[oniisaki]

Hey, i'm relatively new to audio and want to convert or rip music videos

I'm stingy when it comes to loss of audio quality

I've read that converting one lossy audio format(e.g mp3) to another lossy format(e.g acc) will result in loss of audio quality, since they discard bits during the conversion.

My question is what happens if i convert a music video with mp3 audio, to another video format with the mp3 audio and same audio kbps as original (and all the audio settings the same as original)

Would the video converter do something like this?
Decode audio>uncompress it > encode audio(i think this is where more bits gets lost) > compress it

Or that just applies from converting 1 audio format/codec to another different one?

Would it just take the audio untouched and stick it with the new video, so no audio quality is lost?

 

[chewy4]

As far as just a plain old mp3 file, I can do some testing on that later tonight. There probably won't be a major difference in quality but there likely could be a slight degredation. It could depend on bitrate as well.
 
I can't say I know enough about video audio to say how it handles this though. Maybe the audio is already decompressed in it, which in that case it wouldn't matter... It would help if you specified which video formats you were using.

 

[StratocasterMan]

I noticed this other thread which may or may not be helpful:
 
http://www.head-fi.org/t/590285/question-about-audio-quality-on-youtube
 
I'm guessing your question may be related to YouTube videos, but maybe it isn't...
 
On YouTube, the audio quality is changed according to the video quality. Be sure to click that link in post #5 if your question is related to YouTube videos...
 
I know I'm not answering your question completely. I'm just trying to help with some extra information...

 

[oniisaki]

As far as just a plain old mp3 file, I can do some testing on that later tonight. There probably won't be a major difference in quality but there likely could be a slight degredation. It could depend on bitrate as well. I can't say I know enough about video audio to say how it handles this though. Maybe the audio is already decompressed in it, which in that case it wouldn't matter... It would help if you specified which video formats you were using.

No specific video format i have in mind, but i suppose generally use flv and mp4, occasionally avi and mkv.

Also it'll be great if you could test it.

I noticed this other thread which may or may not be helpful: http://www.head-fi.org/t/590285/question-about-audio-quality-on-youtube I'm guessing your question may be related to YouTube videos, but maybe it isn't... On YouTube, the audio quality is changed according to the video quality. Be sure to click that link in post #5 if your question is related to YouTube videos... I know I'm not answering your question completely. I'm just trying to help with some extra information...

Thanks for the link, nice topic to read. Its similar to my question, and yea i suppose my situation is after downloading youtube videos or other video sites in highest quality then converting it for compatibility, video editing, or storage reason or another.

I'll keep the original downloaded video files if i know more video conversions(with same audio settings on new video) will hurt its audio quality, and toss it for more space otherwise.

In that thread i'm not sure if the answers was referring only to converting from an audio format to a different audio format or not, and its video to audio.

In my situation its not downloading from stream, and its video to video, and audio settings (kbps, bit depth, sampling rate, etc) would be the same as original source so things may or may not be different

 

[chewy4]

Alright so I did a little testing on compressed audio files...
 
I converted a wav file to 320kbps mp3. Then back to wav. Then back to mp3. Repeated this about 10-15 times. No audible differences, no harm done.
 
I tried the same thing except with 128kbps instead of 320kbps. The file became a distorted mess.
 
Then I tried testing the effects of transcoding at high bitrates. I converted from 320kbps to 320kbps aac about 10-15 times. To my surprise, no audible effects.
 
So in the end it's going to depend on the format you're using and the rate of compression it's using.

 

[Organgica]

Depends on the quality of original audio file.
 
I use AppGeeker, converts everything into everything. customizable file size or quality.