|
|||||
|
| Porn Users Forum » Technical information |
| 1-16 of 16 Posts | Page 1 |
| Thread Nav : Refresh Page | First Post | Last Post | Porn Forum Home |
| 06-27-12 02:17pm - 4561 days | Original Post - #1 | |
|
gaypornolover (0)
Active User Posts: 153 Registered: Jul 09, '11 Location: Birmingham, UK |
Technical information Hello all I'm always interested in improving my reviews and what some of my early reviews got criticised for was a lack of technical info. I have tried to include it in my later reviews but in truth I find a lot of the terms used a bit confusing, and I sometimes find it hard to extract the information I want to include even when I have joined a site. Could someone please explain some of the technical terms around videos in particular (I tend not to join picture sites). For example, what is a bitrate? Why is higher better, and how do I find out the bitrate of a video I downloaded? I understand about resolutions, but I am confused about what makes HD, and again I can't always find out the resolution of files I've downloaded. If someone could give me a dummies guide on what video (and photo to a lesser degree) info is useful to know, what the terms mean and most importantly how I can find them out when I join a site, it would really help me write better reviews. Anyone? Thanks in advance! | |
|
||
| 06-27-12 02:20pm - 4561 days | #2 | |
|
gaypornolover (0)
Active User Posts: 153 Registered: Jul 09, '11 Location: Birmingham, UK |
Also one other question - I never like to rate how fast downloads or streaming are on a site because for all I know it might be my internet connection that is at fault. Do others think it's fair to comment on this? Many seem too... | |
|
||
| 06-27-12 03:54pm - 4561 days | #3 | |
|
Toadsith (0)
Active User  Posts: 936 Registered: Dec 07, '07 Location: USA |
I think everybody knows that the download speed rating is a YMMV type situation, but it can allude to the speeds that are possible. For example, if you are usually able to download at 1.1 MB/s (using a download accelerator) and with a site you are only able to pull 600 KB/s, that is a major difference and should really be noted. If the site gives you your standard 1.1 MB/s, I'd would recommend noting that this is as fast as you've gotten from any site. That would indicate the site is probably capable of delivering the content even faster than that. "I'm not a number, I'm a free man!" Second Grand Order Poobah in the Loyal Order of the Water Buffalo | |
|
||
| 06-27-12 04:07pm - 4561 days | #4 | |
|
Toadsith (0)
Active User Posts: 936 Registered: Dec 07, '07 Location: USA |
The more technical info can get tricky at times. For example, determining the video quality on a streaming site can be very time consuming and usually isn't worth doing. The first thing I'd recommend doing, is getting the program VLC Player, it is an open-source freeware video player that can play any format except Blu-Ray. When you are watching a video in VLC Player you can press CTRL+J and it will display the codec information, giving you the resolution, bit rate and more. The reason a high bit rate is important is it tells you how much compression was used when encoding the video. Basically, when a video is recorded, it is usually recorded in a way to save as much visual information as possible - this makes for enormous files, especially if the camera is capable of recording in High Definition. So in post-production, after the video has been edited and music and logos or whatever has been added, it needs to be compressed so that people aren't downloading 100 GB per movie. That size isn't an exaggeration. So, what Bitrate tells us is how many bits of information is being used per frame of video. A high resolution video with a bitrate of 1000 kb/s is going to look a lot worse than a video that uses 3000 kb/s. This is because when it is using less information to describe each frame, it has to start approximating the image. So that gentle gradient seen in the dark shadow gets turned into one dark gray block. You can easily see low bitrates in high movement scenarios - one of the hardest things for video to show is water because everything in it is moving, it ends up looking very blocky when it is encoded with very high compression. The second thing, HD is that HD formats measure the vertical lines in an image. So 1080p means 1,080 vertical lines, or 1920x1080 resolution. 720p is 1280x720. These are both considered HD and both are widescreen. If you see 480p, that can be either widescreen or fullscreen, but in either case, it still only has 480 vertical lines. If you want to explore farther, I'd recommend VideoHelp.com - as they have great forums. Also the great wikipedia  "I'm not a number, I'm a free man!"Second Grand Order Poobah in the Loyal Order of the Water Buffalo | |
|
||
| 06-28-12 06:42am - 4560 days | #5 | ||
|
Claypaws (0)
Suspended Webmaster Posts: 144 Registered: May 16, '12 Location: UK |
Horizontal. 1920x1080 is 1920 pixels wide and 1080 pixels high. I am sure it was just a slip, of course.
Also worth adding that the bitrate, as its units imply, is for bits per second, not bits per frame. So, for a given compression level, increasing the frame rate will increase the bitrate. And increasing the resolution (say from 720p to 1080p) will also increase the bitrate. For a given compression level, bitrate is proportional to the frame rate and to the square of the resolution. Frame rates are typically only between 24 fps (frames per sec) in Europe and 30 fps in the US (though US standards are fairly universally adopted) so they do not have a huge effect on bitrate. However, a resolution increase from 720p to 1080p increases the bitrate by a factor of (1080/720)squared, which is 2.25. That is, you need over twice the bitrate to encode 1080p compared to 720p at the same compression level. Bitrate also depends heavily on the codec used to encode the video. As Toadsith explains, compression is required in order to represent the image data in a small enough file to be manageable. So the image data is "compressed", meaning that some information within the data is thrown away. Such compression is called "lossy compression". A codec defines the rules for throwing data away and compressing the remainder; it also defines rules for how to reverse the process and produce the video image from the compressed video file. Different video formats (wmv, mp4, flv and so on) employ different codecs. The filetype does not itself determine the codec. mp4 for example can use mpeg4 part2 compression or h.264 compression, amongst others. h.264 is a very clever compression codec which delivers the same quality as mpeg4 part2 compression but needing only half the bitrate. For a video player to play back the video, it needs to know what codec was used to create the video and it needs to have all the rules for that codec. VLC Player contains rules for almost every codec ever invented - and there are lots of them! There are also loads of different ways to compress and decompress the audio component of a movie. But they have a lesser effect on bitrate than than does video compression. Bitrate will not tell anyone very much unless they also know what resolution (e.g. 720p), frame rate (e.g 30fps) and codec (e,g, mp4 h.264) was used. I must say, I have not bothered to include all that in my reviews (perhaps my bad, as I am not very interested in watching video!). But video enthusiasts get used to what are representative figures for good quality video. So if you can establish (using VLC Player, as Toadsith says) that a site is offering 720p wmv video at a bitrate of 1000 kilobits/s, it would be safe to conclude that the video would not be very good. Toadsith said that much more concisely than I have! I wonder if any video enthusiasts have encountered 1080p video which looks less good than an alternative 720p video due to an inadequate bitrate. My systems cannot play 1080p video at all so I have never been able to compare quality. Similar considerations apply to still images. They are somewhat simpler because we do not need to worry about multiple frames per second. The same considerations of resolution apply though. A 3000x2000 image is 3000pixels wide and 2000pixels high. Uncompressed images are huge and so images are always offered as jpg images. jpg compression is lossy. jpg compression is very clever and almost invariably adequately implemented, despite having many variable parameters which define it. Sometimes sites apply jpg compression using compression parameters which lead to unnecessarily large files. The arty sites are especially prone to this and it results from a misunderstanding of what jpg compression is actually doing (beyond the scope of this answer!). Bigger files are not necessarily better quality. What far more sites (and photographers) get wrong is what they do with colour. They need to get the white balance correct (so that grey and white come out as grey and white instead of orange or blue). And they have to adjust for the colour response of the monitor they used to edit their photos. A lot of photographers and sites get one or both of those aspects wrong. And this is assuming that the photographer has got the picture in focus to begin with. We photo enthusiasts often mentally alter the name of a site so as to include "blur" or "blurry" in its name. I shall not use any real-life examples. But you might alter "BeautyOfSex dot com" to "BlurOfSex dot com"). I tend to regard image resolution more as a mark of what has not been achieved than what has been achieved. A site offering only 1024x768 images in the year 2012 is unlikely to care much about photos. But offering 6500x4000 does not tell me that the images are good. They can still be big but blurry and with incorrectly managed colour. And we have to make allowances for sites which include old content, whether photos or videos, along with recent content. To find the image resolution, Windows Explorer can show it when you display folder contents. Image Dimensions is one of the things available in details to view. And every image viewer (ACDSee, IrfanView, XnView etc) displays the image dimensions. Edited on Jun 28, 2012, 06:55am | ||
|
|||
| 06-28-12 07:31am - 4560 days | #6 | |
|
Toadsith (0)
Active User Posts: 936 Registered: Dec 07, '07 Location: USA |
Good point. I should have said the number of horizontal lines of the vertical resolution. A little mixing of the terminology there, lol "I'm not a number, I'm a free man!" Second Grand Order Poobah in the Loyal Order of the Water Buffalo | |
|
||
| 06-28-12 07:44am - 4560 days | #7 | |||
|
Toadsith (0)
Active User Posts: 936 Registered: Dec 07, '07 Location: USA |
Another good point, this is what I get for writing a reply in a few minutes and not reading it over before posting 
I have a 1080p enabled monitor and I frequently download 720p instead of 1080p because the extra resolution doesn't equate to extra clarity as many sites are using crappy HD cameras. While technically recording 1080p, they are somewhat blurry, so there is pretty much no loss with the 720p and I'm saving a lot of space. If you are a torrent freak in regards to posted hollywood videos (bad yes, not an endorsement) I've noticed that people don't want to upload 9 GB 1080p files, but they haven't any issue uploading 720p files at 4 GB - which means they look a lot better than the 4 GB 1080p files. Video compression can be pretty freaking odd that way.
Frankly this applies to video as well. So many videos end up having a bizarre yellowish hue due to improper white balance correction. "I'm not a number, I'm a free man!" Second Grand Order Poobah in the Loyal Order of the Water Buffalo | |||
|
||||
| 06-28-12 11:19am - 4560 days | #8 | |
|
jberryl69 (0)
Disabled User  Posts: 1,000 Registered: Nov 27, '10 Location: neverland |
I'm glad some of you are into this but honestly, as a porn dog, I just want to know if the vids are good and the vid quality the best. All the technical jargon is going to be lost on the vast majority of this crowd I would think. If it ain't grits, it must be a Yankee. If you're going to lay her head over the pool table and fuck her throat, get your fucking hand off her throat! | |
|
||
| 06-29-12 07:43am - 4559 days | #9 | |
|
Claypaws (0)
Suspended Webmaster Posts: 144 Registered: May 16, '12 Location: UK |
Sometimes I wonder if the people who invent the terminology make it deliberately confusing. | |
|
||
| 06-29-12 07:48am - 4559 days | #10 | |||
|
Claypaws (0)
Suspended Webmaster Posts: 144 Registered: May 16, '12 Location: UK |
And I thought I was the only one who did that.
Thank you for that. I suspected as much but have never been able to see it for myself.
Interesting. At least they cannot get the profile wrong though, since video files cannot use them.  | |||
|
||||
| 06-29-12 07:51am - 4559 days | #11 | |
|
Claypaws (0)
Suspended Webmaster Posts: 144 Registered: May 16, '12 Location: UK |
I agree wholeheartedly. I don't think any reviewers dwell on this stuff. Just a line or two stating the numbers but giving much more prominence to describing the actual content and whether it looks good full screen. | |
|
||
| 06-29-12 05:11pm - 4559 days | #12 | |
|
exotics4me (0)
Active User  Posts: 664 Registered: Jan 12, '07 Location: USA |
One thing to add here, the technical numbers do have one really important part to them besides just quality. A lot of our members have talked about having slower internet connections and limited hard drive space, or like in Pat's case, a download limit from his internet service. The technical numbers combined with time of scene equals how big the file(s) are. An example of this for the original post: Same exact scene in three different qualities from In The Crack. Thirty-two minutes, 1920x1080 @ 7,500kbs bitrate is 1.6 GB Thirty-two minutes, 1280x720 @ 4,000kbs bitrate is 965 MB Thirty-two minutes, 720x480 @ 2,000kbs bitrate is 542 MB That's the biggest reason I look into the technical parts. FuckedHard18 comes to mind since their newest scenes only offer the ultra high option. I can't imagine downloading a 1.6 GB file over a slow connection. My first time I jacked off, I thought I'd invented it. I looked down at my sloppy handful of junk and thought, This is going to make me rich. - Chuck Palahniuk | |
|
||
| 06-29-12 08:33pm - 4559 days | #13 | |
|
rearadmiral (0)
Active User Posts: 1,453 Registered: Jul 16, '07 Location: NB/Canada |
Gaypornlover - here's my take: I have no real idea how resolution and bitrate apply but I realize that many people here do and it is important to them so I try to add that information in a review. My recommendation is to download a small freeware program called Mediainfo. It will give you all the technical specs on a file. Like I said, I use those in reviews, but I always assess them subjectively too. I have no idea why, but some sites have higher numbers and the videos look crappy compared to sites with lower tech numbers. Bottom line for me is that I'll continue to report the tech stuff but continue to enjoy stuff that looks good. | |
|
||
| 07-01-12 12:11am - 4558 days | #14 | |
|
slutty (0)
Active User Posts: 475 Registered: Mar 02, '09 Location: Pennsylvania |
If you have the codec installed, you can right-click on the video, select properties, then click the details tab and it should tell you the resolution, frame rate, audio bitrate, and video bitrate, I find it quicker than opening in VLC, but that may just be me. Personally, I think it is fine to just say something like 4000 kbps mp4, because to me the bitrate is a much more important indicator of quality than the frame size of the video. Hustler's "HD" is often a painfully low bitrate, such that one wonders if they just re-encoded an SD video in a larger frame. I usually just give DL speeds with reference to my overall bandwidth. Properly encoded 1080p sometimes looks slightly better on my large TV, but on my computer monitor I can't tell the difference. I just don't think it is worth the extra space. Bunny Lebowski: I'll suck your cock for a thousand dollars. Brandt: Ah hahahahaha! Wonderful woman. We're all, we're all very fond of her. Very free-spirited. | |
|
||
| 07-01-12 05:00am - 4557 days | #15 | |
|
gaypornolover (0)
Active User Posts: 153 Registered: Jul 09, '11 Location: Birmingham, UK |
Thanks to everyone for their help, I will look into the video players and add-ons you've suggested and try and use them to include in future reviews. Rearadmiral you make a particularly good point and I will keep on just including my own subjective opinion on how good the video looks regardless of technical quality. One last question - what is considered a reasonable bitrate? I know how to find it out now, but I have no clue what's poor and what's good. Anyone give me a rough idea, perhaps in ranges - for example 100 - 1,000 poor, 1,000 - 2,000 average etc? Just so I have some idea what an "average" bitrate would be so I know if a site is above or below what you'd generally expect. Thanka so much for everyone's help again, this has got to be one of the most helpful and polite communities I've ever found online - ironic when we're all porno lovers and a lot of people would consider us degenerates - we're bigger on old-fashioned courtesy and manners than most! We might be perverts, but by heck we're polite and decent perverts! | |
|
||
| 07-01-12 12:54pm - 4557 days | #16 | |
|
slutty (0)
Active User Posts: 475 Registered: Mar 02, '09 Location: Pennsylvania |
The values exotics gave for video I think is pretty typical, I would think SD video bitrate should be 2000-3000, 720p 4000-5000 and 1080p super stupid big like 8000+. As Claypaws said it does depend on the codec that is used. Less than 2000 would probably be considered junk by most folks here, although I am somewhat more tolerant of low quality videos I think. Bunny Lebowski: I'll suck your cock for a thousand dollars. Brandt: Ah hahahahaha! Wonderful woman. We're all, we're all very fond of her. Very free-spirited. | |
|
||
| 1-16 of 16 Posts | Page 1 |
| Thread Nav : Refresh Page | First Post | Last Post | Porn Forum Home |
|
