MIL-CD (Legitimate Music) Exploration and Research. Need your help!

Discussion in 'Sega Dreamcast Development and Research' started by Mrneo240, May 9, 2018.

  1. -=FamilyGuy=-

    -=FamilyGuy=- Site Supporter 2049

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    I assume you meant 5,000 kb/s? As 5,000 kB/s is ~39 Mb/s which is of 1080p MPEG2 level of bitrate, overkill for a Dreamcast for sure.

    The main limitation is the optical drive.
    The DC reads GD-Roms at max 12x and CD-R at 4x IIRC.

    That means hard limits on max bitrates of 12 * 150 kB/s * 8 b/B = 14,400 kb/s for a GD-Rom and 4 * 150kB/s * 8 b/B = 4,800 kb/s for a CD-R. But that's only the read speed at the outer rim on the disc because of CAV.

    Any large file can only reach those speeds near its end, and only if it's at the end of the disc.


    GDEMU could probably help then! But you might get CPU limited at one point.

    Try the kvcd pack, it gives good results most of the time. You can change the bitrate in the script, default is 1,500 kb/s IIRC.
     
    Last edited: Jan 30, 2019
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  2. Mrneo240

    Mrneo240 Peppy Member

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    yes kb/s, pesky units.

    Code:
    Input #0, mpeg, from '.\VIDTRK01.SFD':
      Duration: 00:02:24.48, start: 0.000000, bitrate: 5478 kb/s
        Stream #0:0[0x1c0]: Audio: adpcm_adx, 44100 Hz, 2 channels, s16p, 396 kb/s
        Stream #0:1[0x1e0]: Video: mpeg1video, yuv420p(tv), 352x240 [SAR 200:219 DAR 880:657], 5000 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97 tbc
    from the space channel 5 mil-cd.

    Code:
    Input #0, mpeg, from '.\VIDTRK01.SFD':
      Duration: 00:04:20.28, start: 0.000000, bitrate: 4462 kb/s
        Stream #0:0[0x1c0]: Audio: adpcm_adx, 44100 Hz, 2 channels, s16p, 396 kb/s
        Stream #0:1[0x1e0]: Video: mpeg1video, yuv420p(tv), 352x240 [SAR 200:219 DAR 880:657], 4000 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97 tbc
    from dps - HEARTBREAK mil-cd.
     
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  3. -=FamilyGuy=-

    -=FamilyGuy=- Site Supporter 2049

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    From the doc, it should be 4x for the LD section of a GD-Rom. But maybe that's just because it's at the inner of the disc, and that it can actually reach ~8x at the outer edge of a mil-cd. It won't be 12x because of the CD relatively lower pit density compared to a GD-Rom.

    So ~9,600 kb/s could be attainable as a peak near the outer edge of the disc.

    Both of those videos are short and probably fairly far from the inner edge of the disc. If you put them at LBA0 in the first session of a data/data mil-cd, they might not play smoothly (without buffering).

    A compete movie filling a mil-cd to the brim shouldn't have too high a bitrate. Trial/Error is your friend if you want to optimize that.
     
    Last edited: Jan 31, 2019
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  4. LuizNai

    LuizNai Robust Member

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    You guys are very high level! I feel like a kid here XD !!! Very interesting stuff :)

    I'd love to see what the Dreamcast can do with GDEMU or IDE-MOD on this!!!
     
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  5. Mrneo240

    Mrneo240 Peppy Member

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    IT WORKS!

    This is a very very rough initial port of Grauen no Torikago Kapitel 6: Senritsu (グラウエンの鳥籠 Kapitel 6 「戦慄」) as a Mil-CD ready to be used on the dreamcast. The complete story might be availbale for the first time in an easy to digest way for the world

    Ignore all the metallica stuff, its just what i use as a base for experiments because its quicker than remaking images and setting up everything correctly until im certain the project will work.

    First video track
    [​IMG]

    Showing the menu/software supports 58 tracks.
    [​IMG]

    The final scene of the hour long movie.
    [​IMG]

    The image file is much larger than a regular cd but the player itself doesnt care.
    [​IMG]


    Attatched:
    tools+template (add an sfd called "VIDTRK01.SFD" in SOFDEC)

    better info coming soon. ensure INFO.CDP is 75 sectors from the start of the session! EXACTLY! NO MORE, NO LESS.
    soon, ill have a better version of mkisofs that will do it for you. You must use the version attached. i can add source if you want to compile under linux too.
     

    Attached Files:

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  6. MetalliC

    MetalliC Spirited Member

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    as per CD Extra / Blue Book specs
    https://stuff.mit.edu/afs/sipb/project/cdrecord/src/cdrtools-1.11/cdda2wav/cd_extra.c
    I'd guess modified mkisofs is not the only solution, but there is also can be used any CD mastering software which supports CD Extra/Plus images creation.
     
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  7. Mrneo240

    Mrneo240 Peppy Member

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  8. LuizNai

    LuizNai Robust Member

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    This is awesome! I want to watch all Dragon Ball movies on my Dreamcast now lol!!! Congrats again bro!
     
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  9. Mrneo240

    Mrneo240 Peppy Member

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  10. TerdFerguson

    TerdFerguson ls ~/

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    this is immediately what i thought of when video playback started being discussed. the 90 minute special for the first episode of DBZ would be a pretty damn cool proof of concept release, but funimation dub please

    edit: also, wouldn't we be able to playback slightly-higher-than DVD quality via 480p VGA? sacrificing audio quality for video quality seems like a fair trade to me

    edit2: what about the "passport" functionality? if it is actually an HTML browser i suppose we could translate and make some cool use of it
     
    Last edited: Feb 5, 2019
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  11. -=FamilyGuy=-

    -=FamilyGuy=- Site Supporter 2049

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    Well, not really.

    A DVD has 4.7 GB of data in MPEG2 ~9.8Mb/s @720x480. The DC typically supports MPEG1, not 2. While a decoder for MPEG 2 could be written in theory, the DC CPU probably couldn't keep up with the complexity, especially not at close to 10Mbps. And the CDs are well under a GB, up to one for a GD-Rom.

    The Dreamcast can do vcd quality basically.
     
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  12. PrOfUnD Darkness

    PrOfUnD Darkness Familiar Face

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    SEGA instead of licensing the DVD technology decided to create its own video disc format and that opened the port for piracy helping the console's demise. They barely supported the MIL-CD format. Really stupid idea.
     
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  13. Aleron Ives

    Aleron Ives Rising Member

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    I don't know that I'd call it stupid. The Dreamcast came out almost two years ahead of the PS2, and DVD technology wasn't exactly cheap back then. Sega lowered production costs by extending the lifespan of an existing technology, which was pretty ingenious and thrifty. The GD-ROM format is solid; the problem was Sega didn't protect the MIL-CD format nearly as effectively.
     
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  14. Otello

    Otello Member

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    But the DVD technology was crucial to achieve the success back then. Both PS2 and Xbox were the winners of that generation, because of the DVD support, which was a new, high definition foundation of the modern home entertainment system. Lowering costs by introducing non competitive and proprietary standards is no go.
     
  15. -=FamilyGuy=-

    -=FamilyGuy=- Site Supporter 2049

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    With hindsight it's obvious, but at the time their choice is understandable.
     
  16. MetalliC

    MetalliC Spirited Member

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    back when exactly ? Dreamcast was 1998 console, while PS2 is 2000 and Xbox is 2001. 2-3 years is huuuge difference, taking in account how fast technologies progressed at the time.
    moreover, as far as I know, original Dreamcast was not planned / designed as console for 5 or more years, there was planned update after 2-3 years (no totally new Dreamcast 2 but more like 1.5), about the same time PS2/Xbox/etc was released. quite possible there was planned to use DVD drive instead of GD.

    anyway, returning to topic - why so hype because of Mil-CD SFD videos ? I do not understand.
    back in the days, we had here sh*tload of DivX video discs for Dreamcast (iirc with DCDivX player), and isn't DivX/Mpeg4 produce better image quality than Mpeg1 ?
     
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  17. megavolt85

    megavolt85 Robust Member

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    I myself can not understand why everyone is so holding on to this SFD player, for a dreamcast there is ffmpeg with support for many formats
     
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  18. iiAlexLiveii

    iiAlexLiveii Rapidly Rising Member

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    For me, it's a chance to test the media player that could have been, in an alternate universe where the Dreamcast had more life and Sega stood stronger. That, and I want to make my own MIL-CDs just for fun.
     
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  19. -=FamilyGuy=-

    -=FamilyGuy=- Site Supporter 2049

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    Exactly, it's interesting in and of itself. No need to actually watch videos using it.
     
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  20. Mrneo240

    Mrneo240 Peppy Member

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    For me, just documentation and recreation.
     
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