inaccurate max per-file depth in samtools mpileup

Question

[jing.mengrabbit]

Hi, I run samtools mpileup and set the -d 100 (max per-file depth), and that is the ouput information:

[mpileup] 1 samples in 2 input files

<mpileup> Set max per-file depth to 8000

Why the output is different from What I set?