Because DVD authoring software is on GOTD today...
It's taken many years to develop the code base for the better DVD & Blu-Ray authoring apps. I thought it was nice when newer companies initially started to expand beyond typical converters into authoring software, but then they stopped being ambitious, and never went for the gold so-to-speak. I'm not a fan.
Too many of these apps focus too much on re-encoding video to DVD mpg2, when perhaps the majority of that video should never be put on a video DVD to start with. In so many cases all it accomplishes is a inevitable reduction in quality. Blu-Ray video discs are good if you have high bit rate video [20-40] and prefer them as a method of storage or distribution. When it comes to watching video, a Blu-Ray disc is probably the highest bit rate a consumer can get their hands on. When it comes to the movies you see in theaters, video DVDs are still a popular means of distribution, but almost all original video is higher quality to start with nowadays, while much of the stuff you can download legally is either higher or lower quality, so there's simply not a good fit with the video DVD format.
A case can be made for video DVD projects bringing together a variety of still image &/or video content, though it's diminishing since it's hard to buy a DVD player nowadays [most are Blu-Ray that also handle DVD], while older DVD players have largely expired, or are in the process of expiring. Spend the extra $30 if you can & get a Blu-Ray rather than DVD burner. Either way from my point of view, if your project is about creativity, bringing whatever content together, then you probably want to be creative rather than using cumbersome menus & such that are clearly canned. And that's my big problem with this sort of app. I think viewers would rather see something creative, even if they hate it, rather than be put to sleep out of boredom.
But that's me... Here are some of the basics that should prove of some use at least with video, especially if you're thinking about putting it on a DVD or Blu-Ray disc.
I'll start with the most important stuff 1st... You can create a DVD comparable to what you buy in stores, & while it requires some learning, it isn't terribly difficult &/or expensive. Unless you can code Java, the same cannot be said for video Blu-Ray discs. You can create either without menus, & that's Much easier. You can also use free software to create either, but in that case Blu-Ray video discs are easier, though more time consuming. DVDs are still popular, & with the exception of subtitles, can look surprisingly good on a 1080p, & even some 4k HDTVs. Blu-Ray discs are popular, though their popularity can't compare to DVD, the discs are much more easily damaged, & there are longevity issues with the blank discs you burn.
Popular alternatives are video streaming, as well as mkv & mp4 files on USB or networked storage, but both have their mostly bandwidth-related caveats. It's difficult to deliver high bandwidth video over a network, much more so over a wireless connection, & more so over congested Internet pipes. The chips or electronics also come into play -- many cannot decode & play higher bandwidth video. That lower bandwidth makes for an objective difference [lowering] in video quality, but how we perceive video quality is usually subjective. That means that your experience may often disagree with what you read, so test whatever means of video delivery 1st before you start spending more time & money.
To do much of anything other than play online streaming video & retail DVD & Blu-Ray discs, you should know a little bit about video encoding. The way it works is basically the encoder looks at snapshots throughout the video, then figures out what's different between them, & that's what it'll store, those differences or changes from one frame to the next. Quality is generally determined by how much data is stored -- think of it as the difference between the picture taken by a one megapixel camera vs. a 12 megapixel camera. And just like those 2 pictures, more quality equals more pixels equals bigger files.
Now to play digital video, whatever device has to read a video file, decode it, & send the results to some display. That stream of data is usually referred to as the bit rate, so when you talk about the relative quality of a video, you refer to its bit rate. It does get confusing... a video encoded to AVC is smaller than the same video encoded to mpg2 when each use the same bit rate setting, but the quality may or may not be comparable. If you get up around 20-30 for a Blu-Ray disc for example, you'd likely be hard pressed to tell the difference [if you could tell the difference], but because AVC is so much more efficient, you can drop its bit rate to 1.5-2 for DVD sized video, & the quality might well be equal to DVD mpg2 with a bit rate around 6. Further, the size of that AVC video file might be 1/4 the size of the DVD's mpg2.
One thing that means is that when it comes to Blu-Ray video discs, since the storage space is somewhat irrelevant -- you're going to use a Blu-Ray disc, whether it's filled or not -- some software will use, maybe as its default, mpg2 video encoding because it's so much faster, since there's so much less processing involved. Outside of Blu-Ray discs though there are other considerations.
4k video isn't common yet, so I'll skip the proposed standard methods of encoding -- what the market eventually decides on may be entirely different anyway. One of the most popular video encoding formats is AVC [H.264], which is what most of the hardware in PCs, laptops, cell phones, tablets, media player &/or streaming boxes or electronics, game consoles, & Blu-Ray players are set up for. It's very processing intensive, so the electronics are designed to give a helping hand so-to-speak. Video DVDs started in the 90s, so the mpg2 they use is Much less processing intensive. It's not as efficient as AVC, so files are larger, though as above that difference is much more apparent when you're talking mpg2 files that are 8 GB or less.
Mpg2 is included in the Blu-Ray specs, along with AVC & something called VC1. It's an offshoot of Windows Media that Microsoft developed for Blu-Ray & theaters that can work well, but compatible software is a bit scarce. Speaking of specs, it would be nice if all mpg2 & AVC video was the same, was encoded the same way, but that's Very Much Not the case. There's a Long list of potential encoder settings, & those settings effect quality, compatibility, & particularly with AVC, the amount of processing required. With DVD & Blu-Ray video things can get sticky -- with AVC this is often what determines if a particular device or software can play the video, & how well.
DVD & Blu-Ray players are generally designed to handle the majority of retail DVD & Blu-Ray discs, regardless what the DVD & Blu-Ray specs call for. If you were to send your project out to a facility to have DVD or Blu-Ray discs made, they'd 1st run it through software testing to make sure it was going to be compatible with most players. Retail DVD & Blu-Ray authoring software often includes that same sort of testing, which unfortunately Is Not Standardized. What that can mean is that if you did not encode your video in the same software package that you're using to create the DVD or Blu-Ray layout, it might or might not be accepted. That can sometimes be terribly important, since the encoder included in that DVD/Blu-Ray authoring app or package may not be the best choice, &/or sometimes you may not need to re-encode that video at all. [Note: I say *package* because often a video editor/encoder is bundled with a separate app for DVD &/or Blu-Ray authoring.]
If there's a moral to this story it's take nothing for granted -- Test Everything. Make a short test DVD or Blu-Ray & test it wherever you want to be able to play that disc. Encode a short test clip & try it on every device you want to play your video on, particularly if you're planning on streaming or networked storage. One hint... If you're encoding to H.264 [AVC] or similar, & not for Blu-Ray, there are several *post processing* settings -- these increase quality at the cost of increased processing by the player. You *may* find you get better quality using more post processing but reducing frame size -- when you do that you shift some of the available processing horsepower from dealing with a larger frame [more pixels] to dealing with quality.
DVD & Blu-Ray Authoring Software...
Both specs are tightly controlled with selective licensing, high prices, & NDAs. Most of what you can learn is/was accumulated through experimentation & reverse engineering, plus as above, players don't stick to the specs 100% -- not everything you read or learn will work everywhere every time. Again Test. Be aware that you can produce better & more reliable results if/when you pay for software from a company that has paid whatever licensing fees. Non-licensed AC3 audio encoders are not quite the same, & you'll be hard pressed to encode DVD mpg2, especially using pulldown, that's as nice as what you'll get from the MainConcept encoder in apps like Vegas & Premiere. IMHO, FWIW, ffmpeg's mpg2 is junk.
DVD video should be VBR [Variable Bit Rate] mpg2 using a DVD encoding template -- basically encoder settings that are known to work with [most] all players. If the source was 24 fps [film], for compatibility with NTSC specs it will ideally use pulldown -- flags are inserted into the mpg2 file telling the player which frames to repeat to achieve 29.976 fps. [While it's possible for PAL, often they'll essentially play 24 fps at 25 fps. FWIW some shoot PAL's 25 fps, then run it as 24 fps to mimic film.] Maximum bit rate shouldn't go above 9 [9.5 often, but not always works], while the average bit rate varies depending on the length of the video, generally around 6 for 1.5 hours worth. If the video's 2 hours or more, go dual layer DVD -- it's impossible to get acceptable quality otherwise. You go for the highest bit rate that will allow the file to fit, or put another way, you reduce the bit rate until it does.
DVD video is always 720 x 480 NTSC or 720 x 576 PAL -- if it's 16:9 aspect then the video's anamorphic. What that means is a wider picture is resized, & a flag is inserted into the file saying basically: "Stretch me". Not every software player will read that flag & stretch the video, so you'll often need some sort of DVD player software to view it properly. That's the short, Short version... The whole topic dates back to the 70s & 80s, involves the sampling frequencies of early analog capture hardware, a bunch of math including at times wave theory, analog TV broadcast specs, politics, & marketing. By the time DVDs came around there was never any intention that any average home user would dabble in this sort of thing, & actual specs regarding what the proper 16:9 frame size was/is were never developed. Seriously.
The long & short if it is you have to use your eyes to double check whatever settings your software uses. A briefest summary: 720 width video does not use square pixels, so it too has to be resized by the player to look normal. Not all players will do that. Anamorphic DVD video doesn't use square pixels either, so you have 2 [really 4] frame size distortions -- the original 16:9 video, that video at it's proper, *viewing* aspect ratio, the resized 720 width anamorphic frame, & its proper *viewing* aspect ratio. This stuff drives people, & software nuts -- needless to say many of both [software & users] just ignore the whole mess & produce video at the wrong aspect ratios. And of course it makes things interesting when you re-encode video to AVC for a cell/tablet.
The good news is that you can ignore interlacing. If you don't know what that is, Great. If you read about it somewhere, forget about it. Hardware nowadays will do what's necessary. If you come across it in some old tutorials, skip that part. The only place that I'm aware of that it can matter, is as a setting for the menu video in DVD authoring software. Some of that code is pretty old, and it can handle the interlaced setting for menus in unexpected ways, so try it both ways in tests & see what looks best.
Blu-Ray video probably should be VBR, but VBR can get a bit funky with AVC, so don't worry too much if your software doesn't allow it. Blu-Ray spec mpg2 should be VBR. Blu-Ray spec BTW is pretty liberal about sizes -- DVD video works just fine, which is why the special features on a remastered Blu-Ray are so often straight from the earlier DVD. [The DVD spec actually does allow sizes other than the 720 width frames, but nowadays when most new players are Blu-Ray that also handle DVD, I wouldn't count on too much other than 720 width.] If you're using the cli x264 encoder you can find the settings for Blu-Ray compatibility in its online docs -- otherwise you can & should go by the templates in your software, whether you're encoding mpg2 or AVC.
For audio compatibility you want to use AC3, though other formats are accepted. Generally you want to use standard DVD or Blu-Ray bit rates [go by the settings in your software], though the lower DVD bit rates work well on Blu-Ray too, plus it makes it easier if you're creating Blu-Ray & DVD in the same project.
The simplest reliable DVD software is the free version of muxman, though it will not do anything about menus. Maybe the most reliable, perhaps the most often used at home Blu-Ray authoring software is multiAVCHD, which has some limited menu capability. Neither will strike you as user friendly when you 1st fire them up, but there are guides & they're really not that bad.
DVD & Blu-Ray menus & interactivity are the subject of volumes rather than any short books. Most authoring software makes it approachable, but the difference between what you see & what's going on behind the scenes is great enough that any learning curve is most often about the software itself, as in how do I achieve this in this app. That said, the Java programming on a pro &/or retail Blu-Ray is so far out of reach for most people [software can cost as much as a car], that lower level software doesn't really go beyond the simpler aspects of basic, non-Java menus & such. That's very much not the case with DVDs, where you can do anything any studio can.
The simplest authoring apps used canned menus -- most of those out of China combine that with the open source DVD Author, which basically amounts to Linux code libraries. DVD Author front ends, e.g. DVD Styler, usually let you do more in the way of inserting your own [rather than canned] stuff for the menus. Apps from companies like Roxio & Nero tend to offer the canned stuff but their own [or licensed] code under the hood. There are quite a few apps that let you do an awful lot more, where everything can be original content, but only some of them also let you do Blu-Ray, e.g. the software from Sony & Adobe. Because so much of any learning DVD or Blu-Ray authoring involves learning the software itself, I wanted to present it this way so you can 1st decide how far you want to take it in the future, then figure out which software will let you do just that -- learn Leawo's DVD Creator, & if you want to expand your horizons in the future, you'll have to start over with something else.
I use Sony's DVD Architect -- it's old, it's not the best, but for comparison it lets you use your own intro video, menu background videos, menu buttons placed anywhere, with graphics &/or highlights you design, lets you include scripts, lets you set quite a few things to happen when a button's clicked or you leave a menu page etc. Most any DVD &/or Blu-Ray authoring app lets you set or insert chapters. DVD chapters only occur at cells, which can only occur at complete [key or I] frames. I can set those in Vegas prior to encoding the DVD mpg2, so there's a I frame where I want a chapter, & it'll export a chapter list with the time for each chapter to DVD Architect. Better authoring apps let you preview the video to set chapters, & the best let you set the I frame where it occurs, so you can tell exactly what the viewer will see when they jump to that chapter. The most basic authoring apps will limit you to one chapter every so often, say every 5 minutes or so -- you can only set the interval.
I think talking in depth about dual layer DVDs is beyond this [already overlong] post, but I also think it needs to be mentioned. The player reverses direction when it reaches the end of the 1st layer on a dual layer disc. That split occurs at a cell, & that cell does not have to have a chapter assigned to it, though it's perfectly all right if it does. Most authoring as well as burning software does not deal with any aspect of this -- use ImgBurn, optionally along with PGCEdit, & read up on the topic in their forums &/or docs. Do not assume that your software will handle it -- most don't even mention it. You can however ignore this if/when creating dual layer Blu-Ray -- it gets treated just like single layer, though again I'd recommend ImgBurn.
Better authoring apps will let you use multiple audio tracks, say one in French & one in English, or one 5.1 track & one in stereo. Better apps also let you use subtitles -- better yet some will let you use multiple subtitle tracks. How they deal with subs however varies. An authoring app might accept text subs, or it might only accept subs that have already been rasterized [turned into pictures]. It might or might not give you control over the font, size, placement, colors, or any delays or animation effects.
All subs start out as plain text, & that gets turned into [rasterized into] simple graphics in a sort of video stream that's overlaid on the video when subs are turned on. Subs have 4 colors: one for the letter, one for its outline, one for its shadow, & one for the background [which is usually set to transparent]. Those colors are coded similar to what you see in HTML for a web page, & the player does the actual coloring, e.g. a yellow letter isn't actually stored as a yellow picture of a letter, so the color can be changed.
When you author a DVD or Blu-Ray video disc, the output might be an ISO file, or the individual files arranged in a folder, & most will offer to burn the disc. The individual files are the most flexible -- you can not only play them, but particularly with DVDs, you can optionally edit them with something like PGCEdit. As a rule try not to burn the discs with the authoring software -- generally the burning part is an add-on that doesn't do as well as a dedicated app like ImgBurn.
And finally, a few words on burning discs. There are differences between the brands & models of the blank discs you can buy, and the quality of the burning drive varies, as does any drive in any Blu-Ray/DVD player. To say your mileage may vary would be a gross understatement, yet the quality of all 3, disc, burner, & player, is paramount when it comes to video. This is one area where it's hard to over-research -- look not just for quality but reliability & compatibility, as you'll quite often find discs that will work in your burner but not your player, just as many burners can have trouble burning a disc that a particular brand/model of player will work well with. As manufacturers have tried hard to cut costs, Blu-Ray drive mechanisms do not seem to have great longevity -- I've had 2 Blu-Ray burners each last only a couple of years before discs started having problems in players. The cheapest Blu-Ray blanks can also go bad sitting on the shelf, waiting for you to burn them. Note too that Blu-Ray blanks commonly use a film rather than plastic protective covering like DVDs, so be careful regarding handling & storage. On Blu-Ray discs [burned or retail], a scratch that's barely visible under direct light can ruin the disc if it's parallel to the tracks.