diff options
Diffstat (limited to 'third_party/aom/aom_dsp/binary_codes_reader.c')
| -rw-r--r-- | third_party/aom/aom_dsp/binary_codes_reader.c | 49 |
1 files changed, 46 insertions, 3 deletions
diff --git a/third_party/aom/aom_dsp/binary_codes_reader.c b/third_party/aom/aom_dsp/binary_codes_reader.c index bf304dada..4f38afbc5 100644 --- a/third_party/aom/aom_dsp/binary_codes_reader.c +++ b/third_party/aom/aom_dsp/binary_codes_reader.c @@ -53,6 +53,15 @@ uint16_t aom_read_primitive_quniform_(aom_reader *r, return v < m ? v : (v << 1) - m + aom_read_bit(r, ACCT_STR_NAME); } +static uint16_t aom_rb_read_primitive_quniform(struct aom_read_bit_buffer *rb, + uint16_t n) { + if (n <= 1) return 0; + const int l = get_msb(n - 1) + 1; + const int m = (1 << l) - n; + const int v = aom_rb_read_literal(rb, l - 1); + return v < m ? v : (v << 1) - m + aom_rb_read_bit(rb); +} + uint16_t aom_read_primitive_refbilevel_(aom_reader *r, uint16_t n, uint16_t p, uint16_t ref ACCT_STR_PARAM) { if (n <= 1) return 0; @@ -101,15 +110,42 @@ uint16_t aom_read_primitive_subexpfin_(aom_reader *r, uint16_t n, return v; } -// Decode finite subexponential code that for a symbol v in [0, n-1] with -// parameter k -// based on a reference ref also in [0, n-1]. +static uint16_t aom_rb_read_primitive_subexpfin(struct aom_read_bit_buffer *rb, + uint16_t n, uint16_t k) { + int i = 0; + int mk = 0; + uint16_t v; + while (1) { + int b = (i ? k + i - 1 : k); + int a = (1 << b); + if (n <= mk + 3 * a) { + v = aom_rb_read_primitive_quniform(rb, n - mk) + mk; + break; + } else { + if (aom_rb_read_bit(rb)) { + i = i + 1; + mk += a; + } else { + v = aom_rb_read_literal(rb, b) + mk; + break; + } + } + } + return v; +} + uint16_t aom_read_primitive_refsubexpfin_(aom_reader *r, uint16_t n, uint16_t k, uint16_t ref ACCT_STR_PARAM) { return inv_recenter_finite_nonneg( n, ref, aom_read_primitive_subexpfin(r, n, k, ACCT_STR_NAME)); } +static uint16_t aom_rb_read_primitive_refsubexpfin( + struct aom_read_bit_buffer *rb, uint16_t n, uint16_t k, uint16_t ref) { + return inv_recenter_finite_nonneg(n, ref, + aom_rb_read_primitive_subexpfin(rb, n, k)); +} + // Decode finite subexponential code that for a symbol v in [-(n-1), n-1] with // parameter k based on a reference ref also in [-(n-1), n-1]. int16_t aom_read_signed_primitive_refsubexpfin_(aom_reader *r, uint16_t n, @@ -120,3 +156,10 @@ int16_t aom_read_signed_primitive_refsubexpfin_(aom_reader *r, uint16_t n, return aom_read_primitive_refsubexpfin(r, scaled_n, k, ref, ACCT_STR_NAME) - n + 1; } + +int16_t aom_rb_read_signed_primitive_refsubexpfin( + struct aom_read_bit_buffer *rb, uint16_t n, uint16_t k, int16_t ref) { + ref += n - 1; + const uint16_t scaled_n = (n << 1) - 1; + return aom_rb_read_primitive_refsubexpfin(rb, scaled_n, k, ref) - n + 1; +} |