Fix process_video and add test case

[cdeil]

This PR fixes the process_video function.

There used to be an if-else but somewhere the if fell off the truck resulting in a for-else that doesn't make sense.

This PR also fixes the following case of passing a max_frames that is larger than the frames in the video.
Before this PR is would give Exception: Requested frames are outbound and with it it will simply process the whole video, i.e. treat "max" frames as a max but OK if there are less frames (I think what most users expect/want).

import supervision as sv
from supervision.assets import VideoAssets, download_assets

download_assets(VideoAssets.PEOPLE_WALKING)

video_info = sv.VideoInfo.from_video_path("people-walking.mp4")

sv.process_video(
    source_path="people-walking.mp4",
    target_path="people-talking.mp4",
    callback=lambda frame, _: frame,
    max_frames=1000,
)

I also added a test case (the agent wrote it). Not sure if you want such tests or if/how you want to treat temp dirs and example asset video files in this repo. Let me know whatever you prefer and I can remove that or adjust.

[Borda]

Any assertion or other validation, then it runs?

[Copilot]

Pull request overview

This PR fixes a critical bug in the process_video function where a for-else construct was left after an if statement was removed, and improves the handling of max_frames values that exceed the total frames in a video. It also adds a test case to verify the fix.

Key changes:

• Removed the orphaned else block that was executing duplicate frame processing logic
• Added logic to cap max_frames to the actual video frame count, preventing exceptions when requesting more frames than available
• Simplified the progress bar total calculation by using the adjusted max_frames value directly
• Added a test case to verify the fix for max_frames exceeding total frames

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
supervision/utils/video.py	Fixed the for-else bug by removing the orphaned else block, and added logic to properly handle max_frames values larger than total_frames
test/utils/test_video.py	Added a new test file with a test case for the max_frames scenario and a helper function to create test videos

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[Copilot]

This test lacks assertions to verify the expected behavior. The test should validate that:

1. The target video file was created successfully
2. The video was processed without raising an exception
3. The target video contains the expected number of frames (5, not 10)

Consider adding assertions such as checking that the target file exists and verifying the frame count of the output video.

[Copilot]

Using the 'or' operator here will incorrectly handle the case when max_frames is 0. If a user passes max_frames=0 (meaning process zero frames), this line will replace it with source_video_info.total_frames instead of respecting the 0 value.

Consider using an explicit None check instead, such as:
max_frames = source_video_info.total_frames if max_frames is None else max_frames

Suggested change

	max_frames = max_frames or source_video_info.total_frames
	max_frames = (
	source_video_info.total_frames if max_frames is None else max_frames
	)

[Borda]

@cdeil, due to a large change collision, I was not able to recover the change/fix. Could you please commit it again...

[Borda]

@cdeil, thank you for your effort and for helping to resolve this issue. Regarding the progress and still some non-trivial path to be finished, we will proceed with #2022