Hauppauge HDPVR-1212 Owner's Thread - Page 103

Mine is nothing special.
AMD Athlon dual 2.0ghz
2gb ram / 256mb graphics / vista
Right off the shelf. No problems.. only about $379 at the time.

My Dell desktop is equipped with an Intel Core i7-860 processor.

I used to capture using variable and a setting of 10.5 and up, UNTIL I noticed on a few captures that in the dark areas off to the side of the main picture - there was a noticeable blockiness in the picture (usually in a gray (color) part of the scene. This was not there using constant bit, so that is what I use now and don't care about file size.

Using variable, the main part of the picture was always nice, just on certain things in the dark areas the blockiness appeared.

Try using 720P, it may work slightly better for you using a higher bitrate as a 720P file is much smaller than the 1080i and on most things the picture quality is not any better on 1080i vs. 720P. There are a few things where it is, but many are not.

RCD7210, did you shut off all antivirus and spyware programs??? What antivirus are you using?? Did you turn off bit defender in windows - in vista that is a resource hog! Defrag hard drive??

On laptops, supposedly - and I stress supposedly, the AMD chip units are better at video performance- as well as price!
You can get a quad core AMD for the same price as a dual core intel - and intel plays games with chips. The i3 and most i5's are just dual cores, the i3 has no turbo, etc.
MOST i3 and i5 laptops will use onboard video, while better than the first generation, IMO it still isn't as good as a separate video card that the others use.

AND many use slowwwww hard drives, - just something to consider when picking.

HP GS- 1D60us ??? If you feel like it check that model out and tell me what you think. Just wondering because I saw that Staples has them. They are advertising a $100 off clearance pcs/ laptops right now too. I am going tommorrow to see if that one qualifies.

I did the first day i was experimenting, but havnt since. Ill take a look at the 720p and see if it looks any different too me. The constant, 7 Mbit config looks pretty good to me. Recorded and watched some again last night.

The only thing that affects the final file size is the average bit rate and the total time, 720P or 1080i will not change the file size. You many have less compression artifacts capturing at 720P resolution than with 1080i. But the file size will only change if you change the bit rate or recording time.

Mike T

If they don't have the $100 off maybe look at these. The first two have some usb 3.0 ports - alot faster than usb 2.0 and won't be outdated so quickly.

http://www.bestbuy.com/site/HP+-+15....&skuId=4815065

http://www.bestbuy.com/site/Dell+-+1...&skuId=4830134

http://www.bestbuy.com/site/HP+-+15....&skuId=5015961

or a http://www.staples.com/Toshiba-Satel...product_375473

Are you totally positive on that??? I could swear my 720P captures at a higher bitrate were still smaller than the 1080i at a lower rate.
It would be easy for me to test.
I will test tomorrow and report back.

Although that may very well be technically true, in terms of end user experience, or practice, it may not be in some scenarios. Here's an example.

If I tell my TME program, "Here is a 2hr movie in 1080i. Please use your best judgment using my selection of a 12.3 Mbps variable bit rate to encode it." It most likely, on its own, will choose a higher average bit rate if the content is highly detailed and higher resolution. This is however completely invisible to me, the end user. All that the user sees is that the 2hr movie using a 12.3 variable bit rate has a larger file size end result than the exact same movie recorded at the same 12.3 variable bit rate setting, but that was provided at 480i resolution.

Your advise would apply correctly to constant bit rate use only.

[I pretty much only use variable, for what it's worth.]

The final file size equals the AVERAGE bit rate multiplied by the recording length, that's it. Changing only the resolution has no effect on the file size. If the software changes the average bit rate when you change the resolution then the file size will change ONLY because the average bit rate changed. It does not matter if you use a constant bit rate or a variable bit rate there will always be an average bit rate and that is what determines the final file size, not the recording resolution.

Mike T

You sir are correct. I must have been using variable at the time of doing the 720P captures.
I just checked and indeed using constant the files are the same size between 1080i and 720P. Learn something everyday

I wonder if using 720P might be a bit less (or more) taxing on a marginally spec. laptop computer since most laptops weakest area is the video processing.

And the software consistently selects an overall smaller average bit rate, based on the resolution (detail) of the signal it encounters, and therefore produces smaller file sizes for lower resolution material, even though the user selects exactly the same variable bit rate setting value when they start the two recordings, (one being of 720p and the other 1080i).

Here's an example I just tested with my cable box DVR when changing the resolution output, making a recording of the exact same 30 second clip of a show I had recorded on its internal hard drive to my HDPVR, using the Arcsoft software:

1080i resolution, 13.5 Mbps VARIABLE bit rate, file size: 42.3 MB

720p resolution, 13.5 Mbps VARIABLE bit rate, file size: 20.0 MB

Note: The Arcsoft software may have a memory feature where the bit rate pre-prompts at the previously used setting for the current incoming resolution, so any attempt to verify my data, [PLEASE DO, Y'ALL ], one should make it a point to be sure that besides just changing the incoming source's resolution, that the variable bit rate doesn't accidentally get re-set by the software to a different, default value.]

So to the end user, recordings made using the exact same variable bit rate setting will indeed have a smaller file size if the resolution of the incoming material is smaller.

Why have you been keeping this a secret?
Looks like it's true. I just did a 30sec test and theyre the same size.
Don't know why. 720 resolution should have a smaller file size than 1080.

Maybe its because the 720 is progressive and the 1080 is interlaced? Just a guess.

Wow.... Lots of information. So based on what you all know about the quality vs. file size produced, what settings does everyone like to use? If you were recording a movie.... And planned on archiving it......? And i guess the approach may be different if you planned on burning to a DVD-r?

That's why it is called "constant". It uses exactly the same, constant number of bits per second, regardless of the content of the material. If you use the more efficient mode however, "variable bit rate", it analyzes the content material on the fly and consumes a greater number of bits, variably, only when it deems necessary, based on the image's changing complexity, frame to frame.

The complexity is greater when it is more detailed (example: higher resolution) or when it changes greatly from frame to frame (example: fast motion and camera panning, as opposed to a mostly static image of, for example, a talking head where the only thing really moving, changing, frame to frame is their lips).

"Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. As opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows a higher bitrate (and therefore more storage space) to be allocated to the more complex segments of media files while less space is allocated to less complex segments."

http://en.wikipedia.org/wiki/Variable_bitrate

Opinions vary.
If you're archiving for a hard drive, Then I guess 13.5 would be the best choice.
In Post #2761 (page93) I listed a good starting point for creating files for dvd & dvd-dl.
You can adjust from there.. Everybody has a slightly different way of doing it tho...

You could run the same test at a constant bit rate and do 480i or 480P and it still be the same file size. It is because the final file size is determined only by the average bit rate and the recording total time, that is all, has nothing to do with the number of bits per frame of video.

720P has a lower number of bits per frame (921,600), but it has a higher "time" resolution of 60 frames per second and 1080i has 2,073,600 bits per frame but only about 30 frames per second. Thus in one second of video there would by about 55 million bits in a 720P capture and about 62 million in a 1080i capture, not very different, but this has nothing to do with the final file size as stated above.

This is one of the reasons that ESPN chose 720P, for the higher time resolution for fast moving sporting events, but to gain this advantage it must "stay" 720P through the full broadcast chain all the way to your eyes. A 1080P display may be OK if they have done the up-conversion from 720P to 1080P correctly.

In the real world using the HD-PVR capturing at 720P will probably look better at lower bit rates than will 1080i because much of the program sources are film at 24 frames per second or 1080i video sources at 30 frames per second so the higher frame rate of 720P is just repeating the same picture making it more compressible with less visual artifacts.

I got the HD-PVR as a backup in case my cable box firewire port gets turned off, but so far I have used it to capture streamed content and since I set 7 feet from my 65 inch 1080P HDTV I want to get the maximum quality so I capture at 1080i at the maximum constant bit rate. If the source was film and I want to keep the capture I re-encode the file and change the 1080i to 1080P at 24 FPS and do a small amount of sharping using the Asharp filter in AVISynth to overcome the softening due to the additional analog to digital conversion going on in the HD-PVR to convert analog component into digital format. I am surprised at how good some of this streaming can look and I have seen a lot of video as a retired video design engineer.

Mike T

,
In your three instances of the word "bits" in this passage, you actually mean "pixels".

As m. zillch has already shown with his detailed test results above, this statement is not accurate in the real world. I only use variable bitrate when capturing from my HD-PVR, and the resulting file size difference between 1080i and 720p source feed of the same program from my TiVo boxes is HUGE.

For those who have not already decided on their own capture and recording preferences, here are my suggestions for starting points:

• I always use 720p, variable
• If recording from SD channel, any bitrate over 7 Mbps is just wasted space in your output.
• Even with HD content, for the average movie or indoor-type program, 8.1v will provide perfect results, even up close on a 70" display.
• Lots of fast action and/or lots of picture detail (such as forests and other outdoor scenes, fast camera panning, and just about any active sports program) requires higher bitrates - at least 10 Mbps.
• At 8.1v, you can generally fit 3 hours onto a standard 4.7GB AVCHD.

I primarily record and archive movies, and with over 7,000 of them so far, the physical storage space is of concern to me, meaning I always want to make absolutely the most efficient use of whatever space is available. Now that I am recording AVCHD on both BD5 and BD25 blanks, this has become very easy. Movies around 1:30 in length easily fit two on a standard DVD-R, and the 25GB of a BD blank gives lots of flexibility to mix and match and fill them up without leaving much empty space. In fact, my biggest problem now is finding enough LONGER movies to fill a BD25 with no more than eight programs! Eight is my limit because even using a printer and printable blanks, the type of info I want on the label just won't fit comfortably with more than that.

Couple of questions.
Why only 720p if some content is broadcast in 1080?
How did you come up with 8.1v?
Are these based on your preferences or some type of video encoding logic?
Thanks.

Looked but didnt see that? think im ok though with my settings. just limited for now due to my laptop. I have a question though......how do I change from 1080i to 720p? im sure im missing the obvious, but i looked for a drop down......or do i have to change the source's (STB) output?

Change it at the source.
Surprised you couldnt find page 93

Capture Bit rates depend on content. How fast moving is the video?
Start here and tweak as you like. These should be safe values with great quality. There's nothing worse than having to capture a 2hour program twice because I wanted an extra .5kbps.

I use variable not constant..
720p/5.1 source:
60min 12.0vr dvd5
90min 10.0vr dvd5 13.5vr dvd9
120min 12.0vr dvd9

1080i/5.1
60min 11.0vr dvd5
90min 11.0vr dvd9
120min 9.0vr dvd9

If there's just one title on the disc I use tsmuxer to author. You can choose whatever auto chapters you want (5min for example) and it's fast. (no menu)

If there are multiple titles per disc I use multiavchd for authoring. It can create menus and auto chaptering.

Thanks! Thanks in advance for your patience lol.....what is "vr" and "DVD5" (for example).

vr is variable, DVD5 is a single layer DVD and DVD9 is a dual layer DVD.

My choices are based on many many many hours of testing and the results of 10,000 or so recorded movies. It is very tedious to record the same thing over an over and over with different settings (and then have to review each recording!), but it is the most direct way I know to actually see the results of various choices.

I only use 720p because it produces the best results with the least amount of farting around with my devices. My TiVos produce excellent output at this resolution from all recorded content, including the 1080i programs, and the captured files are MUCH smaller than using 1080i. It does not provide any particular benefit when recording SD source material except that using a fixed 720p output mode on the TiVo reduces various picture flashes and program stream glitches when changing from one resolution to another. This turns out to be a particularly easy choice to make with the TiVo since it has very good up-converting results from SD content.

8.1v is the best compromise I have found that produces decent file sizes and excellent PQ for the vast majority of programs I record. I used to use primarily 7.1v so that I could fit more of the medium sized movies on DVD5 and DVD9 discs, but after I started doing BD25s, I had enough extra space flexibility that I upped it to 8.1v. The .1 is not significant - just that I make most of the bitrate changes using the mouse wheel, which changes it by .2 per notch, and if I use even numbers it gets changed to odd if I roll it up to maximum of 13.5. So it is easier to just leave it on odd increments.

Thanks bpratt and nikknightt. Never used dual layer discs before but ill have to give that a shot. Looks like alot of captures will be over the 4.7 size. Also... Ive seen TSMUXER is the program of choice for burning by many. Is it better than the supplied program for any obvious reason? Just wondering if i should look to download it before getting into any burning.