[solved] DVB-T2 Recordings: Sometimes no Audio after muxing with mkvmerge (1 Viewer)

bta489

Portal Pro
March 17, 2013
163
83
Home Country
Germany Germany
Country flag
Hi there,

I have a strange problem with mkvmerge when processing some recordings from german DVB-T2.

So what's happening:
I record a show on my HTPC. I access the recordings from a different PC to Remux it to MKV, remove unwanted tracks and cut off the beginning and the end with mkvmerge. This usually works fine for me. However on some recordings the remuxed file will not play any audio or won't play at all (it stays on the start frame). The Raw recorded .ts-file plays without problems.

When I just remux a problematic file (keep all tracks, no edits whatsoever), the beginning will play fine up to the program announcements, when the sound cuts out, and the video continues silently. Sometimes the sound returns for the next program at the end of the recording. This appears to be limited to recordings from DasErste/ARD and related channels.

When comparing the MediaInfo of both files there are some differences in Bitrate and Codec-ID:
The Raw recording:
Code:
Audio #1
ID                          : 64 (0x40)
Menu ID                     : 137 (0x89)
Format                      : AAC LC
Format/Info                 : Advanced Audio Codec Low Complexity
Muxing mode                 : LATM
Codec ID                    : 17-2
Duration                    : 41 min 53 s
Bit rate mode               : Variable
Maximum bit rate            : 262 kb/s
Channel(s)                  : 6 channels
Channel layout              : C L R Ls Rs LFE
Sampling rate               : 48.0 kHz
Frame rate                  : 46.875 FPS (1024 SPF)
Compression mode            : Lossy
Delay relative to video     : -873 ms
Language                    : German

The edited MKV:
Code:
Audio
ID                          : 2
Format                      : AAC LC
Format/Info                 : Advanced Audio Codec Low Complexity
Codec ID                    : A_AAC-2
Duration                    : 25 min 56 s
Bit rate                    : 124 kb/s
Channel(s)                  : 6 channels
Channel layout              : C L R Ls Rs LFE
Sampling rate               : 48.0 kHz
Frame rate                  : 46.875 FPS (1024 SPF)
Compression mode            : Lossy
Delay relative to video     : 15 ms
Stream size                 : 23.0 MiB (5%)
Language                    : German
Default                     : Yes
Forced                      : No

Has anyone encountered a similar problem or even has a fix?
 

Paul Shirley

Portal Pro
November 3, 2008
68
3
Country flag
I have probably the same problem with UK Freeview HD. What's happening is the sound track changes format between stereo and 5.1 during the recording. Most tools detect the sound at the video start, not the cut point and throw away everything else.

You need to do a .ts to .ts cut at the point the sound track changes format before converting to any other format. I use H264TS_Cutter.exe, using the mouse scroll wheel to scrub through seems to get the position right more often. Sorry, you'll have to search for it.

If anyone has a better fix, I'll be a happy bunny to hear it.
 

bta489

Portal Pro
March 17, 2013
163
83
Home Country
Germany Germany
Country flag
That seems likely.

I tried the h264 ts cutter (found here) and it sort of works with HEVC/x265. The Preview has problems decoding the image, but if you know the area where to cut you can find a place. I had to change the settings (as a dialogbox suggested) to I-Frames as Cut-In-Points and All-Frames as Cut-Out-Points or else the program would crash.
The processed file however plays fine, and that is what counts. At least there is a way to process these problematic files.
 

Users who are viewing this thread

Similar threads

Can you take a look in Task Manager and let us know how much CPU usage you have when trying to play the vid. in MP and also the same when playing with VLC. Also what graphics do you use and/or does your CPU have integrated graphics?
Can you take a look in Task Manager and let us know how much CPU usage you have when trying to play the vid. in MP and also the...
For some unknown reason I can't play HEVC encoded video with MP1 on my system. I have tried every trick I know, but nothing works...
Replies
1
Views
112
Been testing and mostly solved by using Automatic - yet this morning the TV recording of BBC1 Andrew Marr went out of sync. Windows 7 worked lovely windows 10 on Intel NUC seems to have all sorts of issues (Mostly Windows 10 - MS deciding that it knows best and I got a update/reboot when I'd told it not too!)
Been testing and mostly solved by using Automatic - yet this morning the TV recording of BBC1 Andrew Marr went out of sync...
Have an issue with several AAC 2.0 files going out of sync Video plays fine, audio gets delayed. that is video is ahead of sound -...
Replies
2
Views
2K
Sorry you can't play my files. Basically they are broadcast as 3 x Mpeg-Audio 2.0 tracks (one track has left/right, one has center/LFE, and one has surround left/right). So the only way to get them to "usable" is to convert them...DTS-HDMA is the best choice since it keeps it "lossless". While it's still a transcode, it's a transcode...
Sorry you can't play my files. Basically they are broadcast as 3 x Mpeg-Audio 2.0 tracks (one track has left/right, one has...
I have some .TS files that wouldn't play in MediaPortal. The solution was to check the box in MediaPortal Configuration that says...
Replies
9
Views
2K
BTW, realized I never replied back on this one, in case anyone else runs into it. @Stéphane Lenclud Got me pointed in the right direction. My TV Has an option HD Deep Color Mode, turning this on or off will get the desired results.
BTW, realized I never replied back on this one, in case anyone else runs into it. @Stéphane Lenclud Got me pointed in the right...
Okay, I am having some issues. i will try and go to as much detail in text as I can but the attached short video shows what I am...
Replies
16
Views
3K
Dohhh!!! Looks like it, I downloaded them both at the same and guess I got them mixed up, thanks for your time btw if your using MEDIA BROWSER you need to create a custom profile for the dish hopper /slinks away
Dohhh!!! Looks like it, I downloaded them both at the same and guess I got them mixed up, thanks for your time btw if your using...
I have 318 movies identically encoded, after MANY experiments get my dish hopper dlna dialed in, and the result was mpeg2...
Replies
5
Views
2K
Top Bottom