Commit Graph

7 Commits

Author SHA1 Message Date
Michael M
fcb1eb9d3b dsp_rom: skip bootucode_ax when running from entrypoint
This could cause the first branch of the bootucode procedure, which
takes its parameters from the AX registers, to run during the ROM init
sequence. Since the ROM doesn't set any of the AX registers, the values
aren't meaningful, and can cause bad DMA transfers and crashes.
2017-08-10 10:53:12 -07:00
Michael Maltese
e3531d17d7 Update free DSP ROM and coefficients to support GBA ucode
- coef: Explicitly set 23 different values that are used by GBA UCode,
  and tweaked overall parameters to more closely match those 23 values.
- irom: Moved a few functions to their proper places, updated BootUCode
  to configure DMA transfers using AX registers as well as IX registers
  (the GBA UCode uses this to do two sequential transfers in one call),
  and added partial functions used by GBA UCode.

All functions were reverse-engineered solely based off of observed
effects on the virtual machine: register states before-and-after, dmem
interactions, and DMA transfers. The specific coefficients were observed
being read from dmem, and must be exactly those values to function
properly. I have no knowledge of how the official ROM implements these
functions, or how it is implemented overall.

Tested with The Legend of Zelda: Four Swords Adventures, Final Fantasy
Crystal Chronicles, and Billy Hatcher and the Giant Egg (to download
ChuChu Rocket!).
2017-06-03 15:16:39 -07:00
JosJuice
0f1ce0e1f4 Remove incorrect usage of "ASCII" and "ANSI"
Windows-1252 was sometimes being referred to as ASCII or ANSI
in Dolphin, which is incorrect. ASCII is only a subset of
Windows-1252, and ANSI is (rather improperly) used in Windows
to refer to the current code page (which often is 1252 on
Western systems, but can also be something entirely different).

The commit also replaces "SJIS" with "Shift JIS". "SJIS"
isn't misleading, but "Shift JIS" is more commonly used.
2016-12-26 15:49:39 +01:00
Shane Nelson
388ab13db1 Audio: new dsp_coef.bin with windowed sinc filter coefficients 2015-06-29 22:24:24 -04:00
James Cowgill
f3aea4b5bc Replace gamecube fonts with free alternatives
Previously the gamecube fonts were based on Arial and Lucida which are not
freely distributable. The new fonts are generated using fonts under free
licenses with the "gc-font-tool" program I wrote.
2015-01-14 21:41:25 +00:00
Pierre Bourdon
9a404ca6d4 Ship by default a free DSP ROM that can handle most games with LLE
At the end of July 2011, LM published a free DSP ROM that works with games
using the Zelda UCode. His ROM only has the code to handle UCode loading and a
few utility functions, the rest is missing. This includes the four large sound
mixing functions used by the AX UCode and the DROM containing coefficients used
for polyphase resampling in AX.

This is an improved, updated version of this ROM, which changes the following:

- We now have a free DROM that works for polyphase resampling by "emulating"
  linear interpolation. The coefficients contained in the DROM are normally a
  list of { c1, c2, c3, c4 } which are used to interpolate a sample value from
  four previous samples:
    out_sample = prev1 * c1 + prev2 * c2 + prev3 * c3 + prev4 * c4

  The coefficients are chosen depending on the fractional part of the current
  position (basically, our position between the previous and the next sample).
  We can use this fact to generate (c1, c2, c3, c4) for each possible
  fractional part so that:
    out_sample = prev3 * curr_pos + prev4 * (1 - curr_pos)

  Which is the formula for linear interpolation between prev3 and prev4. Linear
  interpolation is not as good as polyphase resampling but it still works very
  well and I couldn't really hear any difference between the two. If someone
  wants to generate real polyphase filter coefficients, they are welcome to
  submit a patch.

- The IROM now contains the 4 mixing functions used by the AX UCode: mix_add,
  mix_add_two, mix_add_ramp, mix_add_ramp_two. They are large, inlined
  functions (probably for performance reasons) in the official DSP IROM, our
  version prefers to use a loop. This *should* be more performant with our DSP
  JIT implementation, but I did not benchmark that.

Because the new DSP ROM is working just as well as the official ROM in 95% of
cases, it is now shipped by default with Dolphin and will be used with DSPLLE
if you don't have an official DSP ROM in User/GC. It will still display a panic
alert at every boot to notice you that you are using a non official DSP ROM
made by us, which is not perfect.

Games using the CARD, IPL or GBA UCodes are still broken. I don't know what
games this actually impacts, but this is a very small proportion compared to
what works.
2013-03-16 23:54:55 +01:00
Shawn Hoffman
ffe1a671ea added files and svn ignore settings to the new file structure
git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@1069 8ced0084-cf51-0410-be5f-012b33b47a6e
2008-11-04 21:20:12 +00:00