test audio file

jriker1 · 24th October 2023, 16:14

Probably a pointless question but thought I'd try. I have a process to date where I will re-encode a video and leave the audio intact as is. Audio could be DTS, Dolby Atmos, TrueHD, or whatever. My process to date has included running the final result thru a player of some sort, say Shield TV and making sure the voices are in sync and the video plays thru completely.

That has worked for me up until recently. Finding I occasionally get a corrupt audio file where it seems to play fine, and if you jump around it's fine, but if you play it from start to finish there may be like a brief dead spot in the audio and then the voices are out of sync. If you stop and start the video again then it's fine. Something in those "hiccups" causes sync issues. That said, rather than having to watch every video from start to finish, any thoughts on how to scan the audio files for any issues thru some kind of automated check?

von Suppé · 24th October 2023, 16:45

Quote:

Originally Posted by jriker1

...I have a process to date where I will re-encode a video and leave the audio intact as is. Audio could be DTS, Dolby Atmos, TrueHD, or whatever...

...I occasionally get a corrupt audio file where it seems to play fine, and if you jump around it's fine, but if you play it from start to finish there may be like a brief dead spot in the audio and then the voices are out of sync.

Are these audio-issues already with your sourcefiles or after you've recoded video? And particularly, do they perhaps concern Dolby Vision mkv's?

jriker1 · 24th October 2023, 18:57

Quote:

Originally Posted by von Suppé

Are these audio-issues already with your sourcefiles or after you've recoded video? And particularly, do they perhaps concern Dolby Vision mkv's?

Honestly didn't play the original source thru from start to finish so not sure if the source had the issue. Kind of purged it since then. I do not touch the physical file though if that matters just extract it. Are you asking if the source is an MKV with a video that has DolbyVision metadata?

von Suppé · 31st October 2023, 19:06

Quote:

Originally Posted by jriker1

Honestly didn't play the original source thru from start to finish so not sure if the source had the issue.

Well, to make sure not going for ghost-hunting, I would first check if the source suffers from the same issue the recode does.

Quote:

Originally Posted by jriker1

Are you asking if the source is an MKV with a video that has DolbyVision metadata?

Note that next to "basic" video, Dolby Vision can also carry extra "enhancement" video.
But indeed it always carries metadata. So, as answer to your question: yes.

j7n · 18th November 2023, 06:00

Quote:

Originally Posted by jriker1

any thoughts on how to scan the audio files for any issues thru some kind of automated check?

You can try decoding DTS, THD and DTSHD through eac3to and watch for error reports. Not all errors will be displayed.

Try verifying integrity of AC-3 using Foobar 1.x with the foo_ac3 plugin. It may stop decoding early or resync and report a length mismatch. You don't get the position of the error. It does not work with foobar 2.x without a plugin. Even though the format has 2 checksums, nothing reports frame errors.

I have no solutions for EC-3.

24th October 2023, 16:14	#1 \| Link
jriker1 Registered User Join Date: Dec 2003 Posts: 485	test audio file Probably a pointless question but thought I'd try. I have a process to date where I will re-encode a video and leave the audio intact as is. Audio could be DTS, Dolby Atmos, TrueHD, or whatever. My process to date has included running the final result thru a player of some sort, say Shield TV and making sure the voices are in sync and the video plays thru completely. That has worked for me up until recently. Finding I occasionally get a corrupt audio file where it seems to play fine, and if you jump around it's fine, but if you play it from start to finish there may be like a brief dead spot in the audio and then the voices are out of sync. If you stop and start the video again then it's fine. Something in those "hiccups" causes sync issues. That said, rather than having to watch every video from start to finish, any thoughts on how to scan the audio files for any issues thru some kind of automated check?