Hamsalekha S | 8d3d303 | 2015-03-13 21:24:58 +0530 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * |
| 3 | * Copyright (C) 2015 The Android Open Source Project |
| 4 | * |
| 5 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 6 | * you may not use this file except in compliance with the License. |
| 7 | * You may obtain a copy of the License at: |
| 8 | * |
| 9 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 10 | * |
| 11 | * Unless required by applicable law or agreed to in writing, software |
| 12 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 13 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 14 | * See the License for the specific language governing permissions and |
| 15 | * limitations under the License. |
| 16 | * |
| 17 | ***************************************************************************** |
| 18 | * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore |
| 19 | */ |
| 20 | |
| 21 | /** |
| 22 | ******************************************************************************* |
| 23 | * @file |
| 24 | * ih264e_bitstream.h |
| 25 | * |
| 26 | * @brief |
| 27 | * This file contains encoder bitstream engine related structures and |
| 28 | * interface prototypes |
| 29 | * |
| 30 | * @author |
| 31 | * ittiam |
| 32 | * |
| 33 | * @remarks |
| 34 | * none |
| 35 | * |
| 36 | ******************************************************************************* |
| 37 | */ |
| 38 | |
| 39 | #ifndef IH264E_BITSTREAM_H_ |
| 40 | #define IH264E_BITSTREAM_H_ |
| 41 | |
| 42 | /*****************************************************************************/ |
| 43 | /* Constant Macros */ |
| 44 | /*****************************************************************************/ |
| 45 | |
| 46 | /** |
| 47 | ****************************************************************************** |
| 48 | * @brief defines the maximum number of bits in a bitstream word |
| 49 | ****************************************************************************** |
| 50 | */ |
| 51 | #define WORD_SIZE 32 |
| 52 | |
| 53 | /** |
| 54 | ****************************************************************************** |
| 55 | * @brief The number of consecutive zero bytes for emulation prevention check |
| 56 | ****************************************************************************** |
| 57 | */ |
| 58 | #define EPB_ZERO_BYTES 2 |
| 59 | |
| 60 | /** |
| 61 | ****************************************************************************** |
| 62 | * @brief Emulation prevention insertion byte |
| 63 | ****************************************************************************** |
| 64 | */ |
| 65 | #define EPB_BYTE 0x03 |
| 66 | |
| 67 | |
Harinarayanan K K | 134291e | 2015-06-18 16:03:38 +0530 | [diff] [blame] | 68 | /** |
| 69 | ****************************************************************************** |
| 70 | * @brief Stream buffer allocated per frame should be atleast MIN_STREAM_SIZE |
| 71 | ****************************************************************************** |
| 72 | */ |
Harinarayanan K K | d2d469e | 2015-06-19 14:45:44 +0530 | [diff] [blame] | 73 | #define MIN_STREAM_SIZE 0x800 |
Harinarayanan K K | 134291e | 2015-06-18 16:03:38 +0530 | [diff] [blame] | 74 | |
| 75 | |
Hamsalekha S | 8d3d303 | 2015-03-13 21:24:58 +0530 | [diff] [blame] | 76 | /*****************************************************************************/ |
| 77 | /* Function Macros */ |
| 78 | /*****************************************************************************/ |
| 79 | |
| 80 | /** |
| 81 | ****************************************************************************** |
| 82 | * @brief Macro to check if emulation prevention byte insertion is required |
| 83 | ****************************************************************************** |
| 84 | */ |
| 85 | #define INSERT_EPB(zero_run, next_byte) \ |
| 86 | ((zero_run) == EPB_ZERO_BYTES) && (0 == ((next_byte) & 0xFC)) |
| 87 | |
| 88 | /** |
| 89 | ****************************************************************************** |
| 90 | * @brief returns the bit position of a leading 1 (msb) in a code value |
| 91 | ****************************************************************************** |
| 92 | */ |
| 93 | #if !MSVC |
| 94 | #define GETRANGE(r,value) \ |
| 95 | { \ |
| 96 | r = 0; \ |
| 97 | if(0 == value) \ |
| 98 | r = 1; \ |
| 99 | else \ |
| 100 | { \ |
| 101 | r = 32-CLZ(value); \ |
| 102 | }\ |
| 103 | } |
| 104 | #else |
| 105 | #define GETRANGE(r,value) \ |
| 106 | { \ |
| 107 | unsigned long msb_one_bit = 0; \ |
| 108 | r = _BitScanReverse(&msb_one_bit, value) ? (UWORD32)(msb_one_bit + 1) : 1 ; \ |
| 109 | } |
| 110 | #endif |
| 111 | |
| 112 | /** |
| 113 | ****************************************************************************** |
| 114 | * @brief returns bits required to code a value |
| 115 | ****************************************************************************** |
| 116 | */ |
Harinarayanan K K | 134291e | 2015-06-18 16:03:38 +0530 | [diff] [blame] | 117 | #define UE_LENGTH(bits,x) \ |
| 118 | { \ |
| 119 | UWORD32 r_bit; \ |
| 120 | GETRANGE(r_bit,x+1) \ |
| 121 | bits =(((r_bit - 1) << 1)+1);\ |
| 122 | } \ |
Hamsalekha S | 8d3d303 | 2015-03-13 21:24:58 +0530 | [diff] [blame] | 123 | |
| 124 | /** |
| 125 | ****************************************************************************** |
| 126 | * @brief Inserts 1 byte and Emulation Prevention Byte(if any) into bitstream |
| 127 | * Increments the stream offset and zero run correspondingly |
| 128 | ****************************************************************************** |
| 129 | */ |
| 130 | #define PUTBYTE_EPB(ptr,off,byte,zero_run) \ |
| 131 | { \ |
| 132 | if( INSERT_EPB(zero_run, byte) ) \ |
| 133 | { \ |
| 134 | ptr[off] = EPB_BYTE; \ |
| 135 | off++; \ |
| 136 | zero_run = 0; \ |
| 137 | } \ |
| 138 | \ |
| 139 | ptr[off] = byte; \ |
| 140 | off++; \ |
| 141 | zero_run = byte ? 0 : zero_run+1; \ |
| 142 | } \ |
| 143 | |
| 144 | /** |
| 145 | ****************************************************************************** |
| 146 | * @brief Ensures Byte alignment of the slice header |
| 147 | ****************************************************************************** |
| 148 | */ |
| 149 | #define BYTE_ALIGNMENT(ps_bitstrm) ih264e_put_rbsp_trailing_bits(ps_bitstrm) |
| 150 | |
Harinarayanan K K | 134291e | 2015-06-18 16:03:38 +0530 | [diff] [blame] | 151 | /** |
| 152 | ****************************************************************************** |
| 153 | * @brief Gets number of bits coded |
| 154 | ****************************************************************************** |
| 155 | */ |
| 156 | |
| 157 | #define GET_NUM_BITS(ps_bitstream) ((ps_bitstream->u4_strm_buf_offset << 3) \ |
| 158 | + 32 - ps_bitstream->i4_bits_left_in_cw); |
| 159 | |
| 160 | |
| 161 | |
| 162 | /** |
| 163 | ****************************************************************************** |
| 164 | * @macro Align bitstream to byte - Remainig bits are filled with '1' |
| 165 | ****************************************************************************** |
| 166 | */ |
| 167 | #define BITSTREAM_BYTE_ALIGN(ps_bitstrm) \ |
| 168 | if (ps_bitstrm->i4_bits_left_in_cw & 0x07) \ |
| 169 | { \ |
| 170 | const WORD32 len = (WORD32)((ps_bitstrm->i4_bits_left_in_cw) & 0x07);\ |
| 171 | ih264e_put_bits(ps_bitstrm, (UWORD32)((1 << len) - 1), len); \ |
Neelkamal Semwal | 10910bf | 2021-03-10 10:03:39 +0530 | [diff] [blame] | 172 | } \ |
Harinarayanan K K | 134291e | 2015-06-18 16:03:38 +0530 | [diff] [blame] | 173 | |
Hamsalekha S | 8d3d303 | 2015-03-13 21:24:58 +0530 | [diff] [blame] | 174 | |
| 175 | /*****************************************************************************/ |
| 176 | /* Structures */ |
| 177 | /*****************************************************************************/ |
| 178 | |
| 179 | /** |
| 180 | ****************************************************************************** |
| 181 | * @brief Bitstream context for encoder |
| 182 | ****************************************************************************** |
| 183 | */ |
| 184 | typedef struct bitstrm |
| 185 | { |
| 186 | /** points to start of stream buffer. */ |
| 187 | UWORD8 *pu1_strm_buffer; |
| 188 | |
| 189 | /** |
| 190 | * max bitstream size (in bytes). |
| 191 | * Encoded stream shall not exceed this size. |
| 192 | */ |
| 193 | UWORD32 u4_max_strm_size; |
| 194 | |
| 195 | /** |
| 196 | * byte offset (w.r.t pu1_strm_buffer) where next byte would be written |
| 197 | * Bitstream engine makes sure it would not corrupt data beyond |
| 198 | * u4_max_strm_size bytes |
| 199 | */ |
| 200 | UWORD32 u4_strm_buf_offset; |
| 201 | |
| 202 | /** |
| 203 | * current bitstream word; It is a scratch word containing max of |
| 204 | * WORD_SIZE bits. Will be copied to stream buffer when the word is |
| 205 | * full |
| 206 | */ |
| 207 | UWORD32 u4_cur_word; |
| 208 | |
| 209 | /** |
| 210 | * signifies number of bits available in u4_cur_word |
| 211 | * bits from msb to i4_bits_left_in_cw of u4_cur_word have already been |
| 212 | * inserted next bits would be inserted from pos [i4_bits_left_in_cw-1] |
| 213 | * Range of this variable [1 : WORD_SIZE] |
| 214 | */ |
| 215 | WORD32 i4_bits_left_in_cw; |
| 216 | |
| 217 | /** |
| 218 | * signifies the number of consecutive zero bytes propogated from previous |
| 219 | * word. It is used for emulation prevention byte insertion in the stream |
| 220 | */ |
| 221 | WORD32 i4_zero_bytes_run; |
| 222 | |
| 223 | } bitstrm_t; |
| 224 | |
| 225 | |
Neelkamal Semwal | 10910bf | 2021-03-10 10:03:39 +0530 | [diff] [blame] | 226 | /** |
| 227 | ****************************************************************************** |
| 228 | * @brief Inserts 1 byte and Emulation Prevention Byte(if any) into bitstream |
| 229 | * Increments the stream offset and zero run correspondingly |
| 230 | ****************************************************************************** |
| 231 | */ |
| 232 | static inline IH264E_ERROR_T ih264e_put_byte_epb(bitstrm_t *ps_bitstrm, UWORD8 byte) |
| 233 | { |
| 234 | if (INSERT_EPB(ps_bitstrm->i4_zero_bytes_run, byte)) |
| 235 | { |
| 236 | if ((ps_bitstrm->u4_strm_buf_offset + 1) >= ps_bitstrm->u4_max_strm_size) |
| 237 | { |
| 238 | return IH264E_BITSTREAM_BUFFER_OVERFLOW; |
| 239 | } |
| 240 | ps_bitstrm->pu1_strm_buffer[ps_bitstrm->u4_strm_buf_offset++] = EPB_BYTE; |
| 241 | ps_bitstrm->i4_zero_bytes_run = 0; |
| 242 | } |
| 243 | |
| 244 | if ((ps_bitstrm->u4_strm_buf_offset + 1) >= ps_bitstrm->u4_max_strm_size) |
| 245 | { |
| 246 | return IH264E_BITSTREAM_BUFFER_OVERFLOW; |
| 247 | } |
| 248 | ps_bitstrm->pu1_strm_buffer[ps_bitstrm->u4_strm_buf_offset++] = byte; |
| 249 | ps_bitstrm->i4_zero_bytes_run = byte ? 0 : ps_bitstrm->i4_zero_bytes_run + 1; |
| 250 | |
| 251 | return IH264E_SUCCESS; |
| 252 | } |
| 253 | |
| 254 | /** |
| 255 | ****************************************************************************** |
| 256 | * flush the bits in cur word byte by byte and copy to stream * |
| 257 | * (current word is assumed to be byte aligned) * |
| 258 | ****************************************************************************** |
| 259 | */ |
| 260 | #define BITSTREAM_FLUSH(ps_bitstrm, err) \ |
| 261 | { \ |
| 262 | WORD32 i; \ |
| 263 | for (i = WORD_SIZE; i > ps_bitstrm->i4_bits_left_in_cw; i -= 8) \ |
| 264 | { \ |
| 265 | UWORD8 u1_next_byte = (ps_bitstrm->u4_cur_word >> (i - 8)) & 0xFF; \ |
| 266 | err |= ih264e_put_byte_epb(ps_bitstrm, u1_next_byte); \ |
| 267 | } \ |
| 268 | ps_bitstrm->u4_cur_word = 0; \ |
| 269 | ps_bitstrm->i4_bits_left_in_cw = WORD_SIZE; \ |
| 270 | } \ |
| 271 | |
| 272 | |
| 273 | |
Hamsalekha S | 8d3d303 | 2015-03-13 21:24:58 +0530 | [diff] [blame] | 274 | /*****************************************************************************/ |
| 275 | /* Extern Function Declarations */ |
| 276 | /*****************************************************************************/ |
| 277 | |
| 278 | /** |
| 279 | ****************************************************************************** |
| 280 | * |
| 281 | * @brief Initializes the encoder bitstream engine |
| 282 | * |
| 283 | * @par Description |
| 284 | * This routine needs to be called at start of slice/frame encode |
| 285 | * |
| 286 | * @param[in] ps_bitstrm |
| 287 | * pointer to bitstream context (handle) |
| 288 | * |
| 289 | * @param[in] p1_bitstrm_buf |
| 290 | * bitstream buffer pointer where the encoded stream is generated in byte order |
| 291 | * |
| 292 | * @param[in] u4_max_bitstrm_size |
| 293 | * indicates maximum bitstream buffer size. (in bytes) |
| 294 | * If actual stream size exceeds the maximum size, encoder should |
| 295 | * 1. Not corrupt data beyond u4_max_bitstrm_size bytes |
| 296 | * 2. Report an error back to application indicating overflow |
| 297 | * |
| 298 | * @return success or failure error code |
| 299 | * |
| 300 | ****************************************************************************** |
| 301 | */ |
| 302 | IH264E_ERROR_T ih264e_bitstrm_init |
| 303 | ( |
| 304 | bitstrm_t *ps_bitstrm, |
| 305 | UWORD8 *pu1_bitstrm_buf, |
| 306 | UWORD32 u4_max_bitstrm_size |
| 307 | ); |
| 308 | |
| 309 | /** |
| 310 | ****************************************************************************** |
| 311 | * |
| 312 | * @brief puts a code with specified number of bits into the bitstream |
| 313 | * |
| 314 | * @par Description |
| 315 | * inserts code_len number of bits from lsb of code_val into the |
| 316 | * bitstream. If the total bytes (u4_strm_buf_offset) exceeds max |
| 317 | * available size (u4_max_strm_size), returns error without corrupting data |
| 318 | * beyond it |
| 319 | * |
| 320 | * @param[in] ps_bitstrm |
| 321 | * pointer to bitstream context (handle) |
| 322 | * |
| 323 | * @param[in] u4_code_val |
| 324 | * code value that needs to be inserted in the stream. |
| 325 | * |
| 326 | * @param[in] code_len |
| 327 | * indicates code length (in bits) of code_val that would be inserted in |
| 328 | * bitstream buffer size. |
| 329 | * |
| 330 | * @remarks Assumptions: all bits from bit position code_len to msb of |
| 331 | * code_val shall be zero |
| 332 | * |
| 333 | * @return success or failure error code |
| 334 | * |
| 335 | ****************************************************************************** |
| 336 | */ |
| 337 | IH264E_ERROR_T ih264e_put_bits |
| 338 | ( |
| 339 | bitstrm_t *ps_bitstrm, |
| 340 | UWORD32 u4_code_val, |
| 341 | WORD32 code_len |
| 342 | ); |
| 343 | |
| 344 | /** |
| 345 | ****************************************************************************** |
| 346 | * |
| 347 | * @brief inserts a 1-bit code into the bitstream |
| 348 | * |
| 349 | * @par Description |
| 350 | * inserts 1bit lsb of code_val into the bitstream |
| 351 | * updates context members like u4_cur_word, u4_strm_buf_offset and |
| 352 | * i4_bits_left_in_cw. If the total words (u4_strm_buf_offset) exceeds max |
| 353 | * available size (u4_max_strm_size), returns error without corrupting data |
| 354 | * beyond it |
| 355 | * |
| 356 | * @param[in] ps_bitstrm |
| 357 | * pointer to bitstream context (handle) |
| 358 | * |
| 359 | * @param[in] u4_code_val |
| 360 | * code value that needs to be inserted in the stream. |
| 361 | * |
| 362 | * @remarks Assumptions: all bits from bit position 1 to msb of code_val |
| 363 | * shall be zero |
| 364 | * |
| 365 | * @return success or failure error code |
| 366 | * |
| 367 | ****************************************************************************** |
| 368 | */ |
| 369 | IH264E_ERROR_T ih264e_put_bit |
| 370 | ( |
| 371 | bitstrm_t *ps_bitstrm, |
| 372 | UWORD32 u4_code_val |
| 373 | ); |
| 374 | |
| 375 | /** |
| 376 | ****************************************************************************** |
| 377 | * |
| 378 | * @brief inserts rbsp trailing bits at the end of stream buffer (NAL) |
| 379 | * |
| 380 | * @par Description |
| 381 | * inserts rbsp trailing bits, updates context members like u4_cur_word and |
| 382 | * i4_bits_left_in_cw and flushes the same in the bitstream buffer. If the |
| 383 | * total words (u4_strm_buf_offset) exceeds max available size |
| 384 | * (u4_max_strm_size), returns error without corrupting data beyond it |
| 385 | * |
| 386 | * @param[in] ps_bitstrm |
| 387 | * pointer to bitstream context (handle) |
| 388 | * |
| 389 | * @return success or failure error code |
| 390 | * |
| 391 | ****************************************************************************** |
| 392 | */ |
| 393 | IH264E_ERROR_T ih264e_put_rbsp_trailing_bits |
| 394 | ( |
| 395 | bitstrm_t *ps_bitstrm |
| 396 | ); |
| 397 | |
| 398 | /** |
| 399 | ****************************************************************************** |
| 400 | * |
| 401 | * @brief puts exponential golomb code of a unsigned integer into bitstream |
| 402 | * |
| 403 | * @par Description |
| 404 | * computes uev code for given syntax element and inserts the same into |
| 405 | * bitstream by calling ih264e_put_bits() interface. |
| 406 | * |
| 407 | * @param[in] ps_bitstrm |
| 408 | * pointer to bitstream context (handle) |
| 409 | * |
| 410 | * @param[in] u4_code_num |
| 411 | * unsigned integer input whose golomb code is written in stream |
| 412 | * |
| 413 | * @remarks Assumptions: code value can be represented in less than 16bits |
| 414 | * |
| 415 | * @return success or failure error code |
| 416 | * |
| 417 | ****************************************************************************** |
| 418 | */ |
| 419 | IH264E_ERROR_T ih264e_put_uev |
| 420 | ( |
| 421 | bitstrm_t *ps_bitstrm, |
| 422 | UWORD32 u4_code_num |
| 423 | ); |
| 424 | |
| 425 | /** |
| 426 | ****************************************************************************** |
| 427 | * |
| 428 | * @brief puts exponential golomb code of a signed integer into bitstream |
| 429 | * |
| 430 | * @par Description |
| 431 | * computes sev code for given syntax element and inserts the same into |
| 432 | * bitstream by calling ih264e_put_bits() interface. |
| 433 | * |
| 434 | * @param[in] ps_bitstrm |
| 435 | * pointer to bitstream context (handle) |
| 436 | * |
| 437 | * @param[in] syntax_elem |
| 438 | * signed integer input whose golomb code is written in stream |
| 439 | * |
| 440 | * @remarks Assumptions: code value can be represented in less than 16bits |
| 441 | * |
| 442 | * @return success or failure error code |
| 443 | * |
| 444 | ****************************************************************************** |
| 445 | */ |
| 446 | IH264E_ERROR_T ih264e_put_sev |
| 447 | ( |
| 448 | bitstrm_t *ps_bitstrm, |
| 449 | WORD32 syntax_elem |
| 450 | ); |
| 451 | |
| 452 | /** |
| 453 | ****************************************************************************** |
| 454 | * |
| 455 | * @brief insert NAL start code prefix (0x000001) into bitstream with an option |
| 456 | * of inserting leading_zero_8bits (which makes startcode prefix as 0x00000001) |
| 457 | * |
| 458 | * @par Description |
| 459 | * Although start code prefix could have been put by calling ih264e_put_bits(), |
| 460 | * ih264e_put_nal_start_code_prefix() is specially added to make sure emulation |
| 461 | * prevention insertion is not done for the NAL start code prefix which will |
| 462 | * surely happen otherwise by calling ih264e_put_bits() interface. |
| 463 | * |
| 464 | * @param[in] ps_bitstrm |
| 465 | * pointer to bitstream context (handle) |
| 466 | * |
| 467 | * @param[in] insert_leading_zero_8bits |
| 468 | * flag indicating if one more zero bytes needs to prefixed before start code |
| 469 | * |
| 470 | * @return success or failure error code |
| 471 | * |
| 472 | ****************************************************************************** |
| 473 | */ |
| 474 | IH264E_ERROR_T ih264e_put_nal_start_code_prefix |
| 475 | ( |
| 476 | bitstrm_t *ps_bitstrm, |
| 477 | WORD32 insert_leading_zero_8bits |
| 478 | ); |
| 479 | |
| 480 | #endif /* IH264E_BITSTREAM_H_ */ |