Static noise when muxing

KISSMAD

Member
I went to mux 2 files in version 5.1.0.716 and the audio is only static noise.

Info on the files I'm trying to mux.

VIDEO
Format : MPEG Video
Format version : Version 2
File size : 72.4 MiB
Duration : 1mn 27s
Overall bit rate mode : Variable
Overall bit rate : 6 953 Kbps
Video
Format : MPEG Video
Format version : Version 2
Format profile : Main@Main
Format settings, BVOP : Yes
Format settings, Matrix : Default
Format settings, GOP : M=3, N=12
Format settings, picture struc : Frame
Duration : 1mn 27s
Bit rate mode : Variable
Bit rate : 6 953 Kbps
Maximum bit rate : 8 000 Kbps
Width : 720 pixels
Height : 576 pixels
Display aspect ratio : 16:9
Frame rate : 25.000 fps
Standard : PAL
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Compression mode : Lossy
Bits/(Pixel*Frame) : 0.671
Time code of first frame : 00:00:00:00
Stream size : 72.4 MiB (100%)


AUDIO
Complete name : Test.wav
Format : Wave
File size : 16.0 MiB
Duration : 1mn 27s
Overall bit rate mode : Constant
Overall bit rate : 1 536 Kbps
Audio
Format : PCM
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : 1
Duration : 1mn 27s
Bit rate mode : Constant
Bit rate : 1 536 Kbps
Channel(s) : 2 channels
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Stream size : 16.0 MiB (100%)
 

jmc

Active member
How did you get the PCM file?

I am testing DTS conversion in V5 and when I selected LPCM (mediainfo say PCM)
the specs were high - 4600Kbps, 6ch, 24 bit. BUT the sound was very bad. Lots of static.

(this test was creating Mpg files from H264.ts)

Selecting "Mpeg Layer2" had NO static but low specs. 64Kbps,2ch,

Leaving it on "Automatic" stripped out the audio.
----------------------------
EDIT...

MP4 conversions from H264.ts (PCM etc.) were fine. "Automatic" created AAC

V5 audio is a "work in progress".

jmc
 
Last edited:

Dan203

Senior Developer
Staff member
What format did you mux too? Sounds like an endianess issue. Can you upload the files for us so we can see what's going on in the debugger.

jmc - PCM audio in v5 is very different. In v4 all PCM was converted to 2ch big endian. In v5 we leave things alone when possible. Even though the spec of some formats may allow for multi-channel PCM or little endian some players may not handle them correctly, it's up to you to adjust the parameters to fit your needs. (I'll be adding an endianess option in the next version so you can set that manually too)
 

KISSMAD

Member
What format did you mux too? Sounds like an endianess issue. Can you upload the files for us so we can see what's going on in the debugger.
I muxed to MPG.
I tried to do it in v4 but it kept crashing v4.
I have uploaded the two files.
 

jmc

Active member
Dan203; jmc - PCM audio in v5 is very different. In v4 all PCM was converted to 2ch big endian. In v5 we leave things alone when possible. Even though the spec of some formats may allow for multi-channel PCM or little endian some players may not handle them correctly said:
What puzzled me is that I would have thought that the audio processing segment of VRD
would have been it's own separate independent box (so to speak. I am no programer).

And that going from DTS to PCM (or any other allowable combination)
would have no bearing on the container (Mpg or MP4 etc.- except what is allowable or not).
But...

MPG - PCM static
MP4 - PCM no static (all fine)

and the "Automatic" setting...

MPG - audio stripped out
MP4 - AAC (all fine)

thanks,
jmc
 

Dan203

Senior Developer
Staff member
It is it's own leg, but there are some rules based on the output container. In your example the MPG could have static for two reasons... could be the endianess or it could be the channels. By default we output all 6 channels even for PCM, so it could be that the player you're using doesn't like 6ch PCM. Try setting it to 2ch and see if that works. If it doesn't then it could be an endianess issue, which would be a bug I need to fix. MP4 files are the same way except that they allow either endianess, so we really need to know the results of the channel test to know the cause.

For "automatic" certain logic is applied. MP4 doesn't support DTS so it's converted to AAC. MPG does support DTS so it's retained, but there is currently a problem with our PS muxer and DTS audio. If you converted to MP2 it would probably work for MPG.

DTS is still a work in progress. At this point the only format I can guarantee proper output to is MKV. I think there are issues with both the PS and the TS muxers when outputting DTS audio, sorry.
 

KISSMAD

Member
I tried to mux the final project files to mpg but now I cannot mux the files at all.

I get the following error.

Output stream error: Error opening file.
 

jmc

Active member
It is it's own leg, but there are some rules based on the output container. In your example the MPG could have static for two reasons... could be the endianess or it could be the channels. By default we output all 6 channels even for PCM, so it could be that the player you're using doesn't like 6ch PCM. Try setting it to 2ch and see if that works. If it doesn't then it could be an endianess issue, which would be a bug I need to fix. MP4 files are the same way except that they allow either endianess, so we really need to know the results of the channel test to know the cause.

For "automatic" certain logic is applied. MP4 doesn't support DTS so it's converted to AAC. MPG does support DTS so it's retained, but there is currently a problem with our PS muxer and DTS audio. If you converted to MP2 it would probably work for MPG.

DTS is still a work in progress. At this point the only format I can guarantee proper output to is MKV. I think there are issues with both the PS and the TS muxers when outputting DTS audio, sorry.
Ok, Going from H264-DTS.ts to PCM.mpg

VLC-2.1.5 PCM 6ch - static with music ----- (MPClassic173 - No problem)
VLC-2.1.5 PCM 2ch - static only ------------- (MPClassic173 - No problem)

The MP2 does work for MPG.

Thanks,
jmc
 

Dan203

Senior Developer
Staff member
KISSMAD - your problem will be fixed in the next release.

jmc - your issue is that your DTS stream is 24bit and VLC doesn't seem to like 24bit PCM. We have a special dialog for setting profile options that's only available in the Pro version and it has a way to change the bit depth. When I used that to set my sample file to 16bit, and set it to 2ch, then VLC played it just fine. Unfortunately that option is not exposed via the consumer interface so there is no way for you to set it. :( You could use MKV instead, VLC seems to play 24bit 6ch PCM just fine from an MKV. If you really need to convert to PCM in an MPG file then I could expose the bit depth setting in the consumer UI, but I have to run the change by DanR first since it would require modification of the UI.
 

jmc

Active member
KISSMAD - your problem will be fixed in the next release.

jmc - your issue is that your DTS stream is 24bit and VLC doesn't seem to like 24bit PCM. We have a special dialog for setting profile options that's only available in the Pro version and it has a way to change the bit depth. When I used that to set my sample file to 16bit, and set it to 2ch, then VLC played it just fine. Unfortunately that option is not exposed via the consumer interface so there is no way for you to set it. :( You could use MKV instead, VLC seems to play 24bit 6ch PCM just fine from an MKV. If you really need to convert to PCM in an MPG file then I could expose the bit depth setting in the consumer UI, but I have to run the change by DanR first since it would require modification of the UI.
Thanks for the infomation, I don't have any need at this time for that adjustment. (more options are alway better tho!)
You never know when you will wish that option was available.

I was just running through a series of tests to just see what happens after reading KISSMAD's issue.
(I fiddle with DTS every now and then to see what may have changed.)

I did a lot of "trim and Copy" clipping trying to get V5 to catch the 2ch DTS audio in one video but it only
caught the 5.1 segment twice before I finally gave up. Most of the time the DTS channels came up 00.

(So finally I extracted 60sec of a 2ch 16bit DTS show and yep, VLC was happy with the PCM)

Ood bit...even then with the "trim and Copy" segments that did catch the 5.1 DTS channels and I had V5 produce a 6ch DTS.ts file
VLC would lockup! (MPC-no problem). VLC would play the original and step through all the 4 audio streams with no problem tho.

But then DTS is a "work in progress".

I use VLC to speed-watch video/podcasts I want info from.
But it is so flacky with the above issues and jerky camera panning compared to MPClassic(big difference).


Thanks, been a learning experience,
jmc
 

Dan203

Senior Developer
Staff member
I don't even think we're storing DTS in TS correctly. That's one of the things I need to look into.
 

Dan203

Senior Developer
Staff member
Is it a problem in v4? v4 handles PCM audio completely different so it's probably not an issue there.

In any case we're done releasing updates for v4, so this change will only be applied to v5.
 

Dan203

Senior Developer
Staff member
I can reproduce the crash in v4 release but it works fine in debug so I have no idea why it's crashing. It works OK in release if I save to MKV instead. IDK, like I said we've stopped development for v4 so it's not going to get fixed there. It should work fine in v5 as soon as DanR releases the next beta.
 

KISSMAD

Member
I can reproduce the crash in v4 release but it works fine in debug so I have no idea why it's crashing. It works OK in release if I save to MKV instead. IDK, like I said we've stopped development for v4 so it's not going to get fixed there. It should work fine in v5 as soon as DanR releases the next beta.
OK, no worries.
Thanks for letting me know.
 

phd

Super Moderator
Is this occurring with 1 file or all files?

Can Mediainfo display the properties?
 
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