG2 Encoding process. There is going to be some loss of quality due to that process, no matter what DVD recorder or other capturing method you use.

I made the copy using a very nice DVD player, and the s-video analog image it produces is pretty decent, almost impressive. But it is certainly not as sharp and clear as the digital image it came from. Also, the analog playback signal will vary slightly from the digital file it was generated from in terms of color, black level, etc. There's almost no way to get around that, even in the most expensive analog players. Now, DVI (digital video output) players... that's a whole different story...

[gshelley61]

As others have mentioned on this forum, when you record a DV stream via firewire with the DR-M10, the results are excellent. The conversion from DV to MPEG2 is outstanding. Plus, if your DV footage was shot in 16:9 mode (if your camcorder has this feature), the 16:9 flag is also transferred to the DVD recording... it plays back in 16:9 on your DVD player automatically.

Here's a frame grab from a DVD-RW I recorded in XP via firewire from a MiniDV tape I shot with a Canon Opture Pi in 16:9 mode. I resized the frame from 720x480 to 640x360 for posting. When played back on a regular DVD player (or with Power DVD on the computer), it automatically is in 16:9 format. Anyway, the DVD copy looks virtually identical to the original MiniDV tape... I can't tell any difference.



Of course, DV stream conversion to DVD bypasses all the analog filtering and processing the DR-M10 has built in, or any external processing. In the case of this scene, I normally would capture it through the analog s-video method instead so I could use a proc amp to adjust the image a bit (since it is not lit very well).

Another cool thing that some have mentioned doing is editing a complete project on the computer in AVI, then streaming the finished work via firewire from the computer to the DR-M10 for conversion the DVD compliant MPEG2 (if your editing software and hardware will allow it). The DV footage could then be corrected digitally for color, contrast, brightness, etc. with the editing software before conversion to MPEG2... for example:



An improvement, for sure... but I still prefer analog video correction over digital correction in most cases.

[trock]

I've done all the things you describe above but I can't use the DV input professionally because the sync delay through the DR-10MS's DV input - even though minute - is not acceptable to clients.

Using the analog inputs the sync is perfect so I use a DV to analog converter box when using the DR-10MS to encode direct from my NLE.

The tiny sync delay is there whether going from a camcorder or a PC. It's so small that it's almost imperceptible - until you compare it to the original or the same footage going through the analog inputs.

[gshelley61]

I'll have to check on the delay thing you are mentioning. I almost never use the DV input, so I don't know if that is happening with mine.

[trock]

I'd be interested to know if it's only happening with my unit or with others too. It's a very tiny out-of-syncness between the audio and the video. It surprises me that it's on the DV input as I've never seen that before when using DV.

[gshelley61]

I suppose it is possible since the source DV video and audio streams are really two files muxed together that have to be converted to MPG and AC3 respectively.

[lordsmurf]

I suppose it is possible since the source DV video and audio streams are really two files muxed together that have to be converted to MPG and AC3 respectively.

Not really. Remember, LSI is a single-chip system. Both are handled on chip, and part of the reasoning WAS for sync guarantees, in addition to the obvious cost benefits of a single-chip solution. You can read up a bunch of this stuff in all the LSI papers from a couple years ago while the chip was in R&D.