update deprecated function ( avcodec_alloc_frame, get_buffer, avcodec_default_get_buffer )

[Schebb]

avcodec_alloc_frame -> av_frame_alloc
avcodec_default_get_buffer -> avcodec_default_get_buffer2
get_buffer -> get_buffer2

... and clean space at end of line.

need also to update:

• avcodec_default_release_buffer
• release_buffer

[mpenkov]

Hey, thanks for doing the update. I notice there's a lot of unnecessary white space changes mixed in the same commit with good changes; can you please modify the commit to remove them? I don't mind you changing the whitespace, I just think they belong in a separate commit, to keep things easy to understand.

[Schebb]

Done.

Actually, I noticed the whitespace changes after the commit (wrong emacs config :-/). I only changed the functions on this commit.

[ghost]

Actually, it's probably better not to change any whitespace at all. That way, people can diff the most recent version of the source with the old Dranger tutorials and still get a meaningful result.