Keeping 128-level quality

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Keeping 128-level quality

2022-12-24 06:19:59

This is not my first time posting on here, but let's just say it's been a while.

I have a slew of lossily compressed, non-mp3 files on my device that I want to transcode to MP3. I have read that transcoding between lossy formats, but my car device only accepts MP3. Some of the files I have are from games, some are from ripped CDs, a variety of different sources. Because of this, some of them are .aac, others .m4a, .ogg, .opus, and perhaps even others. What they all have in common is the bitrate, 128 kbps.

My sole question: If I transcode these files to 320 kbps (Or even V0) MP3, will the resulting files still manage to sound as good or better than if they were originally 128 MP3s to start with?

I just want to make sure they will sound at least as good as 128 kbps .mp3 files.

Thanks!

Re: Keeping 128-level quality

Reply #1 – 2022-12-24 08:15:29

Every time you save something with a lossy codec, the whole file gets reencoded. This means that you always lose quality.
When using a very high bitrate like 320kbps you will not hear a quality loss, but it is there.

Re: Keeping 128-level quality

Reply #2 – 2022-12-24 10:47:35

For in-car use, I'd be surprised if V0 isn't a giant overkill.
But hey, those files are disposable, right? You aren't going to delete the originals?
* If it sounds bad, then throw them away and transcode over again at a higher bitrate.
* If you need more space, then throw them away and transcode over again at a lower bitrate.

Re: Keeping 128-level quality

Reply #3 – 2022-12-24 17:04:51

Quote from: Mark7 on 2022-12-24 08:15:29

When using a very high bitrate like 320kbps you will not hear a quality loss, but it is there.

So you're saying that 320 kbps transcodes should, in practice, sound as good or better than .MP3's at 128 kbps? Keeping in mind my original files are all 128 kbps files of different sorts, which are known to produce better sound quality than MP3 at said bitrate. As long as they still sound better than an MP3 would sound at 128, I'm happy.

Re: Keeping 128-level quality

Reply #4 – 2022-12-24 22:47:06

Quote from: TerminalReality on 2022-12-24 17:04:51

Quote from: Mark7 on 2022-12-24 08:15:29
When using a very high bitrate like 320kbps you will not hear a quality loss, but it is there.

So you're saying that 320 kbps transcodes should, in practice, sound as good or better than .MP3's at 128 kbps? Keeping in mind my original files are all 128 kbps files of different sorts, which are known to produce better sound quality than MP3 at said bitrate. As long as they still sound better than an MP3 would sound at 128, I'm happy.

They'll never sound better. Encoding to another format at a higher bitrate should minimize any more of the audio information from being discarded. The file size of the new file might even be larger, but nothing new is added. So at best, the new files will sound the same.

Re: Keeping 128-level quality

Reply #5 – 2022-12-25 07:19:32

Quote from: Replica9000 on 2022-12-24 22:47:06

They'll never sound better. Encoding to another format at a higher bitrate should minimize any more of the audio information from being discarded. The file size of the new file might even be larger, but nothing new is added. So at best, the new files will sound the same.

This I know. Transcoding will not make anything sound magically better. But would it still be better than a 128 mp3?

Re: Keeping 128-level quality

Reply #6 – 2022-12-25 07:59:26

It depends upon the source files. You say some of them are 128 kbps AAC, and some AAC encoders are considerably worse than LAME, so they could already sound worse than 128 kbps MP3. The only thing you can say for sure is that transcoding to LAME V0 will have a lower chance of introducing new artifacts than using LAME V5, although the increase in size is probably not justified when the source is already lossy.

Re: Keeping 128-level quality

Reply #7 – 2022-12-25 09:24:50

I would transcode to mp3 around 160 k. I'd avoid VBR in favour of ABR
or CBR. This is to avoid potential negative effects of transcoding to the tonality
estimation model (VBR rely on this).

It might be worth trying -q4 or 5 as it can give a less distorted sound when using abr/cbr
at lower bitrates.

Re: Keeping 128-level quality

Reply #8 – 2022-12-25 13:18:03

Even if it's not advertised I'd try throwing some wav at it to see if it works, if it does you can bypass generational loss entirely assuming storage isn't a big deal.

Re: Keeping 128-level quality

Reply #9 – 2022-12-25 16:54:10

Quote

But would it still be better than a 128 mp3?

Nope, technically it will always be worse. Not even equal.
In practice you will probably not hear a difference though.

Re: Keeping 128-level quality

Reply #10 – 2022-12-26 13:03:21

Quote from: Mark7 on 2022-12-25 16:54:10

Nope, technically it will always be worse. Not even equal.
In practice you will probably not hear a difference though.

If the source is better than mp3@128, the transcoded result might also be better.
For a car stereo I wouldn't worry too much, just use V3 or V4 and test the outcome

Re: Keeping 128-level quality

Reply #11 – 2022-12-27 02:43:42

Quote from: Sunhillow on 2022-12-26 13:03:21

If the source is better than mp3@128, the transcoded result might also be better.

Oh thank you, somebody understood my question! I realize my phrasing may have been a little off. Let's imagine that I have a 192 kbps MP3 file, and that I transcode that to 320 or V0. Will that 320 or V0 file still sound better than 128 kbps MP3? I think I got the correct answer.

Re: Keeping 128-level quality

Reply #12 – 2022-12-27 11:10:16

Quote from: TerminalReality on 2022-12-27 02:43:42

Quote from: Sunhillow on 2022-12-26 13:03:21
If the source is better than mp3@128, the transcoded result might also be better.

Oh thank you, somebody understood my question! I realize my phrasing may have been a little off. Let's imagine that I have a 192 kbps MP3 file, and that I transcode that to 320 or V0. Will that 320 or V0 file still sound better than 128 kbps MP3? I think I got the correct answer.

If you transcoded a 192kbps mp3 to another mp3 with a bitrate above 128kbps, it should (technically) still sound better than a 128kbps file. The higher the new bitrate is, the less likely you'll notice further quality loss. If you transcoded from 192 to 192, the new file might sound worse than the original, but still better than 128kbps.

If storage space for your radio isn't a concern, transcode to the highest bitrate possible. 256kbps would probably be sufficient.

Re: Keeping 128-level quality

Reply #13 – 2022-12-27 20:32:56

Theoretically it is possible that converting high quality lossy to lossy higher than baseline, will produce worse results than lossless to baseline (due to previous artifacts which might be harder to encode, just like converting 1000000 times V0 to V0 shall sound terrible due to generation loss). It's not very likely, but one can't say for sure without listening test...

Re: Keeping 128-level quality

Reply #14 – 2022-12-29 06:49:59

Thank you all for the informative replies.

Re: Keeping 128-level quality

Reply #15 – 2023-03-21 00:36:39

Big numbers and lossy compression is an interesting topic

Re: Keeping 128-level quality

Reply #16 – 2023-03-23 06:47:54

Quote from: TerminalReality on 2022-12-24 06:19:59

I have a slew of lossily compressed, non-mp3 files on my device that I want to transcode to MP3. I have read that transcoding between lossy formats, but my car device only accepts MP3. Some of the files I have are from games, some are from ripped CDs, a variety of different sources. Because of this, some of them are .aac, others .m4a, .ogg, .opus, and perhaps even others. What they all have in common is the bitrate, 128 kbps.

My sole question: If I transcode these files to 320 kbps (Or even V0) MP3, will the resulting files still manage to sound as good or better than if they were originally 128 MP3s to start with?

I just want to make sure they will sound at least as good as 128 kbps .mp3 files.

I think I get what you are saying here...

-Example A) Lossless(FLAC etc) to MP3 @ V5 (130kbps).
-Example B) Opus/AAC etc @ 128kbps (or so) converted to MP3 @ V5 (or whatever bit rate is sufficient for decent sound quality).

you are basically asking whether the sound quality of 'Example B' will be 'at least' as good as 'Example A' or thereabouts.

I would say most likely 'yes' overall assuming your current lossy files are of more than high enough sound quality to start with, which chances are they are, especially given you are playing them on a typical car stereo as I figure when just sitting back enjoying the music I would not expect to be able to hear any obvious sound quality drop offs.

p.s. chances are you won't need 320kbps or anything close to this for car stereo usage as I would try V5 (130kbps) or not much higher than this as chances are that will be good enough and is efficient to.

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