Difference in quality of video uploaded via browser UI vs cvat_sdk.

[pranavchaturved]

My actions before raising this issue

• [x] Read/searched the docs
• [x] Searched past issues

Steps to Reproduce (for bugs)

1. Upload a full HD video from UI. Set Image quality to 100.
2. Upload a same video using cvat_sdk with below spec. with self.client as client: task = client.tasks.create_from_data( spec={ "project_id": project_id, "name": task_name, "image_quality": 100, "use_zip_chunks": True, "use_cache": True, "sorting_method": "lexicographical" }, resource_type=ResourceType.LOCAL, resources=[video_path], )
3. Make comparison.

Expected Behaviour

The video uploaded from cvat_sdk should match the quality of video uploaded using browser UI when seen on the CVAT Tool.

Current Behaviour

The video quality is visibly lower for the one uploaded using cvat_sdk even when using image_quality of 100 in the spec when compared to the one uploaded via browser UI with same params/spec.

Possible Solution

Not sure.

Context

This has direct impact on the judgement of annotators and how they make decision to classify the bounding-boxes/annotations for my usecase.

Your Environment

• Docker version: 23.0.5
• Operating System: Ubuntu 22.04.2 LTS (for the machine running CVAT)
• Operating System: macOS 13.0 (for the system running browser UI)

[pranavchaturved]

Is there any update to this issue?

[rbogad]

We have the same issue. Because of this, it's impossible for us to programmatically create annotation tasks for a large set of videos.

[zhiltsov-max]

Hi, I've tried to reproduce, but couldn't observe any difference. I used a full hd and a 4k video, and checked with the v2.5.0. In both cases quality was 100, use_cache and use_zip_chunks were enabled. In both cases videos have been compressed, so with maximum zoom in UI the images were blurry, which is more or less expected. Could you please add more details how the problem can be reproduced? Please check that your SDK version is >= 2.3.0, where one possible problem was fixed.

[SvanHeumen]

I have the extact same issue, even though the code spec specifies image quality 100, the actual uploaded task is uploaded with 70% image quality (default). Major issue for uploading a large set of videos without any quality loss.