Welcome Guest ( Log In | Register )

WMA lossy to other lossy format - clear answer desperately needed
post Feb 4 2013, 20:58
Post #1

Group: Members
Posts: 1
Joined: 4-February 13
Member No.: 106414

I hope this post isn't redundant, wrongly categorized, or otherwise irritating, but I'm new to this forum today and I'm desperate: I've searched for this answer for weeks and the closest I get to an answer is an answer to the opposite question. We can't even figure out anyone to pay to get an answer to this question. I need a more-or-less black-and-white answer to the following question:

We have several hundred audio recordings of lectures (so all just spoken word), using a 5-year-old Olympus digital voice recorder (the kind of thing you buy in Staples or Best Buy) with a medium quality flat-mic. Unfortunately, the person doing these recordings used the WMA settings instead of MP3, because she had been convinced that WMA was a much better sound quality.

We have a giant archive (thousands more lectures) of these mission critical lecture recordings stored on a Mac Pro using iTunes -- they were all recorded in AAC or MP3 in the first place. We need to add the hundreds of WMAs to the collection (they are some of the most important recordings!) -- they are essential and we need to start adding them to the archive in the next week.

So here's what we need to do:

We need to convert the WMAs into some more universal format. We were planning on AAC (it's universal enough as far as we can see) if the quality and space savings was better; we'd also be happy with the more universal MP3 if we don't loose quality or space.

Here's the confusion and problem:

We want to avoid any significant quality loss. Every article on this subject of Lossy to Lossy transcoding talks about dropping the bit-rate or some other maneuver intended to decrease the file size. We don't care about that -- we are happy to keep it roughly the same size. We just don't want to DOUBLE the file size, which is what happens when we transcode from WMA lossy to some lossless files such as Apple Lossless. Storage is cheap, so we aren't willing to lose much quality to save space, but doubling the space on hundreds of tracks is a problem -- it is decimating our hard drive space and posing countless problems with mobile access strategies for our teaching team through services like iTunes Music Match etc.

The recordings are not exactly audiophile in the first place, but that's all the more reason it is important that they don't lose too much additional quality in the conversion. We have experienced how a casual little effort of "simple" lossy-to-lossy transcoding using some random program can produce a noticeably dramatic quality loss...We can't have hundreds of tracks going from a little difficult to listen to, to sounding like we're using wax cylinders. That would be the opposite exponential problem from filling our hardrives with double-sized lossless files, but even less desirable. And, for space and sanity reasons, we intend to delete the WMAs when we're done, so the transcoded files will become the master files.

So, here's the answer we're looking for:

What do we do to turn lossy WMA files into the AAC or MP3 files that are as close to the same quality as the WMAs as possible, while still remaining about the same file size or smaller, or at least not too much bigger? What software options are there, what settings are critical, etc.? (We would prefer to do it on Mac OS X 10.8, but we do have access to Windows 7 or 8 if necessary just for the conversion process, but would have to get another HDD formatted for Windows)

As I said, we need to do this soon, but need to do it properly from the start, or our mistake will multiply 100's of times. Thank you so much in advance for any help you can provide!
Go to the top of the page
+Quote Post
Start new topic
post Feb 4 2013, 21:06
Post #2

Group: Members
Posts: 173
Joined: 14-June 11
Member No.: 91517

If you don't want to lose quality, lossless is your only choice i'm affraid.
Although it's not what you want i would give LossyWAV a chance and encode the audio with FLAC. You can achieve very good quality this way without encoding the file again with a heavy weight perceptual coder (LossyWAV only adds shaped noise and because you mentioned that the Mic was not the best quality i think you'll not notice any difference in the audio quality). My estimated bitrate would be around ~192kbps with 44.1Khz Mono audio processed through LossyWAV and encoded with FLAC.

This post has been edited by darkbyte: Feb 4 2013, 21:09

WavPack -b4x4hc
Opus --cvbr --bitrate 256 --framesize 5
Go to the top of the page
+Quote Post

Posts in this topic

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:


RSS Lo-Fi Version Time is now: 29th November 2015 - 04:24