WWDC2004 Session 702

Transcript

Kind: captions Language: en welcome to an overview of quicktime codecs session 702 my name is Dennis Backus i'm a senior technical manager in the marketing group that apple and it's my very very distinct pleasure to introduce from ursa major media I got it right cliff and meter cliffs been in the QuickTime business for how many years in minutes now 15 minutes yeah we pulled him off the street you know no I saw always on ears he also runs a really interesting sighs you guys haven't seen that you should go take a look at it's called quick timing gorg it's a it's a very good dissipation site for all things quicktime of both third-party products apple announcements and all sorts of things that you never never heard of but need to use so that further videos we bring clifford onda onstage question and answer we want to hold to the very end and we want to make sure to use the microphones so that we can pick this up for the recording ok thanks that's so will like it applause I have anything done anything yet I love that ok so I'm going to talk a little bit to you about quicktime codecs and try to get through i'll give you a little bit of information kind of an overview of the different quicktime codecs are avail that are available what they're good for what you might want to use them for in production environment which ones are not really all that useful you probably want to skip over as y'all might know quicktime supports about 200 different media types sometimes that can make it a little bit confusing as a technology because out of 200 media types you often faced with the question of ok 200 yeah but which one do I need for what I'm doing today so we're going to try and and cover some of that like I said and argue with enough information so that the next project that comes up you'll be able to at least ask some intelligent questions so what I want to cover specifically criteria for choosing a cadet categories and types of codec strengths and weaknesses of different types of codecs where you might want to use them like I said and also give you some resources where you can learn more so I'm not going to put a lot of time and effort in the beginning of this talking about exactly how codecs work or exactly what they do i do want to cover it just a little bit of information on codecs in general basically we use codecs for three reasons save space and transfer time save bandwidth or save processor cycles get them to play on older slower machines if you're looking at uncompressed ntsc video you're talking about 30 frames a second at two fields per second or 60 images at 640 480 or 27 mega bytes of information passing through if you've got a brand new dual processor g5 you might be able to get playback from that but specifically on on older machines or if you're transmitting video want to transmit video over the web or put it on a CD ROM that's going to be problematic the DV codec which compresses to about 5 1 compression is kind of my example here just to kind of work the man so if we're looking at 27 megabytes per second transfer with uncompressed video we're looking at about 3.5 megabytes per second or about 30,000 kilobits per second with DV which is probably the codec that y'all are most familiar with because it's what every digital video camera out there uses essentially you've got two types of compression I tend to break things down this way a lot you're going to hear me say there's two types of this two types that quite a bit for some reason it just works out that way so with video compressors image compressors audio are specifically with video compressors and image compressors you've got spatial compression and temporal compression spatial compression is what's used for most codecs that you'd be familiar with for images like jpg and ping and Jeff where it's essentially either finding a way to copy the same information more efficiently or it's throwing out some information so that it stores it in a smaller format temporal compression is compression over time hence the stopwatch get the metaphor it's so an example of spatial compression typically when you write an image in an uncompressed format in some manner you're recording the information as individual data blocks for individual pixels in that image so in other words the pixel width coordinate x equals 0 and y equals 0 is black and what happens with uncompressed data is that amount of information is stored for every single individual pixel it's a little bit as if in your on your palm pilot you wrote out Monday 1230 lunch Tuesday 1230 lunch Wednesday 1230 lunch etc etc etc so what the compressor does is it finds a more efficient way of writing that information it essentially says monday through friday 1230 lunch so it's getting rid of information without getting rid of data does that make sense everybody good I like to see the nodding not too shaky jpg that my two examples here at TIFF and JPEG TIFF is essentially a lossless compression so it finds an efficient way of writing that information without actually throwing out any of the important data you don't lose any of the image jpg is a lossy compressor so it does throw out some information it starts out at higher levels of compression throwing out information that's theoretically beyond human perception so colors that we can't see bits of detail that that are mathematically able to be generated but can't really be perceived by people as you squeeze it further and further down it begins to thrill out more and more important information so it in effect it degrades the image you're sacrificing image quality to recover some size so here's an example of the same image compressed at three different levels with JPEG if you look really carefully right in here and right in here and in the table here this is the least amount of compression or the most depending on how you want to look at it so it's it's the most image information the least amount of compression so you don't see a lot of artifacting you don't see a lot of little sort of schmutz technical term should write that one down when you look at this one this is the highest compression you can start right in here particularly they see some artifacting in other words jpg is averaging information across a group of pixels so that it can store that in store the resulting information in a smaller format and then this is medium compression which is still pretty decent quality but just in a few areas particularly in the stained glass in here and like right around in here you can to see some artifacting so temporal compression is what we typically use for video and really good codecs mpeg-4 Sorenson use a combination of spatial compression and temporal compression in other words the temporarily compressed frames you're throwing out more data the codec is examining the video and trying to get just the information that's changed so from frame 1 to frame to the second frame it's trying to store just the difference between those two things and in fact those that second kind of frame we call a delta frame or a difference frame then every once in a while it sets a keyframe which is the nice pristine temporarily compressed image spatially compressed image sorry so here's an example with sinopec compression Sinha pack is kind of an old codec but it it shows the differences off really nice here's the key frame which has a fair amount of detail even though it's obviously it's being blown up quite a bit here and you're getting a lot of jaggies and then here's the delta frame or a difference frame so you can see it's not storing the same amount of detail at all much more detail over here much less here and in large part we get away with that because video moves so we don't always have to be presenting the same level of information to the viewer because it sticks in their brain they don't see the fact that we're degrading from one image to the next so here are the video rules of reduction there's three ways to reduce file size end or bandwidth requirements for piece of video you can reduce the data rate that is increase the compression can reduce the physical size of the image reduce the number of pixels so instead of 640 by 480 we do 240 by whatever you reduce the size you reduce the requirements or you can reduce the frame rate reduce the number of images that you're storing in that video all of those things allow us to deliver video through a narrower pipe so these are the things that I looked at if you if you go to quick timing org go to the resources section you'll find a little place that I call codex central partly as an homage to the old Terran codex central and in codex central I did a comparison of basically every codec I could get my hands on so I sat down and I figured out exactly what it is I want to compare and what my standards were going to be for comparing one code app to another and pretty much in this presentation I'm going to use those same standards and what I look at is quality sighs compatibility and usability so for compatibility specifically I looked at a couple of different things one is how old a version of quicktime will play it can you play this codec in quicktime too can you play it in quicktime 5 and above i also looked at compatibility cross-platform does it work on windows does it work on max doesn't work on linux and i also looked at compatibility with other players besides quicktime okay it's math i'm not going to spend a lot of time on this this is sorensen's formula for kind of helping you figure out what data rates you want to shoot for forgiving audience okay and the idea here is you want to look at coming up with a number based on this formula once you've come up with that number you're usually your best quality is going to be at no more than half that number and you probably aren't going to have to go to more than twice that number now I'll be honest with you from what I've seen so far of h.264 this may all be kind of irrelevant okay so that's that two types thing again there's two types of video codecs transfer codecs and delivery codecs transfer codecs are used to move video from one location to another generally within a production environment so a transfer codec I used to work for a video effects house on LA and generally we used animation best which is a lossless codec at when you're at that level at best and that allowed us to get smaller file sizes reduce our transfer times over the network pixel it is another example of a transfer codec it doesn't give you the kinds of file sizes that you're going to need to be able to deliver say over the Internet to deliver web video but it is going to give you minimally lossy or lossless quality now the other thing is delivery codecs delivery codecs are going to give you just a whole heck of a lot more compression but aren't going to throw out some information that you're going to sacrifice quality to get playability so the first thing we're going to look at is delivery codecs now with delivery codecs with I'm sorry I was distracted by the shiny thing at my feet with delivery codecs you're typically going to see compression rates somewhere up into the ninety percent so if you have a one megabyte file or let's say you have a 1 gigabyte file with a ninety percent that even 99% compression you're talking about being able to compress it down to a few megabytes so some of these things changed yesterday so so I was in the room last night making a few little changes the first thing we're going to look at is the current mpeg-4 in quicktime which is for simplicity's sake if you'll pardon the pun the best way to refer to it I found so far is mpeg-4 simple because it's based on the advanced simple profile good quality it's currently it's somewhat limited by the current mpeg-4 spec the mpeg-4 simple has been around for a long time how many people have ever seen MPEG three yeah see nobody's seen MPEG three it didn't exist because nobody could agree on what the heck it was so they skipped over from mpeg-2 mpeg-4 and it took them a long time to come up with mpeg-4 and by the time everybody got their ducks in a row on it it had already been suppressed surpassed by some more modern codecs like Sorenson three so the quality is okay good we're going to look at 264 here in a second which completely blows it away the size is good the compatibility is excellent works in quicktime works in real there's a ton of third-party players out there and it's been around since the introduction of QuickTime six so which has been a while now and it's a good general purpose codec h.264 or a vc it which is advanced video codec quick overview here excellent excellent excellent excellent we're not going to see it for a while so we're going to talk about some of the other codecs as well and I'm in the same boat that the rest of y'all are in I'm going to go home and I'm going to play around with it and see what I get but again from everything I've seen so far this is going to be the way to go for most general purpose encoding come early next year sorensen video 3 is my current favorite general-purpose codec it's higher quality than mpeg-4 at about the same file size it can get a little bit bigger than mpeg-4 it takes slightly longer to encode but I actually started out as an illustrator so I'm something of an image snob if for pure quality if I'm looking to go with something that's just got to be pretty I always fall back to sv3 quality is excellent the size is good compatibility is good and the usability is good now notice my little footnote down there we'd be having a different discussion a year from now now Sorensen also has an impact for Kodak that is slightly different from Apple's mpeg-4 codec encoder and that's included with sorenson squeeze sweet you get mpeg-4 you get sv3 and you get the spark codec which is for flash which kind of sucks but you know you gotta take the bad with the good good good excellent good again it's based on the mpeg-4 spec its ISO compliant so anything that plays mpeg-4 is going to play the Sorensen codec as well usability is good it's still limited by the mpeg-4 simple profile it it doesn't have the level of quality that you're going to see with some proprietary codecs and it doesn't have the level of quality that h.264 is going to bring us soon in a few months 3i VX is at this point my favorite mpeg-4 variant by the way just so everyone knows all opinions expressed during this presentation or our mind so it's very good quality gives you excellent size the compatibility is excellent it's right now already works for a number of set-top boxes a number of players it's very widespread on the Windows platform and i think i think the usability is is excellent because of all those reasons h.263 is mostly kind of irrelevant at this point but i wanted to touch on most of what you see when you pop up that little export menu in quicktime pro it marginal quality good size very good compatibility it's been around for a long time but I still find the usability is poor now that said there are instances where I will fall back to h.263 because it has very low processor overhead so I've used it to do things like I built a video puzzle for a client where you actually can grab pieces of the video and move them around and all the video is moving on all the pieces all at the same time now if I try to do that with sv3 on anything made before the last two years it would choke and die but with it with h.263 it it was light enough that it actually worked and in that particular instance quality was not paramount playability was Zygo video is another cadet that I like a whole lot it's a third-party codec from zygo digital I think they just changed their name it's the codec I generally go to these days if I'm doing live streams it's again quality is good and high data rates it's clearly inferior to sv3 and mpeg-4 either apples or sorensen's but at very low data rate it really starts to pull ahead of just about everything else that's out there and when you're doing encoding for streaming you don't have the luxury of the kind of spikes that you get day rate spikes that you get with something like sv3 you need something that's going to give you well you know that's just going to get it there so compatibility is fair it's it's not part of the QuickTime delivery when you install quicktime it's something that people will have to go and get and download to be able to look at your video and i always think of that as a disadvantage but i've used it in a couple of places where i have clients who are delivering real streams inside the enterprise and I essentially have control over what goes on all the machines within the enterprise so I can say this has to be installed on everybody's machine for them to watch the president's talk goodness okay side-by-side comparison okay I worked hard on this ah-me noises geez I know you're out there I can hear you breathing okay so this is 3 ivx this piece is Apple's MPEG simple code at and this is the sp3 code app so you can clearly see that there's a little bit of quality difference between the three I actually tried to get it so that the quality was about the same because this is this is what I really wanted to show you this even with when the quality is the same the math is not three ivx I got a file size of 428 kilobytes at a data rate of 105 with apples MPEG I got a file size of one megabyte and a data rate of 254 now there's not a tremendous difference in quality between those two things is there but I'm getting a much more deliverable file size with this and then even sp3 in this particular instance came out a little bit of a little bit ahead so on the encode side though Apple's mpeg-4 had the fastest encode time sv3 had the slowest and three ivx came out somewhere in the middle these are by the way my three choices if you're doing web video or cd-rom I nearly always go with one of these three three ivx has the disadvantage again that they're going to have to go and get it and download it or you're going to have to include it in an installer on on a CD if you're distributing that way Apple's mpeg-4 and sp3 are both part of the current quicktime distribution transfer codex as I said transfer codex exists so that we can compress a little bit retain the information and move things more easily from one place to another hence the transfer so DV I've got like six slides worth of DV there's it's like it's like they're all like they're all Baptists but some of them are Southern Baptists and some of them are like you know evangelical and there's a few Pentecostal you know they're all over the place so DV comes in line or to put it another way Vivi comes in multiple flavors in QuickTime and some of these are are more for the pro apps and some of them are sort of the standard DVD that you're seeing when you buy it go out and buy a camera I'm really going to kind of blow through these a little bit quickly but want to give you a little bit of a little bit of an idea DV NTSC and PAL qualities good sizes fair compatibilities excellent usability is good dvcpro and about to say about the same ok so if we worked our way past DV and now we're to my current favorite transfer codec which is animation and as I was mentioning before back when I worked in a visual effects company animation is what we typically use to move things from one machine to another or make a file small enough a scene file small enough that we could write it to a CD and deliver it to a client or do something like that and one hundred percent animation is lossless it may also not do a whole heck of a lot of compressing for you because it was really designed to work primarily with large flat areas of color and with large flat areas of color you can get really phenomenal levels of compression but if you're looking at standard video at best you're only going to get about fifty percent now that's not so bad fifty percent is about what you can expect from most lossless codecs animation also has the advantage that it supports somewhere here might not be there anyway has the advantage that it supports transparency so it supports alpha channels so if you're working in after effects or something like that it's a good codec to work in it's going to save you a little bit of drive space and it's going to allow you to work with alpha channels and in general just about any professional video editing application is going to support animation pixel it picks looks new how many of you you guys have had a chance to play around with a little bit pixel it does a really really good job as a transfer codec it is lossy not lossless so you are going to give up some data it making it a real good archive codec but you don't want to be opening files and receiving them over and over again because you going to continue to throw stuff away good size you can get a six gigabyte file down at near DVD quality down about 250 megabytes that's pretty decent savings if you're hurting for hard drive space it's a real good way to go I listed the compatibility is poor though right now it really only works you know less 10 and that's kind of limited as I say usability is limited sheer video is a third-party codec that I also liked very much as a transfer kodak it is completely lossless and preserves the image perfectly it's only going to give you about 2 to 1 compression it's os10 only in general I would try animation best first and use pixel it as a fallback unless you happen to work in a studio that is all OS 10 G finds this is the best way to save and transfer video if you can afford it Apple none is none no compression it's completely uncompressed format it's going to take up one heck of a lot of drive space but if you're pulling it into other applications like after effects or Final Cut or something like that to work on it and you're likely to have to be moving files around and chopping them up and saving them in multiple times and you've got the room that's the best way to move things around otherwise go with animation best as your first try and then go to something like share video or pics lit as your second pass if animation isn't giving you the the kind of compression that you need so other codecs there are a bunch of other video codecs digital an hour cream makes one called microcosm which is a 64-bit lossless codec the last time I looked the only thing that really supported 64-bit video was after effects I think six so that makes it poor and the compatibility front digit Lanica also makes something called none 16 which again is a 64-bit lossless no compression codec techsmith makes a codec called in sharpen which was really designed for doing screen captures it deals with detailed things like text extremely well again excellent quality good size poor compatibility it's not part of the standard quicktime distribution it's not part of the Apple component download program they have to know where it is they have to go they have to hunt it out they've got to download it if they want to use it and then there's a whole bunch of legacy codex of which the only one that's really notable at all i think is Sinopec and that's only because sinopec has made something of a comeback in the last year or so as the compressor of choice for the kinoma player which allows you to playback movies on palm devices audio codecs it's at two kinds of thing thing again there's two kinds of audio coccyx I am used myself sorry let me go back to second basically the human ear is more sensitive to slight variations when you're listening to things like music and sound effects then you are when you're listening to things like the human voice so there's really two kinds of codecs for dealing with audio their codecs that are really good at compressing sounds like music like sound effects etc etc and their codecs that are really good at compressing voice and as long as you don't get these two things confused you'll do fine when I looked at these codecs that we're about to go through in terms of usability compatibility etc you'll often see that what I'm saying is for what they're designed for their excellent but if you try to use a Kodak that was designed for dealing with a voice to compress something like music or sound effects you're not going to get a pleasant sounding result and if you try to use a that was designed more to handle music and general compression you're not going to get as much compression so again I'm going to skip over a little bit of the detail but basically music and audio CDs use AIF it's an uncompressed sample they sample the audio 44100 have a data rate of about 150 so one minute of uncompressed audio is about 11 megabytes of storage and that's why on your 650 700 megabytes ed you don't get 100 songs so again with the rules of reduction there are three ways strangely enough to reduce the size and bandwidth requirements for audio you can reduce the sample rate in other words if you go down from 44.1 to 22 or to 11 you're reducing the sample rate you're reducing the size of the audio you can reduce the range of the sound which you know it's flattened out the highs and lows or you can shorten the clips duration now you see really you think about these they equate on an almost one-to-one basis with how video codecs rules of reductions work ok this is the same as reducing the image size this is the same as as increasing the compression and this is the same as reducing the frame rate ok audio codecs mp3 mp3 bugs me I have this whole thing about language and and the misuse of it mpeg1 layer 3 audio it's it's not MPEG 3 it's mpeg-1 which is actually getting kind of long in the tooth at this point and probably should be put out to pasture quality is good I don't think it does very well below 120 8 kilohertz so size is good a whole lot smaller than AIF or WAV files compatibility is excellent you can't fault mp3 for compatibility I think they're they're probably shoes at this point that will play back mp3 files if not I'm sure having said that somebody will have one on the market sometime the next couple of weeks so and the years ability overall is good you got to be willing to sacrifice a little size and flavor plate in favor of playability but it does have its advantages however this is my current favorite audio codec the AAC codec which you'll notice by the way is excellent excellent excellent and say it with me now okay good okay so 128 k now remember i said mp3 is below 128k most people don't think it sounds all that well 128k stereo has been judged indistinguishable from the uncompressed source and this is by i don't know a whole bunch people are supposed to know this stuff you know I audiophiles much smaller files with mp3 at much higher quality cross-platform cross player and cross device compatibility is what the mpeg-4 spec is all about AAC has pretty widespread support at this point even if you ignore iTunes and the ipod and God knows it's awful hard to do that these days so and you know flat out it's quite possibly the only audio codec you're really going to need to use it is a terrific general-purpose codec does a nice job with voice does a fantastic job with music and sound effects I haven't had a chance to play a whole lot yet with the Apple Lossless encoder which is relatively new I think it came out in 651 is it writing something like that okay anyway it's new and the quality is excellent I mean you can't beat lossless las luces well lossless the size is good again it's a lossless encoder you're going to get around fifty percent something like that compatibility and that's a good it's very new you get it to work with iTunes you can get it to work with 651 not a whole lot else right now it's a nice format if you're going to store a whole bunch of music on your hard drive for playback in itunes and you want to squeeze those down and you don't want to sacrifice any of the quality at all IMA for one for a long time this is my codec of choice it was also the codec of choice for a lot of people who do like the movie trailers and things like that it does a terrific job with sound quality I used to work for Sorenson and at their Burbank encoding center we did some tests with it and compressing with IMA for one we discovered that it even retained that the five dot 1 surround-sound information doesn't give you a lot of compression now the size is only good compatibility is only good it's been around for a long time but and it doesn't only it doesn't always give you what you expect when you move from one platform to another the usability is good it's great for high-bandwidth projects it's what I will generally use if I'm going to a project on cd-rom and I know I'm going to be playing back through a like a computer stereo speaker system I want something really really nice qualcomm pure voice now again you're going to see my little caveat with this one in the next slide when used as intended qualcomm pure voice is you guessed it a voice compression codec it was actually designed for use with telephones does a fantastic job with speech it really high levels of compression though it can sound trying to Tinian flat sounds a little bit like you're talking into a paper tube you get this sort of vibrational thing it's kind of weird the size that was excellent if you're doing just spoken word I would go here if you want to get the best compression to size ratio it going to compress the crap out of it with this codec compatibility is good it's been around with every QuickTime distribution since version 3 limited tonal range makes the usefulness for music and sound effects limited as I said this is an excellent codec when you apply it to what it's intended to be used for if you try to use it for something else you're not going to get a very pleasant result okay q design music too is another one that's been around for a very long time does a wonderful job with music and overall I think it's comparable to mp3 in general quality I think AAC beats the pants off of it but it comes in it comes in a solid second other codecs again there are a bunch of other codecs that you'll see Mace's legacy codec 16-bit big in little-endian 24 and 30 bit integer and eula and these are all unless you're doing really high-end stuff but you know you're an audio engineer these aren't really going to be terribly useful to you you la is a UNIX standard and mesas legacy codec that's that's completely outclassed by any any of the more modern codex here's a little thing here's a little comparison thank you here's a little comparison this is aiff uncompressed audio ok so this is what you hear off your CD player at home same thing is AAC 22 kilohertz compression 96 kilobits per second the file size is 212 k backing up again my photos back up there we go compared to three point four megabytes 172 okay let's crank it up boys [Music] back again come on that we go all right sex how many people here are substantial difference between those two things [Music] anybody anybody in your musician entry I think for vast majority of people they're not going to hear a substantial difference between those two things but when you look at the data rate the file size you see there is a phenomenal difference between those two things and that's why AAC is currently my favorite codec in fact I'll often combine if I really need good quality I'll combine sv3 video with AAC encoded audio put those two things together and you get a hell of a mix I said hell I still twice national free time oh okay anyway I note on image codex I'm not going to go through all of the veritable cornucopia of image codecs that are available to you working in quick time but I did want to touch on just a couple of them and give you a little bit of an idea about what makes these three particular codecs kind of special I love this codec this is my favorite image codec I'm crazy about paying particularly ping in quick time I do a lot of stuff with wired sprites and ping is ping is great for very low overhead stuff it just works really nicely it's got sophisticated alpha channel so you can do much nicer compositing than what you could do with something like say Jeff and for for flat total images you're going to get better compression than you do with Jeff files in fact about thirty percent better and for it can't even though it's a little bit larger than jpeg when you use it on continuous tone images like photographs I really like the quality a lot better and unlike jpg ping is a lossless compression format so it which is to say that it compresses similarly to what jiff does which compresses by limit salut I'm sorry compresses by limiting the number of colors in the color palette that's working with the image it's supported on every browser and platform and in quick time since very early on the usability is excellent for working with images for working with particularly with wired sprites and QuickTime or any kind of image file in QuickTime ping is my go-to guy I always use ping even for most of the web work I do these days I avoid using gifs and JPEGs and I stick with pain Oh nobody's even going to go ah ok this is my dog his name is lorcan coo Kieran it's Gaelic it means fierce black hound anything so here's a comparison you may have noticed I'd like to do these things so here is ping 224 k with transparency nice soft anti-aliased lovely lovely just 64 colors 120k with a diffusion dizzer and transparency but now look at the quality difference even though I've got a larger file here I obviously can get better compression with Jeff but when you start looking at the quality difference particularly the way just tends to dither jeff has to use dither to replicate colors that aren't inside its color palette the quality is so much nicer look particularly right around the eye here and right around the eye here and then this is jpg at best 344 and you get no transparency with it and it's lossy so if you have to open the file up edit it again and save it out again it's putting compression on compression on compression jpeg 2000 now is a little bit different thing and jpeg standard jpg and jpeg2000 are completely different codecs jpg is at jpeg 2000 excellent quality good size poor compatibility at this point because not everybody has has caught on to it yet there are still better compressors and in general right now I still think ping is a little bit better compressor than jpeg 2000 it's only available in OS 10 on for quick time there is a photoshop plugin for creating jpeg 2000 files that are is available from this particular vendor from lead technologies and this is a URL for it and you know it'll be enough it'll be in our home game so so here's a little bit of a side-by-side comparison jpeg 2000 uses something called wavelet compression without getting into a lot of detail it's just better this is the Bad Santa so here's jpg here's jpeg 2000 look right around the I particularly and how much artifacting there is jpg JPEG 2000 so even the detail in the mustache and you know it's just scary to look at my own head this large anyway okay so best all-round codecs and the winners are for video delivery mpeg-4 and sv3 mpeg4 for compatibility sv3 for slightly higher quality again a year from now this will be having a different conversation h.264 changes the landscape for audio go with AAC for a general purpose audio codec it's the best thing that you have available to you graphics paying every time and for video and audio transfer my favorite is still animation best for most compatibility and best compression at a lossless level for more information a couple of sites being that the self-serving jerk I am I put mine first so quick timing gorg which strangely enough is at quick timing gorg I have news tutorials reviews all related to quicktime my ultimate goal is is world domination by quicktime so lots and lots of stuff on there i try to cover anything that's related to quicktime and that's almost anything that falls into the digital hub sphere in itunes is quick time I movie as quicktime Final Cut Pro is quick time I DVD DVD Studio Pro is perfect time I'm missing a whole bunch of things here but you know quick time is the architecture that runs all of this stuff and in addition to that i also have a news section that's updated fairly often usually about three times a week sometimes more often if as things are happening and a newsletter that you can sign up for that I refer to as my regular irregular newsletter it kind of goes out either when I have something really important to say or when I feel like it Martin and I've never actually pronounced Martin's last name because I've only met him by email but Martin has a QuickTime compatibility chart on his website own he says hi Amy it is a very very complete listing of all the quicktime codecs audio image video and what version of quicktime they were introduced with really tremendously useful resource and last but not least I wrote a book if if you buy it I don't have to eat my dog anyway quick timers guide your web video will be out in a few weeks if you go to books ursa major media com which is my publishing company because and be honest I'm a control freak and you can actually get it at a discount right now and that's my little commercial message and this is who to contact for more information I'm at cliff at quick timing org fairly easy to remember and then yellow QuickTime man at apple com