I set out not too long ago researching building an HTPC so that I could watch the many movies and TV shows I have on my computer on my TV. I looked in to several options until I realized that I have a PS3 hooked up to that computer - why would I need anything else?
My requirements are basically that the software be very easy to use on the PS3 end of things, and that it transcode from the multitude of formats and codecs I have on my computer (so that I don't need to worry about which codec to download) to one of the supported PS3 formats. I want to be able to watch 1080p quality videos without too much degredation as well.
There are several programs out there (free and pay) that will stream PS3 supported formats, but that would require me to re-encode everything that I have that isn't supported (and the PS3 has pretty poor support for most things, and zero support for .mkv files).
For programs it pretty much boils down to 2 options, one free, the other is $30. The $30 option is Nullriver's Medialink, and the free option is PS3 Media Server - a program that runs on Java. I figured Java would give the software unacceptable overhead so I went with Medialink to start with.
Medialink is very simple and easy to use - basically start it up, point it at the directories you want to share and set your connection speed (for quality). It starts up, and appears on the PS3 XMB. Works very well - or at least it did long enough for me to purchase it. There appears to be a bug between it and the latest PS3 firmware that causes the videos to stop playing after about 10 minutes. I could not find a way around this at all no matter what I tried. Nullriver did not respond to my support request and at this point I consider it a waste of $30. Until the problems are fixed, I would not recommend this software (version 2.0b8).
After the failure of this software I decided to go to PS3 Media Server. I had originally tried this software before going with Medialink but I could not get it to connect to the PS3 consistently (stupid error on my part I found out later). With Medialink off the board I was pretty much forced back to this and quite frankily I'm glad I was. I downloaded the latest Beta version (which had support for dual processer transcoding) and installed it.
PS3 Media Server itself is not the prettiest to look at, and there are tons of different configuration options - it gives you full control over how the transcoding and streaming function, but can be a little unwieldy. You should be fine leaving the settings alone and just setting the directories you want to pull from.
Now, after I installed it I ran in to the same issue as before - sometimes it would see the PS3, sometimes it wouldn't on startup. What was happening was it was selecting one of the virtual network interfaces that VMware Fusion had set up instead of the wired connection of 'en0'. I had to manually change the default interface it used in the general settings tab. Once I did that and restarted it, the PS3 instantly came up.
Since I am using a wired gigabit connection from my Mac to the PS3, I set the transcode settings to "lossless" and turned on the dual core transcoding in the "Mencoder" settings. I switched back over to the "Status" tab, and fired up the 1080p BBC's "Planet Earth" episode about Mountains (lots of high contrast, fine detail shots with movement) that I use for reference, and let it run, watching the buffer size on my computer. It looked amazing on my TV, with almost no transcoding introduced pixelation. There was some slight stuttering during some of the highly contrasted shots with movement, but I found if I paused the movie for even 25 seconds at the very beginning, there would be enough transcoded buffer to handle anything - and this is your outer limit of quality, most blu-ray movie rips aren't quite as contrasty.
So, in the end, I'm glad that Medialink gave me some problems because it just wasn't quite as good as PS3 Media Server. As well, PS3 Media Server updates relatively often - and if you like it please consider donating to them.