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  1. Presentation Time Stamp issues

    I downloaded video from
    https://robodebt.royalcommission.gov.au/
    saved to mp4 using Video DownloadHelper

    Loading the mp4 in Avidemux, it states:
    contains B-frames, presentation time stamps
    missing or monotonically increasing.

    Avidemux can try reconstruct correct PTS by decoding video!

    -------

    The video must be kept in mp4 format.
    It is saved at 240p so I need to keep as much quality as posible.
    I cannot download it again.
    The Downloaded mp4 240p video is over 7 hours long.

    Just splitting the original downloaded mp4 into 1.2 minute segments,
    they failed to upload to twitter.
    My guess is the PTS issue is cause.
    --------

    Avidemux would only save to MKV which is not suitable for twitter.

    What I need if posible:
    A way to repair original mp4 PTS issues.
    So I can then use lossless cut or similar to split for twitter!

    How best to do?
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  2. Member
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    Avidemux / lower left / "output format"
    You can set it to whatever you want as long as the container supports the streams
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  3. Originally Posted by davexnet View Post
    Avidemux / lower left / "output format"
    You can set it to whatever you want as long as the container supports the streams
    Only worked to save as MKV.
    It failed to work with mp4?

    ATM I am recoding ?
    Video Out set to - Mpeg4 AVC (x264)
    Not sure what result will be like.

    Is this my best option to keep original quality and file size?
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  4. Original 1Gig 323kbps

    The recoding ?
    Video Out set to - Mpeg4 AVC (x264)
    552mb 168kbps

    Some loss of quality.
    If no other option the recode may have to do.
    Any other ideas for me to try?
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    Not enough info. You have to hit the "configure" General Tab button and look at the settings.
    For example "encoding mode" should be "control rate factor" and then below that the quality -
    lower numbers produce bigger files/higher quality. Default is around 20
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  6. I did not change any settings.
    Just looking at this now, back in minute
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  7. My fault, very sorry.
    Seems I did not change bottom setting before loading video last time.
    This time I changed it first, than saved as copy.
    Been at this for over 12hrs and was starting to loss it.

    Looks good now, new video is 1.01 Gig.
    Cheers
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    If you save with "video output" set to "copy" those settings are irrelevant since they're not used
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  9. I made copy, correcting PTS and cutting segment with AVIdemux for twitter.
    It still stopped at 99%.

    Not sure what to do now?
    Should I try recoding and cutting with AVIdemux, or would that be waste of time?
    Not my area of knowledge!
    Quote Quote  
  10. control rate factor 20 reduced size
    from 1G 323kbps
    to 552mb 168kbps

    So I need to try *lower number,
    Or,
    Set Video Size to 1.01 Gig


    Recoding also failed to make mp4 for Twitter
    Thats all I know so might have to give up.

    What do you surgest here?
    Last edited by Tom4; 26th Feb 2023 at 22:26. Reason: *Correction
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  11. Member
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    Originally Posted by Tom4 View Post
    Originally Posted by davexnet View Post
    Avidemux / lower left / "output format"
    You can set it to whatever you want as long as the container supports the streams
    Only worked to save as MKV.
    It failed to work with mp4?

    ATM I am recoding ?
    Video Out set to - Mpeg4 AVC (x264)
    Not sure what result will be like.

    Is this my best option to keep original quality and file size?
    if you have ffmpeg installed, just run ffmpeg -i your video.mkv -c copy out.mp4
    this will convert the mkv file to mp4 with no quality loss.
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  12. dit dot dash
    Last edited by Tom4; 26th Feb 2023 at 23:30.
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  13. The stuff about MKV was "my screw up" not setting AVIdemux to MP4 Output before loading video!
    Last edited by Tom4; 26th Feb 2023 at 23:29.
    Quote Quote  
  14. Are there other MP4 correction tools that might fix problems?
    Last edited by Tom4; 26th Feb 2023 at 23:32.
    Quote Quote  
  15. General
    Complete name : C:\Users\Owner\Desktop\Royal Commission into the Robodebt Scheme Small\Royal Commission into the Robodebt Scheme Small.mp4
    Format : dash
    Codec ID : dash (dash/mp42/iso6)
    File size : 1.00 GiB
    Duration : 7 h 19 min
    Overall bit rate mode : Variable
    Overall bit rate : 327 kb/s

    Video
    ID : 1
    Format : AVC
    Format/Info : Advanced Video Codec
    Format profile : High@L2.1
    Format settings : CABAC / 5 Ref Frames
    Format settings, CABAC : Yes
    Format settings, Reference frames : 5 frames
    Format settings, GOP : M=4, N=90
    Codec ID : avc1
    Codec ID/Info : Advanced Video Coding
    Duration : 7 h 19 min
    Bit rate : 267 kb/s
    Nominal bit rate : 300 kb/s
    Width : 426 pixels
    Height : 240 pixels
    Display aspect ratio : 16:9
    Original display aspect ratio : 16:9
    Frame rate mode : Variable
    Frame rate : 30.000 FPS
    Minimum frame rate : 29.412 FPS
    Maximum frame rate : 30.303 FPS
    Color space : YUV
    Chroma subsampling : 4:2:0
    Bit depth : 8 bits
    Scan type : Progressive
    Bits/(Pixel*Frame) : 0.087
    Stream size : 838 MiB (82%)
    Writing library : x264 core 163 r3059 b684ebe
    Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=4 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / stitchable=1 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=infinite / keyint_min=30 / scenecut=40 / intra_refresh=0 / rc_lookahead=20 / rc=abr / mbtree=1 / bitrate=300 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=360 / vbv_bufsize=330 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
    Codec configuration box : avcC

    Audio
    ID : 2
    Format : AAC LC SBR
    Format/Info : Advanced Audio Codec Low Complexity with Spectral Band Replication
    Commercial name : HE-AAC
    Format settings : NBC
    Codec ID : mp4a-40-5
    Duration : 7 h 19 min
    Duration_FirstFrame : 89 ms
    Duration_LastFrame : -1 ms
    Bit rate mode : Variable
    Bit rate : 57.3 kb/s
    Channel(s) : 2 channels
    Channel layout : L R
    Sampling rate : 48.0 kHz
    Frame rate : 23.438 FPS (2048 SPF)
    Compression mode : Lossy
    Stream size : 180 MiB (18%)
    Default : Yes
    Alternate group : 1
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  16. Loading the mp4 in Avidemux, it states:
    contains B-frames, presentation time stamps
    missing or monotonically increasing.

    Avidemux can try reconstruct correct PTS by decoding video!

    -------

    Loading the mp4 in Adobe Premiere, only the audio loads?
    All very odd for a video that plays fine!
    Last edited by Tom4; 26th Feb 2023 at 23:41.
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  17. Member
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    Try re-encoding in FFmpeg with some flags to rebuild the time stamps
    Try this first:
    Code:
    ffmpeg -fflags +genpts  -i "c:\path\sourcefile.mp4" -c:v copy c:\path\out1.mp4"
    As an alternative, try this, to re-encode the video
    Code:
    ffmpeg -fflags +genpts  -i "c:\path\sourcefile.mp4" -c:v libx264 c:\path\out2.mp4"
    Last edited by davexnet; 27th Feb 2023 at 00:28.
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  18. Member
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    Originally Posted by Tom4 View Post
    Loading the mp4 in Avidemux, it states:
    contains B-frames, presentation time stamps
    missing or monotonically increasing.

    Avidemux can try reconstruct correct PTS by decoding video!

    -------

    Loading the mp4 in Adobe Premiere, only the audio loads?
    All very odd for a video that plays fine!
    try the first method in post #2 - https://forum.videohelp.com/threads/405530-Problem-with-B-frames
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  19. Will try all, thanks
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