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  1. Member
    Join Date: Jun 2013
    Location: LV
    Search PM
    Hello guys.
    Please help me solve this problem. I'm a complete noob in these things and not English, but will try my best to explain it.

    I have a video file, created using Galaxy S4 smartphone.
    Details here:
    Code:
    Format                                   : MPEG-4
    Format profile                           : Base Media
    Codec ID                                 : isom
    File size                                : 113 MiB
    Duration                                 : 55s 701ms
    Overall bit rate                         : 17.1 Mbps
    Encoded date                             : UTC 2014-08-15 10:23:32
    Tagged date                              : UTC 2014-08-15 10:23:32
    
    Video
    ID                                       : 1
    Format                                   : AVC
    Format/Info                              : Advanced Video Codec
    Format profile                           : High@L4.0
    Format settings, CABAC                   : Yes
    Format settings, ReFrames                : 1 frame
    Format settings, GOP                     : M=1, N=30
    Codec ID                                 : avc1
    Codec ID/Info                            : Advanced Video Coding
    Duration                                 : 55s 396ms
    Source duration                          : 55s 409ms
    Bit rate                                 : 17.0 Mbps
    Width                                    : 1 920 pixels
    Height                                   : 1 080 pixels
    Display aspect ratio                     : 16:9
    Frame rate mode                          : Variable
    Frame rate                               : 30.000 fps
    Minimum frame rate                       : 21.786 fps
    Maximum frame rate                       : 31.326 fps
    Color space                              : YUV
    Chroma subsampling                       : 4:2:0
    Bit depth                                : 8 bits
    Scan type                                : Progressive
    Bits/(Pixel*Frame)                       : 0.273
    Stream size                              : 112 MiB (99%)
    Source stream size                       : 112 MiB (99%)
    Title                                    : VideoHandle
    Language                                 : English
    Encoded date                             : UTC 2014-08-15 10:23:32
    Tagged date                              : UTC 2014-08-15 10:23:32
    mdhd_Duration                            : 55396
    
    Audio
    ID                                       : 2
    Format                                   : AAC
    Format/Info                              : Advanced Audio Codec
    Format profile                           : LC
    Codec ID                                 : 40
    Duration                                 : 55s 701ms
    Bit rate mode                            : Constant
    Bit rate                                 : 128 Kbps
    Channel(s)                               : 2 channels
    Channel positions                        : Front: L R
    Sampling rate                            : 48.0 KHz
    Compression mode                         : Lossy
    Stream size                              : 859 KiB (1%)
    Title                                    : SoundHandle
    Language                                 : English
    Encoded date                             : UTC 2014-08-15 10:23:32
    Tagged date                              : UTC 2014-08-15 10:23:32
    Using Ripbot (tried 2 different versions) i am trying to decrease the file size a little. I meet all the requirements, Ripbot needed. Everything works, but problem comes when i playback the newly created file. Duration of file is 55 seconds, there is an audible hand clap at 40 seconds (in both files), but in picture i only see it at 48 seconds in the new file. So, audio is always where it should be but video plays back slower and loses several frames at the end.
    The only thing i can think of, is the variable frame rate of original file, and constant 25 fps for my new file.
    If that's the problem, how can i tell RipBot not to touch the frame rate?

    I have these default commands for encoder settings:
    --level 4.0 --aud --nal-hrd vbr --vbv-bufsize 25000 --vbv-maxrate 25000 --b-pyramid none

    Thanks in advance!
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  2. Member
    Join Date: Jun 2012
    Location: USA
    Search Comp PM
    These kinds of problems are typical when interpreting variable frame rate video.

    Try a different encoder. Avanti or Winff are good front ends for ffmpeg. Handbrake may work for you as well.
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  3. Member
    Join Date: Jun 2013
    Location: LV
    Search PM
    Thanks, smrpix. I tried Avanti first and it worked. Now audio and video is sync, as far as i can notice. But anyway, the frame rate came out constant (30 fps) for my new file after setting Frame Rate and Frame Size to Source (i understand as "keep it unchanged"). I can't notice any differences in quality in both files, but i'm worried, there will still be some problems for larger files, where picture quality is better and less hand shaking.
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