Even after correct fps calculation, there might be duplicate timestamps created by old muxers which were not using timescale but using rounding of close frame timings. I am starting to think that the source file is badly muxed, since some other mkv files gave clean mp4 file with no issue if not all.
*) Time base is not necessarily equal inverted fps, as it only means that all timestamps can be expressed as a multiple of the time base: fps <= (1/timebase)
#Mkv mp4 remux archive#
I'd put them all into a single archive (zip, gzip or 7zip). QuoteOnly attaching admlog for no.1, 3, 5 as more than 4 attachments are not allowed. Saving this file in copy mode in Avidemux should also succeed. If it turns out to be perfectly regular, this source mkv is usable for further testing, especially Avidemux should also force timestamps to multiple of time base. I would have reduced all the testing setup to remuxing the source mkv file with ffmpeg to mp4, loading this mp4 in Avidemux and checking admlog.txt to verify that ffmpeg has used the 1001/24000 time base* and how regular the file is (Avidemux prints a histogramm if time base numerator is >= 100 ticks). In sample 5, Avidemux detects too high deviation from the standard 1001/24000 time base while the deviation for 1000/23976 turns out to be lower, so that it forces timestamps to multiple of 1000/23976 and sets DTS from sorted list of PTS. Have I understood correctly that saving these files in copy mode fails? There should not be any problems saving 1 and 3 in copy mode using the MKV or MP4 muxer (unless there is some hidden bug in mkvHeader::enforceFixedFrameRate). In samples 1 and 3 Avidemux finds the standard 1001/24000 time base applicable and forces all timestamps to a multiple of this timebase. Only attaching admlog for no.1, 3, 5 as more than 4 attachments are not allowed. 1, 2, 3, 4, 6 all had non monotonous dts error in ffmpeg and muxed without avidemux error using mp4v2 container. 5 to 6 selected 23976/1000 as viable fps with sum of error not equal to zero for any fps option.ī) Out of all six variants no.5 muxed correctly without any avidemux or ffmpeg error with variable frame rate instead of constant frame rate of source video file.Ĭ) No. 1 to 4 selected 24000/1001 as viable fps with sum of error=0, No. Source video file :- sample.mp4 (changed container from sample.mkv using avidemux)Īt this point I have 6 mkv file variants of the same source and these are my results.Ī) No. Source video file :- sample.mp4 (changed container from sample.mkv using ffmpeg) Muxed raw codec files to mkv using mkvtoolnix. Extracted mkv to remove whatever container header there was. Source video file :- sample.mkv (Random video downloaded from internet)ġ. For testing I have selected the same previous video file. So, I did some testing using everything up-to-date (avidemux, mkvtoolnix, ffmpeg). I am sending avidemux error, mediainfo output and ffmpeg output for the same video file. In ffmpeg I am using vfrdet option to verify variable frames in a video file. Encoding the video with resampling sure solves this issue but it is a very time consuming option.
The error is consistent with h264 and h265 codecs. If I use mp4v2, muxing goes normally but the result is again variable frame rate with min and max delta values in mediainfo and non monotonous increasing decoding timestamp error in ffmpeg. This may happen as result of invalid time stamps in the video." The error occured at 00:43:29,335 ("some two digit number"). Now, I am using the latest nightly builds of avidemux from past week to handle mkv to mp4 muxing which for some videos work nicely but for most of the videos I get this error to be specific (exactly this error with all the video files with 23.976 fps).
So, I was using avidemux 2.7.5 release for a long time, but it has timestamps rounding off issues that makes all constant frame rate videos to variable frame rates whenever using copy mode and this issue is consistent with all 23.976 fps videos (most probably due to the way avidemux handles timestamps instead of using timescale). I want them to be in mp4 container (just because I like it that way). Let me explain, I have multiple files in mkv container with avc/aac. Hi, I have been facing a serious issue which is not mentioned anywhere on this forum.
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