/*
- * AC-3 DSP utils
+ * AC-3 DSP functions
* Copyright (c) 2011 Justin Ruggles
*
* This file is part of Libav.
#include "avcodec.h"
#include "ac3.h"
#include "ac3dsp.h"
+#include "mathops.h"
static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs)
{
int snr_offset, int floor,
const uint8_t *bap_tab, uint8_t *bap)
{
- int bin, band;
+ int bin, band, band_end;
/* special case, if snr offset is -960, set all bap's to zero */
if (snr_offset == -960) {
band = ff_ac3_bin_to_band_tab[start];
do {
int m = (FFMAX(mask[band] - snr_offset - floor, 0) & 0x1FE0) + floor;
- int band_end = FFMIN(ff_ac3_band_start_tab[band+1], end);
+ band_end = ff_ac3_band_start_tab[++band];
+ band_end = FFMIN(band_end, end);
+
for (; bin < band_end; bin++) {
- int address = av_clip((psd[bin] - m) >> 5, 0, 63);
+ int address = av_clip_uintp2((psd[bin] - m) >> 5, 6);
bap[bin] = bap_tab[address];
}
- } while (end > ff_ac3_band_start_tab[band++]);
+ } 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 int ac3_compute_mantissa_size_c(int mant_cnt[5], uint8_t *bap,
- int nb_coefs)
+static void ac3_extract_exponents_c(uint8_t *exp, int32_t *coef, int nb_coefs)
{
- int bits, b, i;
+ int i;
- bits = 0;
for (i = 0; i < nb_coefs; i++) {
- b = bap[i];
- if (b <= 4) {
- // bap=1 to bap=4 will be counted in compute_mantissa_size_final
- mant_cnt[b]++;
- } else if (b <= 13) {
- // bap=5 to bap=13 use (bap-1) bits
- bits += b - 1;
- } else {
- // bap=14 uses 14 bits and bap=15 uses 16 bits
- bits += (b == 14) ? 14 : 16;
+ int v = abs(coef[i]);
+ exp[i] = v ? 23 - av_log2(v) : 24;
+ }
+}
+
+static void ac3_downmix_5_to_2_symmetric_c(float **samples, float **matrix,
+ int len)
+{
+ int i;
+ float v0, v1;
+ float front_mix = matrix[0][0];
+ float center_mix = matrix[0][1];
+ float surround_mix = matrix[0][3];
+
+ for (i = 0; i < len; i++) {
+ v0 = samples[0][i] * front_mix +
+ samples[1][i] * center_mix +
+ samples[3][i] * surround_mix;
+
+ v1 = samples[1][i] * center_mix +
+ samples[2][i] * front_mix +
+ samples[4][i] * surround_mix;
+
+ samples[0][i] = v0;
+ samples[1][i] = v1;
+ }
+}
+
+static void ac3_downmix_5_to_1_symmetric_c(float **samples, float **matrix,
+ int len)
+{
+ int i;
+ float front_mix = matrix[0][0];
+ float center_mix = matrix[0][1];
+ float surround_mix = matrix[0][3];
+
+ for (i = 0; i < len; i++) {
+ samples[0][i] = samples[0][i] * front_mix +
+ samples[1][i] * center_mix +
+ samples[2][i] * front_mix +
+ samples[3][i] * surround_mix +
+ samples[4][i] * surround_mix;
+ }
+}
+
+static void ac3_downmix_c(float **samples, float **matrix,
+ 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[0][j];
+ v1 += samples[j][i] * matrix[1][j];
+ }
+ 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[0][j];
+ samples[0][i] = v0;
}
}
- return bits;
+}
+
+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;
+ }
+}
+
+void ff_ac3dsp_downmix(AC3DSPContext *c, float **samples, float **matrix,
+ int out_ch, int in_ch, int len)
+{
+ if (c->in_channels != in_ch || c->out_channels != out_ch) {
+ int **matrix_cmp = (int **)matrix;
+
+ c->in_channels = in_ch;
+ c->out_channels = out_ch;
+ c->downmix = NULL;
+
+ if (in_ch == 5 && out_ch == 2 &&
+ !(matrix_cmp[1][0] | matrix_cmp[0][2] |
+ matrix_cmp[1][3] | matrix_cmp[0][4] |
+ (matrix_cmp[0][1] ^ matrix_cmp[1][1]) |
+ (matrix_cmp[0][0] ^ matrix_cmp[1][2]))) {
+ c->downmix = ac3_downmix_5_to_2_symmetric_c;
+ } else if (in_ch == 5 && out_ch == 1 &&
+ matrix_cmp[0][0] == matrix_cmp[0][2] &&
+ matrix_cmp[0][3] == matrix_cmp[0][4]) {
+ c->downmix = ac3_downmix_5_to_1_symmetric_c;
+ }
+
+ if (ARCH_X86)
+ ff_ac3dsp_set_downmix_x86(c);
+ }
+
+ if (c->downmix)
+ c->downmix(samples, matrix, len);
+ else
+ ac3_downmix_c(samples, matrix, out_ch, in_ch, len);
}
av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact)
c->ac3_rshift_int32 = ac3_rshift_int32_c;
c->float_to_fixed24 = float_to_fixed24_c;
c->bit_alloc_calc_bap = ac3_bit_alloc_calc_bap_c;
+ c->update_bap_counts = ac3_update_bap_counts_c;
c->compute_mantissa_size = ac3_compute_mantissa_size_c;
+ c->extract_exponents = ac3_extract_exponents_c;
+ c->in_channels = 0;
+ c->out_channels = 0;
+ c->downmix = NULL;
+ c->apply_window_int16 = apply_window_int16_c;
if (ARCH_ARM)
ff_ac3dsp_init_arm(c, bit_exact);
- if (HAVE_MMX)
+ if (ARCH_X86)
ff_ac3dsp_init_x86(c, bit_exact);
}