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Fortun Bawa

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Aug 2, 2024, 7:25:05 PM8/2/24
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Had several bad takes in a take folder. Deleted them using Logic (not the Mac OS Finder), played around with the good take and got into a situation where I could not undo a quantize operation on the audio. Quit Logic and did NOT save (thinking I'd revert to the good unaltered take). Of course, same thing could have happened had I had a Logic crash, I suppose.

2. Since I'm very early in the project, how hard would it be to start a new project and bring in the two surviving intended files *AND* 90+ measures of Superior Drummer MIDI regions (each one separate, one per bar)? How?

I am a legacy Sonar Platinum user. Recently in cleaning up/organizing files on my hard drive, I must have moved the Cakewalk/Sonar audio files. Now when I call up an existing song project, midi files populate the screen, but there are no audio files, vocal, guitar etc. Any suggestions? As far as I know, I did not delete the files. The files never showed up in the recycle bin, that I can find. I cannot find the files any where. Under Cakewalk Projects/Audio, the folders are empty. Anybody have any idea?

If files are missing, Cakewalk will pop up a dialog prompting you to locate them. If you don't get any warnings, then audio clips referencing those files were deleted from the project (or never existed) before it was saved. Deleting a clip does not delete the file, so those files it should still be available to re-import unless you *did* in fact whack them via Windows Explorer.

I suggest you run the Cakewalk Audio Finder utility (Utilities > CWAF Tool) and let it search your all you drives. It will show 'Missing' files that projects are referencing but were not found, 'Orphaned' files that are no longer referenced by any project, and 'Referenced' files that are used by one or more project files.

Recently through an number of super cool random events I got the opportunity to interview actor Chris Conner who plays Poe on Altered Carbon. I'm a big fan of the show but especially Chris. You should watch the show because Poe is a joy and Chris owns every scene, and that's with a VERY strong cast.

I have two Shure XLR mics, a Mic stand, and the Zoom. The Zoom H6 is a very well though of workhorse and I've used it many times before when recording shows. It's not rocket surgery but one should always test their things.

I didn't want to take any chances to I picked up a 5 pack of 32GIG high quality SD Cards. I put a new one in the Zoom, the Zoom immediately recognized the SD Card so I did a local recording right there and played it back. Sounds good. I played it back locally on the Zoom and I could hear the recording from the Zoom's local speaker. It's recording the file in stereo, one side for each mic. Remember this for later.

I went early to the meet and set up the whole recording setup. I hooked up a local monitor and tested again. Records and plays back locally. Cool. Chris shows up, we recorded a fantastic show, he's engaged and we're now besties and we go to Chipotle, talk shop, Sci-fi, acting, AIs, etc. Just a killer afternoon all around.

Right click the drive, check properties. Breathe. This is a 32 gig drive, but Windows sees that it's got 329 MB used. 300ish megs is the size of a 30 minute long two channel WAV file. I know this because I've looked at 300 meg files for the last several hundred shows. Just like you might know roughly the size of a JPEG your camera makes. It's a thing you know.

Interesting Plot Point - I didn't format the SD card. I use it as it came out of the packaging from Amazon. It came preformatted and I accepted it. I tested it and it worked but I didn't "install my own carpet." I moved in to the house as-is.

The Zoom can see folders and files AND the interview itself. And the Zoom can play it back. The Zoom is an embedded device with an implementation of the FAT32 file system and it can read it, but Windows can't. Can Linux? Can a Mac?

Hacky Note: Since the Zoom can see and play the file and it has a headphone/monitor jack, I could always plug in an analog 1/8" headphone cable to a 1/4" input on my Peavy PV6 Mixer and rescue the audio with some analog quality loss. Why don't I use the USB Audio out feature of the Zoom H6 and play the file back over a digital cable, you ask? Because the Zoom audio player doesn't support that. It supports three modes - SD Card Reader (which is a pass through to Windows and shows me the recursive directories and no files), an Audio pass-through which lets the Zoom look like an audio device to Windows but doesn't show the SD card as a drive or allow the SD Card to be played back over the digital interface, or its main mode where it's recording locally.

We have an 32 SD Card - a disk drive as it were - that is standard FAT32 formatted, that has 300-400 megs of a two-channel (Chris and I had two mics) WAV file that was recorded locally by the Zoom H6 audio reorder and I don't want too lose it or mess it up.

What is this though? Remember it's an image of a File System. It just bytes in a file. It's not a WAV file or a THIS file or a THAT file. I mean, it is if we decide it is, but in fact, a way to think about it is that it's a mangled envelope that is dark when I peer inside it. We're gonna have to feel around and see if we can rebuild a sense of what the contents really are.

Both Adobe Audition and Audacity are audio apps that have an "Import RAW Data" feature. However, I DO need to tell Audition how to interpret it. There's lots of WAV files out there. How many simples were there? 1 channel? 2 channel? 16 bit or 32 bit? Lots of questions.

Now THIS is interesting. I can hear audio at normal speed of us talking (after the preamble) BUT it's only a syllable at a time, and then a quieter version of the same syllable repeats. I don't want to (read: can't really) reassemble a 30 min interview from syllables, right?

This "one channel" file above is actually the bytes as they were laid down on disk, right? It's actually two files written simultaneously, a few kilobytes at a time, L,R,L,R,L,R. And here I am telling my sound software to treat this "byte for byte file system dump" as one file. It's two that were made at the same time.

It's like the Brundlefly. How do I tease it apart? Well I can't treat the array as a raw file anymore, it's not. And I want (really don't have the energy yet) to write my own little app to effectively de-interlace this image. I also don't know if the segment size is perfectly reliable or if it varies as the Zoom recorded.

NOTE: Pete Brown has written about RIFF/WAV files from Sound Devices records having an incorrect FAT32 bit set. This isn't that, but it's in the same family and is worth noting if you ever have an issue with a Broadcast Wave File getting corrupted or looking encrypted.

Let me move into Ubuntu on my Windows machine running WSL. Here I can run fdisk and get some sense of what this Image of the bad SD Card is. Remember also that I hacked off the first 0-400 Megs but this IMG file thinks it's a 32gig drive, because it is. It's just that's been aggressively truncated.

Ali Mosajjal thinks perhaps "they re-wrote the FAT32 structure definition and didn't use a standard library and made a mistake," and Leandro Pereria postulates "what could happen is that the LFN (long file name) checksum is invalid and they didn't bother filling in the 8.3 filename... so that complying implementations of VFAT tries to look at the fallback 8.3 name, it's all spaces and figures out "it's all padding, move along."

Ali suggested running dosfsck on the mounted image and you can see again that the files are there, but there's like 3 root entries? Note I've done a cat of /proc/mounts to see the loop that my img is mounted on so I can refer to it in the dosfsck command.

The DUMP.exe util as part of mtools for Windows is amazing but I'm unable to figure out what is wrong in the FAT32 file table. I can run minfo on the Linux command land telling it to skip 8192 sectors in with the @@offset modifier:

And then load it in dump.exe on Windows which is really a heck of a tool. It seems to be thinking thinking there's multiple FAT Root Entries (which might be why I'm seeing this weird ghost root). Note the "should be" parts as well.

The most confusing part is that the FAT32 signature - the magic number is always supposed to be 0x41615252. Google that. You'll see. It's a hardcoded signature but maybe I've got the wrong offset and at that point all bets are off.

I'll update this part as I learn more. I'm exhausted. Someone will likely read this and be like "you dork, seek HERE" and there's the byte that's wrong in the file system. That LFN (long file name) has no short one, etc" and then I'll know.

I skyped with Ali and we think we know what's up. He suggested I format the SD Card, record the same 3 shows (two test WAVs and one actual one) and then make an image of the GOOD disk to remove variables. Smart guy!

See that directory there that's a nothing? A space? A something. It has no Short Name. It's an invalid entry but 7zip is cool with it. Let's go in. Watch the path and the \\. That's a path separator, nothing, and another path separator. That's not allowed or OK but again, 7zip is chill.

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My tip for you: Save every session in its own folder and with its own Audio Files folder. This will minimize the risk of messing up the audio files when moving the session around and it will be easier to find and back up certain sessions with the whole audio.

I created some dictations for my students using the recording tool in Canvas. Everything worked fine but now all of a sudden my students no longer have access to these audio files.
When I have a look at my assignment, the files are still there but when I switch to student view I don't have access to them either.
Some screenshots to make things clear.

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