Hauppauge HD PVR: 1080i or 720p?

[Tom Saurus]

What I typically do is record via Total Media Extreme and our Satellite Receiver is set to output to 1080i. I edit footage with VideoRedo H.264 and then take the edited footage and use Vidcoder to convert it to a 720i file to save room. We don't have any TVs over 30 inches so the picture and sound are superb on the TVs we have.

I noticed that in our Satellite Receiver's settings that there is a way to select 720p as the output. So I was wondering could the software capture device in Total Media Extreme sense the 720p resolution and if it did would the file be quite reasonable in size and if so then I would save all that time encoding down to 720i. I would imagine 720i would be better than 720i.

Thanks in advance for any advice on this matter.

[jagabo]

The file will be the same size unless you capture with a different bitrate. How good 720p60 captures will look will depend in part on how the satellite receiver deinterlaces and downscales (for 1080i sources) compared to what you do in software. Movies broadcast at 720p and captured at 720p will probably look better with the HD PVR's limited bitrate. Basically, you'll just have to test it for yourself.

[Brad]

First, there is no such thing as 720i. Are you talking about encoding down to a DVD resolution 720x480 (480i) file?

If your satellite service is Bell/Telus, you should set the satellite receiver to output 720p because all of their channels are 720p. The software should allow you to capture in 720p but the bitrate selections will be the same as 1080i.

[Tom Saurus]

jagabo: Thank you for this information. I will have to experiment a little bit to see what is best to do.

vaporeon800: I record currently at 1920 x 1080 interlaced. Once the file is edited I encode to 1280 x 720 interlaced with a constant quality of 20. Thank you for the information you have provided.

[gll99]

jagabo: Thank you for this information. I will have to experiment a little bit to see what is best to do.

vaporeon800: I record currently at 1920 x 1080 interlaced. Once the file is edited I encode to 1280 x 720 interlaced with a constant quality of 20. Thank you for the information you have provided.

You can create video at almost any oddball res you want within the limitations of the codec but it doesn't mean every playback device will accept it or scale it properly. IMO converting your videos that way is a waste of time. It would be much better to set and capture 720p from the source if you don't want 1080i. Why add an unnecessary problematic step.

[fritzi93]

I went back and forth on this as well, and now capture 720p. The default for 720p on the HD-PVR is constant bitrate, 3.7 Mb/s (1080i is 7.0 Mb/s). The defaults are adequate, IMO, for cable captures. I don't do it to save space, although that's okay. Two reasons:

1) My Comcast Motorola cable box does a good job deinterlacing and resizing 1080i. And AFAIK, a lot of the content is 720p anyway.
2) I pretty much can't tell the difference on a 70" TV at 8' viewing distance. I should think if the source was good enough, I'd be able to, but it seems not. Which tells me most (?) of what I'm getting is 720p. But football games supposedly at 1080i (CBS, etc) don't look much better. Mind you, I mostly capture old movies and documentaries. For 3D O/U and SbS, I use 1080i of course.

[Tom Saurus]

gll99: Thank you for your input.

fritzi93: Thank you for this information. I will have to do some testing as see what the results are like. The information you provided was quite interesting.

[_Al_]

For sure you compare some 720p60 using QTGMC() against 720i30 (very weird), set CRF20 and check difference in file sizes. It will be much smaller than you think.

[Tom Saurus]

fritz93: I am do a capture right now. I changed the output for the Satellite Receiver to 720p, but the bit rate is 8mb/s and so far 35 minutes of video the size is 2.07 GB which is larger than I want. So next time I do a test I will make sure the bit rate is set to 3.7 MB/s. It is recording progressive with nearly 60fps. I did a small test earlier and didn't notice the bit rate was nearly 8 MB/s. I put it on a thumb drive and it looked good on the Blu-Ray player on the TV screen. I will have to do some more experimenting to see if I want to stick with 720p or revert back to 1080i.

[gll99]

fritz93: I am do a capture right now. I changed the output for the Satellite Receiver to 720p, but the bit rate is 8mb/s and so far 35 minutes of video the size is 2.07 GB which is larger than I want. So next time I do a test I will make sure the bit rate is set to 3.7 MB/s. It is recording progressive with nearly 60fps. I did a small test earlier and didn't notice the bit rate was nearly 8 MB/s. I put it on a thumb drive and it looked good on the Blu-Ray player on the TV screen. I will have to do some more experimenting to see if I want to stick with 720p or revert back to 1080i.

My earlier comment was about the extra conversion you were doing to 720i which I find a waste but as far as 1080i vs 720p it's somewhat in the eye of the beholder, your source material, your tv's video processor etc...

In my case I set the stb to output a constant 1080i even though the originating signal might be anywhere from 480i, 480p, 720p to 1080i because it does a pretty good job of converting and scaling as needed. Although 720p 60fps should produce a smoother image I really don't see much difference even in fast action hockey games. The 46" 1080p tv I most often watch the videos on is a cheaper model. A 1080i signal requires no scaling by the tv to produce its native resolution of 1080p and the old argument that the tv displays odd lines and then even lines for interlaced video doesn't hold for progressive televisions. The 2 fields are displayed simultaneously and the combining is easily handled by the video processor in the tv. It is my belief that scaling from 720p to 1080p requires more effort by the video processor and has a stronger likelihood of introducing artifacts or scaling distortions with a cheap tv. In my observations the image is not as good at 720p. It's my personal taste and I've read many of the pro and con arguments. Bottom line is it will come down to what you like best.

[fritzi93]

fritz93: I am do a capture right now. I changed the output for the Satellite Receiver to 720p, but the bit rate is 8mb/s and so far 35 minutes of video the size is 2.07 GB which is larger than I want. So next time I do a test I will make sure the bit rate is set to 3.7 MB/s. It is recording progressive with nearly 60fps. I did a small test earlier and didn't notice the bit rate was nearly 8 MB/s. I put it on a thumb drive and it looked good on the Blu-Ray player on the TV screen. I will have to do some more experimenting to see if I want to stick with 720p or revert back to 1080i.

Whenever I switch output on my cable box and open the capture module, the bitrate will reset for either 3.7 Mb/s or 7.0 Mb/s, for 720p or 1080i respectively. I presume it's my version of TME doing it.

Forgot to mention earlier, but with most PBS programming I can readily tell the difference. Other channels, not so much, and I can't think at the moment of any that exhibit a clear difference. None that I often watch anyway. I should switch output when capturing Nova or Nature documentaries, but don't bother. They still look good at 720p.

[Tom Saurus]

gll99 & fritzi93: Thank you both for your additional input.

The 720p files even at 3.7 MB/s are too large for my liking. I wonder if variable rate would cause any problems. I notice when I put the 1080i files through Vidcoder that depending on the scenes or the vividness of the color the end overall bit rate varies from file to file.

For example I recorded a file last night at the 720p resolution: The file was 128 minutes in length. It was in black and white and didn't have much action. The file was recorded at 3693 kbs and was 3.85 GB in size.

I ran the file through Vidcoder and quite a good looking file with the 720p resolution with a bit rate of 1338 kbs and the file ended up being 1.57 GB in size.

I am under the impression if I chose variable bit rate in TME that I will end up with corrupted files or their will be some type of problem. Any further advice is appreciated.

[gll99]

Most of my captures are done with a variable (average) bitrate those using the original PVR with TME and also the new pvr2 using Showbiz. If you want a low bitrate to begin with to reduce file size why are you capturing at a higher rate and then re-encoding to a lower one. You gain nothing by doing that and are probably introducing noise by adding the unnecessary re-encode step. If you are just trimming the video then there is no reason to re-encode. There are filter tricks such as softening the picture that might reduce the needed bitrate and fool the eye at a distance but they won't make the image better. In older times we used such tricks out of desperation to fit the max size video on a cd or to clean up really noisy analog captures but with the new digital devices and cheaper, large content media there is little reason to ever do that again.

The version of TME that comes with the Hauppauge HDPVR shouldn't limit you from capturing at a lower bitrate if you want. Only you will know if you like the results.

btw) I have some older 4:3 and 16:9 low bitrate divx captures done with my tuner card and some DIVX from original DVD source (many sub 1500 kbps max frame size 720x480 or less) that are pretty acceptable even on my 46" but even though they look clean I would never mistake them for higher bitrate captures. Keep in mind that you may only have 30" tv's or smaller now but if you intend on keeping these videos for later viewing on a larger set or HD projector you may regret not keeping a reasonable bitrate in spite of the resulting larger size.

[Tom Saurus]

gll99: Thank you, I am learning from what you have written. The 720p capturing has been an experiment. I chose to encode my 1080i captures down to 720p to fit much more on the hard drive and I have read unless you have a large TV there isn't a difference that a person would notice. If TME can record at 720p and the variable bit rate is sensitive to what is being recorded; meaning it increases with the action fast moving scenes and decreases when a more static scene comes up then it would save the extra step for file size reduction.

I watch these files on a Blu-Ray player that is attached to a high quality 480p HD TV that is 20 inches in size. I do have a low quality HDTV with a 24 inch screen and the recordings don't look as good on it as it doesn't seem to like interlaced.

I have to do some more testing and experimenting. Does anyone have some suggestions to watch the parameters should be when setting the bit rate for a 720p recording in TME? Thanks in advance for any additional information.

[fritzi93]

Does anyone have some suggestions to watch the parameters should be when setting the bit rate for a 720p recording in TME?

I just wonder what your captures will look like (to you) when you get a bigger, better HDTV, as you surely will eventually. That is, if you go much lower than the defaults. Maybe consider more hard drive space?

Dunno what kind of quality you're getting from your provider. All I know about is Comcast, which squashes hell of of much content. HD movie channels are borderline, with posterization on occasion. Still watchable though. Which is why the defaults do okay for me, as more bitrate doesn't help much. If the content was better, maybe I'd up the bitrate.

One more thing I forgot to mention: 720p captures edit more readily in tsSniper, which is what I use. With a little practice, one can get nice clean cuts. 1080i edits sometimes exhibit a minor blip at cuts. (On occasion, MPC-HC will freeze at that point, though MPC-BE never does). This makes no difference if there are no commercials, and you're just trimming beginning and end off the capture. I know you don't use tsSniper, but thought I'd mention it. It might be useful to someone reading this.

Good luck.

[Tom Saurus]

fritzi93: I suppose in the future it is possible that I would get a bigger TV; but I have no yearning to get one. I bought VideoRedo H.264 to edit the files with. It does a terrific job. It is good you mentioned the other editing programs as it is likely that is useful to someone out there. I need to buy some more hard drives to back stuff up. I was hoping for some huge leap forward in storage space like the one that went from the GB to the Terabyte. If we had stable 200 TB drives 10 GB files would be small in comparison. Thank you for the information you have provided. I have learned a lot here at VideoHelp, thanks to people such as yourself.

[gll99]

With your current setup you could even go 480p and lower the bitrate to get a smaller file and you'd likely be no worse off than some cheap DVDs based on the older mpeg2 codec. We don't live in the same video world so based on what you have posted for now and as a bit of future proofing 720p is probably the best for you but I would never suggest anything non standard like 720i nor would I suggest 1080i with a very low bitrate like you are using.

On a side note just for the halibut I set my stb to output "480p wide" with a source I know was originally 720p and did a 5 minute cap at variable average of 1400kbps with the peak bitrate set to 6100Kbps, 60fps on my HD PVR2 using Showbiz. I could have tried with a higher peak rate but wasn't sure which was best. The video bitrate of the cap file ended up showing as 1517 Kbps and the ac3 audio was 384 Kbps 6 channels. The total 5 minute filesize is 73,200KB. If you project that out to your 128 minute video you'd end up with a total filesize of about 1.9GB. Certainly not BR quality on a 46". The image fills the 16:9 screen nicely, has no blotches, just a bit of a rough edge but very watchable

[fritzi93]

I suppose in the future it is possible that I would get a bigger TV; but I have no yearning to get one.

Ha, if you lived near me I'd sell you a 42" plasma or a 47" LCD, real cheap. I mean cheap. Both in good working order.

Little does my wife know, but I'm already thinking about getting a UHD set (4k), at least 84". I'll have to wait for more "reasonable" pricing, as she'd just kill me if I got one now.

Your resistance to upgrade-itis is admirable.

[vhelp]

from what i recall, the last time i had an actual 720p source from my OTA receiver/usb capture device, and capturing the tv sereis, Lost. the 720/60p is full frame, not fields, thus, 60p/fps vs 30i/fps. but since the 60p duplicates some of the frames (if film) the compression will be better on those vs if the the 60p/fps is video/sports since those will be different in each frames. so some 60p content will compress/look better than others. with 30i/fps you have harsher compression due to the interlace in video/sports, but slightly better in film content but just as bad if the show/content is time expanded/compressed since they manipulate the cadense which gives you more interlace hence compression artifacts in those frames.

if you really want to test the proficiency of your hdpvr 2, since that is what you are going by as the final master:

then, for a more better or accurate test, you are better off recording the content to your dvr first, and then set it to 1080i and 720p and capture from it with the hdvpr 2.

do a record-to-dvr for a movie source and one for a video/sports source, and capture both. do two capture sessions for the film and video/sports. then judge the quality aspect.

[Brad]

I'm going to reiterate my statement that Bell/Telus satellite is 720p on every HD channel, since the OP ignored it and never said what satellite provider he uses.

[Tom Saurus]

vaporeon800: We have a Shaw Direct receiver. The newest HD channels are .mpeg4 compressed to begin with. It doesn't take much wind tussling tree tops or as I learned the other day only a slight bit of snow on the dish and the signal goes out.

I do have more experimenting to do. I went back to 1080i for now.

[Tom Saurus]

I did a test capture with the satellite outputting a 720p picture. I set the HD PVR to a variable bit rate for capturing and it did not look good. I get better results capturing at 1080i and encoding down to 720i. Well it was an experiment worth performing as I did learn from it.