/** dynamic range table. converts codes to scale factors. */
static float dynamic_range_tab[256];
-/** dialog normalization table */
-static float dialog_norm_tab[32];
-
/** Adjustments in dB gain */
#define LEVEL_MINUS_3DB 0.7071067811865476
#define LEVEL_MINUS_4POINT5DB 0.5946035575013605
int out_channels; ///< number of output channels
float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients
- float dialog_norm[2]; ///< dialog normalization
float dynamic_range[2]; ///< dynamic range
float cpl_coords[AC3_MAX_CHANNELS][18]; ///< coupling coordinates
int num_cpl_bands; ///< number of coupling bands
dynamic_range_tab[i] = powf(2.0f, v) * ((i & 0x1F) | 0x20);
}
- /* generate dialog normalization table
- references: Section 5.4.2.8 dialnorm
- Section 7.6 Dialogue Normalization */
- for(i=1; i<32; i++) {
- dialog_norm_tab[i] = expf((i-31) * M_LN10 / 20.0f);
- }
- dialog_norm_tab[0] = dialog_norm_tab[31];
-
/* generate scale factors for exponents and asymmetrical dequantization
reference: Section 7.3.2 Expansion of Mantissas for Asymmetric Quantization */
for (i = 0; i < 25; i++)
/* read the rest of the bsi. read twice for dual mono mode. */
i = !(ctx->channel_mode);
do {
- ctx->dialog_norm[i] = dialog_norm_tab[get_bits(gb, 5)]; // dialog normalization
+ skip_bits(gb, 5); // skip dialog normalization
if (get_bits1(gb))
skip_bits(gb, 8); //skip compression
if (get_bits1(gb))
if(ctx->channel_mode == AC3_CHMODE_STEREO)
do_rematrixing(ctx);
- /* apply scaling to coefficients (headroom, dialnorm, dynrng) */
+ /* apply scaling to coefficients (headroom, dynrng) */
for(ch=1; ch<=ctx->channels; ch++) {
float gain = 2.0f * ctx->mul_bias;
if(ctx->channel_mode == AC3_CHMODE_DUALMONO) {
- gain *= ctx->dialog_norm[ch-1] * ctx->dynamic_range[ch-1];
+ gain *= ctx->dynamic_range[ch-1];
} else {
- gain *= ctx->dialog_norm[0] * ctx->dynamic_range[0];
+ gain *= ctx->dynamic_range[0];
}
for(i=0; i<ctx->end_freq[ch]; i++) {
ctx->transform_coeffs[ch][i] *= gain;