A little confused about re-encoding digital audio from a video.

[20kHz]

Hello fellow audiophiles, I'm new here and hope to become an active and productive member of your community. The reason I'm making this thread today is because I'm a little puzzled about how to re-encode lossy digital audio properly. I'm fully aware that this is a lost cause, but I want to do it anyway, so hear me out.

Here's the skinny. I've downloaded a video of a live concert in .FLV format from a video sharing site. I want to strip the video, but keep the audio and "un-muddy" it as well. I have two options right now. I can find out the sample rate/bit depth of the audio in the video and re-encode it using those same settings, or I can just "up-convert" the audio, if you will.

My question is, which method is more practical? I'm weary of using the same settings used to encode the audio in the first place because I remember many times when I've given someone a burnt CD that sounded great, but by the time everyone had a copy, it sounded bad because people kept converting their burned copy into lossier audio each time a copy was passed along. I also don't want to waste too much HD space on audio that can't be made to sound better by taking more "snapshots". Thank you for taking the time to read this, I hope some of you can share some insight into this perplexing problem for me.

 

[Boerd]

Hello fellow audiophiles, I'm new here and hope to become an active and productive member of your community. The reason I'm making this thread today is because I'm a little puzzled about how to re-encode lossy digital audio properly. I'm fully aware that this is a lost cause, but I want to do it anyway, so hear me out.

Here's the skinny. I've downloaded a video of a live concert in .FLV format from a video sharing site. I want to strip the video, but keep the audio and "un-muddy" it as well. I have two options right now. I can find out the sample rate/bit depth of the audio in the video and re-encode it using those same settings, or I can just "up-convert" the audio, if you will.

My question is, which method is more practical? I'm weary of using the same settings used to encode the audio in the first place because I remember many times when I've given someone a burnt CD that sounded great, but by the time everyone had a copy, it sounded bad because people kept converting their burned copy into lossier audio each time a copy was passed along. I also don't want to waste too much HD space on audio that can't be made to sound better by taking more "snapshots". Thank you for taking the time to read this, I hope some of you can share some insight into this perplexing problem for me.

I would keep the bitrate and freq of the original - lossless encoding.
Let the DAC or AV processor do any upconversion - don't waste space on the hard disk.
My 2c.
Upconversion doesn't improve the recording (per say) it is creating bits from the existing ones using a lot of Math. The point of upsampling is the improved SNR and THD of the DAC's while using better bit depth/higher sampling freq.
So again - let the DAC/Processor deal with it.

To modify (un-muddy) the PCM - you need a tool (software) for that.

 

[bandphan]

Audio editing software like Adobe Audition will allow for what your looking to do(as will many others) but are not cheap to purchase and will have a slight learning curve.

 

[20kHz]

I would keep the bitrate and freq of the original - lossless encoding.
Let the DAC or AV processor do any upconversion - don't waste space on the hard disk.
My 2c.
Upconversion doesn't improve the recording (per say) it is creating bits from the existing ones using a lot of Math. The point of upsampling is the improved SNR and THD of the DAC's while using better bit depth/higher sampling freq.
So again - let the DAC/Processor deal with it.

Thank you very much for clearing that up for me. I'll do just that.

 

[20kHz]

Audio editing software like Adobe Audition will allow for what your looking to do(as will many others) but are not cheap to purchase and will have a slight learning curve.

I've played with Audition before at a friend's house and it does seem very daunting. I currently use Sony Sound Forge Pro 10 as my main audio editor and was planning on just using the Graphic EQ plugin a bit to un-muddy the sound. Does audition offer any specific plugins or tools that would make it easier for me to accomplish this?

 

[Boerd]

Thank you very much for clearing that up for me. I'll do just that.

Now - if you want to un-muddy the sound (IF the recording is bad) you need software to try fix that as bandphan said in the above post.
But that is a whole different story and it is not always doable. For example once something was compressed for the loudness's sake it's hard to get back the dinamics (attack, etc) and so on ...

 

[BoredSysAdmin]

Lossless Extracting of audio from flv's is possible, but since most likely the encoding to flv audio was lossy and most likely mediocre (useless for anything, but maybe phone ringtones) no matter what you do - the result will still be mediocre.
If you want to listen to quality recording - buy the cd/dvd - then you have the source - you could do lossless or high quality lossy compression to save the space on mobile devices for example...

However there are free tools to help you try to do what you want:
http://www.inspiredgeek.com/2008/03/16/extract-audio-from-flv-files-without-quality-degradation/

Open source audio editor:
http://audacity.sourceforge.net/ - It support wide range of plugins:
http://www.dmoz.org/Computers/Multimedia/Music_and_Audio/Software/Plug-ins/ and much more....

 

[Boerd]

I've played with Audition before at a friend's house and it does seem very daunting. I currently use Sony Sound Forge Pro 10 as my main audio editor and was planning on just using the Graphic EQ plugin a bit to un-muddy the sound. Does audition offer any specific plugins or tools that would make it easier for me to accomplish this?

You'll need to read (educate ) quite a bit to use pro audio software ... That is out of my league - haha... That is an (audio) engineering job.

 

[Boerd]

Lossless Extracting of audio from flv's is possible, but since most likely the encoding to flv audio was lossy and most likely mediocre (useless for anything, but maybe phone ringtones) no matter what you do - the result will still be mediocre.
If you want to listed to quality recording - buy the cd/dvd
...

Agreed 100%
When I said lossless I meant "don't throw away anything that is there, whatever is there".

 

[20kHz]

Now - if you want to un-muddy the sound (IF the recording is bad) you need software to try fix that as bandphan said in the above post.
But that is a whole different story and it is not always doable. For example once something was compressed for the loudness's sake it's hard to get back the dinamics (attack, etc) and so on ...

Yeah it's going to be very tough, haha. It's actually a video of a DJ set, so I'm going to have to play around with each song individually and maybe break the whole set down into gapless tracks.

 

[20kHz]

Lossless Extracting of audio from flv's is possible, but since most likely the encoding to flv audio was lossy and most likely mediocre (useless for anything, but maybe phone ringtones) no matter what you do - the result will still be mediocre.
If you want to listed to quality recording - buy the cd/dvd - then you have the source - you could do lossless or high quality lossy compression to save the space on mobile devices for example...

However there are free tools to help you try to do what you want:

Open source audio editor:
- It support wide range of plugins:
and much more....

I agree with your sentiments about the audio from the lossy rip, but it's the best I can do right now since I can't get in contact with the uploader to get the source video.

Thank you for the link to the FLV audio extractor, I was wondering what I should use in order to extract it since many video editors don't support the .FLV format.

Edit: Links removed because I can't post URLs or Images I think.

 

[bandphan]

I believe that there is a plugin for .flv for soundforge But Im not sure of the correct one. Adobe is easier due to the nature of .flv. The only way to tell if remastering is fruitful, is to rip the audio and examine it