#include #include #include #include "g7221_decoder_lib.h" #include "g7221_decoder_aes.h" /* Decodes Siren14 from Namco's BNSF, a mono MLT/DCT-based codec for speech/sound (low bandwidth). * Reverse engineered for various exes with info from Polycom's reference int decoder. * - Reference decoder and codec info: https://www.itu.int/rec/T-REC-G.722.1/en * * Technically the name is "ITU-T G.722.1 Annex C" (official ITU-T spec), while "Siren14" * was Polycom's original format with slightly different frames, though Namco calls it * "Siren14 Version 3.02 For Products" while using G.722.1's frame format. * Siren7 (7000hz bandwidth) isn't supported, only Siren14 (14000hz). * * Very roughly the encoder works like this: * - Apply a Modulated Lapped Transform (MLT) function over 640*2 samples to get spectrum * coefficients (can be decomposed into a window, overlap and add with a DCT-IV, of samples * from a current frame and samples from a prev frame). * - resulting coefs are divided into 28 bands called "regions" of 500hz. * - Each region contains 20 MLT spectrum coefs, total 28 regions * 500hz = 14000hz. * - Bands above 14khz are ignored (overall output quality isn't high). * - Pack amplitude envelope bits, defined as the RMS (Root-Mean-Square) of the coefs in * the region. First region sets all bits, rest is differentially and huffman coded. * Remaning bits are left to quantize coefs. * - Regions are given a "category" to quantize, that define the number of quantization bits * and other coding parameters. Results are combined into vector indices, * and Huffman-coded (frequent vectors require less bits). * Decoding thus unpacks amplitudes, region coefs and does inverse MLT. * * Namco roughly follows the reference decoder ('refdec') with some differences: * - uses mostly int32, while refdec has int16 with exact rounding/overflow handling (no output diffs) * - modified random number generator (minor output diffs) * - very minor change in bit unpacking (minor output diffs) * - modified DCT-IV optimizations, scaling and window functions (minor output diffs) * - internally PCM16 bufs, but converts to float (sample/32768.0) afterwards if the platform needs it * - less error control (on error decoder is supposed to repeat last coefs) * - can't decode Siren7, and given output diffs it's not actually ITU-compliant * - minor optimizations here and there but otherwise very similar * This decoder generally uses Polycom's terminology, and while some parts like the bitreader could be * reimplemented they are mostly untouched for documentation purposes. * * TODO: missing some validations (may segfault on bad data), * access indexes with (idx & max) and clamp buffer reads */ #include "g7221_decoder_lib_data.h" /***************************************************************************** * IMLT *****************************************************************************/ static int imlt_window(int16_t* new_samples, int16_t* old_samples, int16_t* out_samples) { int i; int sample_lo, sample_hi; int16_t win_val_lo, win_val_hi, new_val, old_val; const int16_t *win_ptr_lo, *win_ptr_hi; int16_t *new_ptr, *old_ptr, *out_ptr_lo, *out_ptr_hi; /* overlap 2nd half of prev frame's samples and 1st half of current frame's samples with * a window function to smooth out between frames */ win_ptr_lo = imlt_samples_window + 0; win_ptr_hi = imlt_samples_window + 640; new_ptr = new_samples + 320; old_ptr = old_samples + 0; out_ptr_lo = out_samples + 0; out_ptr_hi = out_samples + 640; while (out_ptr_lo != out_ptr_hi) { win_val_lo = *win_ptr_lo++; win_val_hi = *--win_ptr_hi; new_val = *--new_ptr; old_val = *old_ptr++; sample_lo = (new_val * win_val_lo + old_val * *win_ptr_hi + 32768) >> 13; if (sample_lo > 32767) sample_lo = 32767; else if (sample_lo < -32768) sample_lo = -32768; *out_ptr_lo++ = sample_lo; sample_hi = (new_val * win_val_hi - old_val * win_val_lo + 32768) >> 13; if (sample_hi > 32767) sample_hi = 32767; else if (sample_hi < -32768) sample_hi = -32768; *--out_ptr_hi = sample_hi; } /* save the 2nd half of the new samples to use above in next frame */ old_ptr = old_samples + 0; new_ptr = new_samples + 320; for (i = 0; i < 320; i++) { old_ptr[i] = new_ptr[i]; } return 0; } /* "dct4_x640_int" */ static int imlt_dct4(int16_t* mlt_coefs, int16_t* new_samples, int mag_shift) { int i, j, k, n; const uint8_t *set1_ptr; int mod_shift, sub_shift; /* vs refdec: very optimized, output is slightly different (louder) but it's massively * faster (around 20% vs float refdec, int refdec was very slow to begin with). * Can't quite clean this due to the complex math simplifications. * Should correspond to: cos(PI*(t+0.5)*(k+0.5)/block_length) */ /* rotation butterflies? (cos/sin 640 groups) */ { int cos_val, sin_val; const uint16_t *cos_ptr, *sin_ptr; int16_t mlt_val_lo, mlt_val_hi; int16_t *mlt_ptr_lo, *mlt_ptr_hi; mlt_ptr_lo = mlt_coefs + 0; mlt_ptr_hi = mlt_coefs + 640; cos_ptr = &imlt_cos_tables[0]; /* cos_table_64 */ sin_ptr = &imlt_sin_tables[0]; /* sin_table_64 */ for (i = 40; i > 0; --i) { cos_val = *cos_ptr++; sin_val = *sin_ptr++; mlt_val_lo = *mlt_ptr_lo >> 1; *mlt_ptr_lo++ = (cos_val * mlt_val_lo + 32768) >> 16; *--mlt_ptr_hi = (sin_val * -mlt_val_lo + 32768) >> 16; cos_val = *cos_ptr++; sin_val = *sin_ptr++; mlt_val_lo = *mlt_ptr_lo >> 1; *mlt_ptr_lo++ = (cos_val * mlt_val_lo + 32768) >> 16; *--mlt_ptr_hi = (sin_val * mlt_val_lo + 32768) >> 16; } for (i = 120; i > 0; --i) { cos_val = *cos_ptr++; sin_val = *sin_ptr++; mlt_val_lo = *mlt_ptr_lo >> 1; mlt_val_hi = *--mlt_ptr_hi >> 1; *mlt_ptr_lo++ = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; *mlt_ptr_hi = (sin_val * -mlt_val_lo + cos_val * mlt_val_hi + 32768) >> 16; cos_val = *cos_ptr++; sin_val = *sin_ptr++; mlt_val_lo = *mlt_ptr_lo >> 1; mlt_val_hi = *--mlt_ptr_hi >> 1; *mlt_ptr_lo++ = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; *mlt_ptr_hi = (sin_val * mlt_val_lo - cos_val * mlt_val_hi + 32768) >> 16; } } /* sum/diff butterflies? */ { int16_t mlt_val_lo, mlt_val_mlo, mlt_val_mhi, mlt_val_hi; int16_t *mlt_ptr, *mlt_ptr_lo, *mlt_ptr_mlo, *mlt_ptr_mhi, *mlt_ptr_hi; mlt_ptr = mlt_coefs + 0; for (i = 2; i > 0; --i) { mlt_ptr_lo = mlt_ptr + 0; mlt_ptr_hi = mlt_ptr + 320; mlt_ptr_mlo = mlt_ptr + 160; mlt_ptr_mhi = mlt_ptr + 160; for (j = 80; j > 0; --j) { mlt_val_lo = *mlt_ptr_lo; mlt_val_hi = *--mlt_ptr_hi; mlt_val_mhi = *--mlt_ptr_mhi; mlt_val_mlo = *mlt_ptr_mlo; *mlt_ptr_lo++ = (mlt_val_hi + mlt_val_lo) >> 1; *mlt_ptr_mlo++ = (mlt_val_lo - mlt_val_hi) >> 1; *mlt_ptr_mhi = (mlt_val_mlo + mlt_val_mhi) >> 1; *mlt_ptr_hi = (mlt_val_mhi - mlt_val_mlo) >> 1; } mlt_ptr += 320; } } /* helper table used in next 3 sections */ set1_ptr = imlt_set1_table; /* rotation butterflies? (cos/sin 160/80/40/20/10 groups) */ { int cos_val, sin_val; const uint16_t *cos_ptr, *sin_ptr, *cos_ptr_lo, *sin_ptr_lo; int16_t mlt_val_lo, mlt_val_hi, mlt_val_mlo, mlt_val_mhi; int16_t *mlt_ptr, *mlt_ptr_lo, *mlt_ptr_hi, *mlt_ptr_mlo, *mlt_ptr_mhi; cos_ptr = &imlt_cos_tables[320+160]; /* cos_table_16 > 8 > 4 > 2 */ sin_ptr = &imlt_sin_tables[320+160]; /* sin_table_16 > 8 > 4 > 2 */ for (n = 160; n >= 20; n /= 2) { mlt_ptr = mlt_coefs + 0; while (mlt_ptr < mlt_coefs + 640) { for (j = *set1_ptr; j > 0; --j) { mlt_ptr_lo = mlt_ptr + 0; mlt_ptr_hi = mlt_ptr + n; mlt_ptr_mlo = mlt_ptr + (n / 2); mlt_ptr_mhi = mlt_ptr + (n / 2); for (k = n / 4; k > 0; --k) { mlt_val_lo = *mlt_ptr_lo; mlt_val_hi = *--mlt_ptr_hi; mlt_val_mhi = *--mlt_ptr_mhi; mlt_val_mlo = *mlt_ptr_mlo; *mlt_ptr_lo++ = mlt_val_lo + mlt_val_hi; *mlt_ptr_mlo++ = mlt_val_lo - mlt_val_hi; *mlt_ptr_mhi = mlt_val_mlo + mlt_val_mhi; *mlt_ptr_hi = mlt_val_mhi - mlt_val_mlo; } mlt_ptr += n; } set1_ptr++; for (j = *set1_ptr; j > 0; --j) { mlt_ptr_lo = mlt_ptr + 0; mlt_ptr_hi = mlt_ptr + n; cos_ptr_lo = cos_ptr + 0; sin_ptr_lo = sin_ptr + 0; for (k = n / 4; k > 0; --k) { cos_val = *cos_ptr_lo++; sin_val = *sin_ptr_lo++; mlt_val_lo = *mlt_ptr_lo; mlt_val_hi = *--mlt_ptr_hi; *mlt_ptr_lo++ = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; *mlt_ptr_hi = (sin_val * -mlt_val_lo + cos_val * mlt_val_hi + 32768) >> 16; cos_val = *cos_ptr_lo++; sin_val = *sin_ptr_lo++; mlt_val_lo = *mlt_ptr_lo; mlt_val_hi = *--mlt_ptr_hi; *mlt_ptr_lo++ = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; *mlt_ptr_hi = (sin_val * mlt_val_lo - cos_val * mlt_val_hi + 32768) >> 16; } mlt_ptr += n; } set1_ptr++; } /* next sub-tables */ cos_ptr += n / 2; sin_ptr += n / 2; } } /* rotation butterflies? (cos/sin 5 groups) */ { int cos_val, sin_val; const uint16_t *cos_ptr, *sin_ptr; int16_t mlt_val_lo, mlt_val_hi, mlt_val_mlo, mlt_val_mhi; int16_t *mlt_ptr; /* n/cos-sin would continue from above but for clarity: */ cos_ptr = &imlt_cos_tables[320+160+80+40+20+10]; /* cos_table_1 */ sin_ptr = &imlt_sin_tables[320+160+80+40+20+10]; /* sin_table_1 */ { n = 10; mlt_ptr = mlt_coefs + 0; while (mlt_ptr < mlt_coefs + 640) { for (j = *set1_ptr; j > 0; --j) { mlt_val_lo = mlt_ptr[0]; mlt_val_hi = mlt_ptr[n - 1]; mlt_val_mlo = mlt_ptr[n / 2 - 1]; mlt_val_mhi = mlt_ptr[n / 2]; mlt_ptr[0] = mlt_val_lo + mlt_val_hi; mlt_ptr[n / 2] = mlt_val_lo - mlt_val_hi; mlt_ptr[n / 2 - 1] = mlt_val_mhi + mlt_val_mlo; mlt_ptr[n - 1] = mlt_val_mlo - mlt_val_mhi; mlt_val_lo = mlt_ptr[1]; mlt_val_hi = mlt_ptr[n - 2]; mlt_val_mlo = mlt_ptr[n / 2 - 2]; mlt_val_mhi = mlt_ptr[n / 2 + 1]; mlt_ptr[1] = mlt_val_hi + mlt_val_lo; mlt_ptr[n / 2 + 1] = mlt_val_lo - mlt_val_hi; mlt_ptr[n / 2 - 2] = mlt_val_mhi + mlt_val_mlo; mlt_ptr[n - 2] = mlt_val_mlo - mlt_val_mhi; mlt_val_lo = mlt_ptr[2]; mlt_val_hi = mlt_ptr[n - 3]; mlt_ptr[2] = mlt_val_hi + mlt_val_lo; mlt_ptr[n / 2 + 2] = mlt_val_lo - mlt_val_hi; mlt_ptr += n; } cos_val = cos_ptr[0]; sin_val = sin_ptr[0]; mlt_val_lo = mlt_ptr[0]; mlt_val_hi = mlt_ptr[n - 1]; mlt_ptr[0] = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; mlt_ptr[n - 1] = (sin_val * mlt_val_lo - cos_val * mlt_val_hi + 32768) >> 16; cos_val = cos_ptr[1]; sin_val = sin_ptr[1]; mlt_val_lo = mlt_ptr[1]; mlt_val_hi = mlt_ptr[n - 2]; mlt_ptr[1] = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; mlt_ptr[n - 2] = (sin_val * -mlt_val_lo + cos_val * mlt_val_hi + 32768) >> 16; cos_val = cos_ptr[2]; sin_val = sin_ptr[2]; mlt_val_lo = mlt_ptr[2]; mlt_val_hi = mlt_ptr[n - 3]; mlt_ptr[2] = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; mlt_ptr[n - 3]= (sin_val * mlt_val_lo - cos_val * mlt_val_hi + 32768) >> 16; cos_val = cos_ptr[3]; sin_val = sin_ptr[3]; mlt_val_lo = mlt_ptr[3]; mlt_val_hi = mlt_ptr[n - 4]; mlt_ptr[3] = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; mlt_ptr[n - 4] = (sin_val * -mlt_val_lo + cos_val * mlt_val_hi + 32768) >> 16; cos_val = cos_ptr[4]; sin_val = sin_ptr[4]; mlt_val_lo = mlt_ptr[4]; mlt_val_hi = mlt_ptr[n - 5]; mlt_ptr[4] = (cos_val * mlt_val_lo + sin_val * mlt_val_hi + 32768) >> 16; mlt_ptr[n - 5] = (sin_val * mlt_val_lo - cos_val * mlt_val_hi + 32768) >> 16; mlt_ptr += n; set1_ptr += 2; } } } mod_shift = mag_shift - 1; sub_shift = 1; if (mod_shift >= 8) sub_shift = 2; mod_shift -= sub_shift; /* dct core? */ { const int16_t *mlt_ptr; int16_t *new_ptr; mlt_ptr = mlt_coefs + 0; new_ptr = new_samples + 0; while (1) { for (i = *set1_ptr; i; --i) { new_ptr[0] = (mlt_ptr[4] + mlt_ptr[3] + mlt_ptr[2] + mlt_ptr[1] + mlt_ptr[0]) >> sub_shift; new_ptr[1] = (19261 * mlt_ptr[1] + 31164 * mlt_ptr[0] - 19261 * mlt_ptr[3] - 31164 * mlt_ptr[4]) >> (sub_shift + 15); new_ptr[2] = (26510 * mlt_ptr[4] + 26510 * mlt_ptr[0] - 10126 * mlt_ptr[1] - 32768 * mlt_ptr[2] - 10126 * mlt_ptr[3]) >> (sub_shift + 15); new_ptr[3] = (31164 * mlt_ptr[3] + 19261 * mlt_ptr[0] - 31164 * mlt_ptr[1] - 19261 * mlt_ptr[4]) >> (sub_shift + 15); new_ptr[4] = (10126 * mlt_ptr[4] + 32768 * mlt_ptr[2] + 10126 * mlt_ptr[0] - 26510 * mlt_ptr[1] - 26510 * mlt_ptr[3]) >> (sub_shift + 15); mlt_ptr += 5; new_ptr += 5; } set1_ptr += 2; if (mlt_ptr >= mlt_coefs + 640) break; new_ptr[0] = ( 5126 * mlt_ptr[4] + 14876 * mlt_ptr[3] + 23170 * mlt_ptr[2] + 32365 * mlt_ptr[0] + 29197 * mlt_ptr[1]) >> (sub_shift + 15); new_ptr[1] = (-14876 * mlt_ptr[4] + -32365 * mlt_ptr[3] + 5126 * mlt_ptr[1] + 29197 * mlt_ptr[0] - 23170 * mlt_ptr[2]) >> (sub_shift + 15); new_ptr[2] = ( 23170 * mlt_ptr[4] + 23170 * mlt_ptr[3] + -23170 * mlt_ptr[1] + 23170 * mlt_ptr[0] - 23170 * mlt_ptr[2]) >> (sub_shift + 15); new_ptr[3] = (-29197 * mlt_ptr[4] + 5126 * mlt_ptr[3] + 23170 * mlt_ptr[2] + 14876 * mlt_ptr[0] - 32365 * mlt_ptr[1]) >> (sub_shift + 15); new_ptr[4] = ( 32365 * mlt_ptr[4] + -29197 * mlt_ptr[3] + 23170 * mlt_ptr[2] + 5126 * mlt_ptr[0] - 14876 * mlt_ptr[1]) >> (sub_shift + 15); mlt_ptr += 5; new_ptr += 5; } } /* swapping and sum/diffs? */ { const uint8_t *set2_ptr; int16_t *mlt_ptr, *new_ptr; int16_t tmp1_val_a, tmp1_val_b; int16_t *tmp0_ptr, *tmp1_ptr, *tmp1_ptr_lo, *tmp1_ptr_mlo, *tmp1_ptr_mhi, *tmp2_ptr; set2_ptr = imlt_set2_table; mlt_ptr = mlt_coefs + 0; new_ptr = new_samples + 0; while (new_ptr < new_samples + 640) { for (i = *set2_ptr; i; --i) { *mlt_ptr++ = new_ptr[0]; *mlt_ptr++ = new_ptr[5]; *mlt_ptr++ = new_ptr[1]; *mlt_ptr++ = new_ptr[6]; *mlt_ptr++ = new_ptr[2]; *mlt_ptr++ = new_ptr[7]; *mlt_ptr++ = new_ptr[3]; *mlt_ptr++ = new_ptr[8]; *mlt_ptr++ = new_ptr[4]; *mlt_ptr++ = new_ptr[9]; new_ptr += 10; } set2_ptr++; *mlt_ptr++ = new_ptr[0]; *mlt_ptr++ = new_ptr[9] + new_ptr[1]; *mlt_ptr++ = new_ptr[1] - new_ptr[9]; *mlt_ptr++ = new_ptr[2] - new_ptr[8]; *mlt_ptr++ = new_ptr[8] + new_ptr[2]; *mlt_ptr++ = new_ptr[7] + new_ptr[3]; *mlt_ptr++ = new_ptr[3] - new_ptr[7]; *mlt_ptr++ = new_ptr[4] - new_ptr[6]; *mlt_ptr++ = new_ptr[6] + new_ptr[4]; *mlt_ptr++ = new_ptr[5]; new_ptr += 10; } /* below is some three way swapping, tmp ptrs change between mlt<>new */ tmp0_ptr = mlt_coefs + 640; tmp1_ptr = new_samples + 640; for (n = 20; n <= 160; n *= 2) { tmp2_ptr = tmp0_ptr + 0; tmp0_ptr = tmp1_ptr - 640; tmp1_ptr = tmp2_ptr - 640; do { for (j = *set2_ptr; j > 0; --j) { tmp1_ptr_mhi = tmp1_ptr + (n / 2); for (k = n / 4; k > 0; --k) { *tmp0_ptr++ = *tmp1_ptr++; *tmp0_ptr++ = *tmp1_ptr_mhi++; *tmp0_ptr++ = *tmp1_ptr++; *tmp0_ptr++ = *tmp1_ptr_mhi++; } tmp1_ptr += n / 2; } set2_ptr++; if (tmp1_ptr >= tmp2_ptr) break; tmp1_ptr_lo = tmp1_ptr + 0; tmp1_ptr_mlo = tmp1_ptr + (n - 1); *tmp0_ptr++ = *tmp1_ptr_lo++; tmp1_val_a = *tmp1_ptr_lo++; tmp1_val_b = *tmp1_ptr_mlo; *tmp0_ptr++ = tmp1_val_b + tmp1_val_a; *tmp0_ptr++ = tmp1_val_a - tmp1_val_b; for (j = (n / 2 - 2) / 2; j > 0; --j) { tmp1_val_a = *tmp1_ptr_lo++; tmp1_val_b = *--tmp1_ptr_mlo; *tmp0_ptr++ = tmp1_val_a - tmp1_val_b; *tmp0_ptr++ = tmp1_val_b + tmp1_val_a; tmp1_val_a = *tmp1_ptr_lo++; tmp1_val_b = *--tmp1_ptr_mlo; *tmp0_ptr++ = tmp1_val_b + tmp1_val_a; *tmp0_ptr++ = tmp1_val_a - tmp1_val_b; } *tmp0_ptr++ = -*tmp1_ptr_lo; tmp1_ptr += n; } while (tmp1_ptr < tmp2_ptr); } } /* final modifications and post scaling? */ { int16_t mlt_val_lo, mlt_val_mhi, mlt_val_mlo, mlt_val_hi; const int16_t *mlt_ptr_lo, *mlt_ptr_hi, *mlt_ptr_mlo, *mlt_ptr_mhi; int16_t *new_ptr; if (mod_shift <= 0) { /* negative scale (right shift) */ mod_shift = -mod_shift; mlt_ptr_lo = mlt_coefs + 0; mlt_ptr_mlo = mlt_coefs + 160; mlt_ptr_mhi = mlt_coefs + 480; mlt_ptr_hi = mlt_coefs + 640; new_ptr = new_samples + 0; mlt_val_lo = *mlt_ptr_lo++; *new_ptr++ = mlt_val_lo << mod_shift; mlt_val_mlo = *mlt_ptr_mlo++; mlt_val_hi = *--mlt_ptr_hi; *new_ptr++ = (mlt_val_hi + mlt_val_mlo) << mod_shift; *new_ptr++ = (mlt_val_mlo - mlt_val_hi) << mod_shift; for (i = 159; i > 0; --i) { mlt_val_lo = *mlt_ptr_lo++; mlt_val_mhi = *--mlt_ptr_mhi; *new_ptr++ = (mlt_val_lo - mlt_val_mhi) << mod_shift; *new_ptr++ = (mlt_val_mhi + mlt_val_lo) << mod_shift; mlt_val_mlo = *mlt_ptr_mlo++; mlt_val_hi = *--mlt_ptr_hi; *new_ptr++ = (mlt_val_hi + mlt_val_mlo) << mod_shift; *new_ptr++ = (mlt_val_mlo - mlt_val_hi) << mod_shift; } *new_ptr = -*mlt_ptr_mlo << mod_shift; } else { /* same but positive (left shift) */ mlt_ptr_lo = mlt_coefs + 0; mlt_ptr_mlo = mlt_coefs + 160; mlt_ptr_mhi = mlt_coefs + 480; mlt_ptr_hi = mlt_coefs + 640; new_ptr = new_samples + 0; mlt_val_lo = *mlt_ptr_lo++; *new_ptr++ = mlt_val_lo >> mod_shift; mlt_val_mlo = *mlt_ptr_mlo++; mlt_val_hi = *--mlt_ptr_hi; *new_ptr++ = (mlt_val_hi + mlt_val_mlo) >> mod_shift; *new_ptr++ = (mlt_val_mlo - mlt_val_hi) >> mod_shift; for (i = 159; i > 0; --i) { mlt_val_lo = *mlt_ptr_lo++; mlt_val_mhi = *--mlt_ptr_mhi; *new_ptr++ = (mlt_val_lo - mlt_val_mhi) >> mod_shift; *new_ptr++ = (mlt_val_mhi + mlt_val_lo) >> mod_shift; mlt_val_mlo = *mlt_ptr_mlo++; mlt_val_hi = *--mlt_ptr_hi; *new_ptr++ = (mlt_val_hi + mlt_val_mlo) >> mod_shift; *new_ptr++ = (mlt_val_mlo - mlt_val_hi) >> mod_shift; } *new_ptr = -*mlt_ptr_mlo >> mod_shift; } } return 0; } /* "inverse_MLT" */ static int rmlt_coefs_to_samples(int mag_shift, int16_t* mlt_coefs, int16_t* old_samples, int16_t* out_samples /*, int p_samples_done*/) { int res; int16_t new_samples[640]; /* block transform MLT spectrum coefs to time domain PCM samples using DCT-IV (inverse) */ res = imlt_dct4(mlt_coefs, new_samples, mag_shift); if (res < 0) return res; /* apply IMLT overlapped window filter function (640 samples) */ res = imlt_window(new_samples, old_samples, out_samples); if (res < 0) return res; //*p_samples_done = 640; /* in Namco's code but actually ignored */ return 0; } /***************************************************************************** * UNPACKING *****************************************************************************/ static inline int calc_offset(const int* absolute_region_power_index, int available_bits) { int region, cat_index; int offset, delta; offset = -32; delta = 32; do { int test_offset = offset + delta; int bits = 0; /* obtain a category for each region using the test offset */ for (region = 0; region < NUMBER_OF_REGIONS; region++) { cat_index = (test_offset - absolute_region_power_index[region]) / 2; if (cat_index < 0) cat_index = 0; else if (cat_index > NUM_CATEGORIES - 1) cat_index = NUM_CATEGORIES - 1; /* compute the number of bits that will be used given the cat assignments */ bits += expected_bits_table[cat_index]; } /* if (bits > available_bits - 32) then divide the offset region for the bin search */ if (bits >= available_bits - 32) { offset = test_offset; } delta /= 2; } while (delta > 0); return offset; } static inline void compute_raw_power_categories(int* power_categories, const int* absolute_region_power_index, int offset) { int region, cat_index; for (region = 0; region < NUMBER_OF_REGIONS; region++) { cat_index = (offset - absolute_region_power_index[region]) / 2; if (cat_index < 0) cat_index = 0; else if (cat_index > NUM_CATEGORIES - 1) cat_index = NUM_CATEGORIES - 1; power_categories[region] = cat_index; } } static inline void comp_powercat_and_catbalance(int* power_categories, int* category_balances, const int* absolute_region_power_index, int available_bits, int offset) { int region, ccp; int max_rate_categories[NUMBER_OF_REGIONS]; int min_rate_categories[NUMBER_OF_REGIONS]; int temp_category_balances[2*NUM_CATEGORIZATION_CONTROL_POSSIBILITIES]; int expected_number_of_code_bits, max, min, max_rate_pointer, min_rate_pointer; /* Namco uses power_categories directly instead of max_rate_categories, but we'll separate for clarity. * It also loads min_rate_categories and expected_number_of_code_bits in the previous region loop */ expected_number_of_code_bits = 0; for (region = 0; region < NUMBER_OF_REGIONS; region++) { int power_category = power_categories[region]; max_rate_categories[region] = power_category; min_rate_categories[region] = power_category; expected_number_of_code_bits += expected_bits_table[power_category]; } max = expected_number_of_code_bits; min = expected_number_of_code_bits; max_rate_pointer = NUM_CATEGORIZATION_CONTROL_POSSIBILITIES; min_rate_pointer = NUM_CATEGORIZATION_CONTROL_POSSIBILITIES; for (ccp = 0; ccp < NUM_CATEGORIZATION_CONTROL_POSSIBILITIES - 1; ccp++) { if (max + min <= available_bits * 2) { int raw_min = 10000; int raw_min_index = 0; /* Search from lowest freq regions to highest for best */ /* region to reassign to a higher bit rate category. */ for (region = 0; region < NUMBER_OF_REGIONS; region++) { if (max_rate_categories[region] > 0) { int tmp = (offset - absolute_region_power_index[region]) - (max_rate_categories[region] * 2); if (tmp < raw_min) { raw_min = tmp; raw_min_index = region; } } } max_rate_pointer--; temp_category_balances[max_rate_pointer] = raw_min_index; max -= expected_bits_table[max_rate_categories[raw_min_index]]; max_rate_categories[raw_min_index]--; max += expected_bits_table[max_rate_categories[raw_min_index]]; } else { int raw_max = -10000; int raw_max_index = NUMBER_OF_REGIONS - 1; /* Search from highest freq regions to lowest for best region to reassign to a lower bit rate category. */ for (region = NUMBER_OF_REGIONS - 1; region >= 0; region--) { if (min_rate_categories[region] < NUM_CATEGORIES - 1) { int tmp = (offset - absolute_region_power_index[region]) - (min_rate_categories[region] * 2); if (tmp > raw_max) { raw_max = tmp; raw_max_index = region; } } } temp_category_balances[min_rate_pointer] = raw_max_index; min_rate_pointer++; min -= expected_bits_table[min_rate_categories[raw_max_index]]; min_rate_categories[raw_max_index]++; min += expected_bits_table[min_rate_categories[raw_max_index]]; } } for (region = 0; region < NUMBER_OF_REGIONS; region++) { power_categories[region] = max_rate_categories[region]; } for (ccp = 0; ccp < NUM_CATEGORIZATION_CONTROL_POSSIBILITIES - 1; ccp++) { category_balances[ccp] = temp_category_balances[max_rate_pointer + ccp]; } } static int categorize(int available_bits, const int* absolute_region_power_index, int* power_categories, int* category_balances) { int offset; /* compensate increased bit usage for higher bitrates (used?) */ if (available_bits > MAX_DCT_LENGTH) { available_bits = 5 * (available_bits - MAX_DCT_LENGTH) / 8 + MAX_DCT_LENGTH; } /* calculate category stuff (originally inline'd) */ offset = calc_offset(absolute_region_power_index, available_bits); compute_raw_power_categories(power_categories, absolute_region_power_index, offset); comp_powercat_and_catbalance(power_categories, category_balances, absolute_region_power_index, available_bits, offset); return 0; } static inline void index_to_array(int index, int* array_cv, int category) { int q, p; int max_bin_plus_one = max_bin_plus1[category]; int inverse_of_max_bin_plus_one_scaled = max_bin_plus_one_inverse_scaled[category]; /* vs refdec: unrolled, inline'd version of the inverted loop, with some ops simplified * (depending on pre-scaled tables), since this is called many times. * From tests it's not too noticeable though. */ p = index; /* fills array (vector_dimension[category] - 1) times inversely */ switch (category) { case 0: case 1: case 2: q = (p * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[1] = p - (q * max_bin_plus_one); p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[0] = p - (q * max_bin_plus_one); //p = q; break; case 3: q = (p * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[3] = p - (q * 5); //max_bin_plus_one = 5 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[2] = p - (q * 5); //max_bin_plus_one = 5 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[1] = p - (q * 5); //max_bin_plus_one = 5 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[0] = p - (q * 5); //max_bin_plus_one = 5 //p = q; break; case 4: array_cv[3] = p & 3; p >>= 2; array_cv[2] = p & 3; p >>= 2; array_cv[1] = p & 3; p >>= 2; array_cv[0] = p & 3; /* not sure how this case is optimized */ break; case 5: q = (p * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[4] = p - (q * 3); //max_bin_plus_one = 3 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[3] = p - (q * 3); //max_bin_plus_one = 3 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[2] = p - (q * 3); //max_bin_plus_one = 3 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[1] = p - (q * 3); //max_bin_plus_one = 3 p = q; q = (q * inverse_of_max_bin_plus_one_scaled) >> 16; array_cv[0] = p - (q * 3); //max_bin_plus_one = 3 //p = q; break; case 6: array_cv[4] = p & 1; p >>= 1; array_cv[3] = p & 1; p >>= 1; array_cv[2] = p & 1; p >>= 1; array_cv[1] = p & 1; p >>= 1; array_cv[0] = p & 1; //p >>= 1; /* not sure how this case is optimized */ break; default: break; } } static int decode_vector_quantized_mlt_indices(uint32_t* data_u32, int* p_bitpos, int bit_count, uint32_t* p_random_value, int* decoder_region_standard_deviation, int* power_categories, int16_t* mlt_coefs) { int16_t standard_deviation; int array_cv[MAX_VECTOR_DIMENSION]; int i, v, region, category, index; uint32_t cur_u32, bitmask; uint32_t* ptr_u32; /* bitreading setup */ ptr_u32 = &data_u32[(*p_bitpos >> 5)]; bitmask = 1 << (31 - (*p_bitpos & 0x1F)); cur_u32 = *ptr_u32; ptr_u32++; /* read MLT coefs per region, differently depending on the category config */ for (region = 0; region < NUMBER_OF_REGIONS; region++) { standard_deviation = decoder_region_standard_deviation[region]; category = power_categories[region]; /* lower categories encode MLT coefs based on vectors incides + huffman (?) */ if (category < 7) { const int16_t* decoder_tree_ptr = table_of_decoder_tables[category]; int16_t* decoder_mlt_ptr = &mlt_coefs[region * REGION_SIZE]; for (v = 0; v < number_of_vectors[category]; v++) { index = 0; do { int bit = (bitmask & cur_u32) != 0; bitmask >>= 1; (*p_bitpos)++; if (bitmask == 0) { bitmask = 0x80000000; cur_u32 = *ptr_u32; ptr_u32++; } index = *(decoder_tree_ptr + (index*2) + bit); } while (index > 0); /* ran out of bits */ if (ptr_u32 > &data_u32[bit_count >> 5]) { category = 7; /* this category doesn't bitread and only noise fills */ /* Namco doesn't set remaining regions to category 7 like the spec, nor checks * when reading sign bits below, but doesn't seem to cause any problems */ //for (i = region + 1; i < NUMBER_OF_REGIONS; i++) { // power_categories[i] = 7; //} break; } index = -index; /* convert index into array of sign bits used to access the centroid table */ index_to_array(index, array_cv, category); /* vs refdec: sign reading slightly simplified */ for (i = 0; i < vector_dimension[category]; i++) { int decoder_mlt_value = 0; int negative; /* non-zero array = results in non-zero coef and encodes bit sign */ if (array_cv[i] != 0) { decoder_mlt_value = standard_deviation * mlt_quant_centroid[category][array_cv[i]]; decoder_mlt_value = decoder_mlt_value >> 12; negative = (bitmask & cur_u32) != 0; bitmask >>= 1; (*p_bitpos)++; if (bitmask == 0) { bitmask = 0x80000000; cur_u32 = *ptr_u32; ptr_u32++; } if (negative == 0) decoder_mlt_value = -decoder_mlt_value; } *decoder_mlt_ptr = decoder_mlt_value; decoder_mlt_ptr++; } } } /* higher categories don't encode all 20 MLT coefs, so rest are filled with * noise to pretend we have something */ if (category >= 5) { static const int noise_fill_factor[3] = {5793, 8192, 23170}; /* 0.176777, 0.25, 0.707107 */ uint32_t random_value; int16_t* decoder_mlt_ptr = &mlt_coefs[region * REGION_SIZE]; int16_t noise_fill_pos = (standard_deviation * noise_fill_factor[category - 5]) >> 15; /* should be int16 */ int16_t noise_fill_neg = -noise_fill_pos; /* vs refdec: updated differently (with hist state), and reupdated after 10 coefs */ *p_random_value *= 69069; random_value = *p_random_value; /* in some versions of Namco's decoder this is unrolled too */ if (category >= 7) { /* all coefs are noise-filled */ for (i = 0; i < REGION_SIZE; i++) { { if (random_value & 1) *decoder_mlt_ptr = noise_fill_pos; else *decoder_mlt_ptr = noise_fill_neg; random_value = (random_value >> 1); } decoder_mlt_ptr++; } } else { /* some coefs are noise-filled */ for (i = 0; i < REGION_SIZE; i++) { if (*decoder_mlt_ptr == 0) { if (random_value & 1) *decoder_mlt_ptr = noise_fill_pos; else *decoder_mlt_ptr = noise_fill_neg; random_value = (random_value >> 1); } decoder_mlt_ptr++; } } } } return 0; } /* unpacks input buffer into MLT coefs */ static int unpack_frame(int bit_rate, const uint8_t* data, int frame_size, /*int* p_frame_size, */ int* p_mag_shift, int16_t* mlt_coefs, uint32_t* p_random_value, int test_errors) { uint32_t data_u32[0x78/4 + 2]; int bitpos, expected_frame_size; int power_categories[NUMBER_OF_REGIONS]; int category_balances[NUM_CATEGORIZATION_CONTROL_POSSIBILITIES-1]; int absolute_region_power_index[NUMBER_OF_REGIONS]; /* a.k.a. RMS_index */ int decoder_region_standard_deviation[NUMBER_OF_REGIONS]; uint16_t categorization_control; int i; int res; /* setup bitreading */ { expected_frame_size = bit_rate / 8 / 50; if (frame_size < expected_frame_size) return 1; //p_frame_size = expected_frame_size; /* Namco returns this, for some reason */ /* Siren14 data is packed into U16 LE, but Namco reads and stores them in a U32 LE temp array for their bitreading */ for (i = 0; i < (expected_frame_size >> 2); i++) { data_u32[i] = (data[0x04*i + 2] << 0) | (data[0x04*i + 3] << 8) | (data[0x04*i + 0] << 16) | (data[0x04*i + 1] << 24); } /* data32 also has extra ints probably against outside reads, which wasn't originally * memset'ed but we'll do just in case (doesn't seem to matter) */ for (i = (expected_frame_size >> 2); i < 0x78/4 + 2; i++) { data_u32[i] = 0; } bitpos = 0; } /* decode amplitude envelope scales */ { int rms_index = 0; /* amplitudes are root-mean-square */ int region; /* get amplitude envelope (5b) for region 0 */ for (i = 0; i < 5; i++) { int bit = (data_u32[bitpos >> 5] >> (31 - (bitpos & 0x1F))) & 1; bitpos++; rms_index = (rms_index << 1) | bit; } absolute_region_power_index[0] = rms_index - ESF_ADJUSTMENT_TO_RMS_INDEX; /* get amplitudes for other regions, coded differentially based on region 0 (done with a temp array in refdec) */ for (region = 1; region < NUMBER_OF_REGIONS; region++) { int diff_index = 0; int region_index = region > 13 ? 13 - 1 : region - 1; do { int bit = (data_u32[bitpos >> 5] >> (31 - (bitpos & 0x1F))) & 1; bitpos++; diff_index = differential_region_power_decoder_tree[region_index][diff_index][bit]; } while (diff_index > 0); absolute_region_power_index[region] = absolute_region_power_index[region-1] - diff_index - DRP_DIFF_MIN; } } /* read categorization info bits */ { categorization_control = 0; for (i = 0; i < NUM_CATEGORIZATION_CONTROL_BITS; i++) { int bit = (data_u32[bitpos >> 5] >> (31 - (bitpos & 0x1F))) & 1; bitpos++; categorization_control = (categorization_control << 1) | bit; } } /* determine categorization config per region */ res = categorize( 8 * expected_frame_size - bitpos, absolute_region_power_index, power_categories, category_balances); if (res < 0) return res; /* adjust power categories (rate_adjust_categories) */ { for (i = 0; i < categorization_control; i++) { int region = category_balances[i]; power_categories[region]++; } } /* recover amplitude envelope deviation (done in decode_envelope in refdec) */ { int region, region_index, max_index /*, test_index*/; /* vs refdec: Namco *doesn't* calc test_index here, so resulting region_index * can be +-1 vs refdec, and final samples around +-10 (usually quieter). * Also reuses and mods absolute_region_power_index but we have decoder_region_standard_deviation for clarity */ //test_index = 0; max_index = 0; for (region = 0; region < NUMBER_OF_REGIONS; region++) { region_index = absolute_region_power_index[region]; if (max_index < region_index) max_index = region_index; //test_index += region_standard_deviation_table[region_index + REGION_POWER_TABLE_NUM_NEGATIVES]; } max_index += REGION_POWER_TABLE_NUM_NEGATIVES; region_index = 9; while ((region_index >= 0) && (/*test_index >= 8 ||*/ max_index > 28)) { max_index -= 2; region_index--; //test_index /= 2; } for (region = 0; region < NUMBER_OF_REGIONS; region++) { int rsd_index = absolute_region_power_index[region] + REGION_POWER_TABLE_NUM_NEGATIVES + region_index * 2; decoder_region_standard_deviation[region] = region_standard_deviation_table[rsd_index]; } *p_mag_shift = region_index; } /* decode the quantized bits into MLT coefs */ res = decode_vector_quantized_mlt_indices( data_u32, &bitpos, 8 * expected_frame_size, p_random_value, decoder_region_standard_deviation, power_categories, mlt_coefs); if (res < 0) return res; /* test for errors (in refdec but not Namco's, useful to detect decryption) */ if (test_errors) { int max_pad_bytes = 0x7; /* usually 0x04 and rarely ~0x07 */ int bits_left = 8 * expected_frame_size - bitpos; int i, endpos, test_bits; if (bits_left > 0) { /* frame must be padded with 1s after regular data */ endpos = bitpos; for (i = 0; i < bits_left; i++) { int bit = (data_u32[endpos >> 5] >> (31 - (endpos & 0x1F))) & 1; endpos++; if (bit == 0) return -1; } /* extra: test we aren't in the middle of padding (happens with bad keys) * After reading the whole frame, last bit position should land near last useful * data, a few bytes into padding, so check there aren't too many padding bits. */ endpos = bitpos; test_bits = 8 * max_pad_bytes; if (test_bits > bitpos) test_bits = bitpos; for (i = 0; i < test_bits; i++) { int bit = (data_u32[endpos >> 5] >> (31 - (endpos & 0x1F))) & 1; endpos--; /* from last position towards valid data */ if (bit != 1) break; } if (i == test_bits) return -8; } else { /* ? */ if (categorization_control < NUM_CATEGORIZATION_CONTROL_BITS - 1 && bits_left < 0) return -2; } for (i = 0; i < NUMBER_OF_REGIONS; i++) { if ((absolute_region_power_index[i] + ESF_ADJUSTMENT_TO_RMS_INDEX > 31) || (absolute_region_power_index[i] + ESF_ADJUSTMENT_TO_RMS_INDEX < -8)) return -4; } } return 0; } /***************************************************************************** * API *****************************************************************************/ struct g7221_handle { /* control */ int bit_rate; int frame_size; /* AES setup/state */ s14aes_handle* aes; /* state */ int16_t mlt_coefs[MAX_DCT_LENGTH]; int16_t old_samples[MAX_DCT_LENGTH >> 1]; uint32_t random_value; }; g7221_handle* g7221_init(int bytes_per_frame) { g7221_handle* handle = NULL; int bit_rate; /* valid only: 0x78, 0x50 or 0x3c */ bit_rate = bytes_per_frame * 8 * 50; if (bit_rate != 24000 && bit_rate != 32000 && bit_rate != 48000) goto fail; handle = calloc(1, sizeof(g7221_handle)); if (!handle) goto fail; handle->bit_rate = bit_rate; handle->frame_size = bytes_per_frame; g7221_reset(handle); return handle; fail: free(handle); return NULL; } int g7221_decode_frame(g7221_handle* handle, uint8_t* data, int16_t* out_samples) { int res; int mag_shift; int encrypted = handle->aes != NULL; /* first 0x10 bytes may be encrypted with AES. Original code also saves encrypted bytes, * then re-crypts after unpacking, presumably to guard against memdumps. */ if (encrypted) { s14aes_decrypt(handle->aes, data); } /* Namco's decoder is designed so that out_samples can be set in place of mlt_coefs, * so we could avoid one extra buffer, but for clarity we'll leave as is */ /* unpack data into MLT spectrum coefs */ res = unpack_frame(handle->bit_rate, data, handle->frame_size, &mag_shift, handle->mlt_coefs, &handle->random_value, encrypted); if (res < 0) goto fail; /* convert coefs to samples using reverse (inverse) MLT */ res = rmlt_coefs_to_samples(mag_shift, handle->mlt_coefs, handle->old_samples, out_samples); if (res < 0) goto fail; /* Namco also sets number of codes/samples done from unpack_frame/rmlt (ptr arg), * but they seem unused */ return 0; fail: return res; } #if 0 int g7221_decode_empty(g7221_handle* handle, int16_t* out_samples) { static const uint8_t empty_frame[0x3c] = { 0x1E,0x0B,0x89,0x40,0x02,0x4F,0x51,0x35, 0x10,0xA1,0xFE,0xDF,0x52,0x51,0x10,0x0B, 0xF0,0x69,0x7B,0xAE,0x18,0x17,0x00,0x52, 0x07,0x74,0xF4,0x65,0xA2,0x58,0xD8,0x3F, 0xD9,0xAA,0x65,0x35,0x2A,0x14,0xE3,0x58, 0xD7,0xC0,0xD2,0x02,0x5B,0x0E,0x2A,0x98, 0xA3,0x04,0x5E,0x51,0xE5,0xC5,0xB2,0x14, 0xBF,0x58,0xFF,0xFF }; int res; int mag_shift; /* This only seems to exist in older exes. Namco's samples don't reach EOF, so this * wouldn't need to be called. Doesn't seem to use encoder delay either. */ res = unpack_frame(24000, empty_frame, 0x3c, &mag_shift, handle->mlt_coefs, &handle->random_value); if (res) goto fail; /* convert coefs to samples using reverse (inverse) MLT */ res = rmlt_coefs_to_samples(mag_shift, handle->mlt_coefs, handle->old_samples, out_samples); if (res) goto fail; return 1; fail: return 0; } #endif void g7221_reset(g7221_handle* handle) { /* initialize old values (others get overwritten) */ memset(&handle->old_samples, 0, sizeof(handle->old_samples)); /* initialize the random number generator */ handle->random_value = 0x10001; /* vs refdec: different default random. Namco used a global, so maybe multiple * bnsf playing at the same time would get slightly different results */ } void g7221_free(g7221_handle* handle) { if (!handle) return; s14aes_close(handle->aes); free(handle); } int g7221_set_key(g7221_handle* handle, const uint8_t* key) { const int key_size = 192 / 8; /* only 192 bit mode */ uint8_t temp_key[192 / 8]; const char* mod_key = "Ua#oK3P94vdxX,ft*k-mnjoO"; /* constant for all platform/games */ int i; if (!handle) goto fail; /* disable, useful for testing? */ if (key == NULL) { s14aes_close(handle->aes); handle->aes = NULL; return 1; } /* init AES state (tables) or reuse if already exists */ if (handle->aes == NULL) { handle->aes = s14aes_init(); if (!handle->aes) goto fail; } /* Base key is XORed probably against memdumps, as plain key would be part of the final AES key. However * roundkey is still in memdumps near AES state (~0x1310 from sbox table, that starts with 0x63,0x7c,0x77,0x7b...) * so it isn't too effective. XORing was originally done inside aes_expand_key during S14/S22 init. */ for (i = 0; i < key_size; i++) { temp_key[i] = key[i] ^ mod_key[i]; } /* reset new key */ s14aes_set_key(handle->aes, temp_key); return 0; fail: return -1; }