1. Create separate debug outputs and properly describe what you do since.
2. Give your thread a proper name.
Don't care about repots or logs, etc.
Looked at the end of the first file, problem there is that QProcess::splitCommand returns
-add
C:\Users\79142\AppData\Local\Temp\2023-09-25@20_42_08_9410_03.265#video:fps=60:name=2023-09-25 11:28:34 UTC:lang=
-brand
hvc1
-add
C:\Users\79142\AppData\Local\Temp\iId_1_aid_0_lang_ru_2023-09-25@20_42_08_9410_01.aac#audio:name=:lang=ru
-mpeg4
-itags
tool=Hybrid 2023.03.17.1
-tmp
C:\Users\79142\AppData\Local\Temp
-new
E:\COOKIE 111\2023-09-25@20_42_08_9410__05.mp4
for:
-add "C:\Users\79142\AppData\Local\Temp\2023-09-25@20_42_08_9410_03.265"#video:fps=60:name="2023-09-25 11:28:34 UTC":lang="" -brand hvc1 -add "C:\Users\79142\AppData\Local\Temp\iId_1_aid_0_lang_ru_2023-09-25@20_42_08_9410_01.aac"#audio:name="":lang="ru" -mpeg4 -itags tool="Hybrid 2023.03.17.1" -tmp "C:\Users\79142\AppData\Local\Temp" -new "E:\COOKIE 111\2023-09-25@20_42_08_9410__05.mp4"]
which is wrong. since it removed all quotes, but the quotes, which is wrong for
-add "C:\Users\79142\AppData\Local\Temp\2023-09-25@20_42_08_9410_03.265"#video:fps=60:name="2023-09-25 11:28:34 UTC":lang=""
which should be turned into:
-add
"C:\Users\79142\AppData\Local\Temp\2023-09-25@20_42_08_9410_03.265"#video:fps=60:name="2023-09-25 11:28:34 UTC":lang=""
=> this will take some time to work around.