Progression of formats... (1 Viewer)

[socialSavant]

I have had something on my mind a while now and was unable to find anything about it on the forums here. If I missed a previous post, please show me the way.

Mostly, I am interested in what the actual progression of formats is when watching/recording/"compress"ing via MP. That is to say, for example, I have the popular Hauppauge PVR-150 which is a Hardware MPEG encoder (as far as I understand) and record live tv via MP; which creates a DVR-MS file. I was wondering if this is absolutely necessary or is simply much easier to implement. It just seems to be a bit superfluous for me to go from MPEG -> DVR-MS -> MPEG (after using the "compress" function). If I am completely off-base, let me know; I am truly new at all this...

Keep in mind, I am just trying to find a tweak or something that allows me to save a bit of space/cpu cycles as well as understand all this a lil' more.

Thanks in advance,
--socialSavant

 

[Taipan]

It just seems to be a bit superfluous for me to go from MPEG -> DVR-MS -> MPEG (after using the "compress" function).

MediaPortal uses Microsoft's "stream buffer engine" for timeshifting and recording, and the sbe only creates DVR-MS files. A DVR-MS file is just the regular MPEG2 file with an MS 'wrapper" around it - so conversion back to a regular MPEG2 file is just a matter of removing the wrapper. There is very little difference in size between the 2 formats.

As this is a query, and not a "Tips and Tricks", I have moved this thread to the correct forum - General Support.

 

[socialSavant]

Ok that makes sense. Thank you and sorry about posting in the wrong forum... am a lil sick today and my wits arent what they should be.

So does this mean that having a hardware encoder still has the same benefits? Or does it matter when using the SBE? That is to say, what can i do to save cpu cycles and is the tuner helping in that respect?

Thanks again,
--socialSavant

 

[Maschine]

As Taipan already said the output of the SBE, the dvr-ms files, are actually MPEG2 videos with just some additional info (similar to ID3-tags for mp3 music files). Next thing is that the SBE requires also MPEG2 video as source. Meaning a digital signal or if it's an analogue signal this needs to be compressed before. This is done either in software or in your case by a hardware encoder. So this encoder is needed for you, if you did the encoding in software (hawing a sw-card) THAT would stress your CPU. I think you're already optimized so don't think about that 8)

Maschine

 

[Taipan]

So does this mean that having a hardware encoder still has the same benefits?

Yes, definitely! The hardware encoder converts the analogue video frames into the MPEG2 stream, and then the SBE writes it to disk as a DVR-MS file.

what can i do to save cpu cycles and is the tuner helping in that respect?

Yes, the tuner is doing its best to "save CPU cycles". If you monitor the CPU% usage while recording a TV program (but not watching TV at the same time) you will see that the CPU% is very low.

About the only other thing you can do is to use a video decoder that utilises DxVA (hardware decoding) like the Nvidia PureVideo decoder, which will off-load the decoding of the MPEG2 stream to the video card. This can easily halve the CPU% used, but is only effective when you are displaying TV or a video/DVD.