Remux MKV to MP4 with correct timestamps?

DragonQ · 21st June 2014, 21:03

I'm trying to use a video editor that doesn't support MKV and it really struggles with TS files too (Sony Vegas Pro). It seems MP4 is the best input format for it, and it works for some files, but I'm not having any joy remuxing some 1080i/25 TV recordings (AVC/AC3 in an MKV) into working MP4s with correct timestamps.

I'm using ffmpeg to remux and have tried a few different things (straight from MKV to MP4, from MKV to TS to MP4, MKV to elementary stream to MP4) but the resulting MP4 just doesn't play properly in MPC-HC, let alone within Vegas Pro (the frames jump around out-of-order). For example, using this input line:

Code:

ffmpeg -i "D:\input.mkv" -vcodec copy -acodec copy "D:\output.mp4"

I get loads of warnings during the remuxing like this:

Code:

Non-monotonous DTS in output stream 0:0; previous: 3119681, current: 3119040; changing to 3119682. This may result in incorrect timestamps in the output file.

Is it even possible to get a working MP4 from an MKV like this? Maybe there's another remuxer I could try or there's some ffmpeg options that will help?

Thanks for any advice.

Simon88 · 21st June 2014, 22:01

extract the video stream & audio stream & ttext (if applicable). Also extract timecodes if you notice sync issues (non-standard frame-rates). Then remux using mp4box (latest GPAC version).

DragonQ · 21st June 2014, 22:07

How do I extract timecodes? Also, I've tried MP4Box (via YAMB), it also produces a dodgy MP4 file like ffmpeg does.

EDIT: OK I see I can use timecodes_v2 (don't see this option in MKV Extract GUI 2). Are there any GUIs that will let me make an MP4 using the timecode files?

EDIT: Every time I download a Windows binary of MP4Box GPAC I get the error "installer integrity check has failed".

Simon88 · 21st June 2014, 22:54

I only use the official, latest GPAC mp4box.exe extracted from the installer. They do have a much older stable release. I don't like using GUIs, the command line has so much more options... Maybe gMKVExtractGUI will work... don't know, haven't tried it before...

An easier method may just be using LATEST!!!!! ffmpeg... it is updated daily...

and mux it into a MP4 then using the GPAC mp4box and remux it into a "better/fixed" MP4...

The method I presented earlier is rather complex, even I get so confused that I use a custom batch script....

DragonQ · 21st June 2014, 22:56

OK well I can't find any information about how to use mp4box to mux using timecodes. Any help?

Simply remuxing the MKV into an MP4 using ffmpeg and then remuxing that MP4 into another MP4 using mp4box doesn't help. Looks like I need the timecodes...

Simon88 · 21st June 2014, 23:08

latest ffmpeg, when convert from mkv to mp4 is suppose to preserve the timecodes... is the mkv file container broken or too old? you may need to "upgrade" the mkv container on your video file to the latest version, then convert using latest ffmpeg... it's trial and error sometimes, when dealing with uncooperative files

DragonQ · 21st June 2014, 23:09

I have the latest ffmpeg (updated yesterday before trying this stuff) and latest MKV Merge. I only made the MKV a few days ago.

ITV HD probably has a dodgy stream though. I know that MediaPortal reports continuity errors constantly when watching ITV HD (not for other channels) even though the video plays fine (50 fps, no dropped frames).

Simon88 · 21st June 2014, 23:16

I see... then you need something like TS-Doctor to fix the captured transport stream file first, before processing with ffmpeg or mkvtoolnix..

DragonQ · 21st June 2014, 23:18

Done that already, I always use TS-Doctor before muxing to MKV.

Simon88 · 21st June 2014, 23:19

OK.. then use mp4fpsmod to insert the timecodes back into the MP4 file, after extraction from MKV. Then your all set...

Simon88 · 21st June 2014, 23:23

The one I listed is just free & a bit buggy, you may wish to search the net for a more easier to use & a bit more polished timecode insertion utility... It was the 1st one I found that was open sourced and cheap...

DragonQ · 22nd June 2014, 00:29

OK using mp4fpsmod I can get a working MP4 with correct timestamps, woo! Unfortunately, Vegas Pro won't bloody open it, despite opening some other MP4 files with AVC fine.

Simon88 · 22nd June 2014, 01:02

perhaps Vegas Pro does not like the container codec ID used by gpac mp4box, so you just re-mux again using ffmpeg or libav and try using Vegas Pro... and remux back using mp4box if needed...

A pain, but may work...

DragonQ · 22nd June 2014, 01:09

If I remove the audio before muxing (don't need it anyway), Vegas Pro opens the file. However, in the preview window the timestamps are all messed up again, even though the MP4 plays fine in MPC-HC. It also says it's 125 fps despite clearly playing at 50 fps in the preview window.

Sigh.

Simon88 · 22nd June 2014, 01:34

Use "Fix bitstream timing information", I believe Mosu added that option not too long ago...

huokok · 22nd June 2014, 02:45

Barely know anything about Sony Vegas, does it accept Avisynth as input?
If you can use mpc-hc to palyback accurately, then there should be a suitable source to open the mkv you made and serve to Sony Vegas.

sef · 22nd June 2014, 06:06

Hi all.. I solved this issue with Sony Vegas Pro, using AVFS and Pismo File Mount..

Ghitulescu · 22nd June 2014, 09:04

I still do not understand the reason of converting MKV to MP4 ...

Vegas Pro accepts individual streams (assets), so a demux should be he only thing you need. Then place them on the timeline (slugs) as needed.

I know no device that records in MKV, but if there is an issue with the MKV, then the problem has to be searched on that device. Again TC/IVTC and NDF/DF are issues not present in raw/captured videos, only in edited ones.

DragonQ · 22nd June 2014, 09:51

Quote:

Originally Posted by Simon88

Use "Fix bitstream timing information", I believe Mosu added that option not too long ago...

I'm confused. How will that help me? I'd still need to demux the "fixed" MKV.

Quote:

Originally Posted by sef

Hi all.. I solved this issue with Sony Vegas Pro, using AVFS and Pismo File Mount..

I guess I'll look into this, thanks.

Quote:

Originally Posted by Ghitulescu

I still do not understand the reason of converting MKV to MP4 ...

Vegas Pro accepts individual streams (assets), so a demux should be he only thing you need. Then place them on the timeline (slugs) as needed.

The timestamps are screwed up when I simply import the H264 stream without a container, just like when using the MP4 file.

Simon88 · 22nd June 2014, 14:53

Quote:

Originally Posted by DragonQ

I'm confused. How will that help me? I'd still need to demux the "fixed" MKV.

The problem is you may handling variable bitrate files and if you take a look at the video w/ MediaInfo you will see alot of strange values... However those values will be carried over when you re-mux to MP4.... "Fix bitstream timing information" adjusts such info to match the container...

21st June 2014, 21:03	#1 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	Remux MKV to MP4 with correct timestamps? I'm trying to use a video editor that doesn't support MKV and it really struggles with TS files too (Sony Vegas Pro). It seems MP4 is the best input format for it, and it works for some files, but I'm not having any joy remuxing some 1080i/25 TV recordings (AVC/AC3 in an MKV) into working MP4s with correct timestamps. I'm using ffmpeg to remux and have tried a few different things (straight from MKV to MP4, from MKV to TS to MP4, MKV to elementary stream to MP4) but the resulting MP4 just doesn't play properly in MPC-HC, let alone within Vegas Pro (the frames jump around out-of-order). For example, using this input line: Code: ffmpeg -i "D:\input.mkv" -vcodec copy -acodec copy "D:\output.mp4" I get loads of warnings during the remuxing like this: Code: Non-monotonous DTS in output stream 0:0; previous: 3119681, current: 3119040; changing to 3119682. This may result in incorrect timestamps in the output file. Is it even possible to get a working MP4 from an MKV like this? Maybe there's another remuxer I could try or there's some ffmpeg options that will help? Thanks for any advice. __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7

21st June 2014, 22:07	#3 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	How do I extract timecodes? Also, I've tried MP4Box (via YAMB), it also produces a dodgy MP4 file like ffmpeg does. EDIT: OK I see I can use timecodes_v2 (don't see this option in MKV Extract GUI 2). Are there any GUIs that will let me make an MP4 using the timecode files? EDIT: Every time I download a Windows binary of MP4Box GPAC I get the error "installer integrity check has failed". __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7 Last edited by DragonQ; 21st June 2014 at 22:42.

21st June 2014, 22:56	#5 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	OK well I can't find any information about how to use mp4box to mux using timecodes. Any help? Simply remuxing the MKV into an MP4 using ffmpeg and then remuxing that MP4 into another MP4 using mp4box doesn't help. Looks like I need the timecodes... __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7 Last edited by DragonQ; 21st June 2014 at 23:01.

21st June 2014, 23:09	#7 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	I have the latest ffmpeg (updated yesterday before trying this stuff) and latest MKV Merge. I only made the MKV a few days ago. ITV HD probably has a dodgy stream though. I know that MediaPortal reports continuity errors constantly when watching ITV HD (not for other channels) even though the video plays fine (50 fps, no dropped frames). __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7 Last edited by DragonQ; 21st June 2014 at 23:12.

21st June 2014, 23:18	#9 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	Done that already, I always use TS-Doctor before muxing to MKV. __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7

21st June 2014, 22:01	#2 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	extract the video stream & audio stream & ttext (if applicable). Also extract timecodes if you notice sync issues (non-standard frame-rates). Then remux using mp4box (latest GPAC version).

21st June 2014, 22:54	#4 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	I only use the official, latest GPAC mp4box.exe extracted from the installer. They do have a much older stable release. I don't like using GUIs, the command line has so much more options... Maybe gMKVExtractGUI will work... don't know, haven't tried it before... An easier method may just be using LATEST!!!!! ffmpeg... it is updated daily... and mux it into a MP4 then using the GPAC mp4box and remux it into a "better/fixed" MP4... The method I presented earlier is rather complex, even I get so confused that I use a custom batch script....

21st June 2014, 23:08	#6 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	latest ffmpeg, when convert from mkv to mp4 is suppose to preserve the timecodes... is the mkv file container broken or too old? you may need to "upgrade" the mkv container on your video file to the latest version, then convert using latest ffmpeg... it's trial and error sometimes, when dealing with uncooperative files

21st June 2014, 23:16	#8 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	I see... then you need something like TS-Doctor to fix the captured transport stream file first, before processing with ffmpeg or mkvtoolnix..

21st June 2014, 23:19	#10 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	OK.. then use mp4fpsmod to insert the timecodes back into the MP4 file, after extraction from MKV. Then your all set...

21st June 2014, 23:23	#11 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	The one I listed is just free & a bit buggy, you may wish to search the net for a more easier to use & a bit more polished timecode insertion utility... It was the 1st one I found that was open sourced and cheap...

22nd June 2014, 00:29	#12 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	OK using mp4fpsmod I can get a working MP4 with correct timestamps, woo! Unfortunately, Vegas Pro won't bloody open it, despite opening some other MP4 files with AVC fine. __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7

22nd June 2014, 01:02	#13 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	perhaps Vegas Pro does not like the container codec ID used by gpac mp4box, so you just re-mux again using ffmpeg or libav and try using Vegas Pro... and remux back using mp4box if needed... A pain, but may work...

22nd June 2014, 01:09	#14 \| Link
DragonQ Registered User Join Date: Mar 2007 Posts: 934	If I remove the audio before muxing (don't need it anyway), Vegas Pro opens the file. However, in the preview window the timestamps are all messed up again, even though the MP4 plays fine in MPC-HC. It also says it's 125 fps despite clearly playing at 50 fps in the preview window. Sigh. __________________ TV Setup: LG OLED55B7V; Onkyo TX-NR515; ODroid N2+; CoreElec 9.2.7

22nd June 2014, 01:34	#15 \| Link
Simon88 Registered User Join Date: Jan 2012 Posts: 91	Use "Fix bitstream timing information", I believe Mosu added that option not too long ago...

22nd June 2014, 02:45	#16 \| Link
huokok Registered User Join Date: Feb 2014 Posts: 14	Barely know anything about Sony Vegas, does it accept Avisynth as input? If you can use mpc-hc to palyback accurately, then there should be a suitable source to open the mkv you made and serve to Sony Vegas.

22nd June 2014, 06:06	#17 \| Link
sef Registered User Join Date: Nov 2013 Location: Russia Posts: 61	Hi all.. I solved this issue with Sony Vegas Pro, using AVFS and Pismo File Mount.. Last edited by sef; 22nd June 2014 at 06:52.

22nd June 2014, 09:04	#18 \| Link
Ghitulescu Registered User Join Date: Mar 2009 Location: Germany Posts: 5,769	I still do not understand the reason of converting MKV to MP4 ... Vegas Pro accepts individual streams (assets), so a demux should be he only thing you need. Then place them on the timeline (slugs) as needed. I know no device that records in MKV, but if there is an issue with the MKV, then the problem has to be searched on that device. Again TC/IVTC and NDF/DF are issues not present in raw/captured videos, only in edited ones. __________________ Born in the USB (not USA)