Using .M2T (M2TS) files on Mac - how?

Discussion in 'Digital Video' started by ArthurDaley, Apr 8, 2008.

  1. ArthurDaley macrumors regular

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    #1
  2. -DH macrumors 65816

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    #2
    MPEG Streamclip should be able to convert the MPEG-2 Transport Stream (.m2t/.m2ts) into an editable format.

    -DH
     
  3. ArthurDaley thread starter macrumors regular

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  4. killmoms macrumors 68040

    killmoms

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    #4
    Shouldn't be, if you're going to HDV, but there COULD be I suppose. You might want to use Apple Intermediate as your in-between codec.
     
  5. ArthurDaley thread starter macrumors regular

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    It is HDV? I mean it's an HDV camcorder.

    The Apple codec is lossy.
     
  6. killmoms macrumors 68040

    killmoms

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    So is HDV, and so would be a successive re-encode to HDV within QuickTime—much moreso than one to Apple Intermediate. I don't believe MPEG Streamclip will pass-through the HDV (long-GOP MPEG-2) from the transport stream and simply wrap it in a QuickTime container.
     
  7. ArthurDaley thread starter macrumors regular

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    What I do not get is if this is just a container issue you'd think there would be one a way to take the PC container (.M2T) and change it to whatever the Mac wants (you know,no transcoding etc).
     
  8. jettoblack macrumors member

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    Unfortunately Apple's method of putting MPEG-2 data into a Quicktime file seems to be a trade secret or patented. iMovie, FCE, and even the Sony FCS plug-in for their hard disk/flash memory HDV recorders will transcode HDV to another codec. Only FCS's built-in capture window can capture HDV directly to Quicktime without transcoding, and even FCS can only open Quicktime files (not .m2t). Other NLE software like Premiere, Vegas, Edius, etc. all support .m2t files natively. This has been a long-outstanding gripe of many FCS users such as myself.
     
  9. ArthurDaley thread starter macrumors regular

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    So let me get this straight.

    On the PC I have Vegas and that will work with the .M2T files.

    I bought a MBP to be superior to the PC for video editing 2 weeks back but you tell me that iMovie/FCS will transcode whatever I play into it from the camcorder?
     
  10. -DH macrumors 65816

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    If you're worried about quality, why compress the footage to MPEG-2? That's a pretty hefty quality hit right there.

    Why not just capture directly from the camera to your Mac?

    -DH
     
  11. LethalWolfe macrumors G3

    LethalWolfe

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    He didn't compress the footage. He used a PC HDV capture utility which captured the footage as M2T files. Which is fine for Vegas, but FCP doesn't read M2T files. Sony has a utility that wraps M2T files into a QT container FCP can read, but I don't know if it will work w/files not generated by the Sony HD or Sony CF card add-on.


    Lethal
     
  12. -DH macrumors 65816

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    #12
    My mistake. As I understood it, .m2t is an MPEG-2 transport stream, with a typical MPEG-2 GOP structure complete with I frames, B frames and P frames. If that is true, then a lot of information gets thrown out in every B and P frame - only the I frames contain the full information - hence my use of the term "compressed."

    My apologies for not knowing that there apparently is an "uncompressed" variety of MPEG-2.

    Also, realizing that HDV is uses a heavily compressed MPEG-2 variant, I would imagine transcoding does add some quality hit.

    -DH
     
  13. LethalWolfe macrumors G3

    LethalWolfe

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    #13
    Yes, his source (HDV) is compressed, but his capturing via HDVsplit didn't add anymore compression (which is what I thought you were saying). It just didn't capture the HDV footage in a way that FCP will recognize it.

    Well, technically, every form of recording is compressed, but there are high quality, I-frame only variants of MPEG-2. Sony's IMX and HDCAM formats, for example, are I-frame only MPEG-2.


    Lethal
     
  14. ArthurDaley thread starter macrumors regular

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    Excuse the novice here but it seems I transferred it without loss using the PC. Which as a side note seems not possible on the Mac, as folks seem to say the capture on Mac looses quality.

    Anyhow now I have it without loss, folks seem to be saying that the Mac can not use these files. So all my family video tapes stored as .M2TS are useless on the Mac?
     
  15. jettoblack macrumors member

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    If you capture your HDV from the camera or deck using Final Cut Studio, the MPEG-2 data will be losslessly wrapped in a Quicktime wrapper in realtime, and can be edited natively without any recompression or quality loss. FCS supports native MPEG-2 editing without transcoding, but ONLY when the footage is captured by FCS. It cannot import .mpg or .m2t files. In theory, a 3rd party could write a program which losslessly takes the MPEG-2 stream out of a .m2t file and re-wraps it in a Quicktime file, the same way FCS does it during capture, but sadly no such utility is currently available. (MpegStreamclip and the others can input a .m2t file and output a .mov file, but they will perform a recompression and hence loss of quality even if the target codec is MPEG-2.)

    Unfortunately iMovie and FCE don't support MPEG-2 editing at all, they can capture HDV from a camcorder or deck but will transcode it to AIC (Apple Intermediate Codec) in realtime during capture. Only FCS supports native MPEG-2 editing.

    Yes, this has been a huge gripe of Mac/HDV users for quite some time now. As long as you capture in FCS it is not a big deal, however for users with a library of .m2t files or who use the Sony hard disk/flash memory HDV recorders, it is a big deal. Unfortunately Apple has given no indication that they are willing to address this problem. On the other hand, if working with .m2t files was so important to you, you probably should have done some research about it before you invested in a Mac/Final Cut system.
     
  16. Alucardx03 macrumors 6502a

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    About a year ago, I found myself in the exact same situation. I bought the same camera an had heard of the fantastic video editing capabilities of Macs. I too was shocked to discover the inability to edit .m2t files. I found a good workaround was using MPEG Streamclip to convert the files to something my Mac played nicely with. Now I capture the video directly in iMovie which saves a lot of trouble.
     
  17. ArthurDaley thread starter macrumors regular

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    thanks

    jettoblack - Thanks for that reply that answers everthing. I wonder what the best long term storage format is - QuickTime or .M2T? By that I mean being able to play with it in 10 years time. Just one point when you say "you probably should have done some research about it before you invested in a Mac/Final Cut system" - after so many people banging on about Mac's and video editing I never thought for a moment it would be so lacking.

    Alucardx03 - as others point out going to iMovie is giving you quality loss compared to the PC way of using .M2T (via say HDVsplit)
     
  18. Alucardx03 macrumors 6502a

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    Yeah, I'm aware that there is quality loss, but at least you can use your video immediately. I figure that I can always archive the tapes for the future and wait for a better solution. That's the good thing about tape media...it's always going to be there.
     
  19. killmoms macrumors 68040

    killmoms

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    #20
    The archival format is your tapes. There's nothing lacking here, except perhaps your unwillingness to buy a software suite that does what you need (which is to say Final Cut Studio). I highly doubt you will notice ANY actual quality loss going from HDV to Apple Intermediate.

    Yes, but it is barely perceptible. And, as noted, Final Cut Pro (as part of Final Cut Studio) will do exactly what you want—native HDV editing—just not from M2T files, you will have to recapture your footage from tape.
     
  20. LethalWolfe macrumors G3

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    #21
    Actually Sony makes a utility to import from their HDD and CF card recording units in to FCP.

    While technically there is a loss you should do a couple of tests to see if the loss is even discernible to the naked eye. There are, what I call, "real world losses" and "on paper losses." In real world losses you can see the difference in quality after going from codec A to codec B (like going from DV to DVD) where as on paper losses are losses where technically you've lost picture information, but you'd be hard pressed to find it even if you busted out diagnostic tools and knew what imperfections to look for. Any time you stray from the native codec you incur a paper loss, but many, many people transcode HDV to AIC, ProRes, DVCPro HD, Cineform, Sheer, uncompressed HD, etc., depending on their needs and have no problems because the real world loss is so low.


    Lethal
     
  21. ArthurDaley thread starter macrumors regular

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    "The archival format is your tapes. There's nothing lacking here, except perhaps your unwillingness to buy a software suite that does what you need (which is to say Final Cut Studio)"

    Eh? I have FCS. The problem is the Mac software will not take .M2TS files which is lame. All my archives are in .M2TS which
     
  22. killmoms macrumors 68040

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    #23
    Then why did you start the thread talking about iMovie? It's already been stated that FCS does native HDV editing, just not with MPEG-2 transport streams. It's based upon the QuickTime framework, so it's really no surprise. It might be inconvenient, but any editor will tell you that the only _truly_ compatible archive system is the original tapes and a deck with which to ingest their content.

    Lethal: Do you happen to have a link to that utility so we could see if it'd solve the OP's problem, or is it a "distributed only with Sony cameras" kind of thing?
     
  23. ArthurDaley thread starter macrumors regular

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    The native editing of FCS seems to be good only if you capture with FCS. But if you have terabytes of Sony HD material already then it sucks.

    I'd prefer using iMovie over FCS as the former looks far easier and I only wish to do very basic things.

    The further problem seems that .M2TS seems better for taking to Blue Ray and that is my plan. To keep the .M2TS and later on share it via blue ray just like many do today with SD and a regular DVD (i.e. family clips with menu on DVD).
     
  24. killmoms macrumors 68040

    killmoms

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    #25
    If you take clips straight across, yes. However, if you're doing any editing at all (clipping between GOPs, adding transitions/titles, or doing color/video tweaking at all) you'll be rendering (re-encoding) to something else, so you're losing that dubious benefit right off the bat. Not to mention the fact that most Blu-ray discs are authored with H.264, so you'll likely be encoding to a more delivery friendly format anyway.

    Convert a clip to Apple Intermediate and see if you can tell the difference between it and the original. I'll bet that you can't. Heck, convert it to Apple's ProRes 422 and use FCP if you're really concerned about quality. ProRes might not be lossless, but it's so close (and so un-fazed by successive re-encodes/renders to ProRes) that it's usable for film-outs. I know it's not what you had in mind, but I highly doubt that AIC is going to degrade HDV footage in any way that's visible to the eye.
     

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