/** * \file * * \author Marko Viitanen ( fador@iki.fi ), * Tampere University of Technology, * Department of Pervasive Computing. * \author Ari Koivula ( ari@koivu.la ), * Tampere University of Technology, * Department of Pervasive Computing. */ #include "cabac.h" #include #include #include const uint8_t g_auc_next_state_mps[128] = { 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 124, 125, 126, 127 }; const uint8_t g_auc_next_state_lps[128] = { 1, 0, 0, 1, 2, 3, 4, 5, 4, 5, 8, 9, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 18, 19, 22, 23, 22, 23, 24, 25, 26, 27, 26, 27, 30, 31, 30, 31, 32, 33, 32, 33, 36, 37, 36, 37, 38, 39, 38, 39, 42, 43, 42, 43, 44, 45, 44, 45, 46, 47, 48, 49, 48, 49, 50, 51, 52, 53, 52, 53, 54, 55, 54, 55, 56, 57, 58, 59, 58, 59, 60, 61, 60, 61, 60, 61, 62, 63, 64, 65, 64, 65, 66, 67, 66, 67, 66, 67, 68, 69, 68, 69, 70, 71, 70, 71, 70, 71, 72, 73, 72, 73, 72, 73, 74, 75, 74, 75, 74, 75, 76, 77, 76, 77, 126, 127 }; const uint8_t g_auc_lpst_table[64][4] = { {128, 176, 208, 240}, {128, 167, 197, 227}, {128, 158, 187, 216}, {123, 150, 178, 205}, {116, 142, 169, 195}, {111, 135, 160, 185}, {105, 128, 152, 175}, {100, 122, 144, 166}, { 95, 116, 137, 158}, { 90, 110, 130, 150}, { 85, 104, 123, 142}, { 81, 99, 117, 135}, { 77, 94, 111, 128}, { 73, 89, 105, 122}, { 69, 85, 100, 116}, { 66, 80, 95, 110}, { 62, 76, 90, 104}, { 59, 72, 86, 99}, { 56, 69, 81, 94}, { 53, 65, 77, 89}, { 51, 62, 73, 85}, { 48, 59, 69, 80}, { 46, 56, 66, 76}, { 43, 53, 63, 72}, { 41, 50, 59, 69}, { 39, 48, 56, 65}, { 37, 45, 54, 62}, { 35, 43, 51, 59}, { 33, 41, 48, 56}, { 32, 39, 46, 53}, { 30, 37, 43, 50}, { 29, 35, 41, 48}, { 27, 33, 39, 45}, { 26, 31, 37, 43}, { 24, 30, 35, 41}, { 23, 28, 33, 39}, { 22, 27, 32, 37}, { 21, 26, 30, 35}, { 20, 24, 29, 33}, { 19, 23, 27, 31}, { 18, 22, 26, 30}, { 17, 21, 25, 28}, { 16, 20, 23, 27}, { 15, 19, 22, 25}, { 14, 18, 21, 24}, { 14, 17, 20, 23}, { 13, 16, 19, 22}, { 12, 15, 18, 21}, { 12, 14, 17, 20}, { 11, 14, 16, 19}, { 11, 13, 15, 18}, { 10, 12, 15, 17}, { 10, 12, 14, 16}, { 9, 11, 13, 15}, { 9, 11, 12, 14}, { 8, 10, 12, 14}, { 8, 9, 11, 13}, { 7, 9, 11, 12}, { 7, 9, 10, 12}, { 7, 8, 10, 11}, { 6, 8, 9, 11}, { 6, 7, 9, 10}, { 6, 7, 8, 9}, { 2, 2, 2, 2} }; const uint8_t g_auc_renorm_table[32] = { 6, 5, 4, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }; cabac_data cabac; /** * \brief Initialize struct cabac_data. */ void cabac_start(cabac_data *data) { data->low = 0; data->range = 510; data->bits_left = 23; data->num_buffered_bytes = 0; data->buffered_byte = 0xff; } /** * \brief */ void cabac_encode_bin(cabac_data *data, uint32_t bin_value) { uint32_t lps; data->ctx->bins_coded = 1; lps = g_auc_lpst_table[CTX_STATE(data->ctx)][(data->range >> 6) & 3]; data->range -= lps; // Not the Most Probable Symbol? if (bin_value != CTX_MPS(data->ctx)) { int num_bits = g_auc_renorm_table[lps >> 3]; data->low = (data->low + data->range) << num_bits; data->range = lps << num_bits; CTX_UPDATE_LPS(data->ctx); data->bits_left -= num_bits; } else { CTX_UPDATE_MPS(data->ctx); if (data->range >= 256) return; data->low <<= 1; data->range <<= 1; data->bits_left--; } if (data->bits_left < 12) { cabac_write(data); } } /** * \brief */ void cabac_write(cabac_data *data) { uint32_t lead_byte = data->low >> (24 - data->bits_left); data->bits_left += 8; data->low &= 0xffffffffu >> data->bits_left; if (lead_byte == 0xff) { data->num_buffered_bytes++; } else { if (data->num_buffered_bytes > 0) { uint32_t carry = lead_byte >> 8; uint32_t byte = data->buffered_byte + carry; data->buffered_byte = lead_byte & 0xff; bitstream_put(data->stream, byte, 8); byte = (0xff + carry) & 0xff; while (data->num_buffered_bytes > 1) { bitstream_put(data->stream, byte, 8); data->num_buffered_bytes--; } } else { data->num_buffered_bytes = 1; data->buffered_byte = lead_byte; } } } /** * \brief */ void cabac_finish(cabac_data *data) { if (data->low >> (32 - data->bits_left)) { bitstream_put(data->stream,data->buffered_byte + 1, 8); while (data->num_buffered_bytes > 1) { bitstream_put(data->stream, 0, 8); data->num_buffered_bytes--; } data->low -= 1 << (32 - data->bits_left); } else { if (data->num_buffered_bytes > 0) { bitstream_put(data->stream,data->buffered_byte, 8); } while (data->num_buffered_bytes > 1) { bitstream_put(data->stream, 0xff, 8); data->num_buffered_bytes--; } } bitstream_put(data->stream, data->low >> 8, 24 - data->bits_left); } /*! \brief Encode terminating bin \param binValue bin value */ void cabac_encode_bin_trm(cabac_data *data, uint8_t bin_value) { data->range -= 2; if(bin_value) { data->low += data->range; data->low <<= 7; data->range = 2 << 7; data->bits_left -= 7; } else if (data->range >= 256) { return; } else { data->low <<= 1; data->range <<= 1; data->bits_left--; } if (data->bits_left < 12) { cabac_write(data); } } /** * \brief */ void cabac_flush(cabac_data *data) { cabac_encode_bin_trm(data, 1); cabac_finish(data); bitstream_put(data->stream, 1, 1); bitstream_align_zero(data->stream); cabac_start(data); } /** * \brief */ void cabac_encode_bin_ep(cabac_data *data, uint32_t bin_value) { data->low <<= 1; if (bin_value) { data->low += data->range; } data->bits_left--; if (data->bits_left < 12) { cabac_write(data); } } /** * \brief */ void cabac_encode_bins_ep(cabac_data *data, uint32_t bin_values, int num_bins) { uint32_t pattern; while (num_bins > 8) { num_bins -= 8; pattern = bin_values >> num_bins; data->low <<= 8; data->low += data->range * pattern; bin_values -= pattern << num_bins; data->bits_left -= 8; if(data->bits_left < 12) { cabac_write(data); } } data->low <<= num_bins; data->low += data->range * bin_values; data->bits_left -= num_bins; if (data->bits_left < 12) { cabac_write(data); } } /** * \brief Coding of coeff_abs_level_minus3. * \param symbol Value of coeff_abs_level_minus3. * \param r_param Reference to Rice parameter. */ void cabac_write_coeff_remain(cabac_data *cabac, uint32_t symbol, uint32_t r_param) { int32_t code_number = symbol; uint32_t length; if (code_number < (3 << r_param)) { length = code_number >> r_param; cabac_encode_bins_ep(cabac, (1 << (length + 1)) - 2 , length + 1); cabac_encode_bins_ep(cabac, (code_number % (1 << r_param)), r_param); } else { length = r_param; code_number = code_number - (3 << r_param); while (code_number >= (1 << length)) { code_number -= 1 << length; ++length; } cabac_encode_bins_ep(cabac, (1 << (3 + length + 1 - r_param)) - 2, 3 + length + 1 - r_param); cabac_encode_bins_ep(cabac, code_number, length); } } /** * \brief */ void cabac_write_unary_max_symbol(cabac_data *data, cabac_ctx *ctx, uint32_t symbol, int32_t offset, uint32_t max_symbol) { int8_t code_last = max_symbol > symbol; if (!max_symbol) return; data->ctx = &ctx[0]; cabac_encode_bin(data, symbol ? 1 : 0); if (!symbol) return; while (--symbol) { data->ctx = &ctx[offset]; cabac_encode_bin(data, 1); } if (code_last) { data->ctx = &ctx[offset]; cabac_encode_bin(data, 0); } } /** * \brief */ void cabac_write_ep_ex_golomb(cabac_data *data, uint32_t symbol, uint32_t count) { uint32_t bins = 0; int32_t num_bins = 0; while (symbol >= (uint32_t)(1 << count)) { bins = 2 * bins + 1; ++num_bins; symbol -= 1 << count; ++count; } bins = 2 * bins; ++num_bins; bins = (bins << count) | symbol; num_bins += count; cabac_encode_bins_ep(data, bins, num_bins); }