Initial version

Change-Id: I7efe9a589cd24edf86e8d086b40c27cbbf8b4017

1 files changed, 401 insertions, 0 deletions

diff --git a/encoder/ih264e_bitstream.h b/encoder/ih264e_bitstream.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_bitstream.h
+*
+* @brief
+*  This file contains encoder bitstream engine related structures and
+*  interface prototypes
+*
+* @author
+*  ittiam
+*
+* @remarks
+*  none
+*
+*******************************************************************************
+*/
+
+#ifndef IH264E_BITSTREAM_H_
+#define IH264E_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
+
+
+/*****************************************************************************/
+/* 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 the bit position of a leading 1 (msb) in a code value
+******************************************************************************
+ */
+#if !MSVC
+#define GETRANGE(r,value)   \
+{                           \
+    r = 0;                  \
+    if(0 == value)          \
+        r = 1;              \
+    else                    \
+    {                       \
+        r = 32-CLZ(value);  \
+    }\
+}
+#else
+#define GETRANGE(r,value)                 \
+{                                         \
+    unsigned long  msb_one_bit = 0;       \
+    r = _BitScanReverse(&msb_one_bit, value) ? (UWORD32)(msb_one_bit + 1) : 1 ; \
+}
+#endif
+
+/**
+******************************************************************************
+ *  @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) ih264e_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;
+
+} bitstrm_t;
+
+
+/*****************************************************************************/
+/* Extern Function Declarations                                              */
+/*****************************************************************************/
+
+/**
+******************************************************************************
+*
+*  @brief Initializes the encoder bitstream engine
+*
+*  @par   Description
+*  This routine needs to be called at start of slice/frame encode
+*
+*  @param[in]   ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @param[in]   p1_bitstrm_buf
+*  bitstream buffer pointer where the encoded stream is generated in byte order
+*
+*  @param[in]   u4_max_bitstrm_size
+*  indicates maximum bitstream buffer size. (in bytes)
+*  If actual stream size exceeds the maximum size, encoder should
+*   1. Not corrupt data beyond u4_max_bitstrm_size bytes
+*   2. Report an error back to application indicating overflow
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_bitstrm_init
+        (
+            bitstrm_t   *ps_bitstrm,
+            UWORD8      *pu1_bitstrm_buf,
+            UWORD32     u4_max_bitstrm_size
+        );
+
+/**
+******************************************************************************
+*
+*  @brief puts a code with specified number of bits into the bitstream
+*
+*  @par   Description
+*  inserts code_len number of bits from lsb of code_val into the
+*  bitstream.  If the total bytes (u4_strm_buf_offset) exceeds max
+*  available size (u4_max_strm_size), returns error without corrupting data
+*  beyond it
+*
+*  @param[in]    ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @param[in]    u4_code_val
+*  code value that needs to be inserted in the stream.
+*
+*  @param[in]    code_len
+*  indicates code length (in bits) of code_val that would be inserted in
+*  bitstream buffer size.
+*
+*  @remarks     Assumptions: all bits from bit position code_len to msb of
+*   code_val shall be zero
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_put_bits
+        (
+            bitstrm_t   *ps_bitstrm,
+            UWORD32     u4_code_val,
+            WORD32      code_len
+        );
+
+/**
+******************************************************************************
+*
+*  @brief inserts a 1-bit code into the bitstream
+*
+*  @par   Description
+*  inserts 1bit lsb of code_val into the bitstream
+*  updates context members like u4_cur_word, u4_strm_buf_offset and
+*  i4_bits_left_in_cw. If the total words (u4_strm_buf_offset) exceeds max
+*  available size (u4_max_strm_size), returns error without corrupting data
+*  beyond it
+*
+*  @param[in]    ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @param[in]    u4_code_val
+*  code value that needs to be inserted in the stream.
+*
+*  @remarks     Assumptions: all bits from bit position 1 to msb of code_val
+*  shall be zero
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_put_bit
+        (
+            bitstrm_t   *ps_bitstrm,
+            UWORD32     u4_code_val
+        );
+
+/**
+******************************************************************************
+*
+*  @brief inserts rbsp trailing bits at the end of stream buffer (NAL)
+*
+*  @par   Description
+*  inserts rbsp trailing bits, updates context members like u4_cur_word and
+*  i4_bits_left_in_cw and flushes the same in the bitstream buffer. If the
+*  total words (u4_strm_buf_offset) exceeds max available size
+*  (u4_max_strm_size), returns error without corrupting data beyond it
+*
+*  @param[in]    ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_put_rbsp_trailing_bits
+        (
+            bitstrm_t   *ps_bitstrm
+        );
+
+/**
+******************************************************************************
+*
+*  @brief puts exponential golomb code of a unsigned integer into bitstream
+*
+*  @par   Description
+*  computes uev code for given syntax element and inserts the same into
+*  bitstream by calling ih264e_put_bits() interface.
+*
+*  @param[in]    ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @param[in]    u4_code_num
+*  unsigned integer input whose golomb code is written in stream
+*
+*  @remarks     Assumptions: code value can be represented in less than 16bits
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_put_uev
+        (
+            bitstrm_t   *ps_bitstrm,
+            UWORD32     u4_code_num
+        );
+
+/**
+******************************************************************************
+*
+*  @brief puts exponential golomb code of a signed integer into bitstream
+*
+*  @par   Description
+*  computes sev code for given syntax element and inserts the same into
+*  bitstream by calling ih264e_put_bits() interface.
+*
+*  @param[in]    ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @param[in]    syntax_elem
+*  signed integer input whose golomb code is written in stream
+*
+*  @remarks     Assumptions: code value can be represented in less than 16bits
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_put_sev
+        (
+            bitstrm_t   *ps_bitstrm,
+            WORD32      syntax_elem
+        );
+
+/**
+******************************************************************************
+*
+*  @brief insert NAL start code prefix (0x000001) into bitstream with an option
+*  of inserting leading_zero_8bits (which makes startcode prefix as 0x00000001)
+*
+*  @par   Description
+*  Although start code prefix could have been put by calling ih264e_put_bits(),
+*  ih264e_put_nal_start_code_prefix() is specially added to make sure emulation
+*  prevention insertion is not done for the NAL start code prefix which will
+*  surely happen otherwise by calling ih264e_put_bits() interface.
+*
+*  @param[in]    ps_bitstrm
+*  pointer to bitstream context (handle)
+*
+*  @param[in]    insert_leading_zero_8bits
+*  flag indicating if one more zero bytes needs to prefixed before start code
+*
+*  @return      success or failure error code
+*
+******************************************************************************
+*/
+IH264E_ERROR_T    ih264e_put_nal_start_code_prefix
+        (
+            bitstrm_t   *ps_bitstrm,
+            WORD32      insert_leading_zero_8bits
+        );
+
+#endif /* IH264E_BITSTREAM_H_ */