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Loading of clips too slow

newbie issues
TTC1
2010-09-09
2012-09-15

  • TTC1

    TTC1 - 2010-09-09

    Hi,

    I have just installed the latest version of LiVES and I am running a Celeron
    2.4Ghz with 1.5GB of RAM under Ubuntu 10.04.

    Loading a 1:12 min clip will take approx 5 min. Now imagine the time it takes
    for an half hour clip. (I tried but cancelled after 15 min.)

    I have checked for any error message either from the message window at the
    bottom of the main window in LiVES or thru the terminal when starting LiVES
    from the command line.

    Everything seems to be OK as I cannot see any error message, if not for this
    xmms... NOT DETECTED in the message window.

    Loading the same clip into KINO or OpenShot is no problem, either loads it
    within seconds. Well actually, KINO do a conversion to DV before opening the
    clip but still the conversion takes a fraction of the length of the clip.

    I know it is an older and slower computer that I have but it should still be
    workable with LiVES, considering the pre-requisite for LiVES is stated as
    800Mhz and 256Mb of RAM.

    Any idea or suggestion to try and solve this clip loading problem?

    Thanks.

     

  • Salsaman

    Salsaman - 2010-09-09

    Well, the loading time depends on a lot of factors like the clip type, frame
    size, frame rate, etc. Some formats can be opened instantly - for example dv
    and ogg/theora. For other formats it is more difficult since for example for
    mpeg, not all of the frames are fully encoded - there are only inter frames
    and intra frames. Since LiVES aims to be frame accurate it is necessary to
    decode each frame when the clip is loaded.

    What type of clip are you trying to open ?

    Note also that when kino converts it to dv format you will lose quality, since
    dv is a lossy format. Openshot may be able to open the clip instantly, but is
    it frame accurate (e.g. can you edit just a single frame from the clip ?).

     

  • TTC1

    TTC1 - 2010-09-09

    Thanks for the quick answer.

    I'm new to this video thing so I don't really understand all the underlying
    stuff.

    I usually try to open 2 types of clips to work with:

    1- from my point&shoot camera (Canon SD-1000)

    According MPlayer, it creates a clip in MPEG-AVI file at 30 frames/sec
    (640X480) with uncompress PCM 16bits mono audio

    2- from my smartphone, a Motorola Milestone (The Droid in USA)

    MPlayer can't read the MP4 files this phone creates.

    VLC tells me it is AVC1 at 720X480 and the frame rate varies around 6.xxx or
    7.xxx. Audio is MP4A at 32K.

    The 1:12min clip I tested earlier was generated by Openshot is an AVI using
    the FFMPEG MPEG-4 codec at 720X480 and 30 frames/sec. Audio is stereo MP3 at
    44.1 Khz/192Kbps

    According Openshot website, it features "Frame stepping, key-mappings: J,K,
    and L keys".

    I guess it does mean it is frame accurate?!?!

    Thanks for taking the time to help out and to give some understanding of the
    video world to this n00b. :-)

     

  • Salsaman

    Salsaman - 2010-09-09

    OK, I can't help with the camera formats yet - although faster opening of mpeg
    files may be impleented in the future. One problem of course is that the mpeg
    formats are patented and licensed so there is not much support for them in
    free software.

    If you are creating files from openshot, see if it has the option to encode as
    ogg/theora or dv. Then you will find that it is much faster to open these
    files in LiVES.

     

  • TTC1

    TTC1 - 2010-09-10

    That little 1:12 min video was actually the end result of the montage done in
    OpenShot. ;)

    But I just did a quick test with a DV file created with Kino and the load
    within LiVES was almost instantaneous.

    I will try with the ogg/theora also.

    I like to work with the best quality possible even if the end result will be
    converted to a less than ideal format.

    What I create is mostly personal and ends up on either YouTube or Facebook so
    no broadcast quality needed here.

    But as in audio, the better the source, the better the end result.

    So I guess my problem is solved now. Thanks a million for your help.

    If I may, one more question:

    would you recommend working with DV or ogg/theora files?

    From the two formats I mentioned for the two devices I usually use, which
    would you say preserves the most the original quality?

    I could use either Kino, Handbrake, OpenShot, AVIdemux to convert my original
    files to the format that LiVES prefer working with.

    Thanks again for your help.

     

  • Salsaman

    Salsaman - 2010-09-10

    For importing into LiVES, I would recommend ogg/theora. Use the highest
    quality settings you can.

    When you come to encode in LiVES, I would recommend using the multi_encoder
    with h264/vorbis high quality.

    Regarding the 2 devices, the end quality will be roughly the same. although
    the frame rate of the smartphone seems rather low for any serious video work.

     

  • TTC1

    TTC1 - 2010-09-10

    Yeah, I was surprised to see such low numbers from the smartphone.

    Though, it still give a decent enough quality for web use: http://www.faceboo
    k.com/yves.chaput?v=app_2392950137#    !/video/video.php?v=430371113876

    I did that with the smartphone stuck on the handles of my bike. But I didn't
    do any frame by frame editing, just rough cuts.

    I will test that out in LiVES though.

    thanks for your help. Very much appreciated.

     

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