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  • ShuMO
    Junior Member
    Junior Member
    • Dec 2002
    • 49

    Multiple questions

    1st off thanks for being here. I've read back to the November posts, and really love the speed of response and participation this forum gets.
    I've been on a high speed learning curve for the last 2 months. Heres some of my questions:

    1.TMPGenc allows Aspect Ratios of 1:1 VGA, etc... If my content is a DivX file do I need/gain anything by calculating the source aspect? let me ask that better. Should I use 1:1 as the source Aspect Ratio for all Divx files?
    2. Arent all divx files (DVDrips from Kazaa) non-interlaced?
    3. I get it that Tmpgenc doesnt do 48k audio... but it does do AC3, why? its reencoding right? (I'm set for external TooLame).
    4. Stripping the Audio with VirtDub works excellent and is quite fast. Takes about 2 mins for it and it converts down to 41000 at the same time and I dont get audio sync problems. Why does my Cooledit take 38 mins to convert from 48k-41k when I use graphedit to stip the audio to PCM? (this is of course for enlightment as the VDub step works perfectly well).
    5. I'm using a JVC XV400 and get jumpy video playback - ie; start and stops when I create SVCD. The VCD plays fine. I run 2-pass VBR and push the bitrate to 2100 or so. Even CBR gets jumpy as well. The Divx files I use normal show a 23.976 Frame rate, so I choose NTSC file during the Tmpgenc wizard. Is this a Framerate problem?
    6. I've created 10 test MPG's (SVCD 2 min clips) and ran tests on the player, including encoding with the Pal Wizard. I use Nero 5.5 to burn the Cue file (I run VCDEasy to create the cue's). Is Nero converting my Pal format to NTSC? It seems to playback on just like the NTSC yet the JVC doc's specificallly state 'no support of PAL'.
    7. A PhotoVCD I made shows perfectly on my PC. during the picture scans of Slides I purposefully left the slide edges. They are visible when played back on the PC. However when played on the TV the edges are off screen. I use a 38" Sony Trinitron that I always thought of as exceptional. Is this some adjustment on my TV thats out maybe? or is it DVD player related? How can I tell?

    Looking forward to all comments/slams/prods and pokes.

    Shu
    ShuMO
  • setarip
    Retired
    • Dec 2001
    • 24955

    #2
    "I get it that Tmpgenc doesnt do 48k audio"

    I don't know where you got that impression. Perhaps you're misinterpreting posts advising that for compliant VCD format one SHOULD NOT use 48,000Hz audio, but use 44,100Hz instead...


    "Arent all divx files (DVDrips from Kazaa) non-interlaced?"

    No one could possibly provide you with a universal answer regarding files that are posted via a filesharing setup...


    "I'm using a JVC XV400 and get jumpy video playback - ie; start and stops when I create SVCD. The VCD plays fine. I run 2-pass VBR and push the bitrate to 2100 or so. Even CBR gets jumpy as well. The Divx files I use normal show a 23.976 Frame rate, so I choose NTSC file during the Tmpgenc wizard. Is this a Framerate problem?"

    If you've created the included audiostream at 48,000Hz, try changing it to 44,1ooHz...

    Comment

    • hanske
      Junior Member
      Junior Member
      • Dec 2002
      • 7

      #3
      jumpy playback

      I had same problem with jumpy playback,

      but I did use 44,1ooHz,

      I tried a lot, NTSC, PAL, NTSC Film, all in SVCD, I also tried different bitrates, CQ, CBR 2520bps in TMPGenc, but some movies always have this jumpy playback one way or the other,

      e.g. I created about 7 versions of the first part of spirit, all with different settings, only two versions where OK exept for the first minute (jumpy) and only one version was completely succesfull,
      now the best version I made was like most of my trials NTSC Film because the source was NTSC 23.97 fps and it weren't always the movies with highest bitrates that played best,

      how come?

      thanx

      Comment

      • UncasMS
        Super Moderator
        • Nov 2001
        • 9047

        #4
        playback on some player actually benefits from a delay in the video part when burning your svcd!

        ~ 400ms can do the job on one player (but might fail on another)

        Comment

        • ShuMO
          Junior Member
          Junior Member
          • Dec 2002
          • 49

          #5
          Thanks for the replies folks. Herniated disk kept me from replying...

          Setarip -
          regarding tmpgenc and 48k, I should have been more specific. if you use the 48k MP3 stream thats muxed into the avi, I ALWAYS get sync problems. I've read that the best method around this is to strip the audio stream and remux at encode time. I've actually not tested how TMPGenc handles it with TooLame as the external audio tool. I am surprised tho that TMPGenc isn't smart enough to recognize that I've got a 41k PCM and still feeds spends a few minutes makeing a PCM out of my PCM *shrug*

          as to the '...filesharing' comment, I was really interested more in a comment that would educate me on how to determine if its interlaced or not. I have found that I can open the video review the frames directly. What I'm finding is that 90% of the files that are DIVX rips from CD are indeed non-interlaced. But clearly of course your right, theres no 1 answer.

          your last portion of response is undoubtedly my poor writing skills. I must have lead you to think that I had 48k audio in the stream. but I dont. But I do have interesting news to share .. well interesting to me.

          I found that VCDEasy will create a Cue/bin thats sets a bit that implies that its NTSC. NTSC Film actually gets played back at NTSC frame rate. So encoding in film mode then using the VCDEasy and Nero to burn the CD results in a confused final product... the data stream may be PAL or NTSC Film but the CD has a flag set that states its NTSC content. I got this info from a tech guy from JVC who seems to travel in these circles and knew what tools are commonly used. Once I re-encoded to NTSC, the playback stopped stuttering. Some laymen like myself might ask why I even attempted to do it or what was the point. I had picked up that if I encoded at 23 odd frames I'd basically save 6 frames /sec worth of data. I thought the standalone player would adjust. It doesn't in most cases. (Some high end players and all computer players do tho). This also explained why a PAL encoded file would play (but stutter a bit).

          UnCasMS - do you mean add 400 ms of no-data frames to the beginning of my movie or as a function of the burner somehow?

          Hanske - sounds like you and are are near the same spot on the learning curve. Dependent on the Chipset used by the manufacturer, the decoder chip has limitations to its performance. My Sony unit (that I gave away) had a maximum decode speed of 2550. My JVC does a whooping 7500~ kbps. However, I just learned that increasing the bitrate for the sake of increasing it does little good in most cases when we're talking about conversion from DIVX to MPEG. A dataloss occurs during the encode to DIVX and the increased Bitrate wont make much difference. Using 2 pass or even 3 pass encodeing actually has much more impact. But, when encoding directly from the original DVD, the bitrate does have a profound effect. It was suggested to me that 2100 for a CBR is more than enough except in extended high action scenes. In movies of that type (Fast and Furious comes to mind) switch to a VBR multipass to get the best results. Many thanks for your comments all!

          Shu
          ShuMO

          Comment

          • UncasMS
            Super Moderator
            • Nov 2001
            • 9047

            #6
            whatever tool is being used for creating the file/image should provide an option to DELAY video streams for some ms.

            bbmepg does so for example - no idea if tmpeg does; i hardly use tmpeg and if at all an old version.

            Comment

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