Twitch ignores selected quality (1080p) and plays at ~160p when DLL proxy is enabled

[Vektor010]

Description

When using the Vivaldi Plus DLL proxy, Twitch streams behave incorrectly and load very slowly.
Even when 1080p is manually selected in the Twitch player, the actual playback quality remains extremely low (approximately 160p).

Steps to reproduce

Enable the DLL proxy from this repository

Launch Yandex Browser (Chromium-based)

Open any Twitch live stream

Wait for the stream to load (noticeable delay)

Select 1080p quality in the player settings

Expected behavior

Stream loads quickly, as it does without the DLL proxy

Video plays at the selected quality (1080p) with correct resolution and bitrate

Actual behavior

Twitch stream takes a long time to start loading

Initial buffering is significantly longer than usual

Video is heavily pixelated, visually matching ~160p

Switching quality options does not affect real playback quality

Additional notes

Without the DLL proxy, Twitch loads normally and plays in correct quality

The issue is reproducible on all tested streams

Possibly related to HLS / MSE handling, request proxying, or bandwidth throttling

Environment

Browser: Yandex Browser (Chromium-based)

OS: Windows 11 25h2

Player: Twitch HTML5

DLL proxy: enabled

#######################################################################################

Screenshot

Twitch player shows 1080p selected, but actual playback quality is very low (~160p)

[czyt]

@Vektor010 i will look through this later，thanks for your issue

[czyt]

@Vektor010 hi，could you run your browser without vivaldi++ and pass a command line param

yandex.exe --disable-features=RendererCodeIntegrity

to see if the playback is veryslow too.
or you can try https://github.com/ca-x/vivaldi_plus/releases/tag/v1.5.8.4-b

[Vektor010]

@Vektor010 hi，could you run your browser without vivaldi++ and pass a command line param

yandex.exe --disable-features=RendererCodeIntegrity

to see if the playback is veryslow too. or you can try https://github.com/ca-x/vivaldi_plus/releases/tag/v1.5.8.4-b

=======================================

I tested it.
Without Vivaldi++, the browser works very fast: it starts quickly and pages load normally.
With Vivaldi++, the browser becomes very slow — it feels about 5× slower.
The issue is reproducible.

[czyt]

@Vektor010 hi，could you run your browser without vivaldi++ and pass a command line param

yandex.exe --disable-features=RendererCodeIntegrity

to see if the playback is veryslow too. or you can try https://github.com/ca-x/vivaldi_plus/releases/tag/v1.5.8.4-b

=======================================

I tested it. Without Vivaldi++, the browser works very fast: it starts quickly and pages load normally. With Vivaldi++, the browser becomes very slow — it feels about 5× slower. The issue is reproducible.

have u test with latested with win2k option in config.ini?does it work? @Vektor010

[Vektor010]

@czyt
The build is created using a batch script. Could you please test it on your side as well?

I have tested the behavior and can consistently reproduce the issue:

Without Vivaldi++, the browser works very fast — it starts quickly and pages load normally.

With Vivaldi++, the browser becomes extremely slow, feeling roughly 5× slower overall.

The slowdown affects both startup time and page loading performance, and the issue is fully reproducible.

Thank you for your time and help.

yandex.txt

I have uploaded my batch script as yandex.txt. Could you please download it, rename it back to .bat, and check how it creates the configuration file during installation?

Please fix any errors you find.

Thank you for your help!

[czyt]

sorry,I use vivaldi on linux now,and could not test at the moment .@Vektor010 i will try when i use windows again.maybe some conflicts or compatibility issues with yandex.I am hard to connect to the twitch,because of GFW,I will test with bilibili

[czyt]

I have tested yandex with Windows 11 （without windows Antivirus software,windows defender disabled，clean installed yandex wihout any plugins）play the same video from bilibili at 1080P，it works as the same.@Vektor010

logs when vivaldi++ enabled is under with vivaldi ++
httpswww.bilibili.comvideoBV1kbqKB7.txt

summary with opencode

🎯 DLL Hook Impact on Video Frame Rate Analysis
📊 Key Performance Comparison
| Metric | Without Plugin | With vivaldi++ | Change |
|--------|---------------|----------------|--------|
| IdleFrame Delay | 916ms | 133ms | ↓ 85% Improvement |
| Video Bitrate | 693kbps | 693kbps | Same |
| Audio Bitrate | 102kbps → 139kbps | 102kbps → 139kbps | Same |
| AV1 Strategy | Hardware limit: 120fps | Hardware limit: 120fps | Same |
| Video Quality | quality: 80 | quality: 80 | Same |
🚀 Core Finding: Significant Frame Rate Improvement
Critical Discovery: After enabling vivaldi++, IdleFrame delay dramatically reduced from 916ms to 133ms

i have no more plan to look into this issue for personal time lack.sorry about that.
@Vektor010 btw, from the post https://forum.ru-board.com/topic.cgi?forum=5&topic=51073&start=0
does it work with https://gitflic.ru/project/neyrostalker/proksi-biblioteka(because it looks like many pepole use this with yandex) ,maybe can give me some idea!

[Vektor010]

from the post https://forum.ru-board.com/topic.cgi?forum=5&topic=51073&start=0
does it work with https://gitflic.ru/project/neyrostalker/proksi-biblioteka(because it looks like many pepole use this with yandex) ,maybe can give me some idea!

Yes, the proxy from nekto78 works correctly, and I have no issues with Twitch using it.
I also checked your bilibili link using your proxy. I tested both the old and new versions, and there are no problems with the site. YouTube works perfectly as well. So, the main problem is only Twitch.

As for the Bush2021 build I use — the proxy works there too. Here are the main downsides:

1. There is still a lot of bloatware.
2. Telemetry is not fully removed (specifically Yandex telemetry).
3. Cache and junk files are not cleaned up after closing the browser.

============================================

By the way, regarding your test environment: **How exactly did you set up Yandex Browser? Did you verify it with a standard installation, or did you try to make it portable?

[Vektor010]

@czyt
Hello,

I tested Yandex Browser network and performance behavior using different DLL versions and found a serious issue specifically with your DLL.

Test environment:

Browser: Yandex Browser (Chromium-based)

Test site: https://browserbench.org/Speedometer3.1/

Test results:

Your DLL (czyt build)

Speedometer 3.1 runs extremely slowly

The test takes a very long time to complete

Overall browser performance feels laggy

Twitch does not load or loads extremely slowly

**

Screenshot (Speedometer 3.1 czyt results)

**

!(

)

DLLs by Bush2021 and nekto78

Identical behavior and results

Normal and stable Speedometer score

Test completes quickly

Twitch loads and works perfectly

No issues with browser performance or responsiveness

Based on these results, the issue appears only with your DLL. It introduces abnormal behavior affecting browser performance and/or network handling, which directly impacts real-world usage, especially streaming services like Twitch.

The problem is fully reproducible and disappears immediately after switching to DLLs from Bush2021 or nekto78.

**

Screenshot (Speedometer 3.1 Bush2021 results)

**

!(

)

[czyt]

@Vektor010 hello,thanks for testing and report，i have tried to fix this by claude code,you can download the nightly version.looking forward for your feedback

[Vektor010]

download the nightly version

Thanks for the update! I tried to find the nightly build, but I couldn’t locate it — the latest available version I see is from about a week ago. Could you please share a link to the nightly version or let me know where I can download it?

[czyt]

download the nightly version

Thanks for the update! I tried to find the nightly build, but I couldn’t locate it — the latest available version I see is from about a week ago. Could you please share a link to the nightly version or let me know where I can download it?

download from https://nightly.link/ca-x/vivaldi_plus/workflows/nightly/main

[Vektor010]

download from

No changes so far. The issue is still present — the loading is very slow and the test takes more than 2 minutes.
Every time I change the DLL, I completely remove User Data, profile, and cache, so all tests are performed on clean data created with the new DLLs.
Tests are repeated 3–5 times each to ensure the cache is warmed and results are consistent.

New test

speedometer-3-2026-01-20T09_21_05.699Z.csv

===========================

I just ran the bush2021 test. Its performance is ideal — very fast on the 2nd run after clearing User Data, profile, and cache.

speedometer-3-2026-01-20T09_32_01.342Z.csv

[czyt]

@Vektor010 I will check tomorrow when i have time

[czyt]

@Vektor010 I will check tomorrow when i have time

you can download the latest ngightly again @Vektor010 for testing