Re-packaging *.mkv--->*.avi does not work with ffmpeg

[pxstein]

I have a video packaged in a *.mkv container. I used ffmpeg to re-package it into an *.avi container with the following command:

ffmpeg -i mymovie.mkv -acodec copy -vcodec copy mymovie.avi

The conversion works in the sense that ffmpeg accepts and processes the command.

However when I want to play the resulting movie in one of the famous video players like

VLC 2.1 or Potplayer

then only audio can be heard. No video output can be seen.

MediaInfo tool shows the following codecs in the *.mkv video (see bottom of this post).

Why can ffmpeg not produce correct and playable *.avi videos?
Yes, I know MKV is the better format but I want to have AVI for this case.
FFmpeg claims to be able to do this job.

Whats wrong?

Thank you



MediaInfo output (for input video):

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1h 29mn
Bit rate : 776 Kbps
Width : 720 pixels
Height : 298 pixels
Display aspect ratio : 2.40:1
Frame rate mode : Constant
Frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.145
Stream size : 497 MiB (66%)
Writing library : x264 core 138 r2358 9e941d1
Encoding settings : cabac=1 / ref=5 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=umh / subme=7 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-3 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=19.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Default : Yes
Forced : No
Audio
ID : 2
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : A_AC3
Duration : 1h 29mn
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 246 MiB (32%)
Language : German
Default : Yes
Forced : N


MediaInfo output (for resulting video in *.avi):

Video
ID : 0
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings, CABAC : Yes
Format settings, ReFrames : 5 frames
Codec ID : H264
Duration : 1h 29mn
Bit rate : 798 Kbps
Width : 720 pixels
Height : 298 pixels
Display aspect ratio : 2.40:1
Frame rate : 50.000 fps
Original frame rate : 25.000 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.074
Stream size : 511 MiB (67%)
Writing library : x264 core 138 r2358 9e941d1
Encoding settings : cabac=1 / ref=5 / deblock=1:-1:-1 / analyse=0x3:0x133 / me=umh / subme=7 / psy=1 / psy_rd=1.00:0.15 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=0 / chroma_qp_offset=-3 / threads=12 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=19.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Audio
ID : 1
Format : AC-3
Format/Info : Audio Coding 3
Codec ID : 00001000-0000-0020-8000-00AA00389B71
Duration : 1h 29mn
Bit rate : 384 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 246 MiB (32%)
Interleave, duration : 32 ms (1.60 video frames)

[poisondeathray]

Probably has to do with something specific to your files , since it works here on many players

Might be the dimensions (mod2) - height is 298 causing problems with the AVI splitter / decoding pathway

[poisondeathray]

Nope, I can't reproduce your issue even with those dimensions. Must be something specific either to your files or versions of players (VLC runs independent of system installed codecs/splitters - so you might try another version)

298.mkv is the source test file

298_copy.avi is the copied version into AVI container using ffmpeg

I didn't use the same encoding settings or audio configuration, but that shouldn't affect it

[El Heggunte]

Why can ffmpeg not produce correct and playable *.avi videos?

Because sometimes it does the job well, and sometimes it doesn't

For example, sometimes you DON'T need to specify the correct framerate for the output, but this time you should have specified it:

Frame rate : 50.000 fps
Original frame rate : 25.000 fps

If possible, I recommend you remux your MKVs to AVIs via VirtualDub's "Direct Stream Copy" (requires the Matroska input plugin). In this way, you can be sure the resulting AVIs will be 100-per-cent *compliant with the specs* Which OTOH, may mean nothing to programs like VLC

[pxstein]

Ok, thank you.

How do I manually specify the framerate at the cmdline?

[smrpix]

How do I manually specify the framerate at the cmdline?

-r

(29.97, 25, 50, etc.)

[pxstein]

Ok, thank you. But want to come back to my initial question:

Why can't such an advanced tool as ffmpeg not simply re-package a *.mkv to *.avi WITHOUT modifying the parameters?

Is there really no automatic simple way?

[Selur]

Is there really no automatic simple way?

The problem is that:

Frame rate                               : 50.000 fps
Original frame rate                      : 25.000 fps

means that the video stream frame rate of the raw stream is 25fps and the video stream rate of the container is 50fps, without any help ffmpeg is not sure is it should use the video frame rate of the video stream itself or the frame rate of the container.
So instead of blindly using one and risking that the user does not get what he/she wants, it complains.

-> tools with 'advanced' options need 'advanced' users