| Index: third_party/libjpeg_turbo/jdct.h
|
| ===================================================================
|
| --- third_party/libjpeg_turbo/jdct.h (revision 0)
|
| +++ third_party/libjpeg_turbo/jdct.h (revision 0)
|
| @@ -0,0 +1,184 @@
|
| +/*
|
| + * jdct.h
|
| + *
|
| + * Copyright (C) 1994-1996, Thomas G. Lane.
|
| + * This file is part of the Independent JPEG Group's software.
|
| + * For conditions of distribution and use, see the accompanying README file.
|
| + *
|
| + * This include file contains common declarations for the forward and
|
| + * inverse DCT modules. These declarations are private to the DCT managers
|
| + * (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
|
| + * The individual DCT algorithms are kept in separate files to ease
|
| + * machine-dependent tuning (e.g., assembly coding).
|
| + */
|
| +
|
| +
|
| +/*
|
| + * A forward DCT routine is given a pointer to a work area of type DCTELEM[];
|
| + * the DCT is to be performed in-place in that buffer. Type DCTELEM is int
|
| + * for 8-bit samples, INT32 for 12-bit samples. (NOTE: Floating-point DCT
|
| + * implementations use an array of type FAST_FLOAT, instead.)
|
| + * The DCT inputs are expected to be signed (range +-CENTERJSAMPLE).
|
| + * The DCT outputs are returned scaled up by a factor of 8; they therefore
|
| + * have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
|
| + * convention improves accuracy in integer implementations and saves some
|
| + * work in floating-point ones.
|
| + * Quantization of the output coefficients is done by jcdctmgr.c. This
|
| + * step requires an unsigned type and also one with twice the bits.
|
| + */
|
| +
|
| +#if BITS_IN_JSAMPLE == 8
|
| +#ifndef WITH_SIMD
|
| +typedef int DCTELEM; /* 16 or 32 bits is fine */
|
| +typedef unsigned int UDCTELEM;
|
| +typedef unsigned long long UDCTELEM2;
|
| +#else
|
| +typedef short DCTELEM; /* prefer 16 bit with SIMD for parellelism */
|
| +typedef unsigned short UDCTELEM;
|
| +typedef unsigned int UDCTELEM2;
|
| +#endif
|
| +#else
|
| +typedef INT32 DCTELEM; /* must have 32 bits */
|
| +typedef UINT32 UDCTELEM;
|
| +typedef unsigned long long UDCTELEM2;
|
| +#endif
|
| +
|
| +
|
| +/*
|
| + * An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
|
| + * to an output sample array. The routine must dequantize the input data as
|
| + * well as perform the IDCT; for dequantization, it uses the multiplier table
|
| + * pointed to by compptr->dct_table. The output data is to be placed into the
|
| + * sample array starting at a specified column. (Any row offset needed will
|
| + * be applied to the array pointer before it is passed to the IDCT code.)
|
| + * Note that the number of samples emitted by the IDCT routine is
|
| + * DCT_scaled_size * DCT_scaled_size.
|
| + */
|
| +
|
| +/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
|
| +
|
| +/*
|
| + * Each IDCT routine has its own ideas about the best dct_table element type.
|
| + */
|
| +
|
| +typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
|
| +#if BITS_IN_JSAMPLE == 8
|
| +typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
|
| +#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
|
| +#else
|
| +typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
|
| +#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
|
| +#endif
|
| +typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
|
| +
|
| +
|
| +/*
|
| + * Each IDCT routine is responsible for range-limiting its results and
|
| + * converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
|
| + * be quite far out of range if the input data is corrupt, so a bulletproof
|
| + * range-limiting step is required. We use a mask-and-table-lookup method
|
| + * to do the combined operations quickly. See the comments with
|
| + * prepare_range_limit_table (in jdmaster.c) for more info.
|
| + */
|
| +
|
| +#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit + CENTERJSAMPLE)
|
| +
|
| +#define RANGE_MASK (MAXJSAMPLE * 4 + 3) /* 2 bits wider than legal samples */
|
| +
|
| +
|
| +/* Short forms of external names for systems with brain-damaged linkers. */
|
| +
|
| +#ifdef NEED_SHORT_EXTERNAL_NAMES
|
| +#define jpeg_fdct_islow jFDislow
|
| +#define jpeg_fdct_ifast jFDifast
|
| +#define jpeg_fdct_float jFDfloat
|
| +#define jpeg_idct_islow jRDislow
|
| +#define jpeg_idct_ifast jRDifast
|
| +#define jpeg_idct_float jRDfloat
|
| +#define jpeg_idct_4x4 jRD4x4
|
| +#define jpeg_idct_2x2 jRD2x2
|
| +#define jpeg_idct_1x1 jRD1x1
|
| +#endif /* NEED_SHORT_EXTERNAL_NAMES */
|
| +
|
| +/* Extern declarations for the forward and inverse DCT routines. */
|
| +
|
| +EXTERN(void) jpeg_fdct_islow JPP((DCTELEM * data));
|
| +EXTERN(void) jpeg_fdct_ifast JPP((DCTELEM * data));
|
| +EXTERN(void) jpeg_fdct_float JPP((FAST_FLOAT * data));
|
| +
|
| +EXTERN(void) jpeg_idct_islow
|
| + JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
| + JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
| +EXTERN(void) jpeg_idct_ifast
|
| + JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
| + JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
| +EXTERN(void) jpeg_idct_float
|
| + JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
| + JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
| +EXTERN(void) jpeg_idct_4x4
|
| + JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
| + JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
| +EXTERN(void) jpeg_idct_2x2
|
| + JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
| + JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
| +EXTERN(void) jpeg_idct_1x1
|
| + JPP((j_decompress_ptr cinfo, jpeg_component_info * compptr,
|
| + JCOEFPTR coef_block, JSAMPARRAY output_buf, JDIMENSION output_col));
|
| +
|
| +
|
| +/*
|
| + * Macros for handling fixed-point arithmetic; these are used by many
|
| + * but not all of the DCT/IDCT modules.
|
| + *
|
| + * All values are expected to be of type INT32.
|
| + * Fractional constants are scaled left by CONST_BITS bits.
|
| + * CONST_BITS is defined within each module using these macros,
|
| + * and may differ from one module to the next.
|
| + */
|
| +
|
| +#define ONE ((INT32) 1)
|
| +#define CONST_SCALE (ONE << CONST_BITS)
|
| +
|
| +/* Convert a positive real constant to an integer scaled by CONST_SCALE.
|
| + * Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
|
| + * thus causing a lot of useless floating-point operations at run time.
|
| + */
|
| +
|
| +#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
|
| +
|
| +/* Descale and correctly round an INT32 value that's scaled by N bits.
|
| + * We assume RIGHT_SHIFT rounds towards minus infinity, so adding
|
| + * the fudge factor is correct for either sign of X.
|
| + */
|
| +
|
| +#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
|
| +
|
| +/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
|
| + * This macro is used only when the two inputs will actually be no more than
|
| + * 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
|
| + * full 32x32 multiply. This provides a useful speedup on many machines.
|
| + * Unfortunately there is no way to specify a 16x16->32 multiply portably
|
| + * in C, but some C compilers will do the right thing if you provide the
|
| + * correct combination of casts.
|
| + */
|
| +
|
| +#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
|
| +#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT16) (const)))
|
| +#endif
|
| +#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
|
| +#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT32) (const)))
|
| +#endif
|
| +
|
| +#ifndef MULTIPLY16C16 /* default definition */
|
| +#define MULTIPLY16C16(var,const) ((var) * (const))
|
| +#endif
|
| +
|
| +/* Same except both inputs are variables. */
|
| +
|
| +#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
|
| +#define MULTIPLY16V16(var1,var2) (((INT16) (var1)) * ((INT16) (var2)))
|
| +#endif
|
| +
|
| +#ifndef MULTIPLY16V16 /* default definition */
|
| +#define MULTIPLY16V16(var1,var2) ((var1) * (var2))
|
| +#endif
|
|
|