I’m currently transferring my old music library to Plexamp and have never had any issues with codec/quality labels, as I use it daily to check which CDs I need to re-rip or upgrade to HD. Today, I was quite surprised to see that the album I added is showing as WAV 44.1 / 24 (why are there spaces before and after the slash now?), even though it should be MP3 192.
So I examined the files in question, and MediaHuman Audio Converter shows me that it’s MP3FLOAT 44100Hz Stereo 192kbps, kid3 shows it’s MPEG 1 Layer 3 192kbps 44100Hz Stereo, and now the interesting details: Plexamp also shows me that it’s MP3 192, but only after a few seconds of playing the track or after I change the track, and then immediately swaps the codec/quality label.
There have obviously been changes to the codec/quality labels, so I wanted to bring this issue to your attention in case there have been further changes to the codec calculation that might now be faulty.
This issue occurred on both my Mac and iPhone.
Attached is a video of the problem (mp4 screen recording in a zip file).
A music album ripped from CD should never show as 24bit. The CD spec is fixed at 44.1kHz and 16 bit stereo PCM.
If your files show as anything else, you seem to have converted it in some way.
But converting a source from 16 to 24 bit doesn’t make sense (unless the CD is actually a HDCD, but those are quite rare, and you need to “unfold” the higher resolution with a special filter/app).
Mediainfo confirms MP3 192, which was the default quality I ripped all my CDs back in the days. I’m just editing ID3 tags and covers for all of my media before I move them to my Plexamp library at the moment (or re-rip them in flac if I still have the CDs to avoid lossy audio).
Here’s the Mediainfo output for the file in the video:
General
Complete name : 01-01 Nasty Girl (Riffs & Rays Remix).mp3
Format : MPEG Audio
File size : 4.30 MiB
Duration : 2 min 57 s
Overall bit rate : 192 kb/s
Album : Clubland 7
Album/Performer : Various Artists
Part/Position : 1
Part/Total : 2
Track name : Nasty Girl (Riffs & Rays Remix)
Track name/Position : 1
Track name/Total : 20
Compilation : Yes
Performer : Inava Day
Genre : Dance
Recorded date : 2005
Cover : Yes
Cover type : Cover (front)
Cover MIME : image/jpeg
Conformance errors : 1
MPEG-Audio : Yes
General compliance : Bitstream synchronisation is lost (conf, offset 0x44CEC6)
Audio
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Duration : 2 min 57 s
Bit rate mode : Constant
Bit rate : 192 kb/s
Channel(s) : 2 channels
Sampling rate : 44.1 kHz
Frame rate : 38.281 FPS (1152 SPF)
Compression mode : Lossy
Stream size : 4.06 MiB (94%)
Image
Format : JPEG
Width : 800 pixels
Height : 800 pixels
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Compression mode : Lossy
Stream size : 241 KiB (5%)
Comparing it to a track from CD2 I can see that the file in question shows a conformance error.
Conformance errors : 1
MPEG-Audio : Yes
General compliance : Bitstream synchronisation is lost (conf, offset 0x44CEC6)
Could this cause the error with the wrong codec quality?
I am not sure. It not impossible, I’d say.
If you don’t have the source CD at hand, try this https://mp3diags.sourceforge.net/
It could possibly fix the file.
Sorry for the late reply. I just got a hold of a Windows PC where I could try this out. This was indeed the solution as removing unknown or cut off streams from a handful of files (especially the first one where PlexAmp probably calculates the quality for the whole album?) with MP3 Diags fixed the problem. Thanks!
