| /****************************************************************************** |
| * |
| * Copyright (C) 2018 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 |
| * ihevce_bitstream.h |
| * |
| * @brief |
| * This file contains encoder bitstream engine related structures and |
| * interface prototypes |
| * |
| * @author |
| * ittiam |
| * |
| ****************************************************************************** |
| */ |
| |
| #ifndef _IHEVCE_BITSTREAM_H_ |
| #define _IHEVCE_BITSTREAM_H_ |
| |
| /*****************************************************************************/ |
| /* Constant Macros */ |
| /*****************************************************************************/ |
| |
| /** |
| ****************************************************************************** |
| * @brief defines the maximum number of bits in a bitstream word |
| ****************************************************************************** |
| */ |
| #define WORD_SIZE 32 |
| |
| /** |
| ****************************************************************************** |
| * @brief The number of consecutive zero bytes for emulation prevention check |
| ****************************************************************************** |
| */ |
| #define EPB_ZERO_BYTES 2 |
| |
| /** |
| ****************************************************************************** |
| * @brief Emulation prevention insertion byte |
| ****************************************************************************** |
| */ |
| #define EPB_BYTE 0x03 |
| |
| /** |
| ****************************************************************************** |
| * @brief Maximum number of NALs in a frame |
| ****************************************************************************** |
| */ |
| #define MAX_NALS_IN_AU 256 |
| |
| /*****************************************************************************/ |
| /* Function Macros */ |
| /*****************************************************************************/ |
| |
| /** |
| ****************************************************************************** |
| * @brief Macro to check if emulation prevention byte insertion is required |
| ****************************************************************************** |
| */ |
| #define INSERT_EPB(zero_run, next_byte) ((zero_run) == EPB_ZERO_BYTES) && (0 == ((next_byte)&0xFC)) |
| |
| /** |
| ****************************************************************************** |
| * @brief returns bits required to code a value |
| ****************************************************************************** |
| */ |
| #define UE_LENGTH(bits, x) \ |
| { \ |
| UWORD32 r_bit; \ |
| GETRANGE(r_bit, x + 1) \ |
| bits = (((r_bit - 1) << 1) + 1); \ |
| } |
| |
| /** |
| ****************************************************************************** |
| * @brief Inserts 1 byte and Emulation Prevention Byte(if any) into bitstream |
| * Increments the stream offset and zero run correspondingly |
| ****************************************************************************** |
| */ |
| #define PUTBYTE_EPB(ptr, off, byte, zero_run) \ |
| { \ |
| if(INSERT_EPB(zero_run, byte)) \ |
| { \ |
| ptr[off] = EPB_BYTE; \ |
| off++; \ |
| zero_run = 0; \ |
| } \ |
| \ |
| ptr[off] = byte; \ |
| off++; \ |
| zero_run = byte ? 0 : zero_run + 1; \ |
| } |
| |
| /** |
| ****************************************************************************** |
| * @brief Ensures Byte alignment of the slice header |
| ****************************************************************************** |
| */ |
| |
| #define BYTE_ALIGNMENT(ps_bitstrm) ihevce_put_rbsp_trailing_bits(ps_bitstrm) |
| |
| /*****************************************************************************/ |
| /* Structures */ |
| /*****************************************************************************/ |
| |
| /** |
| ****************************************************************************** |
| * @brief Bitstream context for encoder |
| ****************************************************************************** |
| */ |
| typedef struct bitstrm |
| { |
| /** points to start of stream buffer. */ |
| UWORD8 *pu1_strm_buffer; |
| |
| /** |
| * max bitstream size (in bytes). |
| * Encoded stream shall not exceed this size. |
| */ |
| UWORD32 u4_max_strm_size; |
| |
| /** |
| `* byte offset (w.r.t pu1_strm_buffer) where next byte would be written |
| * Bitstream engine makes sure it would not corrupt data beyond |
| * u4_max_strm_size bytes |
| */ |
| UWORD32 u4_strm_buf_offset; |
| |
| /** |
| * current bitstream word; It is a scratch word containing max of |
| * WORD_SIZE bits. Will be copied to stream buffer when the word is |
| * full |
| */ |
| UWORD32 u4_cur_word; |
| |
| /** |
| * signifies number of bits available in u4_cur_word |
| * bits from msb to i4_bits_left_in_cw of u4_cur_word have already been |
| * inserted next bits would be inserted from pos [i4_bits_left_in_cw-1] |
| * Range of this variable [1 : WORD_SIZE] |
| */ |
| WORD32 i4_bits_left_in_cw; |
| |
| /** |
| * signifies the number of consecutive zero bytes propogated from previous |
| * word. It is used for emulation prevention byte insertion in the stream |
| */ |
| WORD32 i4_zero_bytes_run; |
| |
| /** Total number of NAL units in the output buffer; Shall not exceed |
| * MAX_NALS_IN_AU */ |
| WORD32 i4_num_nal; |
| |
| /** Pointer to start of each NAL unit in the output buffer */ |
| UWORD8 *apu1_nal_start[MAX_NALS_IN_AU]; |
| |
| } bitstrm_t; |
| |
| /*****************************************************************************/ |
| /* Extern Function Declarations */ |
| /*****************************************************************************/ |
| |
| IHEVCE_ERROR_T |
| ihevce_bitstrm_init(bitstrm_t *ps_bitstrm, UWORD8 *pu1_bitstrm_buf, UWORD32 u4_max_bitstrm_size); |
| |
| IHEVCE_ERROR_T ihevce_put_bits(bitstrm_t *ps_bitstrm, UWORD32 u4_code_val, WORD32 code_len); |
| |
| IHEVCE_ERROR_T ihevce_put_bit(bitstrm_t *ps_bitstrm, UWORD32 u4_code_val); |
| |
| IHEVCE_ERROR_T ihevce_put_rbsp_trailing_bits(bitstrm_t *ps_bitstrm); |
| |
| IHEVCE_ERROR_T ihevce_put_uev(bitstrm_t *ps_bitstrm, UWORD32 u4_code_num); |
| |
| IHEVCE_ERROR_T ihevce_put_sev(bitstrm_t *ps_bitstrm, WORD32 syntax_elem); |
| |
| IHEVCE_ERROR_T |
| ihevce_put_nal_start_code_prefix(bitstrm_t *ps_bitstrm, WORD32 insert_leading_zero_8bits); |
| |
| #endif /* _IHEVCE_BITSTREAM_H_ */ |
