The q parameter allows you to manually control the quality level of the output video by influencing its bitrate.

• q=1–100: Sets a quality level on a scale from 1 (lowest) to 100 (highest). Internally, this adjusts the output bitrate based on a mapping from the original video’s bitrate. This allows for finer control over the resulting file size and visual quality.
• q=0 or no q parameter provided (default): The encoder automatically determines an optimal quality level based on the source content and desired output characteristics. This default mode offers a balanced trade-off between quality and file size without user intervention. By default, quality is set to 75.