For LDPC, the executable can be found at
The C++ executable for Turbo code can be found at
I'm not very familiar with Valgrind so I monitored the memory usage by looking at system monitor on my Ubuntu laptop. The memory usage is almost constant, at around 17.1 Mbs for the ldpc_decoder executable. On GNU Radio, the memory usage jumps by huge steps (100Mb) in a matter of seconds until all the memory (the ram is around 8 gigs) is fully consumed.
Thanks for links to the memory buffer blog post. I will have a look.