I’ve been recording MP4 videos audio off youtube then saving to WAV files. I must be stupid for not knowing this but accidentally dragged and dropped the MP4 file directly into Audacity instead of the player I record from. (MPC-HC)
Apparently I can just load it then save-as WAV to get the same results? To test, I recorded one to a separate track by playing it in to compare the results and see a difference between the two versions. Some volume change but I see different spots of clipping that don’t make sense? The lower volume track (MP4 top) has clips in other locations then the higher volume track (bottom recorded in)? I would think they would be in same locations just more of them in the bottom higher level track? Anyway, here’s a screen shot of the two tracks.
My question is which method of conversion should give the best result considering the decoding types used? After adjusting for volume, I can’t hear any difference but want the best quality file. I see that the MP4 is 32 bit floating and I normally save off as 16 bit “best quality” if that has any consideration. Thanks!
It’s a little weird that the “worse” one isn’t also clipped at the same spots as the “better” one. But… Lossy compression does change the data.
Since there is no “download” link on YouTube, the best you can do is to “capture” (record) with WASAPI loopback while playing directly from YouTube. (Copying/recording is a copyright violation and a violation of their policies.) You are stuck with the existing lossy YouTube compression but as long as there are no “glitches” you can accurately capture the decompressed audio stream as it plays.
Or if you have an audio/video file on your computer, open it directly without “re-recording”.
If you used a website or utility to copy from YouTube and there is no option for lossless audio, it’s likely going through another generation of lossy encoding.
I see that the MP4 is 32 bit floating and I normally save off as 16 bit “best quality” if that has any consideration.
Yes, MP3 & MP4 do use floating-point but they don’t save the individual samples so they don’t actually have a “bit depth”.
Both of these formats can go over 0dB without clipping so if the file is showing (potential) clipping you can reduce the level slightly before exporting to regular (integer) WAV. Of course, if the audio is actually clipped/distorted that’s not going to help.
I see now that I can just DL the audio direct from YouTube…(doh!)
Still not sure which format to use for best audio quality and will still need to convert in Audacity to WAV format as well as trim, etc. I did notice some musical details seemed better on the MP4 DL vs MP3 recording I posted.
Looks like I got more homework but thanks much for getting me on the right track! (pun intended!)
