Newb Question: What is your Favorite Decoder?

[InTheFlow]

Hey Everyone!

I have some questions about decoders...

1. What do the decoders do within Sage TV? Are they for recording or playback? i.e. Do they affect playback of the Mpeg file or the recording of it?

2. In your opinion, what is the best decoder to use & why?

3. Do the decoders work differently between the ATI or nVidia cards or do they only affect how the TV card operates?

If we get a good discussion going on this, it will help all of us newbies decide if the extra investment in seperate decoder software is worth it.

Thanks!

[Wheemer]

Your tv feed comes into the computer through your tuner card as interlaced video. In order to view it properly it has to be deinterlaced by the video decoder. So it affects playback only. There may be slight performance differences between different video cards, but they are generally the same. Some decoder can offer more support of specific video card functions, like DXVA (hardware assisted decoding) or purevideo (Nvidia).

I personally use the Nvidia DVD decoder and find it performs perfectly for me. I am very happy with the resulting picture on my SDTV via Svideo out. The picture is undistiguishable from direct input from my cable box (besides a few jumps and stutters here and there).

[stanger89]

Originally Posted by InTheFlow

Hey Everyone!

I have some questions about decoders...

1. What do the decoders do within Sage TV? Are they for recording or playback? i.e. Do they affect playback of the Mpeg file or the recording of it?

Playback only, they have no effect on the recordings.

2. In your opinion, what is the best decoder to use & why?

nVidia's latest, no doubt.

3. Do the decoders work differently between the ATI or nVidia cards or do they only affect how the TV card operates?

Mostly no, but nVidias decoders do work different on nVidia cards. nVidia's latest cards, the 6 series have a number of features that are (AFIAK) unavailable from any other manufacturer, namely: Film detection/3:2 Pulldown correction, Pixel Adaptive Deinterlacing. Those features are (AFIAK) only available on nVidia cards with nVidia's decoders.

Slight correction, those are only available in HW (DXVA) on nVidia cards, the film detection can be done in software on other cards.

[mikejaner]

I agree with everybody on Nvidia's decoders looking great. I also want to state that the Sonic Decoders look great as well. I like them a little better right now because they behave better than the Nvidia ones when doing 4:3 on my HDTV. For some reason, the Nvidia decoders don't let you set the unused portion of the screen to a color other than black, using the Sage settings. the Sonic ones do.

[korben_dallas]

If you have a DivX/MPEG-4 hardware encoder capable capture card.. the Plextor PX-TV402U and M402U are the only ones currently supported in SageTV.. then whatever DivX codec you have installed with the highest DirectShow merit will be used by SageTV for playback. Same for MPEG-4 (non DivX).

[InTheFlow]

Thanks for the info!

So, are decoders codecs?

[InTheFlow]

Originally Posted by Wheemer

Your tv feed comes into the computer through your tuner card as interlaced video. In order to view it properly it has to be deinterlaced by the video decoder. So it affects playback only.

Ok, so the hardware encoding that is built into the TV card is what actually takes the interlaced video and puts it into a MPEG file..is that correct?

[sharker]

I'm glad this was stated as being a newbie thread...
If I don't have a dvd drive in my computer, do I still need to load a DVD decoder to take advantage of my nvidia hardware decoding? I set dxva to 1, but have no idea whether that takes care of it, or if I should buy the nvdvd to get the most out of the card. Any thoughts?

[InTheFlow]

Hey Sharker,

I don't know the answer to your questions but the people who do will probably need to know what kind of TV card and video card you are using in order to help ya out.

Would you post that info? And, great questions...I'm glad you asked and am looking forward to the answers!

[stanger89]

Originally Posted by InTheFlow

Thanks for the info!

So, are decoders codecs?

Yes and no, I think technically a codec is an encoder/decoder, but the way most people talk, they use the terms interchangably.

[stanger89]

Originally Posted by sharker

I'm glad this was stated as being a newbie thread...
If I don't have a dvd drive in my computer, do I still need to load a DVD decoder to take advantage of my nvidia hardware decoding? I set dxva to 1, but have no idea whether that takes care of it, or if I should buy the nvdvd to get the most out of the card. Any thoughts?

It depends, the Intevideo NonCSS can use DXVA, but I don't know what deinterlacing methods they invoke. The new Sage decoders don't support DXVA.

To get all the features of nVidia's new hardware, you have to be using their decoders, with 67.03+ drivers and VMR9. Any other decoder (that supports DXVA) may get you the deinterlacing if you use VMR9, but I don't think it will get you the film detection.

[InTheFlow]

What is DXVA? A special decoder that works with nVidia hardware only?

[WeatherB]

I'd say the Sonic CinePlayer codec is better than the NVDVD... Having bought both I must say that the colours are more vibrant in the Sonic one (plus it is $5 cheaper)

[stanger89]

DirectX Video Acceleration
This section contains information about Microsoft® DirectX® Video Acceleration (DirectX VA). This is an application programming interface (API) and a corresponding motion compensation device driver interface (DDI) for acceleration of digital video decoding. The following additional DDIs are also provided as part of DirectX VA:

http://msdn.microsoft.com/library/de...6e676f.xml.asp

[stanger89]

Originally Posted by WeatherB

I'd say the Sonic CinePlayer codec is better than the NVDVD... Having bought both I must say that the colours are more vibrant in the Sonic one (plus it is $5 cheaper)

If the colors are very different, then you probably aren't using the same (or similar) color profiles. The differences between good decoders is quite subtle, especially if you're talking about colors.

[WeatherB]

I tried different colour profiles but they didn't look as good as the Sonic decoder.

[sharker]

Please correct me if the following is either false or stupid:
If you want hardware decoding on your card, you need to buy software to turn it on?

Is this because of some licensing thing with the MPEG commitee? I think I may be missing something, so please excuse my ignorance. If I bought Sonic, wouldn't I be buying a license to watch DVDs on my computer (which I can't because no DVD player, but the MPIA's happy) with a free codec thrown in? Couldn't I just get the free codec from someone else, since the idea behind DVD readers needing to be licensed is because of the DVD? I'm confused.

[korben_dallas]

Originally Posted by sharker

Please correct me if the following is either false or stupid:
If you want hardware decoding on your card, you need to buy software to turn it on?

Is this because of some licensing thing with the MPEG commitee? I think I may be missing something, so please excuse my ignorance. If I bought Sonic, wouldn't I be buying a license to watch DVDs on my computer (which I can't because no DVD player, but the MPIA's happy) with a free codec thrown in? Couldn't I just get the free codec from someone else, since the idea behind DVD readers needing to be licensed is because of the DVD? I'm confused.

The difference is between hardware decoding and hardware-accelerated decoding. A PVR 350 (and the Xcard?) does hardware decoding. A 6600GT does hardware-accelerated decoding with all the HD bells and whistles. A 6800 and 9800 do some hardware-accelerated decoding with DirectX 9 functions. A pci Voodoo video card does none and probably wouldn't even work.