+static void ac3_lshift_int16_c(int16_t *src, unsigned int len,
+ unsigned int shift)
+{
+ uint32_t *src32 = (uint32_t *)src;
+ const uint32_t mask = ~(((1 << shift) - 1) << 16);
+ int i;
+ len >>= 1;
+ for (i = 0; i < len; i += 8) {
+ src32[i ] = (src32[i ] << shift) & mask;
+ src32[i+1] = (src32[i+1] << shift) & mask;
+ src32[i+2] = (src32[i+2] << shift) & mask;
+ src32[i+3] = (src32[i+3] << shift) & mask;
+ src32[i+4] = (src32[i+4] << shift) & mask;
+ src32[i+5] = (src32[i+5] << shift) & mask;
+ src32[i+6] = (src32[i+6] << shift) & mask;
+ src32[i+7] = (src32[i+7] << shift) & mask;
+ }
+}
+
+static void ac3_rshift_int32_c(int32_t *src, unsigned int len,
+ unsigned int shift)
+{
+ do {
+ *src++ >>= shift;
+ *src++ >>= shift;
+ *src++ >>= shift;
+ *src++ >>= shift;
+ *src++ >>= shift;
+ *src++ >>= shift;
+ *src++ >>= shift;
+ *src++ >>= shift;
+ len -= 8;
+ } while (len > 0);
+}
+
+static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len)
+{
+ const float scale = 1 << 24;
+ do {
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ *dst++ = lrintf(*src++ * scale);
+ len -= 8;
+ } while (len > 0);
+}
+
+static void ac3_bit_alloc_calc_bap_c(int16_t *mask, int16_t *psd,
+ int start, int end,
+ int snr_offset, int floor,
+ const uint8_t *bap_tab, uint8_t *bap)
+{
+ int bin, band, band_end;
+
+ /* special case, if snr offset is -960, set all bap's to zero */
+ if (snr_offset == -960) {
+ memset(bap, 0, AC3_MAX_COEFS);
+ return;
+ }
+
+ bin = start;
+ band = ff_ac3_bin_to_band_tab[start];
+ do {
+ int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
+ band_end = ff_ac3_band_start_tab[++band];
+ band_end = FFMIN(band_end, end);
+
+ for (; bin < band_end; bin++) {
+ int address = av_clip_uintp2((psd[bin] - m) >> 5, 6);
+ bap[bin] = bap_tab[address];
+ }
+ } while (end > band_end);
+}
+
+static void ac3_update_bap_counts_c(uint16_t mant_cnt[16], uint8_t *bap,
+ int len)
+{
+ while (len-- > 0)
+ mant_cnt[bap[len]]++;
+}
+
+DECLARE_ALIGNED(16, const uint16_t, ff_ac3_bap_bits)[16] = {
+ 0, 0, 0, 3, 0, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16
+};
+
+static int ac3_compute_mantissa_size_c(uint16_t mant_cnt[6][16])
+{
+ int blk, bap;
+ int bits = 0;
+
+ for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
+ // bap=1 : 3 mantissas in 5 bits
+ bits += (mant_cnt[blk][1] / 3) * 5;
+ // bap=2 : 3 mantissas in 7 bits
+ // bap=4 : 2 mantissas in 7 bits
+ bits += ((mant_cnt[blk][2] / 3) + (mant_cnt[blk][4] >> 1)) * 7;
+ // bap=3 : 1 mantissa in 3 bits
+ bits += mant_cnt[blk][3] * 3;
+ // bap=5 to 15 : get bits per mantissa from table
+ for (bap = 5; bap < 16; bap++)
+ bits += mant_cnt[blk][bap] * ff_ac3_bap_bits[bap];
+ }
+ return bits;
+}
+
+static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
+{
+ int i;
+
+ for (i = 0; i < nb_coefs; i++) {
+ int v = abs(coef[i]);
+ exp[i] = v ? 23 - av_log2(v) : 24;
+ }
+}
+
+static void ac3_downmix_c(float **samples, float (*matrix)[2],
+ int out_ch, int in_ch, int len)
+{
+ int i, j;
+ float v0, v1;
+ if (out_ch == 2) {
+ for (i = 0; i < len; i++) {
+ v0 = v1 = 0.0f;
+ for (j = 0; j < in_ch; j++) {
+ v0 += samples[j][i] * matrix[j][0];
+ v1 += samples[j][i] * matrix[j][1];
+ }
+ samples[0][i] = v0;
+ samples[1][i] = v1;
+ }
+ } else if (out_ch == 1) {
+ for (i = 0; i < len; i++) {
+ v0 = 0.0f;
+ for (j = 0; j < in_ch; j++)
+ v0 += samples[j][i] * matrix[j][0];
+ samples[0][i] = v0;
+ }
+ }
+}
+
+static void apply_window_int16_c(int16_t *output, const int16_t *input,
+ const int16_t *window, unsigned int len)
+{
+ int i;
+ int len2 = len >> 1;
+
+ for (i = 0; i < len2; i++) {
+ int16_t w = window[i];
+ output[i] = (MUL16(input[i], w) + (1 << 14)) >> 15;
+ output[len-i-1] = (MUL16(input[len-i-1], w) + (1 << 14)) >> 15;
+ }
+}
+
+av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)