The layout was designed to do subframe deinterleave (when
less-than-a-frame bytes of each channel are interleaved) in an array and
pass it to "mem" decoders.
In practice this only happens in a handful of formats, was only used
with DSP, and since making "mem" decoders is required it's simpler to
make normal decoders handling the byte layout directly.
In an effort to simplify vgmstream's layouts, code, and other esoteric
features I changed the old decode_ngc_dsp_mem for decode_ngc_dsp_subint;
results are byte-exact.
EACS was just DVI (high nibble first) with stereo and mono modes, while
old DVI was mono only.
This unifies both decoders, so DVI_IMA (not interleaved) works with mono
and stereo while DVI_IMA_int (interleaved) forces mono.
Some metas needed to explicitly set DVI_IMA_int but others work with no
change.
To support future MPEGs of uncertain layout and frame variations (namely
EALayer3) the code has been restructured: mpeg_decoder does stream
procesing and decoding, while mpeg_custom_utils_x does init and parsing
(write to data buffer + update offsets), per MPEG subtype. Internals
have changed but still gives byte-exact results.
AHX has been adapted to this format as a test. Some modes
(P3D/EALayer3/LyN/AWC) are defined for later development but will fail
on init ATM.
EA's MT/MicroTalk is not the early version of EAXA as I thought, but a
rarely used VBR codec (ex. FIFA 2001/2002 PS2) seemingly related to
Westwood VBR ADPCM
* tested most variations using EA's tools
* added looping [Need for Speed II PC]
* added DSP support [3DS games]
* fixed PCM/EAXA/MT in some cases [PS2/GC/XBOX/Wii games]
* fixed sample rate/codec defaults, num_samples in some cases
* documented more header patches and other details (ex. "EA ADPCM" is
now EA MT/MicroTalk, as per EA's tools)
* (dev) some internals adapted for EA stuff
I feel they are general-purpose enough that shouldn't depend on FFmpeg
(ex. xma_samples should work whether FFmpeg, libav, or
super_multi_decoder is enabled)
