AVCHD or mp4

Discussion in 'Digital Video' started by loby, Jun 26, 2015.

  1. loby macrumors 6502a

    loby

    Joined:
    Jul 1, 2010
    #1
    Please advise.

    I record videos of lectures for a non-profit organization and add power points to it and some motion effects etc. Would like the best possible quality format from my camera.

    Here is my equipment. I will be using FCPX

    Camera: Canon VIXIA HR R400 (128 gb & 32 gb video SD cards)
    Mac mini 2012 i7 16 gigs 512 SSD
    two Seagate thunderbolt adapters with two 3 TB drives. Now Raid 0 = 1 production drive 6 TB

    I read through my Canon Manual and again searched around and could not determine which format to use for the best video quality for my use.

    Camera is cheap, but does the job (like it) and puts out a decent video image.

    Which format is the best quality for my camera and works well with FCPX?

    Would LOVE a Mac pro and will save up...but the mini works for my current needs and production.

    Any help is appreciated and valued.
     
  2. Gwendolini macrumors 6502

    Gwendolini

    Joined:
    Feb 5, 2015
    Location:
    random
    #2
    MP4 might not be better, but there is less of a hassle with all the AVCHD container crap you might encounter, since it is only one file per clip, compared to the AVCHD container with plenty of clips hidden inside.

    Maybe test it yourself, but both video formats use the H.264 container anyway, which makes FCP X transcoding in the background more often if you do not optimize the video during import.
     
  3. loby thread starter macrumors 6502a

    loby

    Joined:
    Jul 1, 2010
    #3

    I did a test and recorded with both AVCHD and mp4 and it is difficult to tell which is which since mp4 setting records at 35fps and AVCHD is 28fps I believe. I know this camera was advertised that the .mp4 had a higher fps ratio then others (newer at the time - 2013).

    I still don't understand the difference why record in one format over the other? Noticeable is that .mp4 is takes more space (not a big deal) on initial recording, and that it records only 4 gigs files at a time. Heard that .mp4 is easier to work with, but as far as quality, I am still not sure why use one over the other format?

    I will probably use .mp4, but still wondering the differences. Thanks for the reply.
     
  4. Gwendolini macrumors 6502

    Gwendolini

    Joined:
    Feb 5, 2015
    Location:
    random
    #4
    The frame rate seems kinda off, as 35 fps and 28 fps are not standards like 23.97 or 24 or 25 or 29.97 fps.

    As to the file size limit, that is due to the SD card using FAT32 as file system, which limits the maximum file size to 4 GB per file.
    The same would happen in the AVCHD container (as it looks like on Mac OS X, but on Windows it just looks like a folder).

    If you get a better data rate out of MP4, use that, makes it easier to composite strange objects into the lecture to see if the viewers are still paying attention.
     
  5. kohlson macrumors 6502a

    Joined:
    Apr 23, 2010
    #5
    There are lots of factors in determining video quality, but out of a consumer grade camera, I would test from maximum settings for both formats, do an edit or two, and then post to your final destination and see how happy you are with one or the other. This end-to-end workflow analysis will help you decide. It may be that one format has slightly higher quality, but is harder to work with (longer rendering times, slow editing, and so on). It may be that one file looks better on your laptop, but after the hosting site finishes with it there is no difference. I am surprised the 4GB citation is a factor. Yes, 4GB is a file size limit for WinFAT filesystems, but I don't know if that's what's used on Canon camcorders. I used to video my daughter's soccer games start to finish, including halftime about 100 minutes or so - essentially the battery life limit of the camera. I'm pretty sure the file recorded to the SD card was bigger than 4GB.
     
  6. Unami macrumors 6502a

    Joined:
    Jul 27, 2010
    Location:
    Austria
    #6
    it's probably 35 & 28 Mbps, not fps

    avchd and mp4 are only container formats, in this case they both probably contain h.264 encoded video. as avchd specifications used to max out at 28Mbps, maybe they added an mp4 option for a higher bitrate. so the mp4 version is probably the better one, but if you don't see a difference, 28mbps avchd is fine as well. fcpx should handle both without a problem. one of those formats might be a little slower editing natively (but you can always transcode to high quality/proxy files for faster editing), 28 mbps needs 20% less space.
     
  7. Unami macrumors 6502a

    Joined:
    Jul 27, 2010
    Location:
    Austria
    #7
    @filesize limit

    that's due to the sd-card being formated in fat32. avchd tackles this by "spanning" the clips. it also doesn't record files larger than 4gb (look at the .mts files inside the private/avchd/bdmv/stream folder), but adds metadata in the avchd container so the video is played back as one clip.
     
  8. loby thread starter macrumors 6502a

    loby

    Joined:
    Jul 1, 2010
    #8
    Thanks for the help everyone. When working with FCPX it looks like .mp4 wins with just a "slight" richness in color, but almost unnoticeable unless you really compare the two closely. This conclusion is just for this camera of course (Canon VIXIA HR R400) and probably not a general conclusion to comparing the two.
     

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