Poor image quality when opening capture device
Posted: 18 Dec 2021 15:00
Hello,
I use a Magewell HDMI Capture USB interface to record TV programs on my computer in HD. I use ffmpeg and I have upmost quality. I also would like to watch TV live on my computer, and I tried opening the capture device in VLC, the audio is good, but the image quality is of poor quality, the type font outlines are fuzzy/pixelated, and the image is cropped. I tried all possible options in the context menu, but neither can I get the original source quality, nor the image to display in 16/9. Also, the image is either resized without keeping proportions, adding black vertical bars left and right, or the image uses all available screen space but is trimmed up and down. I have a full HD 1920×1080 monitor. If I resize the video bringing the right edge to the left, VLC keeps the black vertical bars on both sides and resizes the whole video. I wondered if the problem would come from the capture device or the set-top-box, but ffmpeg records the TV programs properly in full HD with clean type font outlines. The image quality doesn't come from DRM fallback limits, as I have an HDCP filter in-between, and ffmpeg records in upmost quality. Here are a few screenshots. Thank you for your advice.
Settings
Black vertical bars with option enabled to always fit content to window
Same problem, and with black bars also above as I resize
Fuzzy font outline
Pixelated outline of the TV channel logo
Black vertical bars with poor text outline quality
Image uses whole screen but is trimmed above and below
Thank you.
I use a Magewell HDMI Capture USB interface to record TV programs on my computer in HD. I use ffmpeg and I have upmost quality. I also would like to watch TV live on my computer, and I tried opening the capture device in VLC, the audio is good, but the image quality is of poor quality, the type font outlines are fuzzy/pixelated, and the image is cropped. I tried all possible options in the context menu, but neither can I get the original source quality, nor the image to display in 16/9. Also, the image is either resized without keeping proportions, adding black vertical bars left and right, or the image uses all available screen space but is trimmed up and down. I have a full HD 1920×1080 monitor. If I resize the video bringing the right edge to the left, VLC keeps the black vertical bars on both sides and resizes the whole video. I wondered if the problem would come from the capture device or the set-top-box, but ffmpeg records the TV programs properly in full HD with clean type font outlines. The image quality doesn't come from DRM fallback limits, as I have an HDCP filter in-between, and ffmpeg records in upmost quality. Here are a few screenshots. Thank you for your advice.
Settings
Black vertical bars with option enabled to always fit content to window
Same problem, and with black bars also above as I resize
Fuzzy font outline
Pixelated outline of the TV channel logo
Black vertical bars with poor text outline quality
Image uses whole screen but is trimmed above and below
Thank you.