Audio Help

[biferi]

I know this is not about Video Editing but it is about an Audio Format.

I have a Tracfone 7050 Model.

It can Record Audio in 44.1 kHz or 8. kHz and the Format is .OPUS so I make a Recording in both High and Low Settings.

Now I open both the 44.1 kHz and the 8. kHz in Mediainfo and it says both are 48 kHz how can this be?

I have no 48 kHz Setting I just have 44.1 kHz and 8. kHz Setting.

Can anybody help?

[Cornucopia]

Am betting at least one of those is listed as kbps not kHz.

If it was recorded/sampled at one rate, and played back at another, you would know it very clearly, because it would be pitched down & slower, or would be pitched up and faster.

How about you post the mediainfo text for us all to see?


Scott

[biferi]

I just Attached the File.
But I did Record it on my Phone as 44.1 kHz but in Mediainfo it Says it is 48 kHz.
And if I Record it as 8. kHz on my Phone Mediainfo still Says it is 48 kHz.

[biferi]

Was anybody able to see the Post?

[johnmeyer]

Are you perhaps confusing audio sample rate with the overall video+audio bitrate?

[Cornucopia]

You say "it can record..." meaning your phone. But it doesn't do the recording on its own, a particular software app controls & enables that. What is that app? - you never mentioned it. This can make a big difference in what options are offered, and it could conceivably be written wrong and be putting out incorrect metadata. So there is much possibility for variation & error that we likely cannot pin down until we know this.

Also, you sent the MI text for one file, but not the other...how can we compare?

Note that the one file was 45.5kbps running at 48khz.


Scott

[biferi]

I have a Flip Phone.
It has a Built in Audeio Recorder.

So I Set it to 8. kHz to Record and after I bring it over to Window 7. and open it in Mediainfo it says it is 48 kHz.

I have no App on this Phone.

[Cornucopia]

(Assuming this is a duro d7050, as that is the only tracfone flip model that comes up regularly in a search)...

You do have an app. ALL of them do. Ok, it's built-in, but it's still an app.

I don't see in the manual any option for changing quality of recorded message. Not surprising that opus format is being used for those, as it is both very efficient and opensource. Regardless of what setting you may THINK it is supposed to be, does it play properly, with appropriate quality, in both settings?
If so, I don't really see what the issue is. Even a recording set to the larger of those 2 options would be fine at that bitrate using opus compression. And an 8khz cutoff on speech signals is also appropriate.
Is the issue merely that it is reporting a setting other than what you expected? Or are you trying to do something else with it? (e.g. convert) Or is it an overall filesize difference issue?

Scott

[biferi]

That is my Cell Phone you are Right.

Well if I go into Settings and Pick 8. kHz to Record at this is the FREQ. not the Bit Rate.
It only lets you Pick what FREQ. to Record at.

And when I open it up in Mediainfo the FREQ Says 48 kHz it was Recorded at not 8. kHz.

I thought maybe the File Format can not be Read by Mediainfo?

[Cornucopia]

If it was truly the samplerate (sampling frequency) it would show that in MI. And it would play at whatever samplerate is designated. Since it does not specify that (and I assume since you haven't said otherwise that it plays ok), and since the manual doesn't describe that part of the app's menu gui, I can only surmise that it might refer not to the sampling frequency but to the cutoff filter frequency. They usually go hand in hand (e.g. Fs = 48kHz, so Nyquist Freq=24kHz, so filter lowpass cutoff freq=~20-24kHz). IOW, the anti-aliasing filter frequency.
8kHz (and down to below 4kHz) is common for telephone speech recording. Has been that way for over 65 years.

Hard to tell without a variety of samples using multiple options.

MediaInfo has no trouble reading opus formatted files. Hard to say if there is custom metadata that the recorder app is outputting that MI might not be able to read. Again, without samples.


Scott

[johnmeyer]

I can only surmise that it might refer not to the sampling frequency but to the cutoff filter frequency.
Scott

That's an interesting thought, but I don't know why the app would do that (does it really save much memory space?). Also, 4KHz is the common telephone cutoff. 8KHz is actually pretty high (almost "Hi-Fi").

The number "8" sounds more like bit depth to me. CD audio is 16-bit; 24-bit is what the really high-end audiophiles listen to; and 8-bit is low-rent iPhone recording app stuff.

So, instead of "8 KHz", I'm betting that his audio is 8-bit depth. That used to be pretty common back in the 1990s.

[Cornucopia]

Yeah that makes more sense to me too. Unfortunately screencaps unlikely in solving this question considering the logistics.


Scott