/****************************************************************************** * * Copyright (C) 2015 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * ***************************************************************************** * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore */ /** ******************************************************************************* * @file * ih264_trans_data.h * * @brief * Contains declaration of global variables for H264 transform , qnat and inverse quant * * @author * Ittiam * * @remarks * ******************************************************************************* */ #ifndef IH264_GLOBAL_DATA_H_ #define IH264_GLOBAL_DATA_H_ /*****************************************************************************/ /* Extern global declarations */ /*****************************************************************************/ /* Scaling matrices for h264 quantization */ extern const UWORD16 g_scal_coff_h264_4x4[16]; extern const UWORD16 g_scal_coff_h264_8x8[16]; /** ****************************************************************************** * @brief Scale Table for quantizing 4x4 subblock. To quantize a given 4x4 DCT * transformed block, the coefficient at index location (i,j) is scaled by one of * the constants in this table and right shift the result by (QP_BITS_h264_4x4 + * floor(qp/6)), here qp is the quantization parameter used to quantize the mb. * * input : qp%6, index location (i,j) * output : scale constant. * * @remarks 16 constants for each index position of the subblock and 6 for each * qp%6 in the range 0-5 inclusive. ****************************************************************************** */ extern const UWORD16 gu2_quant_scale_matrix_4x4[96]; /** ****************************************************************************** * @brief Round Factor for quantizing subblock. While quantizing a given 4x4 DCT * transformed block, the coefficient at index location (i,j) is scaled by one of * the constants in the table gu2_forward_quant_scalar_4x4 and then right shift * the result by (QP_BITS_h264_4x4 + floor(qp/6)). * Before right shifting a round factor is added. * The round factor can be any value [a * (1 << (QP_BITS_h264_4x4 + floor(qp/6)))] * for 'a' lies in the range 0-0.5. * Here qp is the quantization parameter used to quantize the mb. * * input : qp/6 * output : round factor. * * @remarks The round factor is constructed by setting a = 1/3 ****************************************************************************** */ extern const UWORD32 gu4_forward_quant_round_factor_4x4[9]; /** ****************************************************************************** * @brief Threshold Table. Quantizing the given DCT coefficient is done only if * it exceeds the threshold value presented in this table. * * input : qp/6, qp%6, index location (i,j) * output : Threshold constant. * * @remarks 16 constants for each index position of the subblock and 6 for each * qp%6 in the range 0-5 inclusive and 9 for each qp/6 in the range 0-51. ****************************************************************************** */ extern const UWORD16 gu2_forward_quant_threshold_4x4[96]; /** ****************************************************************************** * @brief Scale Table for quantizing 8x8 subblock. To quantize a given 8x8 DCT * transformed block, the coefficient at index location (i,j) is scaled by one of * the constants in this table and right shift the result by (QP_BITS_h264_8x8 + * floor(qp/6)), here qp is the quantization parameter used to quantize the mb. * * input : qp%6, index location (i,j) * output : scale constant. * * @remarks 64 constants for each index position of the subblock and 6 for each * qp%6 in the range 0-5 inclusive. ****************************************************************************** */ extern const UWORD16 gu2_quant_scale_matrix_8x8 [384]; /** ****************************************************************************** * @brief Specification of QPc as a function of qPi * * input : qp luma * output : qp chroma. * * @remarks Refer Table 8-15 of h264 specification. ****************************************************************************** */ extern const UWORD8 gu1_qpc_fqpi[52]; #endif /* IH264_GLOBAL_DATA_H_ */