1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Newbie questions

Discussion in 'Other video questions' started by OzzieDude, Sep 28, 2007.

  1. OzzieDude

    OzzieDude Member

    Joined:
    Sep 28, 2007
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    11
    Hello all,

    Let me start by saying what an awesome site this is - so much to learn... so little time.

    I have a number of questions. In order for me to understand thing, I make analogies to things I can understand. Please feel free to correct me where I'm clearly off the path...

    I think of the various audio/video formats as human speakable languages: French, English, Spanish, etc. Let's assume the MPEG-4 is French. In order to speak French, I need to know how to put words together in French so a Frenchman can understand me. Similar to MPEG-4, I need to have the correct structure for some decoder to read it. Each has it's own set of "rules" you must follow, or else you aren't speaking French/MPEG-4. So if I tried to fix a bit of Spanish into my French while talking to a Frenchman, he wouldn't really understand what I was talking about. Similarly, if I mixed RealMedia (RM) content with MPEG you don't really have much of anything. You must follow the "rules" of the format. The Video section of this link kinda explains this well. At least it fit nicely into my analogy:

    http://www.afterdawn.com/guides/archive/basic_dvd_authoring_project_part_ii_page_3.cfm
    > Video
    > Video for DVD needs to have properties that match either PAL or NTSC televisions. That means the resolution and framerate need to be correct. For PAL this means a framerate of 25fps and resolution of 720x576, 704x576, 352x576, or 352x288. NTSC video needs to have a framerate of 29.97fps. Legal NTSC resolutions are 720x480, 704x480, 352x480, and 352x240. The video must also have an aspect ratio matching either SDTV (Standard Definition TV) or HDTV (High Definition TV). This means either 1.33 or 1.78. It must be encoded as MPEG-2, unless the lowest resolution for either television system is used, in which case MPEG-1 is required. Although DVD is intended to be an interlaced technology, MPEG-1 files are always progressive.

    so far so good?

    Now, in order to read and write French, I need a translator, since I speak English. Is it fair to say that CODECs are those translators?

    Where I am a bit confused is with the plethora of CODECs on the market. And I'm confused why do I need/want them. For example, currently I've purchased ULead VS and Nero 7. Each seems to have installed a bunch of CODECs along with Windows Media Player and basically all the content I have, I can play: AVIs, MPGs, WMVs, WMa, MP3s etc. I've used AVIcodec and GSPOT as well as CodecInstaller to have a look at all this stuff. So I'm confused - if I already have myself a "splitter" to mux audio from video, and I already have an MPEG-2 CODEC (from ULead) to play my MPEG-2 encoded video files, then why would I want to grab other tools for the job? for example, why would I want to install FFDSHOW when I already have a decoder to play MPEG?

    Getting back to my analogy - is it possible that one codec is not as good as another. Like one person who translates English to French doesn't do it as well as someone else? Or in codec-speak, some codec just don't do the job as well as others (in other words, the codec may have bugs?) Is that a fair way to think of it and justify why I should get these other tools.

    so now I have like 5 different codecs that will play MPEG-2. How do I know which one to use? when does it matter if I use the one from ULead vs the one from Nero, vs the one the FFDShow installs? I seem to recall that I can control the order in which these are attempted, and I can adjust that to "force" it to use FFDShow to render my picture if I want. but it all comes back to the basic question - why? Surely there must be industry consensus that product "abc" does the best job of muxing the file, and the decoding the MPG stream and it's done! right????


    My second question relates to various formats: NTSC vs PAL being the big 2 I personally target since my goal is to get all my footage shot from my Sony HDR-HC3 onto TV sets here (Australia) and in America. I know that means that a lot of transcoding is going to have to happen. My question is - how in the world did we end up with so many competing formats/standards? And why is content (be it on the web, or your phone, or your TV) not more standardized. When I say standardized I mean in terms of the aspect ratios and or formats that they are encoded with. Why would one use DivX vs XVid to encode a MPEG files? In theory, shouldn't the end result be identical -seeing as how it has to confirm to the MPEG standard? Are there technical reasons why I would use one over the other, or is it a matter of personal preference? Or does each have it's own strengths and weaknesses, so it is relative to the situation as to which is best?


    My last question is about "best practice". After doing tones of reading on this site (and many others), it appears you can break this apart into two types of users:

    * User type #1: power users that wants to "dig under the hood of your car" and get all the intricate details about their media content. They will hand pick the codecs they want and the tools they use, like GSpot/VirtualDub to get the job done. Basically I see them as car mechanics, for multimedia content.
    * User type #2: is more of a "simpleton" (please no insults intended by that comment) or a tire kicker at the car dealership. They don't care so much about how the engine works, or how many I frames, B framess or P frames are in their video. They just want to turn the key and the car starts. Or for our multimedia analogy - they just want to produce a video that works on their HDTV (BTW- is it fair to say that all HDTVs will use the ATSC standard? so no more PAL vs NTSC business? the world is standardizing on ATSC? another side question). So this sort of user were head straight for tools like ULead and Nero (which BTW I find to be a rather ordinary tool, but that's a different topic) and just ask Nero to crunch it all together like sticking a pig in one end of the meat grinder, and get some bacon come out on the other.


    I ask because with the overwhelming number of choices as to software tools to analyse your videos, and codecs to re-encode (transcoding?) the clip to whatever format you want - is simply overwhelming It is like walking up to "Big Bobs Car dealership" that sells everything from sports cars, to SUVs to luxury cars and being complete gobsmacked as to which one I want to buy! "Yeah, I'll take the blue one, thanx!

    I'm sorry my email is a bit vague with the analogies and stuff. I promise my next questions will start to focus better on individual concepts. but I'm not at that point yet. Must see the trees in the forest, before I can take on the landscape.

    kinda regards,
    -randall
     
  2. attar

    attar Senior member

    Joined:
    Jun 17, 2005
    Messages:
    11,509
    Likes Received:
    29
    Trophy Points:
    128
    I'm only addressing the codec issue.
    Please do not install any codecs unless you need them.
    Some programs install their own codecs and these are local to that particular program - they are not used system wide and will be uninstalled when the program is removed.
    WMP and the likes of VirtualDub depend on codecs that are installed and available to any software that needs them.
    If you happen to click on a video file that wont play, use 'GSpot' to find out what it needs then Google for that particular item - else you will end up installing codec packages and find yourself in codec hell!
     
    Last edited: Sep 28, 2007

Share This Page