Video downloader always failed to merge video and audio data

[tianluyao795]

Hi there,

I was previously running Slimjet 38.0.6.0 primarily for its built-in video downloader since it allows me to download any public YouTube video in just one click. However, a day or two ago I noticed that whenever I click on the Download Video button and select Convert to MP4 the separate audio and video data are still downloaded, but as soon as they complete downloading Slimjet immediately shows a pop up saying "Failed to merge video and audio data" and it deletes both instantly. Aside from this unexpected result, one behavior that I noticed became weird was before when the video download and convert function was working correctly, when video and audio data are being downloaded their sizes have already been calculated as soon as the download starts so you can see exactly how much you have downloaded in percentage, whereas now when video and audio data are being downloaded, there's no showing of the full sizes, instead the progress bar just scrolls indefinitely while data sizes keeps growing until it reaches a point where the browser throws the aforementioned error and deletes both data.

I have suspected it might be a version issue so I installed the latest 39.0.4.0 version and tried again, but the same thing happened again. I haven't changed anything regarding transcoders or decoders so I have no idea what went wrong.

I'm using Windows 10 64bit as my operating system.

Any help will be greatly appreciated.

[AllanHigdon]

I don't ordinarily download from YouTube with the Slimjet feature.
I tried it with Slimjet 39.0.5.0 and also saw the message "Failed to merge video and audio data".
Just wanted to confirm the problem.

[Mr_Electro84]

Confirmed on my side !

Report the bug to the developer : https://www.slimjet.com/en/onlinefb.htm

[tianluyao795]

Latest update:

I also tried it on my Linux machine with version 39.0.3.0 and this issue also exists.

I have reported it through their official form using link provided by Mr_Electro84.

[donaldduck]

Same here. W10 64 bits. I can no longer download Youtube. Problem started a few days ago and was the same on v.38 and now the latest 39.0.5 version.

[Papabear502]

Yep. Problem confirmed on my machine as well.

[amcsthrasher]

Same problem here, Failed to merge video and audio data! Windows 11 64 Bit clean install

[Papabear502]

I think Youtube may have changed their algorithms. Many of the Youtube video download extensions are no longer working as well when they worked fine up until about 4-5 days ago. So I don't think the Slimjet program is to blame. I think we can chalk this up to Youtube/Google making life difficult for users like us, again!

[amcsthrasher]

Now, that is a good answer. Thank you

[tianluyao795]

I think Youtube may have changed their algorithms. Many of the Youtube video download extensions are no longer working as well when they worked fine up until about 4-5 days ago. So I don't think the Slimjet program is to blame. I think we can chalk this up to Youtube/Google making life difficult for users like us, again!

That's definitely possible and likely considering this feature was working just fine and all of the sudden it became broken without any modification on Slimjet side. However, I have tried 4K Video Downloader (with premium subscription) and it still can download YouTube videos just fine. The only annoyance is that videos in 4K resolution is only available in MKV format and I have to use another tool to convert them to MP4 after downloading them. I am really curious whether they are using a more versatile approach because of their service is paid instead of free like Slimjet.
Also what's weird is that Slimjet only fails at merge time, not download time. So looks like Slimjet is still able to capture separate video and audio data from YouTube but maybe they changed how those data are encoded and that caused Slimjet to unable merge video and audio data with previous decoder that was compatible with YouTube.