Author Topic: Unable to open m4v file: Cannot find demuxer  (Read 5556 times)

cheerful

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Unable to open m4v file: Cannot find demuxer
« on: July 16, 2016, 02:55:41 AM »
Hi,

I was hoping to join 2 m4v files together.  I saw a post at http://arstechnica.com/civis/viewtopic.php?t=1185636 that suggested avidemux.

I have Windows 10 64-bit and tried both 32 and 64 bit of avidemux.  When I open the m4v file, I got the error "Cannot find a demuxer for".  The file plays fine in MPC.  avidemux has no problem opening m2ts or mp4 files.

Searched and found a post https://forums.freebsd.org/threads/47580/ that have problem with mkv but none has a solution for m4v.

Is there anything that I need to configure or install?

Thanks

Jan Gruuthuse

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #1 on: July 16, 2016, 05:10:25 AM »
You don't give us much information, only indicating the container format (m4v). I tested 2 m4v video files on avidemux 2.6.12, these open without a problem.
Don't mix up containers: MKV, M4V, M2TS, MP4, ....

Quote
The M4V file format is a video container format developed by Apple and is very similar to the MP4 format. The primary difference is that M4V files may optionally be protected by DRM copy protection.
source: Wikipedia M4V

Download MediaInfo and see what this tool is telling you on both video see attachment



cheerful

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #2 on: July 16, 2016, 07:28:39 PM »
It contains only video and it's produced by Adobe Media Encoder.  It's used in Encore for authoring.

Here is from MediaInfo

General
Complete name                            : clip.m4v
Format                                   : AVC
Format/Info                              : Advanced Video Codec
File size                                : 6.71 MiB
Overall bit rate mode                    : Variable

Video
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.1
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 3 frames
Format settings, GOP                     : M=3, N=29
Bit rate mode                            : Variable
Maximum bit rate                         : 35.0 Mbps
Width                                    : 1 920 pixels
Height                                   : 1 080 pixels
Display aspect ratio                     : 16:9
Frame rate                               : 29.970 (30000/1001) fps
Standard                                 : NTSC
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Interlaced
Scan type, store method                  : Separated fields
Scan order                               : Top Field First
Color range                              : Limited

mean

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #3 on: July 16, 2016, 08:05:52 PM »
Short sample would help

cheerful

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #4 on: July 17, 2016, 01:52:33 PM »
Here is one.  Thanks

mean

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #5 on: July 17, 2016, 02:35:56 PM »
It's a h264 ES stream
It is indeed not supported as it is very uncommon.

Workaround :
mkvmerge -o /tmp/xxx.mkv ~/Downloads/sample.m4v

It takes no time at all, just a container change
The resulting file can be opened


cheerful

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #6 on: July 17, 2016, 08:38:11 PM »
This has always been the output format from Adobe Media Encoder.  It outputs the AC3 file separately.  This is the format used by Adobe Encore.

My problem is that I have 3 m4v video file and 1 AC3 audio file. The source video are long gone.  I'd want to join the 3 video together and mux with the AC3 file to produce a single m2ts file for Adobe Encore.

Is there a way to do this?  I've tried many tools.  The only one that could produce a file of the right size is tsMuxser.  However, the second segment is corrupted (mosaic at many places).

Thanks

Jan Gruuthuse

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #7 on: July 18, 2016, 05:29:52 AM »

cheerful

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #8 on: July 19, 2016, 03:24:41 AM »
Have not downloaded yet.  But it looks like it producing mkv file, not m2ts.  Is that the case?

Thanks

Jan Gruuthuse

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #9 on: July 19, 2016, 05:37:07 AM »
Have not downloaded yet.  But it looks like it producing mkv file, not m2ts.  Is that the case?
Yes

Load (joined) videos in mkvtoolnix gui
Load AC3 track in mkvtoolnix gui
Mux into mkv container
Load that mkv container into avidemux
With copy for both audio and video, save with selected output format (container: mp4, mkv, ...) you want.
« Last Edit: July 19, 2016, 09:13:46 AM by Jan Gruuthuse »

cheerful

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Re: Unable to open m4v file: Cannot find demuxer
« Reply #10 on: July 20, 2016, 03:10:03 AM »
mkvtoolnix was successful in joining the segments and mux the video / audio into a single mkv container.  There are 3 segments, A, B and C.  They are all produced by the Adobe Media Encoder.  A and C are long and B is short.  The merged mkv played fine MPC-HC.

I then tried to use tsMuxer to create the m2ts file.  The result file can be played.  But segment B became corrupted with mosaic and jittery frames.  I tried to just put the 3 m4v files to join in txMuxer.  It turned out it actually support it but the same outcome.

Tried tsRemux, unhandled exception.  Does not like any of the input file (mkv included)

Tried Avidemux to ts but Encore wants to transcode it.

Tried Avidemux to ts and then tsMuxer to m2ts.  Same corrupted segment

Tried Avidemux to mp4 (using MP4v2 Muxer).  Encore wants to transcode the result

Tried tsMuxer to demux the mkv.  Encore failed to import the video only file.

Is there any other way to convert mkv to m2ts (so Encore won't transcode it again)?

tsMuxer GUI is showing the following for the muxing job.  Is there any option that can change how does the muxing?

MUXOPT --no-pcr-on-video-pid --new-audio-pes --vbr  --vbv-len=500
V_MPEG4/ISO/AVC, "D:\merged.mkv", insertSEI, contSPS, track=1, lang=und
#A_AC3, "D:\merged.mkv", track=2, lang=und

Thanks