Question in regards to screeners and quality

As most of you know, we’ve been blessed with a lot of screeners in the last few days and I just have a simple question that hopefully someone can answer…
OK, so I see multiple links and multiple file sizes and group names attributed to 1 screener… So how do I know which is the absolute best quality? I’ll use Birdman as an example… I see multiple threads made and some are for a mp4, avi or mkv… some are by PLAYNOW and others by a different group… some are around 700mb, others closer to 1.5 gbs…. so, how do I know which is the best option? I mean, aren’t these all coming from the same source anyways? A screener leaked and everyone is pulling from that?
I just want to know how to determine which one will be the best quality before I download, that’s all. Hopefully someone can help me out…
thanks guys… sorry if this is a “noob” question.
Answer #1
The best would be a full copy of the screener. Generally the larger the file the better the quality unless someone did a poor encode job. There are variables such as which compression was used. An avc encode could be smaller than xvid encode but better quality.
Answer #2
Damn, see, unfortunately, I don’t know how to tell if something is av “avc encode” or an “xvid encode”… I always assumed if the file was larger, it must be better quality, but that’s not always true, right? because avi’s are usually always the largest files, right?
I just want to download the best quality screeners and it’s hard when you have about 7 groups releasing the same damn thing.