I got to annoy you with one huge issue. I always import the files with the Windows Assistant "Import Pictures and Videos" this worked with the 5DMKII and 550D and never had problems. I had the 6D for some weeks and now the MKIV and I did it the same way. Now I wanted to start editing a bigger project and I realized that all the files are broken. Like completely broken. The length and file size is accurate but it's just a black screen and noise as sound.
I now know that I have to open the MKIV like a device and copy the files out of the folder to get around this issue. But there are about 100 files not usable for me. Why is this happening? How can importing files without any error warning destroy videos files completely while photos are fine. And most important ist this issue known to anyone and what can I do with the files? Is there any chance of reencoding them? I tried the usual stuff, various players and decoders, does'nt work, even uploading doesn't work on vimeo cause there's just something broken inside the data.
I'm depressingly looking for help.
Cheers from Berlin
Did you delete the original files from your card? Those files don't get changed when you transfer the images to your computer.
The filesystem on the memory card are industry standard filesystems (cards 32GB and smaller are usually formatted as FAT32 filesystems. Cards larger than 32GB (such as 64GB, 128GB, etc.) are usually formatted as exFAT. Most modern operating systems can read those filesystems without requiring any special software. It is as if they were on a USB thumb-drive.
When you use a USB cable to transfer the images... the computer does not atttach the camera as if it is an external hard drive (like it would if you just inserted the memory card into the computer). Instead it uses a special transfer protocol. This transfer protocol has become an industry standard so typically there is no need to install special software.
HOWEVER... what the computer can do with the data once it has it is another matter.
If you shoot and save images as JPEG, that's a well-understood file type (but there are a lot of reasons why most people prefer to use RAW). RAW isn't a well-understood "file type" per se becuase it's more of a concept than a standard.
RAW simply means that the file is stored in a way that wont alter or lose original data. Since each camera model can have a different type of sensor, the format of a RAW file can change slightly (even though the concept is the same) from camera model to camera model. This means a computer wont just automatically know how to open a RAW file.
Canon provides software (Digital Photo Professional) that DOES know how to open the RAW file for any of their cameras. Many third party photo applications (e.g. Adobe software) provide camera RAW support that is regularly updated (as long as you keep up with their latest software versions). A downside of Adobe is that as they come out with major new releases, they stop providing RAW updates for old releaes. This means if you buy a new camera and your version of say... Photoshop... is a few versions behind, then it may not understand how to properly open your RAW files -- upgrading would get around that.
I'm wondering if you are shooting and storing files as RAW (Canon ".CR2" files) but do not have the latest RAW support on your computer.
If you download and instal the latest version of Canon Digital Photo Professional (it's free) then it SHOULD be able to open any file produced by any of your Canon cameras.