I recently talked to the Youtube user mugg1991 getting some help on how to get started with TAS using Dolphin. With his permission i am putting his information here so that others that might want to TAS on their own might have a little easier time getting started.
Dolphin TASSetup
-To start off you will need Dolphin. Since it is against the TOS to link anything just Google Dolphin and look for r7719. Later builds have issues and earlier ones can be buggy.
-Now you will need the SSBM NTSC ISO. This should be easy to obtain with the abundance of hacking happening these days. If you can't seem to find it there is a good one on Demonoid that i use.
Get it and place it in the same folder Dolphin is in. (Makes searching for it easier)
-Set up your setting to look like this:
http://tasvideos.org/forum/viewtopic.php?p=266039#266039
You may or may not see the dialog box for 'Emulator Display Settings' under the Display tab. Display also may be called Interface. It is the same thing, just match the settings.
-Download these files:
http://www.mediafire.com/?xqwq7a3yvv1y5ew
Un-Zip them and place them in 'Dolphin/User/GC'
Please PM me if these files go down again. Just so the thread isn't cluttered with broken link posts.
These files are necessary for emulation.
-Set up your hotkeys in the config menu, and your GC input.
-Start up SSBM in Dolphin and it should ask you to create a memory card. Once made this memory card file will appear in 'Dolphin/User/GC'
-Download a complete save file from gamefaqs (Must be a .gci file) and import it using Dolphin's Memory Card Manager.
Dolphin TASPlaying the Game
-'Start recording' will start emulation. Each savestate you make contains your button presses. So you can play around, make a state, close dolphin without saving a dtm (file that contains your button input), re-open dolphin and load the state to continue.
WARNING: Always disable read-only mode in the 'Emulation' dropdown menu, since it's broken and if you load a state that contains button input while read-only is active, your movie will stop being recorded!
-'Config' -> 'Interface Tab' -> 'Hotkeys Button', you can set your hotkeys here.
Most important hotkeys are Pause/play, Frame Advance, and the savestate-related keys.
'Frame advance' can be ON or OFF.
When ON, pressing Pause/play will advance 1 frame.
When OFF, pressing Pause/play will only switch between paused mode and nonpaused mode.
-When you're done, save your dtm. Playing it back should always yield the same result. The movie will use the ingame settings that are saved in the memory card, i.e. if you made your movie in english mode with items set to OFF, make sure your memory card uses those settings else it might desync.
-You can use any of 3 possible controls for your inputs. They are keyboard, TAS input dialog box, or Controller. I use both keyboard and TAS input dialog box. Keyboard for button inputs and TAS input panel for fine tuned joystick control.
CAUTION:Even if the settings are the same, there's a slight chance it desyncs anyway. Sometimes trying to play back sufficient amount of times works. For people are having trouble syncing their movies even when using the recommended settings (though my guess is they weren't using the recommended settings).
Dolphin TASUploading to Youtube
-Prior to playing it back, go to graphic settings advanced tab, enable DUMP FRAMES.
In audio settings enable DUMP AUDIO. In */user/dump/audio or frames, it should save the avi and wav.
The AVI will be recorded in the resolution the window used at the time of recording the avi. So you should render to seperate window instead of main window, to make sure it uses 640x480.
-Merge Avi and WAV by using an edit program like sony vegas or movie maker (though movie maker sucks for obvious reasons), or by using avisynth (what I'm doing). Avisynth is a scripting language, you write avs files and load them in virtualdub and save the AVI.
-Sometimes there are frames that take longer than 0.016s (1/60th of a second). NTSC games use 60 FPS (frames per second), when the game loads a level or the next screen etc.
Audio still keeps playing during those frames but the recorded avi only plays 0.016s. So as a result, the audio desyncs and you need to put in extra frames manually to prevent the audio desyncs.
Dolphin TASExtra
-If you press pause while advancing a frame, you can immediately see the pause screen. But sometimes you see it the next frame, due to dolphin behaving weird (I think wak once said it depends on how much time passed since power-on)
This can cause hiccups during any of your runs. So just be mindful that if something doesn't seem right when placing inputs that this may be the reason. In my experience it doesn't happen often but it is hard to notice when it does.

[ Disclaimer - Mileage May Vary; Experimentation Required: This program has a few issues which may cause your game to no longer boot. Use at your own risk, and be sure to create a copy of your game prior to use. A method that you can try if you experience problems can be found here. If you try that, please post whether or not it worked for you, and what you did. Alternatively, you can try the method given here. Although it is not known what exactly causes a problem, in some cases it seems less likely to occur if you keep the total number of songs in your game the same. ]​

20XX freezes after being patched with this tool!

This can happen from time to time. While there are many possible reasons for that, here is what you can do:
1. Unplug your memory card and restart your Wii
If it works now, your previous 20XX had a music file, that isn't on the image anymore, which you selected in one of your playlists. This usually only happens, when the resulting number of tracks is less than before patching.
2. Test the tracks in Dolphin

There may have been a problem converting one of the music-files, the custom-loop was flawed, or my audio-tool simply derped. Test the songs each in Dolphin and make sure they at least start.
You can also test them in your Wii, but Dolphin will be more convenient, as on the Wii, the audio buffer sometimes just gives up and can't play a file when quickly switching through them.


The track-list looks weird and editing titles won't work!

If you are encountering these or similar issues to this post, please have a look at my responses to this and send me regarding information. I haven't encountered this problem myself so I can only fix this with your input.


The Playlist-Menu freezes!

Thats a weird one. It occured to me after I deleted most custom songs and only added a few of my own.
To fix this, just add some more tracks (per default the last track has a hex-number of 76).

What is up with those song titles?

Wellp.
The titles for songs in 20XX are limited to 32 characters in theory. I limit them to 31 characters, because 20XX won't display them correctly otherwise.
To deal with those limitations I've come up with a number of steps that my program automatically does to make up a good title for your audio file:

I first read the files metadata and look for the Artist's name and the Song-Title.

If the artist's name is longer than 15-chars, I look for a known abbreviation in my own little database. If there is none, my tool generates one automagically. My algorithm for abbreviations for example takes the name 'Five Finger Death Punch' and puts '5FDP' out.

If the resulting form of 'Artist - Title' is still longer than 31 characters I shorten the title:
Firstly I look for a leading 'The' to be removed.
After that I get kinda desperate and remove vowels if there are any.

Why does the track-list behave weird sometimes?

I blame Java-Swing and me not having the nerve to fight it's stupidly designed Lists enough to fix all of the issues I had with it. This will probably be fixed in the near future though.

For the audio stuff, there's the thread about my conversion tool.
20XX's filesystem regarding audio files
In standard Melee the audio files have arbitrary names. For instance DreamLand64's music file is called 'old_kb.hps'
This is different in 20XX, as they are now named after a 2 digit hex-value. They begin at 00.hps and would end theoretically at FF.hps which would be a max of 256 music files.
The first 49 of them, going up to 31.hps, are the default melee tracks.
They can be replaced but should not be removed or renamed.
Patching 20XX's binary file

In the new 20XX there is a binary file called 'MnSlChr.usd'.
Aside from refactoring it, Achilles uses this binary to store titles and pointers for the music files.
At 0x3EDD90 is the first 32byte entry, which is used to store the Song-Title for the 32.hps file. The entries go up from there, meaning the Title for 33.hps would be at an offset of 0x3EDD70.
These entries are ANSI encoded and contain one character per byte.
If you're curious, the titles for the default songs begin at 0x3EE1D0 and go down from there. Unlike the entries for custom songs they are tightly packed and can't be changed as comfortably.
Starting at 0x3EDDA8 there are 4byte fill values. I'm not exactly sure if these are pointers to file names/locations, or if they are just there, so 20XX knows how many music-files are on the image.
The first don't seem to follow a strict pattern and aren't of interest if adding or removing custom tracks.
The ones I have to care about start at 0x3EDE6C the values follow a simple pattern. They start with the 4byte value 0x80FDA4A0 going one entry down the file means substracting 0x20 from this value.
There needs to be one value following this pattern for every music file existing in 20XX's image, or you simply can't play it in-game. This is more crucial than the titles since you can theoretically just leave those blank.