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aosp12/external/libavc/encoder/ih264e_cabac.h

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/******************************************************************************
*
* 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
* ih264e_cabac_structs.h
*
* @brief
* This file contains cabac related macros, enums, tables and function declarations.
*
* @author
* Doney Alex
*
* @remarks
* none
*
*******************************************************************************
*/
#ifndef IH264E_CABAC_H_
#define IH264E_CABAC_H_
/*******************************************************************************
@brief Bit precision of cabac engine;
*******************************************************************************
*/
#define CABAC_BITS 9
/**
******************************************************************************
* @macro Reverse bits in an unsigned integer
******************************************************************************
*/
#define REV(u4_input, u4_output) \
{ \
UWORD32 u4_temp = (u4_input); \
WORD8 i; \
u4_output = 0; \
for (i = 0; i < 32; i++) \
{ \
u4_output = (u4_output << 1) + \
((u4_temp >> i) & 0x01); \
} \
}
/**
******************************************************************************
*! Bit manipulation macros
******************************************************************************
*/
#define SETBIT(a, i) ((a) |= (1 << (i)))
#define CLEARBIT(a, i) ((a) &= ~(1 << (i)))
/**
******************************************************************************
*! Cabac module expect atlesat MIN_STREAM_SIZE_MB bytes left in stream buffer
*! for encoding an MB
******************************************************************************
*/
#define MIN_STREAM_SIZE_MB 1024
/*****************************************************************************/
/* Function Declarations */
/*****************************************************************************/
/**
*******************************************************************************
*
* @brief
* Initialize default context values and pointers.
*
* @param[in] ps_ent_ctxt
* Pointer to entropy context structure
*
* @returns
*
* @remarks
* None
*
*******************************************************************************
*/
void ih264e_init_cabac_table(entropy_ctxt_t *ps_ent_ctxt);
/**
*******************************************************************************
*
* @brief
* Initialize cabac context: Intitalize all contest with init values given in the spec.
* Called at the beginning of entropy coding of each slice for CABAC encoding.
*
* @param[in] ps_ent_ctxt
* Pointer to entropy context structure
*
* @returns
*
* @remarks
* None
*
*******************************************************************************
*/
void ih264e_init_cabac_ctxt(entropy_ctxt_t *ps_ent_ctxt);
/**
*******************************************************************************
*
* @brief
* k-th order Exp-Golomb (UEGk) binarization process: Implements concatenated
* unary/ k-th order Exp-Golomb (UEGk) binarization process,
* where k = 0 as defined in 9.3.2.3 of ITU_T_H264-201402
*
* @param[in] i2_sufs
* Suffix bit string
*
* @param[in] pi1_bins_len
* Pointer to length of the string
*
* @returns Binarized value
*
* @remarks
* None
*
*******************************************************************************
*/
UWORD32 ih264e_cabac_UEGk0_binarization(WORD16 i2_sufs, WORD8 *pi1_bins_len);
/**
*******************************************************************************
*
* @brief
* Get cabac context for the MB :calculates the pointers to Top and left
* cabac neighbor context depending upon neighbor availability.
*
* @param[in] ps_ent_ctxt
* Pointer to entropy context structure
*
* @param[in] u4_mb_type
* Type of MB
*
* @returns
*
* @remarks
* None
*
*******************************************************************************
*/
void ih264e_get_cabac_context(entropy_ctxt_t *ps_ent_ctxt, WORD32 u4_mb_type);
/**
*******************************************************************************
* @brief
* flushing at termination: Explained in flowchart 9-12(ITU_T_H264-201402).
*
* @param[in] ps_cabac_ctxt
* pointer to cabac context (handle)
*
* @returns none
*
* @remarks
* None
*
*******************************************************************************
*/
IH264E_ERROR_T ih264e_cabac_flush(cabac_ctxt_t *ps_cabac_ctxt);
/**
******************************************************************************
*
* @brief Puts new byte (and outstanding bytes) into bitstream after cabac
* renormalization
*
* @par Description
* 1. Extract the leading byte of low(L)
* 2. If leading byte=0xff increment outstanding bytes and return
* (as the actual bits depend on carry propogation later)
* 3. If leading byte is not 0xff check for any carry propogation
* 4. Insert the carry (propogated in previous byte) along with outstanding
* bytes (if any) and leading byte
*
*
* @param[inout] ps_cabac_ctxt
* pointer to cabac context (handle)
*
* @return
*
******************************************************************************
*/
IH264E_ERROR_T ih264e_cabac_put_byte(cabac_ctxt_t *ps_cabac_ctxt);
/**
******************************************************************************
*
* @brief Codes a bin based on probablilty and mps packed context model
*
* @par Description
* 1. Apart from encoding bin, context model is updated as per state transition
* 2. Range and Low renormalization is done based on bin and original state
* 3. After renorm bistream is updated (if required)
*
* @param[inout] ps_cabac
* pointer to cabac context (handle)
*
* @param[in] bin
* bin(boolean) to be encoded
*
* @param[in] pu1_bin_ctxts
* index of cabac context model containing pState[bits 5-0] | MPS[bit6]
*
* @return
*
******************************************************************************
*/
void ih264e_cabac_encode_bin(cabac_ctxt_t *ps_cabac, WORD32 bin,
bin_ctxt_model *pu1_bin_ctxts);
/**
*******************************************************************************
*
* @brief
* Encoding process for a binary decision :implements encoding process of a decision
* as defined in 9.3.4.2 . This function encodes multiple bins, of a symbol. Implements
* flowchart Figure 9-7( ITU_T_H264-201402)
*
* @param[in] u4_bins
* array of bin values
*
* @param[in] i1_bins_len
* Length of bins, maximum 32
*
* @param[in] u4_ctx_inc
* CtxInc, byte0- bin0, byte1-bin1 ..
*
* @param[in] i1_valid_len
* valid length of bins, after that CtxInc is constant
*
* @param[in] pu1_bin_ctxt_type
* Pointer to binary contexts
* @param[in] ps_cabac
* Pointer to cabac_context_structure
*
* @returns
*
* @remarks
* None
*
*******************************************************************************
*/
void ih264e_encode_decision_bins(UWORD32 u4_bins, WORD8 i1_bins_len,
UWORD32 u4_ctx_inc, WORD8 i1_valid_len,
bin_ctxt_model *pu1_bin_ctxt_type,
cabac_ctxt_t *ps_cabac);
/**
*******************************************************************************
* @brief
* Encoding process for a binary decision before termination:Encoding process
* of a termination(9.3.4.5 :ITU_T_H264-201402) . Explained in flowchart 9-11.
*
* @param[in] ps_cabac
* Pointer to cabac structure
*
* @param[in] term_bin
* Symbol value, end of slice or not, term_bin is binary
*
* @returns
*
* @remarks
* None
*
*******************************************************************************
*/
void ih264e_cabac_encode_terminate(cabac_ctxt_t *ps_cabac, WORD32 term_bin);
/**
*******************************************************************************
* @brief
* Bypass encoding process for binary decisions: Explained (9.3.4.4 :ITU_T_H264-201402)
* , flowchart 9-10.
*
* @param[in] ps_cabac : pointer to cabac context (handle)
*
* @param[in] bin : bypass bin(0/1) to be encoded
*
* @returns
*
* @remarks
* None
*
*******************************************************************************
*/
void ih264e_cabac_encode_bypass_bin(cabac_ctxt_t *ps_cabac, WORD32 bin);
/**
******************************************************************************
*
* @brief Encodes a series of bypass bins (FLC bypass bins)
*
* @par Description
* This function is more optimal than calling ih264e_cabac_encode_bypass_bin()
* in a loop as cabac low, renorm and generating the stream (8bins at a time)
* can be done in one operation
*
* @param[inout]ps_cabac
* pointer to cabac context (handle)
*
* @param[in] u4_bins
* syntax element to be coded (as FLC bins)
*
* @param[in] num_bins
* This is the FLC length for u4_sym
*
* @return
*
******************************************************************************
*/
void ih264e_cabac_encode_bypass_bins(cabac_ctxt_t *ps_cabac, UWORD32 u4_bins,
WORD32 num_bins);
/**
*******************************************************************************
*
* @brief
* This function generates CABAC coded bit stream for an Intra Slice.
*
* @description
* The mb syntax layer for intra slices constitutes luma mb mode, luma sub modes
* (if present), mb qp delta, coded block pattern, chroma mb mode and
* luma/chroma residue. These syntax elements are written as directed by table
* 7.3.5 of h264 specification.
*
* @param[in] ps_ent_ctxt
* pointer to entropy context
*
* @returns error code
*
* @remarks none
*
*******************************************************************************
*/
IH264E_ERROR_T ih264e_write_islice_mb_cabac(entropy_ctxt_t *ps_ent_ctxt);
/**
*******************************************************************************
*
* @brief
* This function generates CABAC coded bit stream for Inter slices
*
* @description
* The mb syntax layer for inter slices constitutes luma mb mode, luma sub modes
* (if present), mb qp delta, coded block pattern, chroma mb mode and
* luma/chroma residue. These syntax elements are written as directed by table
* 7.3.5 of h264 specification
*
* @param[in] ps_ent_ctxt
* pointer to entropy context
*
* @returns error code
*
* @remarks none
*
*******************************************************************************
*/
IH264E_ERROR_T ih264e_write_pslice_mb_cabac(entropy_ctxt_t *ps_ent_ctxt);
/**
*******************************************************************************
*
* @brief
* This function generates CABAC coded bit stream for B slices
*
* @description
* The mb syntax layer for inter slices constitutes luma mb mode,
* mb qp delta, coded block pattern, chroma mb mode and
* luma/chroma residue. These syntax elements are written as directed by table
* 7.3.5 of h264 specification
*
* @param[in] ps_ent_ctxt
* pointer to entropy context
*
* @returns error code
*
* @remarks none
*
*******************************************************************************
*/
IH264E_ERROR_T ih264e_write_bslice_mb_cabac(entropy_ctxt_t *ps_ent_ctxt);
#endif /* IH264E_CABAC_H_ */
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