Converting lossy to lossless...

ok so I have a video file I want to get the audio from. Am I better converting from mp4 to mp3 or mp4 to FLAC. Yes FLAC would still be lossy but as I understand I won't lose any data during the conversion process as I would if I converted lossy to lossy (mp4 to mp3). So for archival and listening purposes am I better going for FLAC or is the quality different after the transfer going to be negligible?

 

There will be zero improvement in the quality. There will merely be a large increase in the file size.

 

But MP4 to FLAC will keep whatever audio quality is there, so that is best. Lossy MP4 converted to lossy MP3 will add even more compression artifacts, which you may or may not hear.

 

Optimally do not convert at all.

MP4 is a video container - the audio itself may be MP3 or AC3. Or possibly something else. You could rip the audio out with no re-encoding and just leave it as is.

 

The ideal way would be to extract (demux) the audio without any conversion or changes.

 

How do I do that?

 

What @Ham Sandwich suggested - use a demuxer tool.

One freebie / donateware app I know of is tsMuxeR (Windows).

 

Agree with the demuxing. Mpeg4 audio is often higher bitrate than mp3....higher sampling rate, too. But if this is for YouTube audio extraction using an online application, I don't think there's much difference either way....the online extractors seem to do a pretty good job of keeping what little is there.

 

AVADemux.

1. Load the video file.
2. Optional: Set the A & B positions if you want only a portion of the audio track.
3. From the side panel, Audio section, choose copy to save the original audio stream with no loss in quality. Choose the audio codec you want to use e.g. MP3, Vorbis, WAV, AAC, if you with to re-encode.
   
4. Configure the options for your audio codec using the Configure button if you are re-encoding
   
5. Go the menu: Audio → Save.
6. Save the audio file. Name it something like "bleah.aac" if the original audio stream is AAC. That will be the raw audio without a container.

MP4 is a container that can contain both audio and video of differing formats. If it has just audio, Apple renames the extension to m4a.

 

Think YT is still 192 max (not sure), but if he's DL'ing from them who knows what the original up loader may have used.