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[paul1970]

I am considering whether re-encoding some of my SD material at a higher resolution might be a good idea and I'd appreciate any thoughts from those who know or who have been there.

I have a system with lots of disc-space but that is borderline on gfx performance. I generally use Red October HQ with the best upscaling settings I can get away with and this is fine for all of my HD and most of my SD material. Some of my best-loved SD concerts though seem to cause the upscaling engine a bit more trouble and the only thing for it is to use RO Standard. This is Bad for two reasons:
1) I have to start up Remote Mouse on my iPhone to make the change. All a bit fiddly.
2) I do notice the drop in PQ.

So, I think that re-encoding the SD files with upscaled video might be worth a try since I'm not particularly bothered how big the files get if someone can recommend an encoder with good options that will get me in the same ballpark as madVr manages.

I understand that there's always going to be some level of degradation associated with a 2nd gen lossy encoding, but with the right settings I don't see it being an issue for this application.

Thoughts anyone?

[jmone]

Interesting Q!  Generally the answer would be No as the going from the original file via the decoder & renderer during playback would result in the best quality, and these days the decoders & renderers should have both broad enough format support and be quick enough.  You "may" consider pre-transcoding files if you have:
- Compatibility Issues:  eg I transcoded all my DV-AVI files to AVC in M2TS containers as I found support for original DV-AVI was becoming spotty
- Performance Issues:  as in your case if your HW can not decode & render in real time you may want to re-encode but in general you would be better to just buy a better HW (eg GPU for madVR).

While there would be 2nd generational loss, as you would be decoding --> rendering --> encoding in most cases you will not notice any loss.  As an experiment, try using MC's Video conversion to make a stacked file and see you can notice any issues.

Thanks
Nathan

[paul1970]

Thanks for the response.
I'm not sure what you mean by 'stacked file'. I'm only familiar with stacks of particles.

EDIT: And will MC Video Conversion use MadVR as the renderer?

[Hendrik]

Video converison never uses a renderer, the renderer is only used when displaying the video.

For a goal of such high quality, you will likely not find a finished conversion software that does that. Most converters just use "simple" scaling, including MCs video conversion.

[paul1970]

Oh, OK. Thanks. I assumed that it would use a renderer to render the image to an offscreen surface which would then be encoded for the required output. It was worth asking then!

[jmone]

.... if there is no renderer, what is the intermediate format used between the decoder and encoder?

[Hendrik]

In MC all video conversion uses a YV12 or NV12 memory buffer.

[paul1970]

Doesn't the video have to be rendered into that buffer though?

[Hendrik]

No, thats just what the decoder outputs, and what you would usually give to the renderer. Instead of doing that, its just given to the encoder.

[paul1970]

Thanks for clearing that up.

[jmone]

Thanks - so am I understanding correctly that the encoder is working directly on a 12 bit 4:2:0 YUV stream or does something scale the chroma to 4:4:4 at some point?   
Nathan