Hello,
I don't know how precisely you do the job in kdenlive
(you could share the .kdenlive, the .sh.mlt, a screenshot),
one thing I suspect is the track composition (automatic transparency):
if you keep the default high quality choice,
kdenlive adds "composite & transform" transitions that are based on
Qt.
So without gpl / qt module, MLT skips these transitions.
Could you run your test switching to "no transparency"?
(toolbar just above timeline)
Thanks for you enthusiastic investigations :)
Vincent
Le mardi 24 juillet 2018, 23:26:01 CEST johnar1 a écrit :
Hey guys, I have some more info.
Hey Eugen, I have some more info.
For this test I used mlt 6.11, successfully compiled by Dan
Dennedy's build-melt.sh
The test file that I am using is the 1080p version of Sintel.
_https://durian.blender.org/download/_
CPU: i5 6600K, GPU:GTX 750 TI nvidia-390 driver , Platform: Kubuntu
18.04
In order to check melt and isolate the problem I simply rendered
the first minute of the Sintel short film with the following command:
(This is not the /bin/melt, but the script which launches it with
the correct libs)
/home/frank/melt/20180724/melt -profile atsc_1080p_60 sintel.mkv
out=3600 -consumer avformat:result-60.mp4 f=mp4 vcodec=h264_nvenc
preset=slow
[CPU Utilization: 67% - 70% - 68% - 74%] [Video Engine Utilization
(NVENC): 80%] [Render Time: 20s]
It obviously works perfectly.
Now when I select this melt in the kdenlive environment, and also
ffmpeg, ffplay, ffprobe and the profiles path from Dan's melt
folder, yields the following results when rendering the first
minute of Sintel.
[CPU Utilization: 100% - 7% - 10% - 18%] [Video Engine Utilization
(NVENC): 8%] [Render Time: 2m54s]
Something in kdenlive breaks parallel processing, only allowing 1
single core to be fully utilized.
And I have tested every single version of kdenlive available on
this earth.
Every app image, including the refractoring version and every
single ppa version, including stable, dev and master.
Also generating and launching the render script from the terminal
yields the same result.
RENDERER="/home/frank/kdenlive/bin/kdenlive_render"
MELT="/home/frank/melt/20180724/melt"
SOURCE_0="file:///home/frank/Documents/scripts/script001.sh.mlt"
TARGET_0="file:///home/frank/Documents/untitled.mkv"
PARAMETERS_0="-pid:2664 in=0 out=3052 $MELT atsc_1080p_60 avformat
- $SOURCE_0 $TARGET_0 vcodec=nvenc_h264 threads=4 real_time=-1"
$RENDERER $PARAMETERS_0
I have also tested different kdenlive_render executables/libs with
the same result.
I should note, that using the kdenlive_multirender script in
conjunction with the generated render script by kdenlive, while
specifying 4 threads, the CPU uses 2 cores at 100%.
_https://github.com/unfa/kdenlive-multirender_
Now as I have described before, when I compile melt without
enabling gpl, the 1 minute of Sintel renders perfectly again, with
full utilization on both the CPU and GPU, but from within Kdenlive
this time.
I conclude that this problem is somehow caused by Kdenlive and
related to qt, but I do not possess the knowhow to further analyze it.
With the latest 18.08 Beta18 and the most recent QT version, 2
cores instead of 1 are now being utilized at 100% with the NVENC
profile and 100% on all 4 cores using the MP4 h264 profile.
So this is 100% a QT issue with NVENC, but I need further insight
from a professionals like yourselves.
Sent with _ProtonMail_ <https://protonmail.com> Secure Email.
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On July 16, 2018 7:51 AM, johnar1 <john...@protonmail.com> wrote:
System: i5 6600K, 1050TI, Ubuntu 18.04, Kernel 4.16
I have successfully compiled mlt and ffmpeg with nvenc support
using the official nvenc headers stripped from the Nvidia SDK.
Rendering the first minute of the 1080p Sintel version, with 4
threads specified and my nvenc profile, finishes in 10 seconds.
Sintel can be downloaded here:
_https://durian.blender.org/download/_
<https://durian.blender.org/download/[/url>
Nvenc Profile: (compatible with recent mlt versions who are nvenc
enabled by deafult)
f=mp4 vcodec=nvenc_h264 global_quality=21 vq=21 preset=slow bf=2
ab=384k
Now here is the problem that I do not understand:
Using the latest version of kdenlive from the kdenlive-master ppa
combined with the newly compiled versions of ffmpeg and mlt works
perfectly, but only under very specific circumstances.
I have only been able to get rendering with nvenc to work properly
when I use and open this specific kdenlive [b]save file[/b] which I
made of the first minute of the Sintel short film with the Appimage
Version of Kdenlive. After launching the ppa/installed version of
kdenlive and opening this save file, rendering with nvenc works
flawlessly.
If I simply start a new project, adding the whole Sintel short film
to the project bin, cutting the first minute and render it, nvenc
simply does not work and the render time is tripled, despite having
changed nothing else, including the nvenc render profile.
If I create a save file of the first minute of Sintel with the
installed version and open it on the Appimage version, nvenc does
not work again.
Conclusion: There must be something in this save file, maybe a
parameter, additonal settings or any type of code not present in
the default kdenlive project profiles, which enables NVENC.
I would greatly appreciate it if we could find out the source of
this problem together.
Kdenlive Appimage Save File with which NVENC works:
_https://pastebin.com/rzjR57DJ_
PPA/Installed Version of Kdenlive created Save File which breaks
NVENC:
_https://pastebin.com/3uQ8sP0C_
