PicVideo MJPEG users wanted!!!

[jlietz]

I have 200GB of hard drive space to play with. I need to capture 40-50 hours of vhs (which I will be editing.) I don't want to buy the PICVideo MJPEG codec unless it is going to help me out. That's where you folks come in. How many hours of video can I expect to store using the MJPEG codec with a quality level of 18? Or, approximately what quality setting would I need to use to fit 40 hours of video on a 200GB hard drive. I would like to capture at 720x480, but would settle for 352x480.
Thanks for your replies.

[trevlac]

I think 40 hours will = 200gig at 1/2D1.

However, compression tends to be variable based upon the source.

Why don't you just try a sample? It's free to download. You have to pay the $28 to remove their logo.

[jlietz]

1/2D1

[FulciLives]

1/2D1

Full D1 = 720x480 NTSC or 720x576 PAL

Half D1 = 352x480 NTSC or 352x576 PAL

You will be able to record more video at Half D1 than Full D1

I use the PICVideo MJPEG codec on the 19 (out of 20 with 20 being best) quality setting.

The compression ratio of the codec is dependant on the source.

My most recent capture was a VHS capture at Full D1 using PICVideo MJPEG at 19 and 16-bit 48k Stereo audio and this capture had a running time of approximately 83 minutes (short movie). The file was exactly 15 GB in size.

- John "FulciLives" Coleman

[jlietz]

Thanks.
This leads me to another question. What is the downside to capturing 1/2 D1 vs Full D1? Since VHS-C resolution is 352x240 (I think) am I just wasting space capturing in Full D1? I will be eventually converting to MPEG2 for DVD.

[trevlac]

So ... 83/60 = 15/? = 10.8 per hour = 432 Gig for 40 hours.

That's 720x480 at 19. What's 18? Also, 352x480 is 49% of 720x480. Yada yada ....

I say test. That be a bit faster than weeding thru posts of questionable value. :P

PS:
FulciLives' comments were great. As he/she noted. Don't forget the audio ! 40 hours of PCM probably takes up some space too.

[jlietz]

Yeah, I get the same numbers you do, Trevlac.

My last question pertains to loss of quality though. If I am not gaining anything by capturing Full D1, then it looks like 40 hours at Half D1 will come pretty close to fitting. So, do I lose anything by capturing VHS at Half D1?

Thanks

[FulciLives]

Thanks.
This leads me to another question. What is the downside to capturing 1/2 D1 vs Full D1? Since VHS-C resolution is 352x240 (I think) am I just wasting space capturing in Full D1? I will be eventually converting to MPEG2 for DVD.

For VHS you will find that Half D1 is usually good enough.

However you will get slightly better results if you capture at Full D1 and then resize to Half D1 while doing your MPEG-2 encoding.

Also if you capture Full D1 and leave it as Full D1 for your MPEG-2 encoding the final output will look ever-so-slightly sharper.

So if you are a real quality nut and/or these recordings are extremely important to you (aka family videos etc.) then you might want to use Full D1 as it will give you a lil wee bit extra quality in the end.

However when it is all said and done the difference between using Full D1 and Half D1 from a VHS source is not that big of a difference. The Half D1 may look just a wee-bit softer but will still look pretty darn good especially if you encode it to MPEG-2 using a high bitrate.

Keep in mind that Half D1 will hit the MAX bitrate at around 5000kbps where as Full D1 can go up to 8000kbps

So ... try capturing the same VHS clip at Half D1 and then again at Full D1. Encode the Half D1 to MPEG-2 at a CBR of 5000kbps and the Full D1 to MPEG-2 at a CBR of 8000kbps and compare the two then decide what you think looks better or if you are happy with the ever-so-slightly lower quality of the Half D1 video. I say to use 5000kbps for Half D1 and 8000kbps for Full D1 since that is the MAX bitrate for the two formats. You can of course use any bitrate you like in the end but it makes sense to compare the two at the best bitrate for each format.

- John "FulciLives" Coleman

[trevlac]

What is the downside to capturing 1/2 D1 vs Full D1? Since VHS-C resolution is 352x240 (I think) am I just wasting space capturing in Full D1? I will be eventually converting to MPEG2 for DVD.

The short answer probably is:

Your card most likely converts from analog to digital at 1 size. It then resizes to what you ask. So if the resize works well, the quality would be around the same. You gotta test to know. Actual results mean much more than some theory someone gives you.

By the way. I believe VHS is 240 across the picture. Not up and down. 240x480. Unfortunately, "resolution" is not what you may think. DVD "resolution" is at most 540x480. Actually, a 16x9 DVD has a horizontal resolution of ~400 on a 16x9 TV. That's about the same as SVHS on a 4x3 TV.

Be aware, I don't fully understand all of the details of "resolution".

Here is a chart someone put out: He says DVD is only 500 !
http://www.cs.tut.fi/~leopold/AV/VideoFormats.html

[trevlac]

Yeah, I get the same numbers you do, Trevlac.

My last question pertains to loss of quality though. If I am not gaining anything by capturing Full D1, then it looks like 40 hours at Half D1 will come pretty close to fitting. So, do I lose anything by capturing VHS at Half D1?

Thanks

Again, FulciLives gives some very good advice.

I'd like to add a short rundown of how I think the process works, and why you would get any difference. Just for a better understanding.

352:
Your card goes from analog VHS info to digital pixels at 1 big size. It then resizes to 352 loosing some small amount of info. This goes to mpeg2 and looses more info. Your DVD player then probably reesizes or streatches the image to fill your TV.

720:
Is much the same except the resizing is not as much. Therefore the error off of the original capture is less. AKA the details (even if they were fuzzy) are better represented. Will this make the picture look better? Probably not. But it is better. As a test, make a picture in a program like photoshop. Make it big, then small, then big, .... If you put text on it you will see the difference after not too many rounds.

PS:
I believe a good way to capture vhs is by using an svhs deck with s-video out to your card. This should be a nice inprovement. My understanding is that the color and b&w parts of the picture are stored seperately on a vhs tape. Mixing them thru an RCA type of out causes problems. Unfortunately, I don't cap tapes. So you'd have to test or read up to know if it is worth it.

[SatStorm]

Why 40Hours in the raw?
And what about post capture proccessing?

I suggest you to capture realtime mpeg 2 if you are on the hurry and don't want top quality. If you capture @ 352 x 576/480 with an average bitrate of 3500Kb/s, you gonna have good results the fast way.

If you want quality, you can't do it on the raw. Better do is like this: Capture 12 hours. They need about 12 hours for postproccesing (lite filtering) if you have a modern CPU (~ 2.5Gmhz or more). Encode to mpeg 2 and continue with the next 12 hours.

Keep in mind that 4 hours in excellent quality is possible on one DVD-R. More has some macroblocking or noise.

@trevlac: This "resizing" is an issue for NTSC.
With PAL, the picture comes negative and the tuner change it to real colours. That's why PAL has better colours. This "reconstruction" of the source don't have the issues of the resizing with NTSC. In PAL, the missing dots of a horizontal line don't be replaced by noise like NTSC (or the average of the near dots). So, a scretched PAL picture includes only the usefull info of the transmission.
I don't know that good english to explain it better, maybe someone else from the PAL land?

Some high end cards are capable to emulate some PAL issues, so capturing higher helps. But not the cards we use for capturing. The general rule is : With NTSC capture the higher you can, filter, resize to your final framesize, encode. With PAL, capture at the framesize of your target framesize direct, filter the less possible, encode.
I repeat: This is the "general" practical rule. If you have a top quality many thousent of euros equipment, you can capture higher with PAL.

Also, with cards like ATI, optimased primary for NTSC captures, we the PAL users have really bad captures. If you are in PAL Land, better use products made for us first, not for US and then adapted by us in PAL side of the world. This is something most americans can't realise when they advice PAL users for what to use for capturing!

[trevlac]

This is something most americans can't realise when they advice PAL users for what to use for capturing!

Thanks for the info. I should have qualified that I was talking NTSC. I don't know PAL. I'd like to learn, but it I can't test and there is so much mis-information out there. I hardly know NTSC.

I assume the original poster is NTSC because they have an ATI card in their profile. From what you say; if they are using an ATI card for PAL "God help them!"


Edit: Your English is much much better than my Greek. I think I will try to learn more about pal.

[Gazorgan]

It's worth the money, trust me on this. It's 'nearly as good' as Huffyuv. I don't think you can get all the cpatures on your drive at one time, but you can do 1/2 easily, with plenty of room to write out finished products.

[Richard_G]

Also, with cards like ATI, optimased primary for NTSC captures, we the PAL users have really bad captures. If you are in PAL Land, better use products made for us first, not for US and then adapted by us in PAL side of the world. This is something most americans can't realise when they advice PAL users for what to use for capturing!

What makes you think ATI cards are optimised for NTSC capture? If you have really bad captures, don't immediately blame the hardware. My ATI AIW Radeon 7500 does perfectly good PAL captures as did the ATI AIW 128 I had before it. I'll admit the earlier ATI software (MMC 6.1 and earlier) may well have been optimised for NTSC but it was crap anyway. With the AIW 128 I used the PicVideo codec (on setting 18 or 19) and Virtualdub to capture and had no problems with capturing performance or quality.

I'm not even sure if ATI make their own cards any more or just make the chipsets and supply them to other manufacturers. My current card is actually a Hercules Prophet All-in-Wonder 7500 Radeon and made by Hercules in France but it can still deal with NTSC, PAL and even SECAM. Whether the tuner can deal with NTSC I have no idea, but most TV sets have multistandard tuners these days so I suspect the AIW is the same.

[jlietz]

Thanks all.
Yes, I am in the States, so NTSC for me.

SatStorm wrote

Why 40Hours in the raw?
And what about post capture proccessing?

I want to capture the entire 40 hours because I am not sure which clips I will be putting on which DVD. I intend to create some "theme" DVD's like "family Christmas 1994-2002", etc... That's why I want all clips available on my hard drive. Also I don't yet have a DVD burner. I figure if I capture the 40 hours first - which at my speed will take a few months - I will be able to buy a DVD burner at less cost than they are being offered now.
That's the plan...now we'll see if it is feasible. I'm going to go ahead and purchase the PICVideo MJPEG codec.