So what values do have the next variables of your PHP:
memory_limit
max_execution_time
?
For the successful convertation of similar big videos the server should have good size of memory. The SSD hard drive and powerful processor will be good too.
Had the same issue. It was fixed by adjusting this setting: "post_max_size" to a larger value than the video size. I used 200M as I want to upload large videos. It worked.
