The swr_init function in libswresample/swresample.c in FFmpeg before 1.1.3 allows remote attackers to have an unspecified impact via an invalid or unsupported (1) input or (2) output channel layout, related to an out-of-bounds array access.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.