Planning on releasing a series of free lessons on Digital Video - need input!

[Blue_MiSfit]

Hey all,

So I had a brainstorm this evening while washing dishes. I've always wanted to teach a lesson in the basic concepts of Digital Video, but none of my friends ever want to listen! :)

So why not make a series of lessons, and post them for free on the internet? I think it's something that I could do in my spare time, and would be good fun! I would narrate the whole thing and make some sort of rudimentary graphics / animation and tie the whole thing together with an NLE, and then release it through a filesharing website like rapidshare, or maybe Bit Torrent if there was enough interest.

Part of this would certainly involve me writing a script for narration, and having experts (read: you guys) review it and make comments / corrections, to make sure I'm providing correct information. What do you think? If I posted scripts, would anybody read them and offer their ideas?

A rudimentary outline of what I've got in mind is available here (http://home.comcast.net/~blue_misfit/). Please excuse my dreadfully simple HTML, I literally learned on the fly :)

Let me know what you think!

~MiSfit

[linx05]

One tip from me is however you release them, do not put them on rapidshare. There are many much better sites out there for this type of thing. Please stay away from rapidshare.

I like number 5. Do you think there could be something along the lines of copy-prevention on DVDs? I would be interested in that.

[Blue_MiSfit]

That's definitely a possibility. What other file sharing websites do you know of? I'm only personally familiar with rapidshare, though I know some have real problems with it.

[setarip_old]

(Just kidding!) So, who's going to do the dishes while you're putting this together?

[Blue_MiSfit]

:D Nobody, they will just stack up..

Oh wait, that's no real change! :)

Seriously though I'm going to start writing a script for the first part tomorrow (or is that today?)

[Blue_MiSfit]

So I caved and started writing... The first roadblock I ran into is figuring out how to explain the difference (in grandma terms) between digital and analog video.

I realize that digital video in its lowest level is a series of bits, but what's the equivalent for analog video? Varying voltages I'm sure, but how would you express that in equally simple terms like 'zeroes and ones'?

A not nearly 1/10 complete version of part 1 is posted on my website...

[*.mp4 guy]

The difference between digital video and analog video, in grandma terms is that digital video is completely certain, that red pixes is exactly r225 g25 b27, while with analog there is a degree of uncertainty since the signal isn't finite the pixel could be r227.338 g22.713 b27.113. In the simpleset terms its the difference between a tape and a cd, the tape will sound different depending upon the quality of the tape player, while the cd will always be the same, the tape will degrade over time while the cd will either work, or not work (Digital technology is in reality analog technology with results quantized to a point where there is no precision below the noise floor, so in effect you have perfect information, or none at all, while with analog you are always at some point inbetween).

[Blue_MiSfit]

That's a good way to explain it. Do you mind if I lift (and adjust accordingly) some of your post and add it to the project? Proper credit will be given of course!

[*.mp4 guy]

Nope, I don't mind, take anything you want from it.

[Jay Bee]

...while the cd will either work, or not work...

I always believed this too, until I noticed that some of my older, music CD-R's would play with hissing and noise, even after digitally extracting them.

I didn't understand how this is possible while data on CD-R would always be either perfect or declared unreadable. AFAIK now this is because the error protection methods used for the Audio CD format is poor, although I don't know if this is the fault of the format itself or of the way the players deal with errors.

This means that in fact digital data does not automatically mean error-free data, as some people assume, but fortunately I haven't encountered this kind of problem in the digital video world.

[*.mp4 guy]

Its either bad software, or bad firmware for the drive, probably a combination of both, You wouldn't beleive how horribly mangled some of the cds I've extracted perfect (as far as I can hear) audio from have been, but I'm lucky enough to have a nice yamaha cd drive that would probably read anything even marginally salvagable. Your right about digital not meaning error free though, what I meant was that you either have information (in the cased of a cd music plays), or you don't (no music) because there are errors, with digital its all or nothing if you have readable data you can be sure that its in pristine condition, but you won't always have readable data.

[Jay Bee]

Its either bad software, or bad firmware for the drive, probably a combination of both...

Hmm, I'm not sure, I think it's something more fundamental:

I use Exact Audio Copy (http://www.exactaudiocopy.de/), which was developed specifically to do better error correction than other CD-grabbers and I've used it with many different drives. When it finishes it gives you a quality value for each track in %. Quite often this value is lower than 100% for some tracks (I can't hear the difference though).The fact that this happens a lot more often than errors happen while reading from data CD's indicates to me that bit-perfect extraction is for some reason difficult with Audio-CD's.

[zilog jones]

I think a good way of explaining the difference between analog and digital data would be to start off with audio instead of video, showing a graphical representation of PCM sampling (like on the Wikipedia article (http://en.wikipedia.org/wiki/PCM)). Then go on to show how a TV video line is just a much more sophisticated waveform, and how digital video samples it into pixels and whatever, and then go on to the advantages/disadvantages like what *.mp4 guy said.

Places like YouTube and Google Video may be good for releasing the series, whoever you will have to take into account the crappy bitrate and 320x240 restriction on those two sites. If you want decent looking video, BitTorrent is probably your best bet (give a link to uTorrent and their guide on your website).

Where applicable, I would like to see equal coverage of international formats (well in English speaking parts of the world at least), i.e. NTSC and PAL (esp. regarding different types of telecine), and if you go into talking about broadcasting ATSC and DVB, etc. I'm sure there's enough of us foreigners here to be able to help you out with all that ;)

[Soulhunter]

Cool! Planed something similar for my own page (http://soulhunter.chronocrossdev.com/index.html) [yes, learned HTML on the fly as well XD] but I had to surrender thru chronic lack of time... :\

...the tape will sound different depending upon the quality of the tape player, while the cd will always be the same...
Nah, the information on the CD will be always the same, but same as tapes they will sound different depending upon the quality of the CD player and the other hardware... I think the main difference between analog and digital is that a digital copy is lossless [explain the stuff with the 0's n 1's and that digital copys are bit -> bit exact] while a analog copy is lossy [think the photocopier compare does it... 1st gen copy = good... 100th gen copy = uber ugly] huh?


Bye

[neuron2]

I think Grandma is lost, even with the simplified explanation. Perhaps educating Grandma is an over-ambitious objective.

[Soulhunter]

Hehe, true! My grandma doesnt even know how to use a pc... same goes for my mom/dad! Awaiting some basic knowledge from the readers/watchers is legitim imo!


Bye

[Jay Bee]

One last post on the subject of bit-perfect copying of Audio-CD's:

A bit of googling quickly confirmed my suspicion that Audio-CD's are in fact rarely read in a bit-perfect manner and it does indeed have to do with the way error correction is implemented in the Audio-CD standard. The second post of this (http://www.cdrlabs.com/phpBB/viewtopic.php?t=3210&highlight=bit+perfect+audio+copy+impossible&sid=e0f223afab18f705bcd26074f85ab3fc) thread has some technical details.

So I guess we have to be careful with the assumption that digital data can only be either perfect or "broken".

[*.mp4 guy]

After reading that It looks like this scenario only applies to audio cd's, do to uncorrectable temporal jitter that quite simply wouldn't be tolerated in a digital system since it is an error and digital systems cannot use data with errors in it; if it were a data cd the infromation would be there or it wouldn't. I suppose I was wrong about music cds being digital, anything that can tolerate and produce none finite errors is analog.

[Jay Bee]

Let's agree on "kinda digital". ;)

[Blue_MiSfit]

Thanks for all the replies people! And indeed, the objective isn't to educate grandma, neuron2:) Some progress has been made, I will hopefully upload an update tonight.

~MiSfit

[neuron2]

The first roadblock I ran into is figuring out how to explain the difference (in grandma terms)

the objective isn't to educate grandma

Ummm...if a project like this is to succeed, you need to be clear about your objectives.

[Blue_MiSfit]

I think you may have misunderstood, and I may have overstated. I was being facetious :)

by grandma terms I didn't literally mean terms simple enough for grandma to understand - there would be little point to such a project IMO. I just meant really simple term.

The objective is simple, to provide an easy to understand (for the beginner with a bit of computer knowledge) series of lessons about using video with the computer.

[Soulhunter]

For 3b... Dont forget to explain the difference between containers and streams somewhere before! Most noobs dont know about this and think avi n mpg are just two different kinds of compressions, hehe... Maybe use a diagram with a box where you put video [pictures] audio [CDs] and subtitles [books] in... Then explain that each kind of box [container formats] needs a different sort of arrangement for the stuff you put in, coz the shapes [specs] are different... Also some basic info about stream (de)muxing would be good imo! ^^


Bye

[Gerard V]

Speaking as a comparative noob, I second Soulhunter's comment. Understanding the many to many relationships between file types and contents, and also explaining the concept of codecs etc. would really help getting started.

You would change the world if you could impart useful information that would raise the average quality of clips on youtube etc.

[Blue_MiSfit]

:) I don't know about changing the world - maybe for a few interested people in the way that learning about all this cool stuff has done for me!

I will definitely include some material on the relationship between streams, containers, etc...

~MiSfit

[Digga]

Most noobs dont know about this and think avi n mpg are just two different kinds of compressions, hehe... Maybe use a diagram with a box where you put video [pictures] audio [CDs] and subtitles [books] in... Then explain that each kind of box [container formats] needs a different sort of arrangement for the stuff you put in, coz the shapes [specs] are different...that a simple and nice round up, I have to memorize that one :)

@ Blue_MiSfit:
as for the question of webhosting services (post #2 & #3):
in this case I don't see what speaks against Rapidshare. if you go this route it might be a good idea to host it on some other services too like MegaUpload. for now your site is certainly enough IMHO.

nice effort btw :)

[linx05]

@Digga
Rapidshare is probably one of the worse uploader sites out there. If you download something, you can only download one at a time. Once you connect to the download, there is a time between when you can start you next download. Some people find that they cannot download because the IP they are using was used by a previous person, so now they must wait 30 or so minutes.