Bitrate is reported incorrectly for VBR MP3

Elliott B

If I play a V0 MP3, RuneAudio displays the bitrate as 32kbps. Mediainfo says 32kbps is the "minimum bit rate", a measurement which is mostly irrelevant. It would be more useful to display the average bit rate, which is 238kbps in this case.

ACX

You are right, current bitrate visualization is bound to MPD status changes. RuneUI works in an asynchronous way and information are updated every time an MPD event occurs. Bitrate value is read on the fly and may show very low values in some points of the tracks, so for a more accurate report we should show an average value. But that's not a perfect solution:
http://mpd.wikia.com/wiki/Music_Player_Daemon_MP3_VBR_Troubleshooting

Elliott B

Hmm interesting. So maybe I'll run that to "fix" the tags of my music.
Is MPD also the reason sample format is incorrectly shown as 24 bit for all my V0 songs?

ACX

Elliott B wroteIs MPD also the reason sample format is incorrectly shown as 24 bit for all my V0 songs?

Yep, I also noticed the same behaviour on some files.

Midnight

ACX wroteYou are right, current bitrate visualization is bound to MPD status changes. RuneUI works in an asynchronous way and information are updated every time an MPD event occurs.

So this means the bitrate is updated at track change or e.g. when pressing a button (play, pause)? This also means that a file with silence at the beginning shows a bitrate of 0 kbps.

ACX wroteBitrate value is read on the fly and may show very low values in some points of the tracks, so for a more accurate report we should show an average value.

Is it possible to get the average bitrate from mpd?

ACX wroteBut that's not a perfect solution:
http://mpd.wikia.com/wiki/Music_Player_Daemon_MP3_VBR_Troubleshooting

It's not only a problem for VBR MP3 files but also for FLAC and Ogg Vorbis.

ACX

Midnight wroteSo this means the bitrate is updated at track change or e.g. when pressing a button (play, pause)? This also means that a file with silence at the beginning shows a bitrate of 0 kbps.

Exactly, MPD reads the instant value.

Midnight wroteIs it possible to get the average bitrate from mpd?

I haven't found it in the protocol docs yet.

Midnight wroteIt's not only a problem for VBR MP3 files but also for FLAC and Ogg Vorbis.

The rate instant value problem or the wrong bit depth value?

Midnight

The rate instant value problem

ACX

Midnight wroteThe rate instant value problem

So the answer is: yes, it's the way MPD works. Maybe there's a workaround, we already thought in calculating the average bitrate with a background function and then display it correctly in the UI, but that was a non-optimal solution in terms of performances.

Midnight

BTW: Actually the bit rate is irrelevant for lossless formats like FLAC and there is no need to show it

But still a solution for lossy formats would be nice

ACX wrotewe already thought in calculating the average bitrate with a background function and then display it correctly in the UI, but that was a non-optimal solution in terms of performances.

Thought about that, too. But I also think it's a performance killer.

wick

Redbook ALAC files show up as: 32 bit, 44,1 kHz.
This ought to be 16 bit, no?

Does MPD mean 16x 2 channels?
Or is it just listed incorrectly?