VideoHelp Forum
+ Reply to Thread
Results 1 to 11 of 11
Thread
  1. If i am going to convert a dvd movie into x264 should i leave the resolution at 720X480 or should i let the program determine the resolution. What would be the advantage of the program picking 640X480? Will it still be the same size on my TV? In other words if the dvd takes up the full screen on my tv, and the resolutuin is changed by my encoding program, will it still take up the full screen or add bars or sommething? Thanks
    Quote Quote  
  2. Always Watching guns1inger's Avatar
    Join Date
    Apr 2004
    Location
    Miskatonic U
    Search Comp PM
    640 x 480 is the square pixel (PAR 1:1) resize of 720 x 480. Both will play back correctly. Not all players handle non-square PARs correctly outside DVD structures, so to play it safe 1:1 PAR resizing can be applied. It also, in this case, reduces the overall resolution, which may give you better bang for your encoding buck.
    Read my blog here.
    Quote Quote  
  3. Thanks for your answer. So if i am using handbrake and it chooses 720X384 just go with that? Or should i over ride it and make it stay at 720X480?
    Quote Quote  
  4. Always Watching guns1inger's Avatar
    Join Date
    Apr 2004
    Location
    Miskatonic U
    Search Comp PM
    Personally, I would go with what Handbrake suggests, if it looks correct in the preview. I assume that handbrake is cropping off black bars and adjust for PAR. I don't use handbrake, and I don't know what your source is like, so I can't give you an absolute answer.
    Read my blog here.
    Quote Quote  
  5. I usually leave the video at its original resolution and set the PAR/DAR flags. All my players now support that.
    Quote Quote  
  6. Originally Posted by mohawkcr View Post
    Thanks for your answer. So if i am using handbrake and it chooses 720X384 just go with that? Or should i over ride it and make it stay at 720X480?
    For highest quality, you should use Strict Anamorphic to retain the original resolution (which also sets the correct flags to make the encode display at the right aspect ratio). Remember to use Auto-crop too.

    Originally Posted by gunsl1nger
    It also, in this case, reduces the overall resolution, which may give you better bang for your encoding buck.
    Only if the bitrate is extremely low, like 500kbps. For normal and higher bitrates, original resolution (no resizing) is always better.
    Quote Quote  
  7. Far too goddamn old now EddyH's Avatar
    Join Date
    Jan 2003
    Location
    Soul sucking suburbia! But a different part since I last logged on.
    Search Comp PM
    Question: which is it of the below shapes?
    a/ 4:3 (ie "narrowscreen")
    b/ letterboxed (black bars as a part of the actual video, NOT added e.g. by the television/DVD player when playing a widescreen film on a narrow TV --- so you have to "zoom" on a widescreen to make it look correct)
    c/ fullscreen 16:9 (widescreen) --- if you're unsure, then without adjustment, everything will look squashed at 720x480

    In which cases, if you want the FULL quality with no vertical resizing/deinterlacing/etc:
    a/ 720x480 if you can rely on the player auto-reshaping it. 640x480 for square pixels.
    b/ 720x352 (or 360, 368), or again 640 wide for squares
    (if it's letterboxed from some aspect other than 16:9 this may be different - i.e. 408 high for wierdass 14:9, 400 for 16:10, and various sizes LESS than 350 for cinemascope and the like)
    c/ 720x480, or 848 (854)x480.

    If it's a film or you don't mind an adaptive deinterlacing step with slight loss of vertical clarity, c/ could also be something like 720x400, 640x360 etc.

    strict anamorphic, correct flags, etc
    Mind that this only works if the PLAYER software supports the flags, which some don't - including the lowest common denominator, i.e. Win Media. You'll have to use something like VLC. In which case, why not just bite the bullet and get a hard disk big enough to store the original DVD rips?
    720x384 sounds like a wierd setting, by the way (80% of original height, for a 10:6 ratio). I wonder what the reason is?

    only for very low bitrate, e.g. 500k
    Damn, man. 500k is the point where I'm looking to step down FURTHER from, e.g, 640x360. You do start getting additional artefacts at that point, and that's with quiet, low-motion stuff (for perspective, you'd get over 2.5 hours on a CD with 128kbit audio).

    For full-D1-rez NTSC, I'd peg the divider closer to 750 or more - again, for quiet stuff (typical movie is still a single disc at 960+128). More action will increase the need, and reducing pixel area is a good way of countering it, as you get exponential gains. (0.8 reduction on each axis = 0.64 area).

    It will depend, really, on how much space you can throw at each hour of video, what storage media you're using, and how long the shortest acceptable unbroken segment is. And depending on material and encoder, YMMV from what I get from my own kilobits anyway.

    Downloaded movies I've seen don't tend to be over 640x352 for an hour and a half inside 700mb, mind, and even so their quality could be better. 576x324 is a near imperceptably smaller alternative allows about a 15% saving. And of course, this is for full-frame, if there's any letterboxing you can trim it harder (not saving a great deal because nothing happens in the borders, but it helps you do the math).

    Resizing loses you pixel definition, it's true, but if you get to the point where there's obvious MPG artefacting, the image has been hurt in far more painful ways than what is effectively a slight softening.
    Last edited by EddyH; 22nd Apr 2010 at 11:00.
    -= She sez there's ants in the carpet, dirty little monsters! =-
    Back after a long time away, mainly because I now need to start making up vidcapped DVDRs for work and I haven't a clue where to start any more!
    Quote Quote  
  8. Originally Posted by EddyH View Post
    strict anamorphic, correct flags, etc
    Mind that this only works if the PLAYER software supports the flags, which some don't - including the lowest common denominator, i.e. Win Media.
    WMP 11 (and several versions back) will obey PAR/DAR flags if the other Directshow components support it (file reader/splitter, video decoder, etc.). It works properly with all my MPEG/Divx/Xvid/h264 MPG/AVI/MKV/MP4 files.
    Quote Quote  
  9. So it sounds like the best option is to re encode the video in the same 720X480 Resolution without resizing?
    Quote Quote  
  10. Originally Posted by mohawkcr View Post
    So it sounds like the best option is to re encode the video in the same 720X480 Resolution without resizing?
    Yes, using Strict Anamorphic.

    Originally Posted by EddyH View Post
    Mind that this only works if the PLAYER software supports the flags, which some don't - including the lowest common denominator, i.e. Win Media. You'll have to use something like VLC. In which case, why not just bite the bullet and get a hard disk big enough to store the original DVD rips?
    How does that follow?? In the first place, WMP can't/couldn't even play x264-in-MKV files on its own, so obviously another player is being used, or a codec and splitter have been installed, etc. I myself haven't used WMP in maybe 8 years, and lots of people I know use other players and codec packs. Why should storing the original DVD ISOs be necessary?

    only for very low bitrate, e.g. 500k
    Damn, man. 500k is the point where I'm looking to step down FURTHER from, e.g, 640x360. You do start getting additional artefacts at that point, and that's with quiet, low-motion stuff (for perspective, you'd get over 2.5 hours on a CD with 128kbit audio).
    Well, I'm not advocating 500kbps at all - just giving an example of when it makes sense to downscale. At normal bitrates of 1200-1800, there's simply no point in resizing unless your player is a piece of shit that can't read anamorphic flags. (Not being able to display MKV/MP4 video anamorphically is pretty pathetic, seriously.)

    For full-D1-rez NTSC, I'd peg the divider closer to 750 or more - again, for quiet stuff (typical movie is still a single disc at 960+128). More action will increase the need, and reducing pixel area is a good way of countering it, as you get exponential gains. (0.8 reduction on each axis = 0.64 area).
    Sure, 750 is a good dividing line for choosing when to downscale.
    Quote Quote  
  11. Forget bitrates and use constant quality (or quantizer) encoding. You'll always get the quality you specify.
    Last edited by jagabo; 22nd Apr 2010 at 22:49.
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!