I am using avconv to convert MPEG Transport Streams to H264. My main goal is to capture high-quality screenshots from the source video files.
The TS files are interlaced, so I am first converting to H264 and attempting to capture screenshots from the encoded video. However, the quality is lacking - I see jagged edges in high contrast areas of the screen, as well as some noise that looks similar to JPEG compression artefacts.
I am experimenting with various combinations of quality presets, Yadif deinterlacing and noise reduction, but the quality still seems to be lacking.
File size is not important - I don't mind if I end up with huge video files, as long as the screenshots are of high quality. Compression time is somewhat important, but I don't mind if the encoding step takes a long time.
Which settings should I be using to achieve the highest quality screenshots from these video files? Assuming I have a 1080i input, how can I produce a screenshot that is as close to 1080p as possible? Of course, the output can not be higher quality than the input, but I want to get as close as possible.
I will be using avconv to extract the screenshots from the video, but for my testing I am pausing VLC to examine the quality.