sm64pc/tools/aifc_decode.c

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2019-08-25 06:46:40 +02:00
/**
* Bruteforcing decoder for converting ADPCM-encoded AIFC into AIFF, in a way
* that roundtrips with vadpcm_enc.
*/
#include <unistd.h>
#include <assert.h>
#include <math.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
typedef signed char s8;
typedef short s16;
typedef int s32;
typedef unsigned char u8;
typedef unsigned short u16;
typedef unsigned int u32;
typedef unsigned long long u64;
typedef float f32;
#define bswap16(x) __builtin_bswap16(x)
#define bswap32(x) __builtin_bswap32(x)
#define BSWAP16(x) x = __builtin_bswap16(x)
#define BSWAP32(x) x = __builtin_bswap32(x)
#define BSWAP16_MANY(x, n) for (s32 _i = 0; _i < n; _i++) BSWAP16((x)[_i])
#define NORETURN __attribute__((noreturn))
#define UNUSED __attribute__((unused))
typedef struct {
u32 ckID;
u32 ckSize;
} ChunkHeader;
typedef struct {
u32 ckID;
u32 ckSize;
u32 formType;
} Chunk;
typedef struct {
s16 numChannels;
u16 numFramesH;
u16 numFramesL;
s16 sampleSize;
s16 sampleRate[5]; // 80-bit float
u16 compressionTypeH;
u16 compressionTypeL;
} CommonChunk;
typedef struct {
s16 MarkerID;
u16 positionH;
u16 positionL;
} Marker;
typedef struct {
s16 playMode;
s16 beginLoop;
s16 endLoop;
} Loop;
typedef struct {
s8 baseNote;
s8 detune;
s8 lowNote;
s8 highNote;
s8 lowVelocity;
s8 highVelocity;
s16 gain;
Loop sustainLoop;
Loop releaseLoop;
} InstrumentChunk;
typedef struct {
s32 offset;
s32 blockSize;
} SoundDataChunk;
typedef struct {
s16 version;
s16 order;
s16 nEntries;
} CodeChunk;
typedef struct
{
u32 start;
u32 end;
u32 count;
s16 state[16];
} ALADPCMloop;
static char usage[] = "input.aifc output.aiff";
static const char *progname, *infilename;
#define checked_fread(a, b, c, d) if (fread(a, b, c, d) != c) fail_parse("error parsing file")
NORETURN
void fail_parse(const char *fmt, ...)
{
char *formatted = NULL;
va_list ap;
va_start(ap, fmt);
int size = vsnprintf(NULL, 0, fmt, ap);
va_end(ap);
if (size >= 0) {
size++;
formatted = malloc(size);
if (formatted != NULL) {
va_start(ap, fmt);
size = vsnprintf(formatted, size, fmt, ap);
va_end(ap);
if (size < 0) {
free(formatted);
formatted = NULL;
}
}
}
if (formatted != NULL) {
fprintf(stderr, "%s: %s [%s]\n", progname, formatted, infilename);
free(formatted);
}
exit(1);
}
s32 myrand()
{
static u64 state = 1619236481962341ULL;
state *= 3123692312231ULL;
state++;
return state >> 33;
}
s16 qsample(s32 x, s32 scale)
{
// Compute x / 2^scale rounded to the nearest integer, breaking ties towards zero.
if (scale == 0) return x;
return (x + (1 << (scale - 1)) - (x > 0)) >> scale;
}
s16 clamp_to_s16(s32 x)
{
if (x < -0x8000) return -0x8000;
if (x > 0x7fff) return 0x7fff;
return (s16) x;
}
s32 toi4(s32 x)
{
if (x >= 8) return x - 16;
return x;
}
s32 readaifccodebook(FILE *fhandle, s32 ****table, s16 *order, s16 *npredictors)
{
checked_fread(order, sizeof(s16), 1, fhandle);
BSWAP16(*order);
checked_fread(npredictors, sizeof(s16), 1, fhandle);
BSWAP16(*npredictors);
*table = malloc(*npredictors * sizeof(s32 **));
for (s32 i = 0; i < *npredictors; i++) {
(*table)[i] = malloc(8 * sizeof(s32 *));
for (s32 j = 0; j < 8; j++) {
(*table)[i][j] = malloc((*order + 8) * sizeof(s32));
}
}
for (s32 i = 0; i < *npredictors; i++) {
s32 **table_entry = (*table)[i];
for (s32 j = 0; j < *order; j++) {
for (s32 k = 0; k < 8; k++) {
s16 ts;
checked_fread(&ts, sizeof(s16), 1, fhandle);
BSWAP16(ts);
table_entry[k][j] = ts;
}
}
for (s32 k = 1; k < 8; k++) {
table_entry[k][*order] = table_entry[k - 1][*order - 1];
}
table_entry[0][*order] = 1 << 11;
for (s32 k = 1; k < 8; k++) {
s32 j = 0;
for (; j < k; j++) {
table_entry[j][k + *order] = 0;
}
for (; j < 8; j++) {
table_entry[j][k + *order] = table_entry[j - k][*order];
}
}
}
return 0;
}
ALADPCMloop *readlooppoints(FILE *ifile, s16 *nloops)
{
checked_fread(nloops, sizeof(s16), 1, ifile);
BSWAP16(*nloops);
ALADPCMloop *al = malloc(*nloops * sizeof(ALADPCMloop));
for (s32 i = 0; i < *nloops; i++) {
checked_fread(&al[i], sizeof(ALADPCMloop), 1, ifile);
BSWAP32(al[i].start);
BSWAP32(al[i].end);
BSWAP32(al[i].count);
BSWAP16_MANY(al[i].state, 16);
}
return al;
}
s32 inner_product(s32 length, s32 *v1, s32 *v2)
{
s32 out = 0;
for (s32 i = 0; i < length; i++) {
out += v1[i] * v2[i];
}
// Compute "out / 2^11", rounded down.
s32 dout = out / (1 << 11);
s32 fiout = dout * (1 << 11);
return dout - (out - fiout < 0);
}
void my_decodeframe(u8 *frame, s32 *state, s32 order, s32 ***coefTable)
{
s32 ix[16];
u8 header = frame[0];
s32 scale = 1 << (header >> 4);
s32 optimalp = header & 0xf;
for (s32 i = 0; i < 16; i += 2) {
u8 c = frame[1 + i/2];
ix[i] = c >> 4;
ix[i + 1] = c & 0xf;
}
for (s32 i = 0; i < 16; i++) {
if (ix[i] >= 8) ix[i] -= 16;
ix[i] *= scale;
}
for (s32 j = 0; j < 2; j++) {
s32 in_vec[16];
if (j == 0) {
for (s32 i = 0; i < order; i++) {
in_vec[i] = state[16 - order + i];
}
} else {
for (s32 i = 0; i < order; i++) {
in_vec[i] = state[8 - order + i];
}
}
for (s32 i = 0; i < 8; i++) {
s32 ind = j * 8 + i;
in_vec[order + i] = ix[ind];
state[ind] = inner_product(order + i, coefTable[optimalp][i], in_vec) + ix[ind];
}
}
}
void my_encodeframe(u8 *out, s16 *inBuffer, s32 *state, s32 ***coefTable, s32 order, s32 npredictors)
{
s16 ix[16];
s32 prediction[16];
s32 inVector[16];
s32 saveState[16];
s32 optimalp = 0;
s32 scale;
s32 ie[16];
s32 e[16];
f32 min = 1e30;
for (s32 k = 0; k < npredictors; k++) {
for (s32 j = 0; j < 2; j++) {
for (s32 i = 0; i < order; i++) {
inVector[i] = (j == 0 ? state[16 - order + i] : inBuffer[8 - order + i]);
}
for (s32 i = 0; i < 8; i++) {
prediction[j * 8 + i] = inner_product(order + i, coefTable[k][i], inVector);
e[j * 8 + i] = inVector[i + order] = inBuffer[j * 8 + i] - prediction[j * 8 + i];
}
}
f32 se = 0.0f;
for (s32 j = 0; j < 16; j++) {
se += (f32) e[j] * (f32) e[j];
}
if (se < min) {
min = se;
optimalp = k;
}
}
for (s32 j = 0; j < 2; j++) {
for (s32 i = 0; i < order; i++) {
inVector[i] = (j == 0 ? state[16 - order + i] : inBuffer[8 - order + i]);
}
for (s32 i = 0; i < 8; i++) {
prediction[j * 8 + i] = inner_product(order + i, coefTable[optimalp][i], inVector);
e[j * 8 + i] = inVector[i + order] = inBuffer[j * 8 + i] - prediction[j * 8 + i];
}
}
for (s32 i = 0; i < 16; i++) {
ie[i] = clamp_to_s16(e[i]);
}
s32 max = 0;
for (s32 i = 0; i < 16; i++) {
if (abs(ie[i]) > abs(max)) {
max = ie[i];
}
}
for (scale = 0; scale <= 12; scale++) {
if (max <= 7 && max >= -8) break;
max /= 2;
}
for (s32 i = 0; i < 16; i++) {
saveState[i] = state[i];
}
for (s32 nIter = 0, again = 1; nIter < 2 && again; nIter++) {
again = 0;
if (nIter == 1) scale++;
if (scale > 12) {
scale = 12;
}
for (s32 j = 0; j < 2; j++) {
s32 base = j * 8;
for (s32 i = 0; i < order; i++) {
inVector[i] = (j == 0 ?
saveState[16 - order + i] : state[8 - order + i]);
}
for (s32 i = 0; i < 8; i++) {
prediction[base + i] = inner_product(order + i, coefTable[optimalp][i], inVector);
s32 se = inBuffer[base + i] - prediction[base + i];
ix[base + i] = qsample(se, scale);
s32 cV = clamp_to_s16(ix[base + i]) - ix[base + i];
if (cV > 1 || cV < -1) again = 1;
ix[base + i] += cV;
inVector[i + order] = ix[base + i] * (1 << scale);
state[base + i] = prediction[base + i] + inVector[i + order];
}
}
}
u8 header = (scale << 4) | (optimalp & 0xf);
out[0] = header;
for (s32 i = 0; i < 16; i += 2) {
u8 c = ((ix[i] & 0xf) << 4) | (ix[i + 1] & 0xf);
out[1 + i/2] = c;
}
}
void permute(s16 *out, s32 *in, s32 scale)
{
for (s32 i = 0; i < 16; i++) {
out[i] = clamp_to_s16(in[i] - scale / 2 + myrand() % (scale + 1));
}
}
void write_header(FILE *ofile, const char *id, s32 size)
{
fwrite(id, 4, 1, ofile);
BSWAP32(size);
fwrite(&size, sizeof(s32), 1, ofile);
}
int main(int argc, char **argv)
{
s16 order = -1;
s16 nloops = 0;
ALADPCMloop *aloops = NULL;
s16 npredictors = -1;
s32 ***coefTable = NULL;
s32 state[16];
s32 soundPointer = -1;
s32 currPos = 0;
s32 nSamples = 0;
Chunk FormChunk;
ChunkHeader Header;
CommonChunk CommChunk;
InstrumentChunk InstChunk;
SoundDataChunk SndDChunk;
FILE *ifile;
FILE *ofile;
progname = argv[0];
if (argc < 3) {
fprintf(stderr, "%s %s\n", progname, usage);
exit(1);
}
infilename = argv[1];
if ((ifile = fopen(infilename, "rb")) == NULL) {
fail_parse("AIFF-C file could not be opened");
exit(1);
}
if ((ofile = fopen(argv[2], "wb")) == NULL) {
fprintf(stderr, "%s: output file could not be opened [%s]\n", progname, argv[2]);
exit(1);
}
memset(&InstChunk, 0, sizeof(InstChunk));
checked_fread(&FormChunk, sizeof(FormChunk), 1, ifile);
BSWAP32(FormChunk.ckID);
BSWAP32(FormChunk.formType);
if ((FormChunk.ckID != 0x464f524d) || (FormChunk.formType != 0x41494643)) { // FORM, AIFC
fail_parse("not an AIFF-C file");
}
for (;;) {
s32 num = fread(&Header, sizeof(Header), 1, ifile);
u32 ts;
if (num <= 0) break;
BSWAP32(Header.ckID);
BSWAP32(Header.ckSize);
Header.ckSize++;
Header.ckSize &= ~1;
s32 offset = ftell(ifile);
switch (Header.ckID) {
case 0x434f4d4d: // COMM
checked_fread(&CommChunk, sizeof(CommChunk), 1, ifile);
BSWAP16(CommChunk.numChannels);
BSWAP16(CommChunk.numFramesH);
BSWAP16(CommChunk.numFramesL);
BSWAP16(CommChunk.sampleSize);
BSWAP16(CommChunk.compressionTypeH);
BSWAP16(CommChunk.compressionTypeL);
s32 cType = (CommChunk.compressionTypeH << 16) + CommChunk.compressionTypeL;
if (cType != 0x56415043) { // VAPC
fail_parse("file is of the wrong compression type");
}
if (CommChunk.numChannels != 1) {
fail_parse("file contains %d channels, only 1 channel supported", CommChunk.numChannels);
}
if (CommChunk.sampleSize != 16) {
fail_parse("file contains %d bit samples, only 16 bit samples supported", CommChunk.sampleSize);
}
nSamples = (CommChunk.numFramesH << 16) + CommChunk.numFramesL;
// Allow broken input lengths
if (nSamples % 16) {
nSamples--;
}
if (nSamples % 16 != 0) {
fail_parse("number of chunks must be a multiple of 16, found %d", nSamples);
}
break;
case 0x53534e44: // SSND
checked_fread(&SndDChunk, sizeof(SndDChunk), 1, ifile);
BSWAP32(SndDChunk.offset);
BSWAP32(SndDChunk.blockSize);
assert(SndDChunk.offset == 0);
assert(SndDChunk.blockSize == 0);
soundPointer = ftell(ifile);
break;
case 0x4150504c: // APPL
checked_fread(&ts, sizeof(u32), 1, ifile);
BSWAP32(ts);
if (ts == 0x73746f63) { // stoc
u8 len;
checked_fread(&len, 1, 1, ifile);
if (len == 11) {
char ChunkName[12];
s16 version;
checked_fread(ChunkName, 11, 1, ifile);
ChunkName[11] = '\0';
if (strcmp("VADPCMCODES", ChunkName) == 0) {
checked_fread(&version, sizeof(s16), 1, ifile);
BSWAP16(version);
if (version != 1) {
fail_parse("Unknown codebook chunk version");
}
readaifccodebook(ifile, &coefTable, &order, &npredictors);
}
else if (strcmp("VADPCMLOOPS", ChunkName) == 0) {
checked_fread(&version, sizeof(s16), 1, ifile);
BSWAP16(version);
if (version != 1) {
fail_parse("Unknown loop chunk version");
}
aloops = readlooppoints(ifile, &nloops);
if (nloops != 1) {
fail_parse("Only a single loop supported");
}
}
}
}
break;
}
fseek(ifile, offset + Header.ckSize, SEEK_SET);
}
if (coefTable == NULL) {
fail_parse("Codebook missing from bitstream");
}
for (s32 i = 0; i < order; i++) {
state[15 - i] = 0;
}
u32 outputBytes = nSamples * sizeof(s16);
u8 *outputBuf = malloc(outputBytes);
fseek(ifile, soundPointer, SEEK_SET);
while (currPos < nSamples) {
u8 input[9];
u8 encoded[9];
s32 lastState[16];
s32 decoded[16];
s16 guess[16];
s16 origGuess[16];
memcpy(lastState, state, sizeof(lastState));
checked_fread(input, 9, 1, ifile);
// Decode for real
my_decodeframe(input, state, order, coefTable);
memcpy(decoded, state, sizeof(lastState));
// Create a guess from that, by clamping to 16 bits
for (s32 i = 0; i < 16; i++) {
origGuess[i] = clamp_to_s16(state[i]);
}
// Encode the guess
memcpy(state, lastState, sizeof(lastState));
memcpy(guess, origGuess, sizeof(guess));
my_encodeframe(encoded, guess, state, coefTable, order, npredictors);
// If it doesn't match, randomly round numbers until it does.
if (memcmp(input, encoded, 9) != 0) {
s32 scale = 1 << (input[0] >> 4);
do {
permute(guess, decoded, scale);
memcpy(state, lastState, sizeof(lastState));
my_encodeframe(encoded, guess, state, coefTable, order, npredictors);
} while (memcmp(input, encoded, 9) != 0);
// Bring the matching closer to the original decode (not strictly
// necessary, but it will move us closer to the target on average).
for (s32 failures = 0; failures < 50; failures++) {
s32 ind = myrand() % 16;
s32 old = guess[ind];
if (old == origGuess[ind]) continue;
guess[ind] = origGuess[ind];
if (myrand() % 2) guess[ind] += (old - origGuess[ind]) / 2;
memcpy(state, lastState, sizeof(lastState));
my_encodeframe(encoded, guess, state, coefTable, order, npredictors);
if (memcmp(input, encoded, 9) == 0) {
failures = -1;
}
else {
guess[ind] = old;
}
}
}
memcpy(state, decoded, sizeof(lastState));
BSWAP16_MANY(guess, 16);
memcpy(outputBuf + currPos * 2, guess, sizeof(guess));
currPos += 16;
}
// Write an incomplete file header. We'll fill in the size later.
fwrite("FORM\0\0\0\0AIFF", 12, 1, ofile);
// Subtract 4 from the COMM size to skip the compression field.
write_header(ofile, "COMM", sizeof(CommonChunk) - 4);
CommChunk.numFramesH = nSamples >> 16;
CommChunk.numFramesL = nSamples & 0xffff;
BSWAP16(CommChunk.numChannels);
BSWAP16(CommChunk.numFramesH);
BSWAP16(CommChunk.numFramesL);
BSWAP16(CommChunk.sampleSize);
fwrite(&CommChunk, sizeof(CommonChunk) - 4, 1, ofile);
if (nloops > 0) {
s32 startPos = aloops[0].start, endPos = aloops[0].end;
const char *markerNames[2] = {"start", "end"};
Marker markers[2] = {
{1, startPos >> 16, startPos & 0xffff},
{2, endPos >> 16, endPos & 0xffff}
};
write_header(ofile, "MARK", 2 + 2 * sizeof(Marker) + 1 + 5 + 1 + 3);
s16 numMarkers = bswap16(2);
fwrite(&numMarkers, sizeof(s16), 1, ofile);
for (s32 i = 0; i < 2; i++) {
u8 len = (u8) strlen(markerNames[i]);
BSWAP16(markers[i].MarkerID);
BSWAP16(markers[i].positionH);
BSWAP16(markers[i].positionL);
fwrite(&markers[i], sizeof(Marker), 1, ofile);
fwrite(&len, 1, 1, ofile);
fwrite(markerNames[i], len, 1, ofile);
}
write_header(ofile, "INST", sizeof(InstrumentChunk));
InstChunk.sustainLoop.playMode = bswap16(1);
InstChunk.sustainLoop.beginLoop = bswap16(1);
InstChunk.sustainLoop.endLoop = bswap16(2);
InstChunk.releaseLoop.playMode = 0;
InstChunk.releaseLoop.beginLoop = 0;
InstChunk.releaseLoop.endLoop = 0;
fwrite(&InstChunk, sizeof(InstrumentChunk), 1, ofile);
}
// Save the coefficient table for use when encoding. Ideally this wouldn't
// be needed and "tabledesign -s 1" would generate the right table, but in
// practice it's difficult to adjust samples to make that happen.
write_header(ofile, "APPL", 4 + 12 + sizeof(CodeChunk) + npredictors * order * 8 * 2);
fwrite("stoc", 4, 1, ofile);
CodeChunk cChunk;
cChunk.version = bswap16(1);
cChunk.order = bswap16(order);
cChunk.nEntries = bswap16(npredictors);
fwrite("\x0bVADPCMCODES", 12, 1, ofile);
fwrite(&cChunk, sizeof(CodeChunk), 1, ofile);
for (s32 i = 0; i < npredictors; i++) {
for (s32 j = 0; j < order; j++) {
for (s32 k = 0; k < 8; k++) {
s16 ts = bswap16(coefTable[i][k][j]);
fwrite(&ts, sizeof(s16), 1, ofile);
}
}
}
write_header(ofile, "SSND", outputBytes + 8);
SndDChunk.offset = 0;
SndDChunk.blockSize = 0;
fwrite(&SndDChunk, sizeof(SoundDataChunk), 1, ofile);
fwrite(outputBuf, outputBytes, 1, ofile);
// Fix the size in the header
s32 fileSize = bswap32(ftell(ofile) - 8);
fseek(ofile, 4, SEEK_SET);
fwrite(&fileSize, 4, 1, ofile);
fclose(ifile);
fclose(ofile);
return 0;
}