Avidemux Forum

Avidemux => Main version 2.6 => Topic started by: phaolo on June 16, 2021, 12:27:20 AM

Title: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: phaolo on June 16, 2021, 12:27:20 AM
I tried encoding a clip of 5mins to Hevc x265 in Avidemux, but it took like 30mins.
I then tried Handbrake with similar settings and it managed to do the full 45min video in something more than 1h.
Is there some problem with the encoder in Avidemux?
Title: Re: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: szlldm on June 16, 2021, 07:32:15 PM
IMHO it must be that similar != same. Both Handbrake and Avidemux use ffmpeg libraries for encoding.
Title: Re: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: eumagga0x2a on June 16, 2021, 09:17:09 PM
Assuming that Handbrake uses x265 (either directly like Avidemux or indirectly via libavcodec), compare the output of mediainfo regarding the x265 version (you could post both mediainfo reports here). It is possible that Handbrake uses a more recent version of the x265 library.

However, encoding with x265 at a speed near real time is possible only with an absolutely top-notch hardware or with a preset sacrificing quality for speed. I hardly ever get two-digit frame rates with a 720p source when encoding to HEVC using x265.
Title: Re: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: phaolo on June 17, 2021, 06:35:27 AM
Mm.. maybe it's my fault, because I wanted to set a GOP min=30 max=60.
But to do that in Avidemux you have to use Advanced Config, and that disables the presets.
In Handbrake you can keep the presets and then just add parameters for keyint.

How do you even setup a "veryfast" method in Avidemux with adv config?
Title: Re: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: eumagga0x2a on June 17, 2021, 04:41:31 PM
Quote from: phaolo on June 17, 2021, 06:35:27 AMI wanted to set a GOP min=30 max=60.
But to do that in Avidemux you have to use Advanced Config, and that disables the presets.

I'll need to investigate untying GOP size from advanced config.

Quote from: phaolo on June 17, 2021, 06:35:27 AMHow do you even setup a "veryfast" method in Avidemux with adv config?

If https://www.ramugedia.com/rate-control-of-x265 (https://www.ramugedia.com/rate-control-of-x265) is valid, "veryfast" matches a x265 command line

-b-adapt 0 -b 4 --tu-inter-depth=1 --tu-intra-depth=1 --rd 0 --subme=1 --me=1 --max-merge=2  --no-amp --no-rect --no-tskip --early-skip
But this would be clumsy way to achieve this. Instead, if enforcing GOP size limits can coexist with presets, the corresponding controls need to be made accessible in the simple / non-advanced mode.
Title: Re: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: phaolo on June 17, 2021, 04:48:20 PM
Quote from: eumagga0x2a on June 17, 2021, 04:41:31 PMBut this would be clumsy way to achieve this. Instead, if enforcing GOP size limits can coexist with presets, the corresponding controls need to be made accessible in the simple / non-advanced mode.
OMG I hope so..
Btw in case you'll manage to do it, could you add the setting like OBS does?
It allows a keyint in seconds and it's quite convenient because you won't have to check the video's framerate.
Title: Re: Avidemux 2.7.8 - encoder HEVC (x265) too slow?
Post by: eumagga0x2a on June 17, 2021, 04:50:52 PM
Quote from: phaolo on June 17, 2021, 04:48:20 PMBtw in case you'll manage to do it, could you add the setting like OBS does?
It allows a keyint in seconds and it's quite convenient because you won't have to check the video's framerate

I would call this a minor inconvenience.