Encoded videos start at -0.007000

[Sonic Angel Knight]

It's something I been noticing with the videos I encode. It's bugging me too. I also notice the every time these videos start, it has a loud cracking noise just as it starts to play. But it plays fine. I just curious if the sound issues is related to this starting time stamp which is weird to exist.

 

[tech3475]

What encoder do you use? Have you tried a different one or another version?

 

[Sonic Angel Knight]

I use ffmpeg, the latest version for windows. I have not tried other encoders, not sure what others to pick since most seem to be using some form of ffmpeg anyway.

 

[Tom Bombadildo]

Post the full command you're running, can't really help without knowing exactly what it is you're putting into ffmpeg.

But generally, no, that's not what would be causing the clipping sound, that timestamp is usually how ffmpeg processes start times.

 

[tech3475]

In regards to the audio, I’d try opening the audio stream in something like audacity to see if that’s the issue.

 

[Sonic Angel Knight]

In regards to the audio, I’d try opening the audio stream in something like audacity to see if that’s the issue.

Audacity doesn't have this issue. I tried both files before and after encoding and audacity doesn't have the issue with either. Only when is being played through a video player after encoding with ffmpeg does the sound happen. I tried in vlc player, MPC HC, even web browser.

Post the full command you're running, can't really help without knowing exactly what it is you're putting into ffmpeg.

If you want to know how I encoded it I used this

ffmpeg -i input.avi -pix_fmt yuv420p out.webm

ffprobe -i out.webm

The second line is how I got the status of the encoded file that is in the image.

 

[The Real Jdbye]

I use ffmpeg, the latest version for windows. I have not tried other encoders, not sure what others to pick since most seem to be using some form of ffmpeg anyway.

x264

 

[Tom Bombadildo]

Audacity doesn't have this issue. I tried both files before and after encoding and audacity doesn't have the issue with either. Only when is being played through a video player after encoding with ffmpeg does the sound happen. I tried in vlc player, MPC HC, even web browser.


If you want to know how I encoded it I used this

ffmpeg -i input.avi -pix_fmt yuv420p out.webm

ffprobe -i out.webm

The second line is how I got the status of the encoded file that is in the image.

What audio format does the input file use?

 

[Sonic Angel Knight]

What audio format does the input file use?

It's raw pcm

 

[Sonic Angel Knight]

After complete accident, I found out how to avoid that "-0.007000" problem. It seems to happen when you set the output file to webm extension. So to avoid it, it's possible to simply use mkv extension. Not a huge problem, but I think is just a ffmpeg issue or oversight. Maybe it will get fixed if word spread. I still have no idea why it causes the problem though. Guess is better anyway since using mkv means more flexible audio codecs including lossless ones.

I originally thought it might been that I wasn't using a 2-pass feature, since it is recommended for vp9 encodes. After actually managing to set up a two pass and using it, it didn't solve the issue. But I guess it doesn't matter anymore.

I also had another question, when I encode videos, should I be using yuv420p or yuv444p? The guide for ffmpeg says that yuv420p is moe compatible, but yuv444p looks better. Especially when I record videos from emulators which always seem to use rgb24. The conversion from rgb to 420 looks bad, but 444 looks nearly identical. It also has lower file size in 444p compared to rgb.