Amazon S3 (AWS ) NSMutableData

Question

I have a project related on Amazon S3 DOWNLOADING big file sizes above 50MB. It stops without error and I chunk the file into smaller memory due to it's large data file size and download it simultaneously. When I append the chunk data into single [NSMutableData] in correct order the video won't play. Any Idea about this related subject?..

Please Help me I'm sitting my ass for the whole week of this project T_T..

No errors. But the downloaded file is Corrupted after cut into chunk and merge using NSMutableData — Cjames, May 10 '13 at 08:42

score 1 · Answer 1 · edited May 23 '17 at 12:29

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You shouldn't manage this amount of data using RAM memory only.

You'd rather use secondary memory (namely NSFileManager) as explained here When you're done downloading the file, play it normally. If you're sure the user won't really need it anymore, just delete it right after playback.

[edit]

Or,you might as well just use MPMoviePlayerController pointing to that URL directly.

edited May 23 '17 at 12:29

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answered May 10 '13 at 09:05

Alejandro Benito-Santos

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It's the memory of the file that is to be downloaded,because the file downloaded is greater than 50MB that's why I chunk the file into pieces and reconstruct again... any better way to handle the file to avoid corruption? Thank you for your response – Cjames May 10 '13 at 09:15

score 1 · Answer 2 · answered May 10 '13 at 12:37

What you need to do is create a file of the appropriate size first. Each down loader object must know the offset in the file to put the data, which it should write as it appears and not store in a mutable data object. So this will greatly lower the memory footprint of this operation.

There is a second component: you must set the F_NOCACHE flag of the open file so iOS does not keep the file writes in its cache.

With both of these it should work fine. Also use a lot of asserts during development so you know ASAP if something fails - so ou can correct whatever the problem is.

Amazon S3 (AWS ) NSMutableData

2 Answers2