I ask if at all possible to include screenshots of movies you rip, really helps everyone who's downloading know what quality to expect, that the release is verified and there won't be any nasty surprises along the way. You can see how to take screenshots above, and are free to upload screendumps here:
Define Quality retail DVD?
By this, I refer to a properally mastered DVD, meaning DVDs that are for sale in shops from any region, but have been 'professional' transfered to DVD. This does not always mean it has to be brilliant quality, most low budget films have hideous transfers, but it must be from a proper source, meaning tvtransfers, pirate DVDs and DVD screeners should not be posted in this section.
So what's Quality?
By this wordage, I'm trying to seperate the 'best possible copies' from releases that may not be the best the film is currently available in. For example, many regions get better mastered DVDs (ie. widescreen prints, etc.), some maybe sub-par or VHS quality and if that's the case, and the quality doesn't seem decent or perhaps as extreme as near unwatchable
Secondly, this also refers to quality of rips. The following are some common mistakes that mean that your rip may be moved to the lesser quality section.
Bad/Lack of proper De-interlacing.
What is Interlacing?
A video display technique in which the electron beam refreshes (updates) all odd-numbered scan lines in one sweep of the screen and all even-numbered scan lines in the next. Interlacing takes advantage of both the screen phosphor's ability to maintain an image for a short time before fading and the human eye's tendency to average subtle differences in light intensity. By refreshing alternate lines, interlacing halves the number of lines to update in one screen sweep.
Basically its a trick that doesn't show up on tvs to display an image by quickly flashing images on the screen. However, with more sophisticated viewing devices on PCs, this means interlaced sources are terrible to watch (see the following examples), or more accurately unwatchable. You *must* always apply a deinterlacing filter when ripping to avoid this symptom in interlaced sources. Other wise the following examples are what is shown when watching:
How do I de-interlace?
My recommendation is to apply decomb or another deinterlacing filter, use gknot
to rip movies and follow the guide.
It is vital to crop off all black boarders when encoding for many reasons. Firstly, and most importantly, encoding with them present wastes the a chunk of video data on the useless black space that isn't needed with MPEG4. By leaving the boarders on a rip and encoding, you can not acheive maximum quality that you could acheive, as xvid is unable to determine between picture and the surrounding black space, allocating the bits to represent the useless part of the picture. Secondly, and with the first at the front of your mind, the boarders serve no purpose other than to reduce the quality of the encode in MPEG4. They are present in MPEG2 purely to maintain aspect ratio, but this data is stored within the container head with MPEG4. They are there on DVDs to maintain an AR, but this is not needed with xvid codecs which will resize and render necessacary boarders on the fly. You should therefore crop out every single black pixel surrounding the frame, to ensure your bits are allocated where they are needed
How to avoid
You should always remove the black boarders that surround the video when ripping a movie. To do so, they must be cropped off right up to the picture's edge.
Once again my recommendation is to use gknot
to rip movies and follow the guides provided at doom9.org. You simply press the crop button (under crop), then select smart auto crop all. This isn't garanteed to work but it gets close and you should examine the picture after doing this. This also ensures you don't get a bad AR (aspect ratio, squashed heads or fat heads). Group releases are considered 'bad' if they have a AR error of greater than +/- 3%.
For these reasons, a release may
be moved from this section, in addition to a partcularly poor video or audio source on the DVD. If its the latter this is unavoidable by the ripper, but unfortunately the distributor hasn't done the film justice with the dvd release.