Automatically import raw data files?

[robotman]

I'm creating recordings using the RODE app on my iPhone and then copying the raw files to my MBP.

Is there a way to have Audacity automatically recognize and import the files as raw data files so I don't need to choose "Import Raw Data" for each file? It would be much easier to be able to click on the file in the Finder and have Audacity open them then have to choose "Import Raw Data" and then search for each file.

The file extensions are .00 (left channel) and .01 (right channel) but I can change to whatever I need to. I've tried changing them to .raw or .pcm but Audacity still doesn't recognize them as raw files.

Thank you for any ideas!

[kozikowski]

This forum is for Audacity 2.x on Mac OS X 10.4 and later.
Please state which version of OS X you are using, the exact three-section version of Audacity from Audacity > About Audacity and whether you obtained the .dmg installer or the zip.

You're doing something weird, right? I can't imagine a respected microphone maker presenting you with files in a non-standard sound format. So what are you really doing?

Koz

[robotman]

OS = 10.10.4
Audacity = 2.1.0

I am copying the raw files directly from my iPhone onto my MBP so I can process them faster in Audacity.

RODE does give export options to different sound file formats, but they are all extremely slow. I also don't believe they have an option for exporting the raw data, but there are lossless formats like CAF, ALAC, and FLAC. I'm guessing there's not any difference with the raw data versus the lossless formats in Audacity, but let me know if there is an advantage to using one format over another or the raw files.

The main issue is that processing the files on the iPhone before they can be exported via RODE's iPhone web interface is extremely slow and then transferring such large files through the RODE interface is slow. It's faster for me just to copy the raw data to my MBP and import as raw data into Audacity.

Thanks for your help.

[cyrano]

You've copied Rode Rec's internal sound files. You should first export from the Rode Rec app to a format such as wav or aiff and email the file.

I don't use the app myself, but that seems to be the standard way.

[robotman]

Yes, I know I'm using RODE's internal files. They are the ones who told me about them. For a long recording, exporting to a different format takes several minutes on my iPhone vs. seconds if I save the original file to my MBP and then import into Audacity to convert. It's iPhone vs. MBP processing power.

My original question is if there's a way to have Audacity automatically import the raw files instead of me having to select "Import Raw Data" for each file? For example, if I add .raw, Audacity does not recognize the files as raw data when I click to open them in Audacity. So I'm wondering if there's some extension or way to make Audacity automatically import raw data files.

Thanks for your help.

[steve]

RODE does give export options to different sound file formats, but they are all extremely slow. I also don't believe they have an option for exporting the raw data, but there are lossless formats like CAF, ALAC, and FLAC. I'm guessing there's not any difference with the raw data versus the lossless formats in Audacity, but let me know if there is an advantage to using one format over another or the raw files.

IF the raw format used by Rode was some sort of raw PCM data, then "converting" to WAV would be very quick because all it would need to do is create a valid WAV header.
The fact that the conversion is very slow indicated that the "raw" data is not standard PCM audio data and that converting requires some sort of decoding of the data. In other words, the "raw" data is not actually raw data, but is encoded in some way.

"Import RAW" allows you to import raw (headerless) PCM audio data. Obviously if you try to import encoded data as raw PCM data, the result will be garbage.

The problem is that we don't know what format the "raw" data is, and the only format converter that you have is software on your iPhone. You have discovered that simply copying the data does not work, so the best solution that I can think of is to use the product according to the manufacturers instructions and export to a standard format.

The most standard format in the world is "Microsoft PCM WAV", which I assume is the "WAVE" option in the "create audio" menu of your software. I would recommend using that option.

If you have further questions about the Rode app, you should use their support channels: http://www.rode.com/faq

[cyrano]

I have no idea what the internal format is for Rode's recording app. I've only used it on a couple of occasions, on a friend's iphone. I'd expect those to be PCM and that should work.

Also, changing the extension doesn't usually work. On a Mac, extensions don't mean much. It might work with very simple files (txt, csv...) but usually not on anything a little more complex.

[steve]

I have no idea what the internal format is for Rode's recording app. I've only used it on a couple of occasions, on a friend's iphone. I'd expect those to be PCM and that should work.

That's the problem, we don't know, and Rode do not have that information on their website as far as I can see.

"Raw PCM" would seem like a good guess, but if that were the case then "converting" to WAV or AIFF should be a quick process. If you use the same sample rate for the WAV file as the raw PCM data, then no change is required to the audio data and all that would be required is adding a valid RIFF header. Also, "Import RAW" in Audacity should work. However, robotman tells us that the conversion is very slow and Import Raw does not work, so I'm guessing that the data on the iPhone is not Raw PCM.

Given the above, if I had to guess what the format is on the iPhone, then I'd guess that it could be some form of ATRAC. ATRAC is a family of proprietary audio compression algorithms developed by Sony (not supported by Audacity).

[Gale Andrews]

I'd guess that it could be some form of ATRAC. ATRAC is a family of proprietary audio compression algorithms developed by Sony (not supported by Audacity).

Audacity should decode ATRAC if you add FFmpeg to your computer. Decoding will not work if the file is encrypted (most ATRAC files are encrypted).

MediaInfo would tell you what the file was if it actually has headers and is not raw data. MediaInfo does not claim support for OS X 10.10.

Audacity can't pass a file with .RAW extension directly to the "Import Raw Data" dialogue.


Gale

[steve]

Audacity should decode ATRAC if you add FFmpeg to your computer. Decoding will not work if the file is encrypted (most ATRAC files are encrypted).

There are many variations of ATRAC so I'd not be confident that FFmpeg (using a reverse engineered decoder) will succeed. Would FFmpeg be able to correctly identify ATRAC if it is headerless? Perhaps worth a try though.