The VideoLAN Forums

I'm creating this new topic for Android users.

I have a dedicated folder on my device called video library, in that folder I have more than 45 different karaoke files.
Over the last two releases I have noticed that playback is slower causing the music of the file to be out of tune by 0.5 in the first minute or so.
I have to speed up the player by 0.5 for everything to be back in tune this is especially when just a guitar or a piano is playing in the file. As a performer I took notice of this because I have a keyboard that stays in tune of course. When I start the file if I do not intervene it is out of tune with my piano by 0.5 but later after the file has been playing for a minute or so it corrects itself and everything sounds back in tune.

That would be a serious bug! Many musical ears would notice if VLC "corrected itself" one minute in by changing the pitch by one-half note! Does it start sharp and then go flat? or vice versa? What is the file type and what can you say about the encoding it uses?

Yes, I've noticed that issue too from time to time. What is your device make/model and file format being played?

If you have ffmpeg installed you can use 'ffprobe' to dump out the details.

I have a musical ear that can notice. I can also research frequencies (sound, physics) to figure out more about what is happening. But mainly I have a good ear. Please tell me if I can help you as a former engineer who has a good ear.

Update: the type files I use .MP4
The song is flat when it starts so I either have to not play along with my piano during the time it is flat or speed up the song by .5 so my piano does not sound flat.

As far as encoding? I really have no way of knowing that without a computer and software to analyze them.

Now, if encoding makes the difference, well the I'll just shut up at this point and wait till I get another computer lol

I play exclusively MP3 and have no such problem. MP4s carry video as well and would be more compute-intensive. You have one ex-engineer* engaged on the thread; if you could share your MP4, he might re-create and analyze the problem. My next question is whether the rise in pitch is instant or gradual. Also: Do you know that the pitch after the shift is the correct pitch?

*Actually, for our purposes, "Once an engineer, always an engineer"!

You can also get the information inside VLC. During video playback, hit "..." and go to "Video Information". You should see an overlay appear on top of the video. (It hides with the controls, so you may need to tap the screen once to get it to reappear).

Can you provide the details in both the video and audio sections?

Any chance the audio is in Opus format?

https://forum.videolan.org/viewtopic.php?f=35&t=155590
https://forum.videolan.org/viewtopic.php?f=35&t=156302