fetchMediaListWithCompletion: fails when the SD card has a lot of photos...

[jgrantr]

iOS Device: iPad Air 2
Xcode version: 7.3.1
iOS version: 9.3.1
DJI SDK version: 3.3

Once the SD card has a certain number of files, the [DJIMediaManager fetchMediaListWithCompletion:] fails with the following error:

Error Domain=DJISDKErrorDomain Code=-1003 "Execution of this process has timed out(code:-1003)" UserInfo={NSLocalizedDescription=Execution of this process has timed out(code:-1003)}

I have tried this on both the iPad Air 2 connected to the drone, and in the simulator connected to the drone over the DJIBridge app, and it fails in both cases with the same error.

I don't know what the exact limit on the number of files is, only that it worked when there were just a few hundred (200-500) but once I hit the current amount (779) it fails.

Please let me know what can be done to fix this. We are building an app around this, and this is a big showstopper for us to use DJI products.

[dji-dev]

Hi @jgrantr , thanks for your feedback. This is a known issue. We will investigate and fix it in our future SDK release. Here are the explanations:

The DJI Phantom 3 series, Inspire 1 series and Phantom 4 use the DJI Lightbridge to fetch the media files. When you are fetching a large number of media files(Like 779 as you mentioned), it requires a much more stable Lightbridge communication link. If the link is not stable during the process, it's easy to time out.

Here, we provide you with a temporary solution, you can use the following delegate method of DJICamera to get the latest generated media file and manage them by yourself:

- (void)camera:(DJICamera *_Nonnull)camera didGenerateNewMediaFile:(DJIMedia *_Nonnull)newMedia;

Hope this help!

[jgrantr]

Yes, I am aware of that delegate method, but it is an un-tenable solution, as there is no way that I can see in the SDK to be able to re-create a DJIMedia object.

An example will probably illustrate what I am talking about.

I want to take a series of photos, group them together, and then download them. As the photos are taken, I use the camera:didGenerateNewMediaFile: delegate method to save local information about each photo (taken from the DJIMedia object) along with a groupId. Some time later (could be the same run of the app, could be a day later after the app has been re-started), I want to then go and download those media files. I can't download them right when that delegate method gets called, as the camera is in shooting mode, not downloading mode. So, how would I then go download those media files at a later time without first grabbing the DJIMedia objects from the SDK? Those objects don't appear to conform to the NSCoding protocol, so I can't just archive them to disk, and all the properties are read-only, so I can't create a blank DJIMedia object and set the correct properties.

Am I missing something? Am I incorrect that I can't download the images from within that delegate callback?

[dji-dev]

Hi @jgrantr, if the app is not restarted, it can still work. You can cache the DJIMedia file, switch the DJICameraMode to DJICameraModeMediaDownload and then invoke the fetchMediaDataWithCompletion: method of DJIMedia to download it.

We will investigate this bug and fix it in the future SDK release.

[Michael-DJI]

did you resolve your issue with new version?
if not, pls report the issue to dev@dji.com it's the official channel to request DJI SDK support now.