Placeshifter: use b-frames?

[sainswor99]

I'm placing this message in the Beta section because I'm running the latest release candidate for 6.1; however, I'm not sure if this is related to 6.1 or not.

I have an older laptop that I'm using as a PlaceShifter client; I've been having a devil of a time getting it to run without stutter (wired or wireless; LAN or Internet). Tonight I disabled the following setting:

use B-frames in video encoding

and suddenly my stutter problems went away. Any clue as to what this setting is? It must be related to the graphics capability of the client machine, because I have the same setting enabled on my main PC, and have never had an issue.

TIA,
Stu

[bcjenkins]

http://www.afterdawn.com/glossary/terms/b_frames.cfm

Less filling!

[sainswor99]

B Frames

B Frames can be found in MPEG video streams. They are not full frames and predicted by both the previous frame(s) and the next frames. Since they are not full frames, they use the least amount of space to store the frame data.

Sooooo..., any ideas why turning this on/off would affect placeshifter performance?

Stu

[bcjenkins]

Sure, only getting b-frames would be less data therefore easier to process for older equipment

B

[sainswor99]

But (unless I misunderstand the nature of the check box) the inverse is happening; the placeshifter client is performing better with b-frames disabled on the laptop (Pentium M 1000; 1 Gig Ram). It's a Toshiba Portege, with a relatively horrible video processor, but it's very lightweight.

I have not filed a bug report with this yet; I want to test a few more scenarios first. However, I'm just trying to understand what could be happening. Obviously, the checkbox is there for a reason; I'm just trying to understand what the reason is.

Thanks!

Stu

[Narflex]

If you have B-frames disabled, 2 things happen:

1) the compression will not be as good
2) it takes less CPU power & memory to decode and encode the video (benefit on the server and the PS client)

[sainswor99]

Thanks for the clarification; that makes sense.

May I suggest that you include that answer in Appendix N of the Sage manual? Right now, the description for the additional options under Placeshifter reads something like:

"These are some additional options. You can click them when you click here."



Stu

[Mikey_Likes_It]

I have a Core 2 Duo 2.4Gh, 2GB and a 7600GT Fata1lity everything seem
to work great initially, until I have over 5 hours of HD OTA recordings.
Then the sagetvtranscoder.exe hogs the system with max. harddrive activity
for minutes when ever I start playback. After the harddrive activity
settles down, I can watch the recorded program without audio and video shutter problems.
Memory activity and memory paging activity durning this
time are off the charts. I have read in the forums that my Raid 0
cannot keep up with the I/O requests. If this was true then shuttering problem wouldn't go away.

I just downloaded 6.1, and I'll give it a try, then I look at changing
xcode_process_priority=idle
xcode_reduce_process_priority=true
as suggested earlier.

Before the problem started, HD 1080i playback only consumed 34% of one
of two cores. When the sagetvtranscoder.exe starts being a hog, 100%
and 90% of core 1 and core 2 are being utilized.

Are there any other suggestions I can take a look at?
Thanks,