diff options
Diffstat (limited to 'libavcodec/ac3dsp.c')
| -rw-r--r-- | libavcodec/ac3dsp.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/libavcodec/ac3dsp.c b/libavcodec/ac3dsp.c index 511a94f212..ec0b82d4fc 100644 --- a/libavcodec/ac3dsp.c +++ b/libavcodec/ac3dsp.c @@ -20,6 +20,7 @@ */ #include "avcodec.h" +#include "ac3.h" #include "ac3dsp.h" static void ac3_exponent_min_c(uint8_t *exp, int num_reuse_blocks, int nb_coefs) @@ -101,6 +102,53 @@ static void float_to_fixed24_c(int32_t *dst, const float *src, unsigned int len) } 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; + + /* 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; + int band_end = FFMIN(ff_ac3_band_start_tab[band+1], end); + for (; bin < band_end; bin++) { + int address = av_clip((psd[bin] - m) >> 5, 0, 63); + bap[bin] = bap_tab[address]; + } + } while (end > ff_ac3_band_start_tab[band++]); +} + +static int ac3_compute_mantissa_size_c(int mant_cnt[5], uint8_t *bap, + int nb_coefs) +{ + int bits, b, 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; + } + } + return bits; +} + av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact) { c->ac3_exponent_min = ac3_exponent_min_c; @@ -108,6 +156,8 @@ av_cold void ff_ac3dsp_init(AC3DSPContext *c, int bit_exact) c->ac3_lshift_int16 = ac3_lshift_int16_c; 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->compute_mantissa_size = ac3_compute_mantissa_size_c; if (ARCH_ARM) ff_ac3dsp_init_arm(c, bit_exact); |