Combined MP4's into a 17-hour video, but video player says it's 13 hours

[Hypersonic1]

After combining many SD MP4 files into a 17-hour MP4 file, the video players show that the video is only 13 hours long. However, the entire 17 hours of video can still be played without errors. I used Avidemux, but other tools have a similar problem. MKV doesn't have this problem.

[poisondeathray]

Did you try remuxing the mkv that "doesn't have this problem" into mp4 ?

[LigH.de]

Is the result larger than 4 GB?

[Hypersonic1]

I tried converting it from mkv to mp4, but Avidemux displays it as a 30-hour video, and it doesn't play properly after it is converted.

The file size is 46GB.

[DB83]

I have to ask. While it is your 'baby' why would you want to have a 17 hour video ? It's not as if you could watch it all at one go.

So. How did you go about creating the monster ? Just select copy for video etc. in avidemux or re-encode the whole thing.

[JVRaines]

What is the timescale value of this monster video? (FFProbe is one way to find out.)

[Hypersonic1]

So. How did you go about creating the monster ? Just select copy for video etc. in avidemux or re-encode the whole thing.

No, I just selected copy because I didn't want to re-encode.

What is the timescale value of this monster video? (FFProbe is one way to find out.)

It appears the same amount as before. 13 hours.

[DB83]

This is only a guess since I have not done anything like this but is it possible that the un-joined files had different qualities ie bit-rate and the reported length just refers to the first clip suitably adjusted for file size.

[Hypersonic1]

This is only a guess since I have not done anything like this but is it possible that the un-joined files had different qualities ie bit-rate and the reported length just refers to the first clip suitably adjusted for file size.

That wouldn't make sense because I combined 36 clips. If that were true, the reported length would be much shorter.

They used VBR with a target of 6 Mbps, so the bit rate will be slightly different for each clip. If I combine into MKV, it works fine, but I prefer MP4 for compatibility.

[JVRaines]

What is the timescale value of this monster video? (FFProbe is one way to find out.)

It appears the same amount as before. 13 hours.

No, that is the duration. I am asking for the timescale value, which is technical metadata. Run FFProbe on the file and post the result here.

[DB83]

This is only a guess since I have not done anything like this but is it possible that the un-joined files had different qualities ie bit-rate and the reported length just refers to the first clip suitably adjusted for file size.

That wouldn't make sense because I combined 36 clips. If that were true, the reported length would be much shorter.

They used VBR with a target of 6 Mbps, so the bit rate will be slightly different for each clip. If I combine into MKV, it works fine, but I prefer MP4 for compatibility.

Not so sure. What you can do is post a mediainfo(text mode report) of the combined video.

Also. Is the combined clip similar in size to the sum of the individual clips ? Not the run-length. We know that. The file size.

[Hypersonic1]

FFProbe:

ffprobe version N-90378-ge4eaaf7bf6 Copyright (c) 2007-2018 the FFmpeg developers
  built with gcc 7.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
  libavutil      56. 11.100 / 56. 11.100
  libavcodec     58. 14.100 / 58. 14.100
  libavformat    58. 10.100 / 58. 10.100
  libavdevice    58.  2.100 / 58.  2.100
  libavfilter     7. 13.100 /  7. 13.100
  libswscale      5.  0.102 /  5.  0.102
  libswresample   3.  0.101 /  3.  0.101
  libpostproc    55.  0.100 / 55.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'c:\Users\Daniel\Videos\Video.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
    creation_time   : 2018-03-22T02:41:20.000000Z
  Duration: 13:15:21.86, start: 0.000000, bitrate: 8290 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, smpte170m), 720x480 [SAR 8:9 DAR 4:3], 5978 kb/s, 51.52 fps, 29.97 tbr, 90k tbn, 59.94 tbc (default)
    Metadata:
      creation_time   : 2018-03-22T02:41:20.000000Z
      encoder         : JVT/AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
    Metadata:
      creation_time   : 2018-03-22T02:41:20.000000Z

MediaInfo:

General
Complete name                            : C:\Users\Daniel\Videos\Video.mp4
Format                                   : MPEG-4
Format profile                           : Base Media / Version 2
Codec ID                                 : mp42 (mp42/isom)
File size                                : 46.1 GiB
Duration                                 : 4 h 10 min
Overall bit rate mode                    : Variable
Overall bit rate                         : 26.3 Mb/s
Encoded date                             : UTC 2018-03-22 02:41:20
Tagged date                              : UTC 2018-03-22 02:46:46

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L3.1
Format settings                          : CABAC / 4 Ref Frames
Format settings, CABAC                   : Yes
Format settings, RefFrames               : 4 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 4 h 10 min
Source duration                          : 17 h 25 min
Bit rate mode                            : Variable
Bit rate                                 : 5 323 kb/s
Maximum bit rate                         : 6 000 kb/s
Width                                    : 720 pixels
Height                                   : 480 pixels
Display aspect ratio                     : 4:3
Frame rate mode                          : Variable
Frame rate                               : 51.517 FPS
Minimum frame rate                       : 9.997 FPS
Maximum frame rate                       : 62.805 FPS
Original frame rate                      : 29.970 (30000/1001) FPS
Standard                                 : NTSC
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.299
Stream size                              : 10.4 GiB (23%)
Source stream size                       : 43.7 GiB (95%)
Encoded date                             : UTC 2018-03-22 02:41:20
Tagged date                              : UTC 2018-03-22 02:46:46
Color range                              : Limited
Color primaries                          : BT.601 NTSC
Transfer characteristics                 : BT.601
Matrix coefficients                      : BT.601
mdhd_Duration                            : 15033751

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : mp4a-40-2
Duration                                 : 4 h 10 min
Source duration                          : 17 h 25 min
Bit rate mode                            : Variable
Bit rate                                 : 317 kb/s
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 kHz
Frame rate                               : 46.875 FPS (1024 SPF)
Compression mode                         : Lossy
Stream size                              : 569 MiB (1%)
Source stream size                       : 2.32 GiB (5%)
Title                                    : Stereo
Encoded date                             : UTC 2018-03-22 02:41:20
Tagged date                              : UTC 2018-03-22 02:46:46

[Hypersonic1]

Is the combined clip similar in size to the sum of the individual clips ? Not the run-length. We know that. The file size.

Separated files: 49,445,966,079 bytes
Combined file: 49,452,108,394 bytes

[JVRaines]

With a timebase of 90,000 per second, a 17-hour video will require timestamps counting up to about 5.5 billion. This is greater than the number which can be represented (4,294,967,296) by the four bytes allocated in various MP4 Version 0 duration fields. It seems that the players are not properly reading Version 1 duration fields, which can count up to 18,446,744,073,709,551,616.

[DB83]

And a quick look at the mediainfo file (thank you) reveals inconsistencies.

The audio does report at 17 hours. Good. The video reports both 4 hours AND 10 hours !!!!!!!.

Methinks the problem here is not the variable bit rate but the variable frame rate. The only way to even attempt correctly reported run length for the video is to re-encode and even that could be thwarted by the variable frame rate. It may work properly with fixed frame rate videos but these ?

[Hypersonic1]

Methinks the problem here is not the variable bit rate but the variable frame rate. The only way to even attempt correctly reported run length for the video is to re-encode and even that could be thwarted by the variable frame rate. It may work properly with fixed frame rate videos but these

The clips all have a fixed frame rate. Most clips are 59.94, but a few clips that were added are 29.97. I really don't want to re-encode because it loses more quality. I've already encoded them.

[Marsia Mariner]

The clips all have a fixed frame rate. Most clips are 59.94, but a few clips that were added are 29.97. I really don't want to re-encode because it loses more quality. I've already encoded them.

also:

MKV doesn't have this problem.

My suggestion: get the timestamps from the MKV file and use them with mp4fpsmod.

Besides: forget Avidemux.

[DB83]

Ok. Mediaifo is not a perfect tool. It has been known to get thing wrong but then it can be fooled by something that is a 'mish-mash'

I misread the '10' bit. That was the reported stream size of the video. Even that conflicts to an earlier report at 4 gig.

Just how do you expect something that has different qualities to join AND display the correct attributes ?

MKV is different. Could it possibly be reporting a playlist of individual files rather than a combination of them. ?

Just for a giggle. Make an mkv as you did before and post that mediainfo report.

[Hypersonic1]

Actually, now I just noticed that all of my 59.94 videos all have variable frame rate. The audio sync is not perfect as a result. When I exported these from uncompressed AVI to H.264, Adobe Premiere did not give me the option to choose a constant frame rate.

[poisondeathray]

Actually, now I just noticed that all of my 59.94 videos all have variable frame rate. The audio sync is not perfect as a result. When I exported these from uncompressed AVI to H.264, Adobe Premiere did not give me the option to choose a constant frame rate.

As a general rule , premiere only exports CFR . The timeline is CFR.

There is something else going on. For example there were a few buggy voukoder plugin builds that messed up timecodes. But I think the problmes were fixed in recent updates. But all AME, PP default exports are CFR only

What did you use to export , and what settings ?

How are you determining that the videos are VFR ?

[Hypersonic1]

Every time I combine or split clips via copy using Avidemux, the resulting clip has a variable frame rate. I used MediaInfo to find out.

[poisondeathray]

Every time I combine or split clips via copy using Avidemux, the resulting clip has a variable frame rate. I used MediaInfo to find out.

If it's caused by avidemux...maybe don't use avidemux ?

[DB83]

Before you edit ie split these 59.94 fps mp4's in avidemux are they still CFR ?

As pdr mentions, something else appears to be going on. Why, for example, are you exporting at 59.94 fps whilst, I guess, that the original uncompressed are 29.97. And are the original 29.97 actually uncompressed or have you done something to the original clips to get there ?

Even so. If you mix 59.94 with 29.97 I would still have a guess that mediainfo has to report vfr.