L-SMASH Source

[-QfG-]

I have trouble with the last both versions. Except Violation Error, if i will indexing my DNxHR HQX Content in a Quicktime Container.

[Atak_Snajpera]

Originally Posted by HolyWu

https://github.com/HolyWu/L-SMASH-Wo...ks_20190914.7z

• VideoSource: Fix fallback to software decoder in prefer_hw.
• LWLibav: Fix access violation in file name manipulation.

I'm not able to fix it. Need investigation by the origianl developer. A workaround is to extract the video track as .m2v file and it will work fine. Or alternatively use MPEG2Source which should be reliable for MPEG2 streams.




Please try and see whether the latest build fix your issue.

Ok. Would IT be difficult to add that auto option regarding hardware decoding? I'm asking because in distributed encoding mode some machines may have NVIDIA GPU and some Intel GPU.

[HolyWu]

https://github.com/HolyWu/L-SMASH-Wo...ks_20190917.7z

• VideoSource: Add prefer_hw=3.

[Atak_Snajpera]

Originally Posted by HolyWu

https://github.com/HolyWu/L-SMASH-Wo...ks_20190917.7z

• VideoSource: Add prefer_hw=3.

It is almost perfect... However... Lsmash does not check if hardware decoder supports specific codec. I have a Kepler GPU which does not support HEVC decoding and in this case prefer_hw=1/3 returns an error message.

[redbtn]

First of all, thank you HolyWu for updates!
Can I ask what matter to use hardware decoder? I have Nvidia RTX 2060, but I did test and didn't notice difference in encoding speed.
What decoder is preferred in my case? Thank you!

[poisondeathray]

Originally Posted by redbtn

First of all, thank you HolyWu for updates!
Can I ask what matter to use hardware decoder? I have Nvidia RTX 2060, but I did test and didn't notice difference in encoding speed.
What decoder is preferred in my case? Thank you!

It depends on your scenario

e.g if the bottleneck is your encoder/ encoding settings, or some filters, maybe offloading the decoding to GPU might not make much of a difference

eg. If decoding only uses 0.5% of your CPU (maybe SD footage), it might not make much of a difference either

Other scenarios might be different. e.g. Decoding UHD/4K footage might take significant CPU resources. Offloading that decoding task to GPU should free up CPU cycles to encode faster (if using a "CPU encoder" )

[redbtn]

Originally Posted by poisondeathray

It depends on your scenario

e.g if the bottleneck is your encoder/ encoding settings, or some filters, maybe offloading the decoding to GPU might not make much of a difference

eg. If decoding only uses 0.5% of your CPU (maybe SD footage), it might not make much of a difference either

Other scenarios might be different. e.g. Decoding UHD/4K footage might take significant CPU resources. Offloading that decoding task to GPU should free up CPU cycles to encode faster (if using a "CPU encoder" )

Thank you for explaining. I encode 4k HDR > 1080p HDR using x265 and VapourSynth. So, I will try again, maybe I will see the difference. Is it right, that both software and hardware decoders work the same and no difference in quality or stability? Can I safely choose hardware decoder for all my encodes and don't worry about something goes wrong?

[poisondeathray]

Originally Posted by redbtn

Thank you for explaining. I encode 4k HDR > 1080p HDR using x265 and VapourSynth. So, I will try again, maybe I will see the difference. Is it right, that both software and hardware decoders work the same and no difference in quality or stability? Can I safely choose hardware decoder for all my encodes and don't worry about something goes wrong?

Money back guarantee

There were differences in earlier versions with CUVID, but this version looks to have fixed it

I don't think there has been enough testing to ensure everything works 100%

If something goes wrong, report it . That's the only way stuff gets fixed

[stax76]

Can I ask what matter to use hardware decoder? I have Nvidia RTX 2060, but I did test and didn't notice difference in encoding speed.
What decoder is preferred in my case? Thank you!

How many CPU cores? I don't think you gain something substantial if you have more than 4 cores, that's what my encoding test showed, sw 60 fps, hw 61 fps.

StaxRip hasn't the most efficient drawing implementation, dealing with 4K in the crop and preview dialog users get a noticeable improvement with a HW decoder.

[redbtn]

Originally Posted by stax76

How many CPU cores? I don't think you gain something substantial if you have more than 4 cores, that's what my encoding test showed.

StaxRip hasn't the most efficient drawing implementation, dealing with 4K in the crop and preview dialog users get a noticeable improvement with a HW decoder.

I have I5-9400f 6 core processor. On preset Slower x265 with some minor changes i get 2.4-2.6 fps.
So, if I can't see any difference after tests, the best way choose software decoder, right?

[Atak_Snajpera]

Originally Posted by redbtn

I have I5-9400f 6 core processor. On preset Slower x265 with some minor changes i get 2.4-2.6 fps.
So, if I can't see any difference after tests, the best way choose software decoder, right?

No wonder you see no differences with hardware decoding if encoder is only requesting on average 1 frame every 400ms.

[MeteorRain]

Hardware decoder can easily reach 200fps on 1080p source.

[Atak_Snajpera]

Originally Posted by MeteorRain

Hardware decoder can easily reach 200fps on 1080p source.

Decoding speed with blu-ray avc source is around 130fps on Kepler.
For comparison:
Q8200@2.8GHz reaches 100fps (~85% cpu usage)
Xeon E5-2690@3.2GHz reaches 440fps (~75% cpu usage)

[MeteorRain]

Thanks for correcting. Although those fps are "free" fps that does not fight with encoding speed at all. When transcoding HEVC 4k, having hardware decoder can free up large portion of CPU resources and leave them for encoding. I'd still use hardware decoder whenever possible to me.

[Atak_Snajpera]

Originally Posted by MeteorRain

Thanks for correcting. Although those fps are "free" fps that does not fight with encoding speed at all. When transcoding HEVC 4k, having hardware decoder can free up large portion of CPU resources and leave them for encoding. I'd still use hardware decoder whenever possible to me.

In theory yes but in practice no. Encoder will still be responsible for about 98% of CPU time. You will only see difference If you encode hevc 4k 100Mbps to low resolution with x264 and preset superfast.

[DJATOM]

If you're using heavy filters (like eedi3 or mdegrain), you'll definitely see an improvement in speed with HW decoder.

[Atak_Snajpera]

Originally Posted by DJATOM

If you're using heavy filters (like eedi3 or mdegrain), you'll definitely see an improvement in speed with HW decoder.

Nope because those filters work on CPU creating additional bottleneck.

[DJATOM]

Originally Posted by Atak_Snajpera

Nope because those filters work on CPU creating additional bottleneck.

Yeah, and offloading decoder to GPU saves CPU cycles for encoder and filters.

[sneaker_ger]

Atak_Snajpera is right. The more of my CPU time "cake" is spent on filtering and encoding the less impact HW decoding will make on speed. It doesn't mean HW decoding won't make encoding faster it's just that the percentage goes down. (Exception is if my CPU isn't utilized 100%.)

Imagine you use AV1 encoder with placebo settings and very slow filtering (QTGMC+waifu2x) and software decoding of source. Then 99% of CPU time is spent on encoding+filtering, 1% on SW decoding. If you replace SW decoding with HW decoding you only free up that 1%. If you use no filtering and very fast encoder settings (x264 preset ultrafast) maybe you have 70% encoding and 30% SW decoding. Then replacing SW by HW decoding can increase speed much more.

[Atak_Snajpera]

Originally Posted by DJATOM

Yeah, and offloading decoder to GPU saves CPU cycles for encoder and filters.

You do not realize how encoding chain works. Encoder determines how fast IT needs frames from decoder. Any filtering in avisynth will only slow down frame requests.