iPhone videos will not play

When I try to play a video from my camera roll I am receiving the error message "the operation could not be completed". I also cannot take a video with my camera. At the same time this started to happen my sound and speakers stopped functioning. i have not been able to restore my sound (ring tones, alarms,etc.), however I can now hear when connected to a phone call (still has some scratching noises during the phone call). the phone did not loose functionality during a Bluetooth call via my car. I'm not sure what triggered this to start functioning but originally I was not able to make a phone call due to no sound.

i have restarted my phone multiple times.

i have rebooted using the home and sleep/wake button.

i have gone to ->settings->general->reset all settings

i have tried inserting headphones, still no working sound. Also the phone is not stuck in headphone volume.

i have tried connected to my computer and syncing to itunes

Leek week the Apple Store replaced my cracked screen and the phone was functioning fine for a few days after that, so I don't think they are connected but figured it was worth mentioning.

I have iPhone 6plus with ios 8.4

i would appreciate any help or suggestions anyone has about this.