[HN Gopher] The Illustrated Guide to Video Formats: fifty years ... ___________________________________________________________________ The Illustrated Guide to Video Formats: fifty years of video history Author : asicsp Score : 106 points Date : 2022-07-18 13:30 UTC (9 hours ago) (HTM) web link (archivesoftomorrow.com) (TXT) w3m dump (archivesoftomorrow.com) | allturtles wrote: | I'm struggling to see who the intended audience is for this book. | | Based on the preview, it appears to be 86 pages of illustrations | in a cartoon style with a little bit of descriptive text in the | form of 'fun facts.' It reminds me of the style of a children's | pictorial encyclopedia. | | This seems way too simple for a serious video geek, archivist, or | historian, but who else will be interested in learning about | dozens of historic video formats? | [deleted] | ablwr wrote: | It's for funsies. Haven't you ever done something for funsies? | | Mostly I just wanted to make some nice open-license | illustrations and the book is just kind of a bonus. I'm not | trying to make a buck; everything you need is available on the | website. | | I've been teaching archivists for a long time and everybody has | to start somewhere. I think this is a good starting place, | especially for folks that need to know how to figure out what | something even is, or the potential content or historical | context/era. Especially for folks that don't work with video | often, they can get easily freaked out/overwhelmed. I think | it's going to be either required or recommended reading for at | least three archives courses this fall that I know about. | dylan604 wrote: | The strangest video format I've worked with was a 1/4" open reel | black & white format. I don't even know the time frame of when it | was used, but the engineering staff had to dig up an old machine | and restore it just to be able to playback the footage we | received. It was the one and only job while work for that company | that I ever saw it. Then again, there was a Fisher Price like toy | camera that recorded similar b&w footage to an audio cassette.[0] | | My favorite tape based trivia is that all but one tape format has | the supply hub on the left side and the take up reel on the | right. Only the 3/4 Umatic format has the supply reel on the | right. | | [0]https://www.youtube.com/watch?v=TCXJ5twf5tM | Gordonjcp wrote: | That's not quite true, Philips VCR (N1500/N1700) has the hubs | stacked one on top of each other. I'm sure there was one other | like that but I can't remember the name. | dylan604 wrote: | But which way did the tape wind? I've found no information in | my brief searching about this format. I'll gladly add it to | my list of right to left tape formats, but I'm seeing no such | evidence. | g-schro wrote: | Does this book also explain NTSC and PAL formats? Or is that a | different world? | ablwr wrote: | It doesn't, it's a pretty simple book, intentionally. I had to | remove a lot of more technical "fun facts" and replace them | with something more historical / market-context-oriented so it | would be fun for total novices (I had my mom tell me what was | too confusing for her and swapped those out). | | I think one of the best books out there for really getting into | video (algorithms, et al) is Charles Poynton's Digital Video | and HDTV. | dylan604 wrote: | Kind of hard to illustrate NTSC and PAL. | | These are the physical media. The tapes were not concerned with | the types of signals that went on them. This is showcasing the | physical nature of the video formats. | | If I were try to illustrate NTSC, the red would all be shifted | to the right in the image in a blurry fasion. Not the hue | itself shifted to the right, but the physical position of the | red information ghosted to the right of the actual source in | the image which would still be a shade of red, but most | definitely, it wouldn't actually be red. | TheOtherHobbes wrote: | NTSC was also known as "Never The Same Colour". | | NTSC and PAL were video encoding specs and also recording | specs. The framerate and line resolution were part of the | format, so PAL and NTSC recorders/tapes weren't compatible. | | For capture, PAL is basically 576 interlaced at 50Hz. NTSC is | 480 interlaced at a little less than 60Hz. The physical line | count is higher - 625 for PAL, 525 for NTSC - but these extra | lines are either blank or used for supporting data. | | Most professional hardware could record/play either format, | and a few systems could interconvert on the fly. But that | took significant processing. The recordings themselves were | one or the other. | | This carried through to video recorded on disk. Consumer | analog video capture cards tended to be PAL or NTSC, sold by | region. | taffronaut wrote: | From BBC Engineering in the 1970s: | | NTSC - "Never Twice the Same Colour" (US) | | SECAM - "System Exactly Contrary to the American Method" | (France) | | PAL - "Perfection At Last" (UK - BBC of course) | dylan604 wrote: | Most people don't realize that PAL came 10 years after | NTSC. It also did not have to worry about maintaining | backwards compatibility with the pre-existing black&white | only format that was only a couple of years old. | | As much as I hate all of the pain that compatibility | caused, it was an impressive feat of engineering. | 30000/1001 was such a magic number that haunts me to this | day. | tialaramex wrote: | > It also did not have to worry about maintaining | backwards compatibility with the pre-existing black&white | only format that was only a couple of years old. | | The BBC was broadcasting TV shows in black and white, and | they were being received, in black and white, on people's | black and white televisions for many years before PAL was | developed. | | So yes of course compatibility was important, the | existing sets continued to show (in black and white) | newer colour shows, PAL is a method to _encode_ colour on | an existing black and white television signal just like | NTSC. PAL isn 't better because of somehow not worrying | about backward compatibility, it's just a better | technology. | asicsp wrote: | Links to illustrations and data: | | * https://github.com/ablwr/illustrations/tree/main/cables | | * https://archivesoftomorrow.com/illustrations/video/ | | * https://archivesoftomorrow.com/data/video/ | kloch wrote: | "UHF" connectors are very unfortunately named. They shouldn't | be used for anything above 30 MHz (HF), but are often used on | VHF (~150MHz) radios even though they have poor performance | already at those frequencies: | | https://www.hamradio.me/connectors/uhf-connector-test-result... | | > The stunning result is all the UHF connectors in the test | have worse performance than all the other connectors. One | immediate conclusion concerning 'UHF' connectors is they will | function at these higher frequencies, but one must decide if | using the PL259 or SO239 is worth it in an age where its | deficiencies have been made moot by ALL connector designs since | WWII. | | N connectors work excellent all the way up to ~1GHz and also | have decent power ratings. Above that SMA/SMC is popular for | low power applications, and waveguides for high power. | | TNC connectors were popular in the 1980's for analog cell | phones and 800MHz public safety radios. | dylan604 wrote: | Next up, Illustrated Guide to Video Codecs | | 01011010110011100101000111001010101010110101110001 or something | ablwr wrote: | I _do_ want to do a history of video codecs (codec wars, etc) | but I'll have to actually write words for that one :'-) | h3mb3 wrote: | Another entertaining take from the perspective of consumers, | while not just focusing on the typical VHS/Beta and newer stuff: | "The Forgotten History of Home Video" by Cathode Ray Dude: | | https://youtu.be/30Uc-JxJzYI ___________________________________________________________________ (page generated 2022-07-18 23:01 UTC)