Mount blank file system on msdos partition table

Question

I need to get into a partition on an SD card, but it has no file system and I can't figure out how to mount it. When I type

parted /dev/sdc print

I get

Model: USB Mass  Storage Device (scsi)
Disk /dev/sdc: 129GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type     File system  Flags
 1      4194kB  62.9MB  58.7MB  primary  fat16        lba
 2      62.9MB  129GB   129GB   primary

I have not been able to figure out how to mount #2, but I really have to get to it.

Background: This is an SD card I used on a Raspberry Pi. The pi was acquiring video data and saving it to the file system. Like an idiot, I plugged in the SD card to my Ubuntu machine, it automounted both boot (#1) and the Linux file system (#2). I watched a few of the videos and they were awesome. I DID NOT copy the files over to my computer (big mistake). Now, after unmounting and coming back later, I can't get into #2. My videos are sitting there and I want them. The Pi will no longer boot on its own so I can't get in that way.

Trying to mount the partition with ext3, ext4, vfat, or msdos gives some variant of the following

mount -t ext4 /dev/sdc2 /media/pi

returns

mount: wrong fs type, bad option, bad superblock on /dev/sdc1,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so

And

dmesg | tail

gives

[2068799.476208] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00006520)
[2068799.476329] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00006c6c)
[2068799.476397] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00007620)
[2068799.485943] FAT-fs (sdc1): error, invalid access to FAT (entry 0x000076b3)
[2068799.486050] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00006e65)
[2068799.495272] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00006001)
[2068799.495389] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00004000)
[2068799.495505] FAT-fs (sdc1): error, invalid access to FAT (entry 0x00006573)
[2068799.495564] FAT-fs (sdc1): error, invalid access to FAT (entry 0x0000414d)
[2068946.845907] EXT4-fs (sdc2): VFS: Can't find ext4 filesystem

Trying to mount as vfat or msdos gives

dmesg | tail
[2069137.546806] FAT-fs (sdc2): bogus number of FAT structure
[2069137.546809] FAT-fs (sdc2): Can't find a valid FAT filesystem

Trying to mount as ntfs gives

NTFS signature is missing.
Failed to mount '/dev/sdc2': Invalid argument
The device '/dev/sdc2' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

dmesg | tail

[2069279.102188] usb 2-6: reset high-speed USB device number 27 using ehci_hcd
[2069279.358047] usb 2-6: reset high-speed USB device number 27 using ehci_hcd
[2069279.490651] sd 26:0:0:0: [sdc] Unhandled error code
[2069279.490654] sd 26:0:0:0: [sdc]  Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
[2069279.490657] sd 26:0:0:0: [sdc] CDB: Read(10): 28 00 00 01 e2 00 00 00 08 00
[2069279.490661] end_request: I/O error, dev sdc, sector 123392
[2069279.490665] Buffer I/O error on device sdc2, logical block 64
[2069279.605895] usb 2-6: reset high-speed USB device number 27 using ehci_hcd
[2069280.444934] sd 26:0:0:0: [sdc] No Caching mode page found
[2069280.444937] sd 26:0:0:0: [sdc] Assuming drive cache: write through

Answer 1

but it has no file system and I can't figure out how to mount it.

If it has no filesystem then for sure you cannot mount it. Mounting it fundamentally an operation on a filesystem. (If there is no filesystem then there is nothing to mount.)

However, if you meant that it has an unknown filesystem type, rather than no filesystem at all, then I suggest this command to identify what type of filesystem it is:

file -Ls /dev/sdc2

If file is able to identify the filesystem type, then you will know what argument to pass to the -t option of mount. If file is unable to identify the filesystem type, then the block device might contain something else than a filesystem or it might be empty.