Spud's Ripping Tips
First things first, this is just advice, not rules, or orders. Second of all, this is concerned with MPEG4 predominantly. I may add MPEG2 help regarding DVD and general DVD authoring, but this material is in abundance on the net. I will also write up something about how I capture video from analogue sources.
I'd also like to add, criticism of ripping processes is extremely productive and worthwhile. Criticism is essential in the path to enlightenment. Quality ripping is knowing the best options to take given choice.
Here are my 'frequently voiced tips' on how to improve your rip by avoiding simple mistakes, making informed choices, and just general help (I hope). I'm going to start off with the basic setup, what you need, and what you should avoid. They are purposely non-technical.
Any commercial products, that claim to be a one click solution are best left undownloaded. 90% of the time, the claims are flat out fraudulent. There is the odd notable exception, like Nero Recode. However, the strength here is the codec, not the software.
I would strongly urge the use of gknot
(note: gknot, not autogknot). This moulds the functionality of all the best applications into one clean user interface. It is extremely simple despite claims to the contrary. I really don't want to do a guide for the program because I'd just end up copy and pasting the existing guide from doom9.org. I will however highlight your aims in doing a rip.
The small text advice is now redundant, after lots of discussion some alternative sizes are available here:
The issue is to aim for a size, not just hit encode and hope for the best.
With the rise of DVDr media, 700mb maybe odd, why not 708mb? larger? Well there's many reasons. Firstly, the obvious is that not everyone has a DVD writer, duh! Okay now here's the more significant, by basing the rip around 700mb you are proving a) that you are a competant ripper, you know what your doing b) that the rip should be of a certain standard. An undersized isn't a technical flaw, however, when facing 640mb vs 700mb, in my experience the rip that aimed for a certain quality standard has acheived that, that being the latter. The next reason is that current quality standards are often tied in with the filesize. 700mb is suitable for a movie of length 90mins and under, and you can often fit more on, but the longer the film gets, the lesser the quality standard is.
So it is best, at least for the time being to stick strictly to the 700mb boundary, for everyones sake
- Removed 14/02/2006
Your choice on how many CDs you need is mixed and up to you, but a smart decision is best. Look at the length of the film, is it 90mins or less? Most likely a 1cd candidate. Long films nearly always need more than one cd, however with horror, remember it maybe best to do a 1cd to keep the spread of the file easy and readily available. Read carefully about audio codecs, is AC3 needed? If its not, then you may not need a 2cd.
Codecs and Bitrates
Very technical, but here's my two cents.
Divx 3.11 - flat out don't use it, its redundant, and very old now. At lower bitrates its prone to extreme blockiness
Divx4 - Also redundant, its better than divx3, but is inferior to 'newer models'
Divx5 - A respectable codec in its own right. However, it is ad supported by default, it does normally require more CPU power to decode, and the results are varying. I would voice in favour of Xvid. For b&w content, however, Divx does exceptionally well and is worth real consideration
Xvid - Top gun in its field. I nearly always use this codec.
Nero - Very impressive results for a very young codec, it actually surpassed Xvid in the doom9 benchmarking so is considered "the best". Or would be, if not for some major problems. It can only be used in the MP4 container, it can only be played back in Nero ShowTime and as such requires a bit of hacking to play back in other software. No standalone stupport. Keep an eye on this, but for the time being, not a release usable codec.
RV9/10 - Use if you want your film looking like it was made with crayons. This is propreity codec with dodgy support and more importantly, crappy results. Tends to loose details and as such is better for cartoon/cel shaded. I wouldn't use however, as it lacks standalone compatability, looses too much detail and is not as good as the alternatives. This is widely used on asian sites because of anime.
Video Bitrate and Bits/Pixel
This is a rough, but normally quite sensible quality quantifier. I will explain in a bit. If you are making a rip, and the average bitrate comes out at under 800kb/s, there's a high chance of blockiness and video artifacts. The higher the bitrate the better. If its in excess of 1000kb/s, then this is very good. Remember ripping is the best compromise. If your bitrate is very low reduce your resolution (warning: read about resolution later), if its extremely high, and your resolution is low, increase the size of it. Once resolution reaches the high 6xx, and your bitrate is still extremely high, you should re-evaluate your audio codec and bitrate (see the appropriate sections). If you have a huge excess of bitrate, and are performing a 2cd rip, consider doing a 1cd. It is an indication that a 2cd is 'overkill'.
Bits/Pixel is one extremely rough way of measuring quality, supported by gknots compressability test. Use this in accordance to the gknot guide @ doom9. It should at least give a rough help in making choices regarding the rip format.
You've got a few choices, but these should be done case by case
. Its not a smart or necessary to always include AC3 tracks because they're "better". It will probably sound better, but its extremely wasteful. Don't go down this route. If the sound track is not of a high quality, the film is old, or the track is not 5.1, then you need to think hard about whether you should bother including it as AC3. With black and white films, its often a good idea to use the AC3 track since compressability is often huge. MP3 is the better option the vast majority of the time. It allows for decent preservation of sound quality and vastly reduced filesized (given intelligent allocation). Ogg is a fair codec too, it is the best choice for extremely low bitrates, and can maintain multi-channel surround sound. It does have problems associated with it mind. There are other options, but I'd stick with one of these three, with mp3 underlined in your bright green crayons.
Audio bitrate and bit allocation
If your re-encoding the audio, and assuming its MP3, you can go the dynamic allocation of the static allocation, VBR and CBR. With CBR you get a constant allocation of bits, even for scenes not "needing them". As such it is very wasteful and on technical basis, VBR offers much, much, much more. Its a variable bit allocation meaning the bits are spent where they are needed most, rather than wasting bits on silence, they are then used on scenes with frequent noise and as such the overall quality of the mp3 track is far greater. Not only do you get better sound, you also get a smaller filesize.
The issue with VBR comes not from the process itself, but from a flaw in the AVI container. Its use can lead to sync problems (extremely rare) and for a technical elitest, they tend to argue against it. However, I'd still stand by VBR even when muxed into the avi container because of the filesize and quality benefits. As said the problems are rare. This is entirely to do with the AVI container, other containers do not have this 'problem'. note
Go with gknot on this one, the defaults are good, just up or down the bitrate appropriately.
In terms of bitrate, you should aim for as decent as possible. In most cases, 128kb/s is the best option. This gives perfectly acceptable sound quality, especially when using VBR. 192 kb/s is a good choice for better soundtracks and you have the space available, once again, VBR is preferable. You can go for 96kb/s VBR, but I would recommend this only for tought rips or mono sound tracks. With mono sound, the quality is likely to be none too hot. You can go for 80 ABR also here, this is also good for Audio commentray (mono too for commentary). Using CBR at these lower bitrates I would not recommend. If you have a high video bitrate and a high resolution you should not neglect the audio, it should be at least 128kb/s.
Best for 2cd releases if you have to, you shouldn't degrade your encode by including unless you have the space. Best combination when muxing is a suitable sized main audio 192kb/s or 128kb/s and a smaller 96kb/s or 64kb/s VBR track.
An even better option is encode your rip without including the audio commentry or taking it into account and then releasing the audio as a seperate audio file. This can be muxed, but this isn't a requirement, intelligent players such as MPC can play extra unmuxed audio tracks.
Here there's no clear choice.
AVI - old, globally used, but does not natively support VBR, and as such VBR muxing is only acheived by a hack. This can lead to synch problems, but to be quite honest its extremely rare. Most likely use.
OGM - pretty nice, annoying if you hate Ogg, or the letter O in general
MKV - new, but seems to be used very inappropriately. Its all in one nature is used as an excuse to disregard ripping standards, and quality suffers. Just because you can fit 4 dubs, 16 subtitles and menu in the container, doesn't mean you should degrade video quality to do so. Use wisely people, its a very nice container and open standards, unfortunately its not universally supported yet
I've done a little bit about cropping in the high/low quality stickies. Please take a look.
You should try to crop off every single black pixel, right up to the frame so none are visible. Overcropping by a single pixel or two is infinitely more favourable than undercropping. The whole purpose of cropping is to save vast amounts of video data. The black matting takes up some of your bitrate on every single frame of the movie. The hard transition between matte black and picture is a difficult change to be stored and mpeg4 codecs are not good at storing this data efficiently. As such, bad cropping means that your image is likely to be of far lesser quality and prone to blocking than in a rip that is correctly cropped. This is why scene rips are nuked for such an error and that it is frowned upon. AR can be maintained without the need for black matting. With moving border rips, try your best to crop off all the black borders, and not crop off the movie. It is hard to achieve 100% boarderless rips here. Although borders will be present ocassionally, they jump around and at least don't take up a constant bitrate that can be avoided.
In regards to choosing the correct resolution, you have three words to think about scope
and aspect ratio
. You have to stay close to both. By scope I refer of course to the choice of resolution between two points, the first should be regarded as the minimum resolution you should encode at, the second is the maximum resolution you should encode at.
The maximum is easy to define. This is the actual resolution of the content on the DVD. Zooming in on this material is extremely stupid, your are compressing the movie and making the resolution bigger... its not a smart thing to do. With that in mind, it should be very rare that you have a rip that is in the 7xx region with a 1cd rip, its just too big and if you don't have the bits will probably block and break up. Larger resolutions are more likely on highly compressible and large filesize rips. The other end of the scope is tiny resolutions, if its too low, say in the 3xx, quality is very poor when resized up (remember on playback, no one ever watches on a tiny screen). With this in mind, I will recommend a minimum resolution of 480x for 4:3 (fullscreen material), and 512x for widescreen material (well those are from scene rules but they are pretty sound). If you go below these, then I'd say your rip is going to be too small in resolution, and you'll have noticable problems when its scaled up.
In reality, if your able to get a resolution inbetween 512-640 then all is well, higher 6xx is good too if you have enough bitrate. if your at 720 and your not using a large filesize, I'd say something's you may need to check if something is wrong in other departments, that should be fixed before the resolution was increased this far. This does not include ARF or large 2/3cd rips, you can probably get a decent resolution out of these.
Your horizontal resolution is best being divisible by 32x and your vertical by 16x. If not, you will most likely get playback problems on a few older machines, but this is a rarity. Problems may occur on standalones though.
The ultimate bit of advice here is, you should only make the resolution as high as allowable. An arbritrarily high resolution isn't smart, and zooming in on a source is defies logic. With a VCDrip, your working from a resolution that is already small, but the same advice stands. Don't go above the source, which will be 352x. The logical choice is preservation of size but just cropping off black borders. For a VCDrip, 350mb rips are ideal given you've essentially got half the resolution of a DVD.
It is absolutely essential that you get it as close as possible to the original. There are some standard ARs, most popular are 1.33:1, 1.66:1, 1.83.:1, 2.35:1. However, they vary. Normally Gknot is intelligent enough to handle all this for you, but you must
always check a) cropping gets everything and b) the AR looks correct. If you see melon heads, or fatties you've messed up the AR. Even with borders cropped, you should be able to maintain AR.
- For anamorphic DVDs, you may want to uncheck the "Follow ITU-R" option, under "Options" in Gknot. Most of the times the AR will probably be closer to how it should be. The xyz% error reported by gknot isn't an actual absolute value, its only based upon whatever option you checked as the source size. Look at the picture, ideally round objects and ask yourself if they are stretched.
PAL is always 25fps, you should not change this. Keep it at 25fps, it is correct.
a) 23.976 - This is the 'correct' framerate for movies 99% of the time. The exception here are those shot with digital cameras, some of which are 'true' NTSC. However, if you have a movie that's NTSC, you must force the correct FPS the vast majority of the time. This is straight from Gknot itself:
Press this button to create a DGIndex - project file (.d2v).
Press F3 and select the first VOB you just ripped, the following VOBs are selected automatically. Press "OK".
Press F5 for a preview, let it run for a while, then press "ESC". If "Framerate" is 29.970 (NTSC) and "Video Type" is FILM at a percentage higher or
equal to 95% check "ForceFilm" in "Field Operation", otherwise make sure it is NOT checked. In "Dolby Digital" check "Demux All Tracks". Finally
press F4 to save the project file. This will take a few minutes.
Thanx to Jackei for the best decoder available!
If you get a high percentage FILM, do as it says.
The reason for doing this is extremely important. The actual fps is not 29, but infact 23, but is artificially high to give the illusion of being NTSC content. The method may seem advanced, but needless to say it is not hard to do at all; and if you encode at 29fps when it shouldn't be, video quality will be hugely
degraded, since instead of encoding every frame in a second once, you are artificially duplicating and inserting repeat frames every second (23->29 =~6fps it might not seem like much, but add up the seconds to minutes, then the minutes to hours, then oh dear, look at all the wasted frames... that's a lot - not only this, playback will stutter). Always make sure you get the correct frame rate. Their is also another method incase FORCEFILM fails. This is covered in the doom9 guides.
b) 29.970fps - Excluding in the above case, this maybe true particularly of home movies, low budget affairs and tv material. This is natural framerate, if you drop this down it will loose actual frames. Most of the time though, this number is wrong if it is reported, it should actually be 23fps.
c) Other framerates, rare and just don't encode movies at them unless you know what your doing.
Read the following:
With that in mind, there are many options to take. For a clean PAL print, try the following:
This should be inserted in replacement of gknot's. You can do this on the save and encode->edit screen after setting up all the options. Be aware, clean is the predominant word. If you use it on a grainy source, it does have the tendancy to double and stretch the noticable film grain and artifacts.
A slower but quite rigorous deinterlacing filter is FieldDeinterlace. This tends to blur the picture slightly. You should do some google here if you want to read up on the best option.Summary
As you've just read this is all simple stuff, but the results of doing each
simple steps is the best possible result you can get. If you do each of these, your rip can't be really faulted, and the result is accountable to how much compression you decided to do (CDs) and how good the source is. You should make sure you've taken all of the above into account, and performed adequet cropping and deinterlacing.Subtitles
Don't forget them! Remember, people aren't all english/spanish/german/italian/etc. and it can be really difficult to follow movies without them. Since you should always be avoiding dubs (because they're gay), this simple step is really appreciated. It takes a couple of minutes in gknot, follow gknot.doom9.org 's detailed guides.General Gknot advice
As said, read a proper guide if you want to know the how-tos, this is just advise that is often omitted that you should consider when releasing a rip... quality isn't always in mind with guides
- Perform a compressability test. Its quick and does give a vague hint on what's going to happen. Encoding is slow, so this may save you from an obvious mistake without waiting hours.
- Use the length of the movie to determine what to do. If its long, think about 2cds, if its short 1cd.
- If its modern, think about AC3, if its old, ignore it for now.
- Default your rip to 128 VBR audio, and adjust later once everything is setup.
- Make sure view>resized is checked in the preview window
- Choose the correct input resolution format, as well as input AR. If it is tv ratio -> 4:3, if its widescreen -> 16:9.
- look at the preview screen, does it look right!
- Hit auto crop, it most of the time does everything fine, but still check!
- If its got it all, check Smart Crop All
- Now look at your bits/pixel and adjust the resolution accordingly. Remember the scope, notice the box that says W-Zoom, if that's over 100% your, far, far to high, if the Width goes below 480/512, likewise your too low.
- For PAL clean DVD prints (ie. not much noise, this is the best deinterlace filter:
Replace your detinerlacing lines with this (hit save and encode, then edit after ensuring all the correct options are selected.)