How To Determine File Format

I have an Olympus VN-7000 Digital Voice Recorder. I would like to be able to use it to record people then upload the files into Audacity.

I have no idea what the file attributes are for the digital files stored on the device. Nothing I can find on the web pages for this device gives me this information.

If anyone can tell me what file formats are used and how to get them into Audacity, I would be very grateful. Failing that, can anyone suggest how I might find out more about the files it captures?


What is the “file extension” of those files? Not really a reliable indicator, but should give a first idea.

Furthermore, what does MediaInfo say about those files?

Thanks for the response Gunnar.

I have no idea what the file extensions are because the device does not list file names, only folders and numbers. I have found no information about the files.

I tried connecting a cable between Line In on my PC and the earphone output jack on the device and capturing it in Audacity. Audacity does not see the file. I get no indication of signal in Audacity when I play from the recorder.

I’m using these settings in Audacity . . . the same as I use when recording from a cassette deck.
Audacity Settings.gif


Can you post a screenshot how it looks in Windows Explorer after you have connected your recorder to the PC via USB?

(Alternatively, you could also remove the SD card from your recorder and connect the SD card directly to the PC - provided that your recorder uses a SD card and that you have an SD card reader)

Re-recording the files analogously, through the “line in”, probably is the worst method to get those files on your PC :confused:

That’s because with this method the files will go trough a Digital/Analog conversion first and then tough another Analog/Digital conversion. This will cause quality loss, of course.

And there is even more loss if you save the recorded files to some lossy format (e.g., MP3) in Audacity.

So, unless there really is no other way, you should copy the original files 1:1 to your PC - rather than going through a pointless cycle of D/A + A/D conversion…

Windows intentionally hides file extensions, but you can make it stop doing that.

Hidden File Extensions - Windows
– Start > My Computer > Tools > Folder Options > View > [ ] Hide Extensions for Known File Types (deselect)
– Apply (to this folder) or Apply to All Folders
– OK

Windows does that to make the filenames “less confusing,” but as you’re finding, that only works if nothing goes wrong. File extensions can be very handy for diagnostics.


That’s not good news.


What are the main features of this model?

The Olympus VN-7000 digital voice recorder employs CELP (Code Excited Linear Prediction) technology to maximize recording capacity. Its three recording quality modes offer users the option to record high-quality sound files or to use a lower-quality mode in order to extend the remaining recording time. The VN-7000 also includes an alarm and can be configured to automatically record unattended for a preset time period. The microphone and earphone jacks allow the use of audio accessories.

–What is CELP?

Code Excited Linear Prediction (CELP) is an audio technology initially developed for use in cell phones. CELP works by comparing incoming sound signals to a model of human voice phonetics and saving the difference as an error report. When playing back the file, the error report is compared to the model to reconstruct the recording. The benefit is a very detailed file that employs lower bit rates and lower sampling frequencies, resulting in more efficient use of the flash memory in the recorder.

–What is subband coding?

Subband coding is a data compression strategy that enables higher-quality compression of an audio file by dividing the input audio signal into subbands of the frequency range and separately encoding each subband using psychoacoustic technology. A common example of subband encoding is the mp3 (MPEG 1 audio level III) audio format.

When an audio signal reaches the human ear, the louder frequencies with higher energy mask nearby frequencies with lower energy, so the listener does not hear them. Subband coding discards the inaudible lower energy frequencies from the saved digital audio file, resulting in smaller digital files that can be played back using a lower bit rate.


They recommend in another posting to process the work in one of the Olympus editing or production products and then convert to something more conventional. I’d be surprised if FFMpeg has support for that, but it’s possible.


Thank you, all, for the responses!

This device does not have any PC cable connection capability except the cable from its earphone port to the LIne In port. I cannot access the files in Windows explorer.

I will see if I can find software proprietary to Olympus that will allow me to extract the audio files on the device.

Again, Thank you, All!

CELP/CELT is one of the two formats that became the “Opus” hybrid Codec. Actually I’d be surprised if FFmpeg does not support this.

But I have no idea in what container CELP streams would be stored typically…

Sure they recommend using their own products :wink:

If that is really true (it’s hard to believe though!), your only possible way to get the recorded files onto your PC is accessing the memory card directly.

And if that isn’t possible either, e.g. because there only is an “internal” memory but no SD card slot, then this is a lost case!

As sad as it may be, analogous re-recording will be your only way in that case. And, to answer your initial question, the player’s “internal” file format is completely irrelevant then…

How should it be possible to “extract the audio files”, if there only is an analog line-out (earphone) connector ??? :open_mouth:

(It’s not, I suppose. Except they emulate a 56k modem over the analog connection lol)

I can do better/worse.
Hold the recorder’s speaker up to the computer’s microphone.
The computer about which we know very little, by the way. If it’s a laptop, it’s very normal for it not to have a blue Stereo Line-In.

On my recording devices, I have to press certain buttons to tell it I want it to connect to an external device to exchange files. It’s not just plug it in and go, even on a Mac. Did we read our instruction book?


FFmpeg 2.2.2 supports QCELP and G.729, at least. If you had used MediaInfo as Gunnar suggested, we could have seen the information provided as to the exact codec and container. However you should get the version of MediaInfo without the installer, because the installer can be confusing or dangerous.

It may be worth installing Audacity 2.0.6 from then installing FFmpeg from .

If FFmepg recognises the files it saves you a lot of effort.


Sadly enough, this all doesn’t work with this device.
Some Olympus products indeed allow only capturing the output via the head phones output. What’s more, this doesn’t seem to work very well.
It’s the major complaint in reviews and forums.

I’m afraid my project is a lost cause. I cannot find a way to get the information off of this device. It is an inexpensive Olympus dictating and note taking device. It has a mic jack and an earphone jack and no other connection capability. I thought that I might be able to transfer the sound from the device to the LineIn port on the PC just like I do with analog cassette tapes, but Audacity does not seem to recognize the signal (which is really nothing more than analog sound, I think, even though the device is digital) coming from LineIn. That’s why a posted a screenshot of my Audacity settings . . . I thought I might have them wrong and was looking for any suggestions for changing them.

My computer is home-built from assembled parts: Intel Core i5 3570K 3.40 GHz, 16 GB RAM, ECS Z77 H2-A3 Mobo Windows 7 HP 64-bit. There is an NVidia graphics card but nothing for audio except what came on the mobo. I have about 5 terabytes of hard disk storage including both internal and external drives. For digitizing and saving old cassette tapes, I use an old Advent cassette deck that is attached to the LineIn port with a 3.5 stereo jack. I start the tape deck then start Audacity and in a few seconds I see the graph showing the signal being received. I also listen on the PC’s speakers as I play the tapes. I was hoping that I could do the same with the Olympus but apparently LineIn is not seeing the signal or Audacity is set up incorrectly. I have the cable in the earphone jack on the recorder and LineIn on the PC; so, obviously, I cannot monitor the sound while transferring.

Sorry to have used up so much bandwidth without providing adequate data. I hope this answers any questions, but feel free to ask any others I might not have thought about.

Again, thank you, all, for your advice.

rabbithutch, we need to distinguish two things here:

  1. Will you be able to copy the files over from your recorder to your PC? From all what you described so far, the answer is no :frowning:

  2. Will you be able to re-record the stored audio through an analog audio connection? Definitely possible! It’s sub-optimal, yes. But if there is no other way, it should be better than nothing, I suppose :stuck_out_tongue:

    So what you need to do is: Connect the “earphone jack” of your recorder with the “line in” port of your PC’s soundcard, using an analog cable. Then you play the track on your recorder and, at the same moment, you record it in Audacity. The file format that is on the recorder doesn’t matter at all here, because we just grab the analog signal from the earphone jack! “Audacity does not seem to recognize the signal” is not even possible, don’t worry :wink:

(If Audacity doesn’t record the audio signal that you feed into the “line In” port, i.e. your recorded file only contains silence, this means you have selected the wrong “recording device” in Audacity - or the recording volume is way too low)

Thank you, Gunnar!

I will continue to try the method you described. It is exactly what I do to capture cassette tape analog signals while digitizing them and later exporting them as MP3.

Again, thank you for the help!!!

Indeed the VN 7000 has no USB or SD Card capability - I just checked.

Your settings here look OK, although your recording level might be low:

Make sure when you play the file on the recorder that the volume is turned up. Turn on Transport > Software Playthrough in Audacity then you can hear what is being recorded in the computer sound device. Try Effect > Amplify… on what you record. If Amplify shows “New Peak Amplitude” of -Infinity, you are recording absolute silence and something is wrong with the cable or the connections.

Note that the output of the earphone may be too low for your line-in. Try connecting to the computer microphone input. Then turn the playback volume down on the recorder, change the Audacity input to microphone, turn the Audacity input level down, then record.