When I try converting mkv to mp4 using ffmpeg, the following error occurs:

version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers   built on Jun 12 2012 16:52:09 with gcc 4.6.3  
 *** THIS PROGRAM IS DEPRECATED ***   This program is only provided for compatibility and will be removed in a future release. Please use
 avconv instead.   [matroska,webm @ 0x1e939c0] max_analyze_duration
 reached   [matroska,webm @ 0x1e939c0] Estimating duration from
 bitrate, this may be inaccurate   Input #0, matroska,webm, from
 'input.mkv':     Duration: 00:01:00.76, start: 0.000000, bitrate: 384
     Stream #0.0(eng): Video: h264 (High), yuv420p, 1280x544, PAR 1:1 DAR 40:17, 25 fps, 25 tbr, 1k tbn, 50 tbc (default)  
     Stream #0.1(eng): Audio: ac3, 48000 Hz, 5.1, s16, 384 kb/s (default)  
     Stream #0.2(eng): Subtitle: [0][0][0][0] / 0x0000   Output #0, ipod, to 'output.m4v':     Metadata:  
     encoder         : Lavf53.21.0  
     Stream #0.0(eng): Video: libx264, yuv420p, 1280x544 [PAR 1:1 DAR 40:17], q=2-31, 25 tbn, 25 tbc (default)  
     Stream #0.1(eng): Audio: ac3, 48000 Hz, 5.1, 384 kb/s (default)   Stream mapping:     Stream #0.0 -> #0.0     Stream #0.1 -> #0.1  
 Press ctrl-c to stop encoding   [ipod @ 0x1e9b740] Application
 provided invalid, non monotonically increasing dts to muxer in stream
 0: -2 >= -2 av_interleaved_write_frame(): Invalid argument

I used this command to convert the file:

ffmpeg -i input.mkv -vcodec copy -acodec copy -absf aac_adtstoasc output.m4v

The input file has the following characteristics:

mediainfo input.mkv 

>Unique ID                                : 200459305952356554213392832683163418790 (0x96CF0ED8DB5914CBB9E18163689280A6)  
>Complete name                            : input.mkv  
>Format                                   : Matroska  
>Format version                           : Version 2  
>File size                                : 1.46 GiB  
>Duration                                 : 1h 5mn  
>Overall bit rate                         : 3 168 Kbps  
>Encoded date                             : UTC 2010-09-26 21:44:02  
>Writing application                      : mkvmerge v2.9.5 ('Tu es le seul') built on >Jun 17 2009 16:28:30  
>Writing library                          : libebml v0.7.8 + libmatroska v0.8.1  
>ID                                       : 1  
>Format                                   : AVC  
>Format/Info                              : Advanced Video Codec  
>Format profile                           : [email protected]  
>Format settings, CABAC                   : Yes  
>Format settings, ReFrames                : 4 frames  
>Codec ID                                 : V_MPEG4/ISO/AVC  
>Duration                                 : 1h 5mn  
>Bit rate                                 : 2 910 Kbps  
>Width                                    : 1 280 pixels  
>Height                                   : 720 pixels  
>Display aspect ratio                     : 16:9  
>Frame rate                               : 25.000 fps  
>Color space                              : YUV  
>Chroma subsampling                       : 4:2:0  
>Bit depth                                : 8 bits  
>Scan type                                : Progressive  
>Bits/(Pixel*Frame)                       : 0.126  
>Stream size                              : 1.31 GiB (90%)  
>Writing library                          : x264 core 105 r1724 b02df7b  
>Encoding settings                        : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-2 / threads=18 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=0 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc=2pass / mbtree=0 / bitrate=2910 / ratetol=1.0 / qcomp=0.60 / qpmin=10 / qpmax=51 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / pb_ratio=1.30 / aq=1:1.00  
>Default                                  : Yes  
>Forced                                   : No  
>ID                                       : 2  
>Format                                   : AC-3  
>Format/Info                              : Audio Coding 3  
>Mode extension                           : CM (complete main)  
>Codec ID                                 : A_AC3  
>Duration                                 : 1h 5mn  
>Bit rate mode                            : Constant  
>Bit rate                                 : 256 Kbps  
>Channel(s)                               : 2 channels  
>Channel positions                        : Front: L R  
>Sampling rate                            : 48.0 KHz  
>Bit depth                                : 16 bits  
>Compression mode                         : Lossy  
Stream size                              : 121 MiB (8%)  
Language                                 : English  
Default                                  : Yes  
Forced                                   : No  

Being new to ffmpeg, I'm not sure what the error means or how to correct it.


  • there is already an answer about this askubuntu.com/questions/50433/… the basic concept is that both the MKV and the MP4 are containers, they are just containers, you basically have to unpack and re-pack the audio and video tracks if you want to switch between the two.
    – user827992
    Jul 4, 2012 at 21:06
  • I read that but I'm trying to learn how to do it with ffmpeg instead of those other tools. I use handbrake all the time but that doesn't help me understand how to do it in ffmpeg. Just trying to learn something new.
    – JohnS
    Jul 4, 2012 at 21:48
  • ffmpeg is probably not the best choice, because it always try to re-encode everything and you waste time and resources doing this, anyway forum.doom9.org/showthread.php?t=164683 this can probably become a good starting point for you.
    – user827992
    Jul 4, 2012 at 21:51
  • @user827992 This is incorrect. ffmpeg does not always try to re-encode everything. Did you even read the details in the question? The example in the question is clearly attempting to copy the streams, not re-encode.
    – llogan
    Jul 7, 2012 at 19:45
  • @user827992: both ffmpeg and avconv are able to losslessly re-pack from container to another without re-enconding content.
    – MestreLion
    Oct 2, 2012 at 0:32

6 Answers 6


As I've already written here, I suggest you change a few details in your command line:

  • If you're using an Ubuntu release older than 15.04, replace ffmpeg for avconv, as it was the fork used by Ubuntu for a few years (see the comments)
  • Do you really need -absf aac_adtstoasc? It had some issues that may not have been corrected in current Ubuntu's ffmpeg. I suggest you to try without it first.
  • -vcodec copy -acodec copy can be simplified to -codec copy or -c copy. It would also prevent tampering other streams besides video and audio, like subtitles.

So the winner is...

ffmpeg -i input.mkv -c copy output.m4v

If that does not work, please post all terminal output.


To automatically convert all files in a folder from MKV to MP4 you can create an alias:

alias mkv2mp4="for f in ./**/*.mkv; do ffmpeg -n -i \"\$f\" -c copy \"\${f%.mkv}.mp4\" && rm \"\$f\"; done"

This command performs the following steps:

  • Recursively loops through the current directory looking for .mkv files
  • Converts each file & all its sources to .mp4, not overwriting (-n) existing files
  • Removes the source file when the conversion was successful

I know its a very old thread, but I've found a solution to successfully run ffmpeg. Don't use -vcodec copy -acodec copy, use just ffmpeg -i input.mkv output.m4v instead. It will start running.

But in my case, I convert a .mkv to .mp4, the result output is just trash. It losses frame accuracy.

  • 5
    If you don't use the copy codec, it will reencode and lose quality.
    – Alexia
    Jul 13, 2015 at 11:53

Try This one:: Libav in Linux

Installation: run command

sudo apt-get install libav-tools

Video conversion command::Go to folder contains the video and run in terminal

avconv -i oldvideo.mkv -ar 22050 convertedvideo.mp4

Got this on Xubuntu 14.04 when trying to burn a DVD of MP4s using DVDStyler; Bombono produces the same error. ffmpeg #1154 suggests this might have been fixed in ffmpeg, though perhaps not in avconv? libav #478 is still marked open.

Also see: https://unix.stackexchange.com/questions/127522/avconv-error-av-interleaved-write-frame

I filed Launchpad #1339980; in summary, use a current release of ffmpeg, and not avconv.


Using -codec copy didn't work for me (Ubuntu 22.04). Instead, this command did the trick:

  • Video-only mkv file:

    ffmpeg -i input.mkv -codec mpeg4 output.mp4
  • Video+audio mkv file:

    ffmpeg -i input.mkv -vcodec mpeg4 -acodec aac output.mp4

Notice that for an mkv file with audio track I had to explicitly specify that mpeg4 is the video codec (vcodec) and that aac is the audio codec (acodec).

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