There are many recovery programs dedicated to recovering photos and other multimedia files from memory cards. Most, such as Stellar Phoenix Photo Recovery 5 work well--assuming they don't encounter anything oddball.
I put Phoenix Photo Recovery 5 through its paces with some files erased from an SDHC card and it found nearly everything, including all my deleted photos, and some of the .mov files I'd erased. However, it did not find the separate, linked headers that the Canon camera writes to the card. Without these headers, the recovered .mov files won't play. To be fair, only one program I've tried recovered these headers--the free, command line-based PhotoRec--and even it wouldn't merge them with the corresponding data files. Currently, to the best of my knowledge, you must use a hex/sector editor such as hexedit and merge these files manually.
Stellar Phoenix works as well as most of the myriad pay photo recovery programs I've tried and its simple interface and straightforward approach make it easy to master. However, when there's a free alternative such as PhotoRec that works as well or better, any pay program is going to be a tough sell.
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