Quality reduction on Burn

[barkingcat]

I tried to search the forums to see if this was already answered somewhere - please accept my apology if it has been and I didn't see it.

I have run thru my authoring process step by step -

captured on a usb2.0 vidbox device to MPEG2
create dvd image on hard disk (ie the VIDEO_TS directory)
burned directory to a DVD -
pioneer 112D
sony dvd-r 4.7 g media, also tried maxell
wrote at 4x

the quality is very close to the original VHS until it is written to the DVD - I viewed the DVD and compared to VHS using the capture device to ensure apples to apples. Also compared by viewing on my TV - switching between VCR and DVD.

I have read that the media matters but everywhere I looked, both the sony and maxell media are good.

I also have the option in my authoring software - Roxio Easy Media 10 - to choose hardware vs software rendering but I am not sure if that applies to the capture or burn to DVD.

Any help is greatly appreciated.

Thanks!

[redwudz]

My first guess is your Roxio program is re-encoding the file and decreasing the quality. The brand of media has really nothing to do with quality. Bad media may have skips and other problems, especially towards the end, but the quality should still be the same. But I would suggest using Verbatim or TY media as you will have less playback problems. Though most Sony DVDs are decent quality.

If you have a DVD compliant MPEG-2 file with good quality, try authoring with a freeware program like GUI for dvd author. Then burn with ImgBurn, also freeware. Authoring shouldn't make any changes in quality, unless your video is not compliant and the program decides to re-encode it.

And welcome to our forums.

[barkingcat]

I forgot to mention that I have tried burning to DVD with a couple other programs - WinDVD and HonesTech VHS to DVD. That is why I went step by step and emulated a 'burn' to the hard disk so I check if it was the encoding step or actually the 'burn' to the DVD (it looks like the program goes thru the encoding when it creates the VIDEO_TS directory). The MPEG compared to the VHS looked good, the emulated 'burn' to hard disk looked good but the DVD seemed to lose a bit of quality. Both the WinDVD and the Roxio software have a program that takes a disk image and copies (burns) it to the DVD - it looks like it does this part without re-encoding - I was trying to isolate each step - maybe I am being too picky also. It isn't that it looks bad - it is just slightly worse quality on the DVD VIDEO_TS files than on the Hard drive files - but enough to notice. Just slightly less 'sharp'. I will try the freeware programs too!

Do you have any ideas about the hardware vs software rendering?

Thanks!

[theewizard]

redwuz is correct..

don't confuse encoding & processing with burning, the are different things

many programs like ROXIO or NERO will RE-encode / convert your file, even though the files you have are already DVD compliant/ready

burn the DVD with a BURNING ONLY program that will NOT re-encode the video

imgBURN or deep burner or NTI

[redwudz]

Do you have any ideas about the hardware vs software rendering?

Not sure what you are asking. Some video cards like Hauppauge use hardware encoding during capture. Generally hardware encoding is much faster, but the quality is usually preset in the hardware, so you don't have much in the way of options, including output size.

Software encoding is very CPU intensive, usually using 100% of your CPU power, so a faster CPU is necessary to do it in the minimal amount of time. But software encoding is much more versatile, especially if you need to fit a video to certain size for your media. And the quality depends on the software encoder settings. For example, you can do 2 pass encoding in software, but that would be very difficult with a hardware encoder. Audio and other options are just about unlimited, depending on what final format you are using.

Generally, the best process is to start with a high quality video file, encode to MPEG-2 with a standalone software encoder, such as HC, CCE, or others. Then author that file to DVD format with a standalone authoring program, GUI for dvd author, TDA, DVD Lab, etc. Then burn with a good program to quality discs. I would suggest ImgBurn to burn and TY or Verbatim for media.

[barkingcat]

Thanks everyone for the replies. I think I understand the hardware vs software rendering now - it is on the capture side of things. Possibly a video board with composite or s-video ports to capture analog. The setup I have now is a USB 2 device with composite or s-video and I believe it is software driven. I can set bit-rate, size, quality, NTSC vs PAL, etc. I am pretty happy with the MPEG2 results. I don't use Roxio to 'capture' my file to MPEG2 - I use the software that came with the capture device. I know I can get a better card or device probably but like I said, I am pretty happy with the MPEG2 result.

Yesterday I tried the GUI for dvdauthor with the ImgBurn - using an MPEG2 file that I was happy with. I noticed the same thing when burning to the DVD - it is slightly lighter and not as sharp as the original MPEG2 or the image / directories that are written to the hard drive before burning to DVD. I am now doing a comparison between the program I was using to 'burn' the image file to DVD and the ImgBurn program.

I do understand that when capturing there is some compression when the MPEG2 is created and I do understand that when creating the image files there is usually some more encoding. I don't think the program I used to create the DVD from the image files did any further compression or encoding - it acts like ImgBurn. But I will soon see if there is any difference between the DVD output from the two programs.

What do you use as a capture device - I see a lot about All in Wonder. I haven't pursued the capture side of things as a problem since I am pleased with the MPEG2 files that in device is producing. I know I could probable get a better device since mine doesn't have a proc amp sharpness setting.

Thanks again.

[Nelson37]

There should be ABSOLUTELY NO encoding going on in the authoring stage. NONE. If there is, you are doing something wrong and this is where the change occurs.

The "rendering" question should not come up.

You start with an MPG,and Play it. HOW? What Software? What device? What display?

Then you author a DVD, and Play it. See above questions.

There should be no quality difference whatsoever. If you are comparing PC playback and Standalone to TV playback, there may be significant differences which have nothing at all to do with the video itself.

If playback is on the same device and software, and encoding during authoring is eliminated, then look for software playback settings which are different for DVD as oppossed to MPG. From your description, de-interlacing may be the problem.

[barkingcat]

Thanks everyone. never mind the question about the capture card - i found out how to see it on the forum.

[Nelson37]

If you solved your problem, how about sharing your solutions?

Or where you just here to waste somebody's time?

[barkingcat]

Sorry - no, I didn't solve it but I think it must be the playback device as you suggested. I compared the DVD created with ImgBurn to the one created with my other program that does the same thing and they were pretty much the same. I compared them played on media player on the computer vs the DVD player hooked up to the computer. First the ImgBurn in media play then the one from the other program. When playing in media player the quality looked better than when playing in the DVD hooked up to the computer. Don't know if this is to be expected but I don't want to waste anyone's time anymore.

[barkingcat]

Forgive my ignorance about this - I am fairly new at it - but I happened to discover that my problem seems to be between interlacing and progressive. I have been burning prior DVDs using 'interlaced'. When I playback on my DVD player - no matter which one - the playback is not so sharp. I recently burned a DVD as progressive and it is a LOT sharper when played back on my player.

My player is progressive so does that mean it handles the fields the same way as a computer - so is it better to burn it 'progressive'?

Is it standard in the player world these days that a DVD should be burned 'progressive'?

Is that what Nelson37 was meaning when he said my problem may be de-interlacing? I was thinking I should burn 'interlaced' but now I am wondering if the standard should be 'progressive' (de-interlaced?)?

Are HD TVs progressive?

Thanks again for the help and please forgive me if the questions are answered elsewhere - I have looked but wanted to get a more specific answer.

[bendixG15]

Easy question - Are you comparing the quality between a computer monitor and a TV screen ??
What is your TV ?

[barkingcat]

I am comparing the original VHS to the DVD I created on my 27 in Panasonic CT27SL14 TV and Panasonic DVD/VCR combo PV-D4734S. The DVD player has a setting for progressive - I tried it both ways. Not sure how to tell if the TV is progressive or not - it doesn't say in the manual.

I am also trying to understand what the standard should be for normal and HD TVs. Thanks for any help

[Nelson37]

You are confusing some steps.

You do not Burn or Author as either Interlaced or Progressive, this decision happens during Encoding. You are probably using one program to do all steps, as you have not yet learned why this is not a good idea. There is really nothing inherently wrong with this, mainly it concerns options that are not available with combination programs.

The decision as to which to do is based primarily on the Source Video. A secondary consideration is the intended playback device.

Taking an Interlaced video and forcing it to Progressive can result in dramatically reduced quality, by throwing out one-half of the available resolution. Yes, this can be avoided.

HDTV is mostly progressive in terms of the source, all HDTV display units are capable of Progressive display, all PC monitors are inherently Progressive.

IVTC is the subject you want to read up on. You are not yet ready for a full explanation of this topic.

[barkingcat]

I thought I understood the decision was during encoding as well and tried to find the choice in my Hauppauge capture software but couldn't find one - at first I thought it was de-interlacing and I had to set it to interlace. I am separating the steps (taking the advice I have gotten before here) when I can but I will explain what I have been able to do so far.

I am using the WINTV2000 software that came with the hauppauge card to capture.* But I tried to use DVD author and ImgBurn to create the DVD and kept getting errors (see below).*

So I used MyDVD (one piece of Roxio) to burn to DVD and that is where it gave me the choice to do progressive vs interlaced (it is actually an encoding option but I think it does reencode on burn (I know it is not a good thing).

I tried DVD Author and Imgburn on a file I captured on another device which had mux ok=Yes and it was fine but I still didn't like the output as well as when I chose progressive on MyDVD.

The problem is that I unexpectedly like the result better when I burned it as progressive - again that surprised me.* I burned the file from the hauppauge and the other device using interlaced on MyDVD too and did not like the results.

To summarize my results for what I could try:

• file captured on Hauppauge, burn MyDVD progressive - Looked sharper
  file captured on Hauppauge, burn MyDVD interlaced - looked blurry
  file captured on USB VidBox, burn MyDVD progressive - looked sharper
  file captured on USB VidBox, burn MyDVD interlaced - looked blurry
  file captured on USB VidBox, burn dvd auth/imgburn- looked blurry

DVD Author problem with Hauppauge file:When I drag my file to dvd author I get this – with a file created on the hauppage-150:

"Inconsistent timecodes ... GFD will use SCR for duration"

Then because MUX OK=No when I get ready to create DVD it says:

"GFD has not found navigation packets in your mpg file (Mux OK = No).* This will cause authoring error in 99%.* To avoid use elementary streams (demultiplex your input) or use another multiplexer."
If I ignore it gives mostly warnings that it skipped sectors (as you would imagine).

Sorry for the dissertation.

[barkingcat]

Can I ask one very basic, maybe stupid question? What are broadcast quality DVD inputs initially encoded at - interlaced or progressive?

[Nelson37]

Broadcast-quality DVD input??? What exactly do you mean by this?

Most Broadcast TV is interlaced (SD), most DVD are Progressive. This gets complicated because the DVD usually contain a 3:2 pulldown flag to make the playback partially interlaced.

I want to re-emphasize an important point. You do NOT burn as either progressive or interlaced, you encode as one or the other. The actual burn has NOTHING WHATSOEVER to do with these factors.

Interlaced is intended for standard TV playback, does not look good on PC monitor. The most common method for making Interlaced video Progressive is to throw away one-half of the resolution. READ THAT AGAIN. If you do not understand this concept, do some searches and read up.

More information results in a better understanding of your issue. MyDVD is re-encoding your input. ELIMINATE THIS.

Simple solution. De-mux your input, supply the demuxed input to GuiforDVDAuthor. This should get rid of the error, and also the need to run your video thru MyDVD.

Your evaluation of the video quality is not at all unusual, WHEN VIEWED ON A PC MONITOR. When viewed on a standard TV, Interlaced is generally preferred.

If you really want progressive, there IS a way to capture it in full resolution. HD programming, when downsampled at the box and output thru the S-Video port, uses a special kind of interlacing called Telecining. Only two of every five frames are actually interlaced. This can be removed with NO LOSS of resolution, resulting in NTSC FILM type video. This is what most DVD use, if you have a DVD player and TV which support Progressive playback you can compare the two. Outside of this special case, De-Interlacing is almost always a bad thing.

[barkingcat]

Thank you for your patience Nelson37. I do understand that MyDVD is re-encoding - sorry I keep using 'burn' when I know it is actually re-encoding when I am creating the DVD. You say that 'my evaluation is not unusual WHEN VIEW ON A PC MONITOR' but my evaluation was based on viewing the DVDs on my TV. I thought I had understood that interlaced was best for standard TV so I was confused when I preferred the progressive re-encoded DVD on my TV.

I like the quality of the MPEG2 file when I play it back on my PC monitor. I used GSpot to check to see if my MPEG2 file is indeed interlaced - if it is captured as NTSC and the fps is 29.97, from what I have read it is interlaced. Is that correct?

So basically in most cases, capture the file and encode as interlaced. Then
ensure that when authoring, that it does NOT re-encode. This will create a DVD that has interlaced output. What you are saying is that interlaced is supposed to be fine on any standard TV. HDTV too?

Just to make sure I understand the special case - HD Programming - does that mean it would be good to telecine input from an HD camcorder or a recording from an HDTV? (I may be a little slow on the uptake but I will get it).

But I am still confused - when comparing 2 DVDs, created from the same interlaced MPEG2 file: 1) re-encoded as progressive using MyDVD 2)burning it using DVD author and Imgburn - that I like 1) better because it looks sharper. Both are being played on the same standard TV with the same DVD player. Maybe it is just preference. I am going to take them both over to my friends house and compare on their HD, big screen TV.

Thanks again for your help and patience.

[Nelson37]

Ah, the bulb is beginning to glow, we just need to supply more voltage.

Captured, 720x480 NTSC, 29 FPS is almost always going to be interlaced. Virtually guaranteed. 720x240 would be non-interlaced, if capped from a standard source.

Load a capped MPG into VirtualDub. If you don't have this prog, get it. Do it now. The single most useful piece of software for doing video that there is.

Step through a motion sequence, you will see the clear interlacing pattern. Use Vdub's various de-interlacing filters, note the difference carefully. By dropping half the Fields (NOT frames) you eliminate the interlacing artifacts, at the cost of half the resolution, or significant blurring. That it "looks better" is an illusion, sort of. Since each field is a different point in time, motion can become choppier when half the fields are lost.

Now load a vob from a commercial DVD and again, step thru a motion sequence. You will see a pattern of 3 clear frames and two frames interlaced. This is Telecined. The only purpose is to take 24 FPS film and convert to 29 FPS for broadcast. The extremely important difference from normal interlacing is that only four frames out of five contain ALL the video information, the interlacing can be removed with NO LOSS. This is called Inverse Telecining, or IVTC.

Just to confuse you more, the MPG from the commercial DVD is NOT actually Telecined, it is (usually) 24 FPS MPG with an embedded flag which instructs the player to perform the Telecine. DVD of this type you just remove the flag. When an HD prog is captured thru S-Video, what you get is the result of this process, removing the flag is not an option, you must software process. Very different from just removing Interlacing.

Interlacing is basically not supposed to be visible on a standard TV, though IMO it sometimes is. Output from an HD camera could be several different formats, I don't yet have one. But Telecining is something to avoid, if you have a 720x480, full-res, 24 FPS progressive mpg it doesn't get any better than that.

Unfortunately, this is something a Hauppage card can't do. But an ATI AIW can, with an HD source capped thru the tuner box's S-Video port. Ah, Nirvana! in real-time, yet! Sorry about that, I just like to rub it in a little for the Hauppage folks. At least your card is still in production.

[barkingcat]

Thank you so much! I downloaded virtualdub but won't be able to work with it for several days. One question though - are you saying that your card - ATI AIW 128 can capture at 24 fps? Do you use the virtual dub software to capture? Is the AIW a hardware or software encoder - or choice? I have been leary of getting an AGP card as my computers manual says not to pull more than 5V from each card install or a total of 2Amp. I just haven't been able to find that spec on any of the web sites but read that an AGP card can pull a lot of power. Maybe I am mistaken.

Thanks again for your help!

[Nelson37]

ATI AIW cards have the capability to do an IVTC in real-time. They receive a 29fps source and can store it as 24fps progressive. Latest cards, good MMC, and excellent source required. Unfortunately, these cards are no longer manufactured. This capability works best on later models, 9000 series or later. ATI software works best for this feature.

There are various methods of running an IVTC post-capture, I haven't used these in several years. VERY time-consuming and far from perfect.

The ATI cards are hardware-assisted, it is not pure hardware or software. Their HD-tuner cards are hardware compression, but these only have an advantage for OTA broadcast.

Never had a problem with power usage through 5 or 6 of various AIW models.

Experiment with Vdub, it will show you many details and allow much testing.