Player with good quality Slow Down function

[Bencuri]

I need to watch a video slowing down its speed. The average slowing down I need is about 50% of the original speed, but at some parts I need to watch it even slower. I could create a 50% slow version of it with Sony Vegas and Audacity, and that way the results are quite good. Audacity can do a very good job on the audio side. But it would really help if I could get the same results with a player, where I can alter the speed. I only tried VLC so far, but that does not do a very good job, the audio becomes fragmented, not continuous when I set the playback slower. Any recommendation for a player that can do a recent job in this regard?

[Dreamer]

PotPlayer? Speed from 0.2x speed. Perhaps it's possible to increase fps somehow, to improve playback.

[jagabo]

VLC works fine for me. It can either timestretch (keep pitch, but ratty autotune sound) the audio or slow the sample rate (change pitch, but clean sound). Pretty much all the free players can do the same. MPCHC, MPCBE, KMPlayer, PotPlayer, SMPlayer...