Sound Shutter/lag in recorded File

[DerSani1988]

I just tried to record a livestream what worked very well. The file was written with "Written 232.2 MB (5m10s @ 739.7 KB/s)".

i noticed followin by playing the file with VLC:

• On the beginning of each record I have an 15 secon ad (this is fine for me)
• after closing the record or stream ending, i checked the files an every record on every stream has a shuttering sound
• I also noticed: the voice is much deeper then in real life or on livestream.
• also tried with ffmpg disabled

My Setup:

• Win 10
• Python 3.9
• streamlink
• ffmpg
• Recording to SSD
• 0% Usage of SSD while recording
• 20% Usage of CPU while recording

[cli][info] Found matching plugin twitch for URL twitch.tv/gronkh
[cli][info] Available streams: audio_only, 160p (worst), 360p, 480p, 720p, 720p60, 1080p60 (best)
[cli][info] Opening stream: 1080p60 (hls)
[download][..oy - FREiAB18   ff6.mp4] Written 368.1 MB (8m8s @ 738.5 KB/s)

Tried to fix with:
ffmpeg -err_detect ignore_err -i video.mkv -c copy video_fixed.mkv

this only fixed the lengh of the file and not the sound problem

1. I don't know why the bitrate is so low, I have a 1Gbps Download.
2. Why do the sound shutter/lag

Do anyone have an idea? I searched for hours and found nothing helpfull

[starvald]

i've been having similar problems, i always have ffmpeg disabled and noticed problem since ads were embedded.

1. sometimes the 13 second ad screen will just loop constantly and kodi/smplayer/vlc can't get passed it.
2. as you found running it through ffmpeg will alter the voices.

i did find a program to fix individual streams but its windows based and not free but it does work with wine.
TS-Doctor €34.9.
though a problem afterwards is i have to turn off adjust refresh rate in kodi or my TV will keep changing modes.
if someone finds a better way i would be interested in trying it.

[DerSani1988]

Okay I found the solution by try and error.

Just Change this line and i don't have any problem:

["streamlink", "--twitch-oauth-token", self.access_token, "twitch.tv/" + self.username,
 self.quality, "-o", recorded_filename])

you have to add following parameter:
--twitch-disable-ads

The line after adding this looks like:

["streamlink", "--twitch-disable-ads", "--twitch-oauth-token", self.access_token, "twitch.tv/" + self.username,
 self.quality, "-o", recorded_filename])

After this the file is no longer corrupted, the voice is not pitched and don't lag anymore

[starvald]

last time i tried that command it kept splitting the stream into separate files, have they fixed that?

[DerSani1988]

last time i tried that command it kept splitting the stream into separate files, have they fixed that?

This do the trick for me, no splitted files.
Maybe it will split the files, if twitch plays mid rolls.

[Stefomat]

I had the same issues as @DerSani1988 . His/Her solution worked for me as well (--twitch-disable-ads).
Does anybody know how to fix already recorded streams? TS-Doctor didn't really work for me. Maybe User error?

PS @DerSani1988 : Kam bisschen überraschend hier plötzlich FREiAB18 zu lesen. Bin wohl nicht der Einzige. :)

[mouarflenoob]

I'm also looking for a software to clean up my files. I can't use TS Doctor because it gives me an error.
Would the V.O.D. be fixable using ffmpeg?

[DerSani1988]

I had the same issues as @DerSani1988 . His/Her solution worked for me as well (--twitch-disable-ads).
Does anybody know how to fix already recorded streams? TS-Doctor didn't really work for me. Maybe User error?

Sadly I don't have "corrupted" files left to test.
What I mentioned is, that a cutting tool called LosslessCut have replayed the sound correct, So maybe it is worth to give it a try and reexport the file. Another solution may be to convert the file.
If you can send me a short file (5-10 Minutes) I can try some ways to restore the sound (You can cut out the segment with LosslessCut)

I'm also looking for a software to clean up my files. I can't use TS Doctor because it gives me an error.
Would the V.O.D. be fixable using ffmpeg?

As I mentioned above to @Stefomat

PS @DerSani1988 : Kam bisschen überraschend hier plötzlich FREiAB18 zu lesen. Bin wohl nicht der Einzige. :)

Hey, ja genau, seit der DMCA-Geschichte bei Twitch werden leider keine VODs gespeichert und somit fehlt mir das Ritual am Wochenende den nicht gesehenen Part (gerade die Talks) nachzuschauen ^^

[mouarflenoob]

@DerSani1988

If you can send me a short file (5-10 Minutes) I can try some ways to restore the sound (You can cut out the segment with LosslessCut)

Here is a link to a 5 minute clip of distorded voice : https://mab.to/eOEMqODpx (230 MB)
In VNC it stutters every other second. In LosslessCut it doesn't stutter, but the voice is still distorded in the preview. I have no clue as to what to do in LosslessCut to fix the voice. I will be trying things, but you may find the solution very much quickier than me ^^.

[DerSani1988]

Here is a link to a 5 minute clip of distorded voice : https://mab.to/eOEMqODpx (230 MB)
In VNC it stutters every other second. In LosslessCut it doesn't stutter, but the voice is still distorded in the preview. I have no clue as to what to do in LosslessCut to fix the voice. I will be trying things, but you may find the solution very much quickier than me ^^.

Do you have a short clip of the accurate voice so i can test the pitching of the voice.

[Stefomat]

@DerSani1988
Finally i had the time to upload my samples.

First file:
Cut out with LosslessCut, voice distorded in VLC, MPC-HC and LosslessCut Preview
https://www.dropbox.com/s/1cog9iab4sc88vf/gronkh%20-%202020-11-01%2019h18m22s%20-%20%20Heute%20ab%2019%20Uhr%20wieder%20HUNDE%20BEOBACHTEN%20%20ff6-01.41.19.888-01.51.22.057.mp4?dl=0

Second file:
A complete recording, but starting in the middle of the stream (internet went down, it continued recording to a new file).
You can see the 15 second ad section in the beginning.
https://www.dropbox.com/s/s86g6qa3m8j5eyq/gronkh%20-%202020-11-07%2002h26m03s%20-%20Freitag%201830%20Uhr%20FREiAB18%20%20Assassins%20Creed%20Valhalla%2020%20Uhr%20%20ff6.mp4?dl=0

I guess for this streamer you don't need a known good example of his voice? ^^
Thanks.

[mouarflenoob]

Here is the public VOD from which it came I think : https://www.twitch.tv/videos/805889919

[ancalentari]

I was very busy lately and I come back to twitch ads messing up things...

Well I merged the pull request with the --twitch-disable-ads parameter.

As for the "voice is much deeper" issue, unfortunately I will not be able to look into it right now since I am very busy still but might be a matter of adjusting/adding parameters to the processing of the recorded file maybe? Or is it deeper before file is processed?

[starvald]

deeper after ffmpeg processing.

[DerSani1988]

I was very busy lately and I come back to twitch ads messing up things...

Well I merged the pull request with the --twitch-disable-ads parameter.

As for the "voice is much deeper" issue, unfortunately I will not be able to look into it right now since I am still very busy still but might be a matter of adjusting/adding parameters to the processing of the recorded file maybe? Or is it deeper before file is processed?

I didn't check before processing. But this idea is worth to look into it.

I've tested:

• reencode with ffmpeg
• reencode with other tools
• change video speed

All the same result:

• Voice still laggy (in VLC)
• Voice much deeper

I had no time to look into it deeper but I'll try some things.

[Stefomat]

For me it didn't matter if ffmpeg processing was enabled or disabled (--disable-ffmpeg),
it always gave me the same distorded results.
Using the option "--twitch-disable-ads" solved all related problems - stuttering, deep voice, crashing VLC.

Small detail i just remember: VLC always crashes at the exact moment the ad countdown (see my uploads) is over and the normal video starts.

[DerSani1988]

For me it didn't matter if ffmpeg processing was enabled or disabled (--disable-ffmpeg),
it always gave me the same distorded results.

I can confirm this

Using the option "--twitch-disable-ads" solved all related problems - stuttering, deep voice, crashing VLC.

Correct but I assume that more people are still looking for a fix for previously recorded files

Small detail i just remember: VLC always crashes at the exact moment the ad countdown (see my uploads) is over and the normal video starts.

Only sometimes for me

[H-B-Schmidt]

I can fix previous recorded files when reencoding with handbrake.

[DerSani1988]

I can fix previous recorded files when reencoding with handbrake.

Yes partially, I tried this and this will fix the sound lags but not the deeper pitched voice

[H-B-Schmidt]

I can fix previous recorded files when reencoding with handbrake.

Yes partially, I tried this and this will fix the sound lags but not the deeper pitched voice

I can't detect any deeper pitched voice. Perhaps the difference is small and my ears are too old.

[DerSani1988]

I can fix previous recorded files when reencoding with handbrake.

Yes partially, I tried this and this will fix the sound lags but not the deeper pitched voice

I can't detect any deeper pitched voice. Perhaps the difference is small and my ears are too old.

Maybe @Stefomat can make 2 examples so you can compare the voice. I am not on my computer today so I can't.

[Stefomat]

I sure can.

You can use the links i posted a couple of days ago. Both have the problem with the deep voice.

First file:
Cut out with LosslessCut, voice distorded in VLC, MPC-HC and LosslessCut Preview
https://www.dropbox.com/s/1cog9iab4sc88vf/gronkh%20-%202020-11-01%2019h18m22s%20-%20%20Heute%20ab%2019%20Uhr%20wieder%20HUNDE%20BEOBACHTEN%20%20ff6-01.41.19.888-01.51.22.057.mp4?dl=0

Second file:
A complete recording, but starting in the middle of the stream (internet went down, it continued recording to a new file).
You can see the 15 second ad section in the beginning.
https://www.dropbox.com/s/s86g6qa3m8j5eyq/gronkh%20-%202020-11-07%2002h26m03s%20-%20Freitag%201830%20Uhr%20FREiAB18%20%20Assassins%20Creed%20Valhalla%2020%20Uhr%20%20ff6.mp4?dl=0

For comparison you can listen to the official VODs from Twitch:
https://www.twitch.tv/gronkh/videos?filter=archives&sort=time

If you need more examples or information, just get in touch.