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-rw-r--r--media/libjpeg/jcphuff.c1113
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diff --git a/media/libjpeg/jcphuff.c b/media/libjpeg/jcphuff.c
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+/*
+ * jcphuff.c
+ *
+ * This file was part of the Independent JPEG Group's software:
+ * Copyright (C) 1995-1997, Thomas G. Lane.
+ * libjpeg-turbo Modifications:
+ * Copyright (C) 2011, 2015, 2018, 2021-2022, D. R. Commander.
+ * Copyright (C) 2016, 2018, 2022, Matthieu Darbois.
+ * Copyright (C) 2020, Arm Limited.
+ * Copyright (C) 2021, Alex Richardson.
+ * For conditions of distribution and use, see the accompanying README.ijg
+ * file.
+ *
+ * This file contains Huffman entropy encoding routines for progressive JPEG.
+ *
+ * We do not support output suspension in this module, since the library
+ * currently does not allow multiple-scan files to be written with output
+ * suspension.
+ */
+
+#define JPEG_INTERNALS
+#include "jinclude.h"
+#include "jpeglib.h"
+#include "jsimd.h"
+#include <limits.h>
+
+#ifdef HAVE_INTRIN_H
+#include <intrin.h>
+#ifdef _MSC_VER
+#ifdef HAVE_BITSCANFORWARD64
+#pragma intrinsic(_BitScanForward64)
+#endif
+#ifdef HAVE_BITSCANFORWARD
+#pragma intrinsic(_BitScanForward)
+#endif
+#endif
+#endif
+
+#ifdef C_PROGRESSIVE_SUPPORTED
+
+/*
+ * NOTE: If USE_CLZ_INTRINSIC is defined, then clz/bsr instructions will be
+ * used for bit counting rather than the lookup table. This will reduce the
+ * memory footprint by 64k, which is important for some mobile applications
+ * that create many isolated instances of libjpeg-turbo (web browsers, for
+ * instance.) This may improve performance on some mobile platforms as well.
+ * This feature is enabled by default only on Arm processors, because some x86
+ * chips have a slow implementation of bsr, and the use of clz/bsr cannot be
+ * shown to have a significant performance impact even on the x86 chips that
+ * have a fast implementation of it. When building for Armv6, you can
+ * explicitly disable the use of clz/bsr by adding -mthumb to the compiler
+ * flags (this defines __thumb__).
+ */
+
+/* NOTE: Both GCC and Clang define __GNUC__ */
+#if (defined(__GNUC__) && (defined(__arm__) || defined(__aarch64__))) || \
+ defined(_M_ARM) || defined(_M_ARM64)
+#if !defined(__thumb__) || defined(__thumb2__)
+#define USE_CLZ_INTRINSIC
+#endif
+#endif
+
+#ifdef USE_CLZ_INTRINSIC
+#if defined(_MSC_VER) && !defined(__clang__)
+#define JPEG_NBITS_NONZERO(x) (32 - _CountLeadingZeros(x))
+#else
+#define JPEG_NBITS_NONZERO(x) (32 - __builtin_clz(x))
+#endif
+#define JPEG_NBITS(x) (x ? JPEG_NBITS_NONZERO(x) : 0)
+#else
+#include "jpeg_nbits_table.h"
+#define JPEG_NBITS(x) (jpeg_nbits_table[x])
+#define JPEG_NBITS_NONZERO(x) JPEG_NBITS(x)
+#endif
+
+
+/* Expanded entropy encoder object for progressive Huffman encoding. */
+
+typedef struct {
+ struct jpeg_entropy_encoder pub; /* public fields */
+
+ /* Pointer to routine to prepare data for encode_mcu_AC_first() */
+ void (*AC_first_prepare) (const JCOEF *block,
+ const int *jpeg_natural_order_start, int Sl,
+ int Al, UJCOEF *values, size_t *zerobits);
+ /* Pointer to routine to prepare data for encode_mcu_AC_refine() */
+ int (*AC_refine_prepare) (const JCOEF *block,
+ const int *jpeg_natural_order_start, int Sl,
+ int Al, UJCOEF *absvalues, size_t *bits);
+
+ /* Mode flag: TRUE for optimization, FALSE for actual data output */
+ boolean gather_statistics;
+
+ /* Bit-level coding status.
+ * next_output_byte/free_in_buffer are local copies of cinfo->dest fields.
+ */
+ JOCTET *next_output_byte; /* => next byte to write in buffer */
+ size_t free_in_buffer; /* # of byte spaces remaining in buffer */
+ size_t put_buffer; /* current bit-accumulation buffer */
+ int put_bits; /* # of bits now in it */
+ j_compress_ptr cinfo; /* link to cinfo (needed for dump_buffer) */
+
+ /* Coding status for DC components */
+ int last_dc_val[MAX_COMPS_IN_SCAN]; /* last DC coef for each component */
+
+ /* Coding status for AC components */
+ int ac_tbl_no; /* the table number of the single component */
+ unsigned int EOBRUN; /* run length of EOBs */
+ unsigned int BE; /* # of buffered correction bits before MCU */
+ char *bit_buffer; /* buffer for correction bits (1 per char) */
+ /* packing correction bits tightly would save some space but cost time... */
+
+ unsigned int restarts_to_go; /* MCUs left in this restart interval */
+ int next_restart_num; /* next restart number to write (0-7) */
+
+ /* Pointers to derived tables (these workspaces have image lifespan).
+ * Since any one scan codes only DC or only AC, we only need one set
+ * of tables, not one for DC and one for AC.
+ */
+ c_derived_tbl *derived_tbls[NUM_HUFF_TBLS];
+
+ /* Statistics tables for optimization; again, one set is enough */
+ long *count_ptrs[NUM_HUFF_TBLS];
+} phuff_entropy_encoder;
+
+typedef phuff_entropy_encoder *phuff_entropy_ptr;
+
+/* MAX_CORR_BITS is the number of bits the AC refinement correction-bit
+ * buffer can hold. Larger sizes may slightly improve compression, but
+ * 1000 is already well into the realm of overkill.
+ * The minimum safe size is 64 bits.
+ */
+
+#define MAX_CORR_BITS 1000 /* Max # of correction bits I can buffer */
+
+/* IRIGHT_SHIFT is like RIGHT_SHIFT, but works on int rather than JLONG.
+ * We assume that int right shift is unsigned if JLONG right shift is,
+ * which should be safe.
+ */
+
+#ifdef RIGHT_SHIFT_IS_UNSIGNED
+#define ISHIFT_TEMPS int ishift_temp;
+#define IRIGHT_SHIFT(x, shft) \
+ ((ishift_temp = (x)) < 0 ? \
+ (ishift_temp >> (shft)) | ((~0) << (16 - (shft))) : \
+ (ishift_temp >> (shft)))
+#else
+#define ISHIFT_TEMPS
+#define IRIGHT_SHIFT(x, shft) ((x) >> (shft))
+#endif
+
+#define PAD(v, p) ((v + (p) - 1) & (~((p) - 1)))
+
+/* Forward declarations */
+METHODDEF(boolean) encode_mcu_DC_first(j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data);
+METHODDEF(void) encode_mcu_AC_first_prepare
+ (const JCOEF *block, const int *jpeg_natural_order_start, int Sl, int Al,
+ UJCOEF *values, size_t *zerobits);
+METHODDEF(boolean) encode_mcu_AC_first(j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data);
+METHODDEF(boolean) encode_mcu_DC_refine(j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data);
+METHODDEF(int) encode_mcu_AC_refine_prepare
+ (const JCOEF *block, const int *jpeg_natural_order_start, int Sl, int Al,
+ UJCOEF *absvalues, size_t *bits);
+METHODDEF(boolean) encode_mcu_AC_refine(j_compress_ptr cinfo,
+ JBLOCKROW *MCU_data);
+METHODDEF(void) finish_pass_phuff(j_compress_ptr cinfo);
+METHODDEF(void) finish_pass_gather_phuff(j_compress_ptr cinfo);
+
+
+/* Count bit loop zeroes */
+INLINE
+METHODDEF(int)
+count_zeroes(size_t *x)
+{
+#if defined(HAVE_BUILTIN_CTZL)
+ int result;
+ result = __builtin_ctzl(*x);
+ *x >>= result;
+#elif defined(HAVE_BITSCANFORWARD64)
+ unsigned long result;
+ _BitScanForward64(&result, *x);
+ *x >>= result;
+#elif defined(HAVE_BITSCANFORWARD)
+ unsigned long result;
+ _BitScanForward(&result, *x);
+ *x >>= result;
+#else
+ int result = 0;
+ while ((*x & 1) == 0) {
+ ++result;
+ *x >>= 1;
+ }
+#endif
+ return (int)result;
+}
+
+
+/*
+ * Initialize for a Huffman-compressed scan using progressive JPEG.
+ */
+
+METHODDEF(void)
+start_pass_phuff(j_compress_ptr cinfo, boolean gather_statistics)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+ boolean is_DC_band;
+ int ci, tbl;
+ jpeg_component_info *compptr;
+
+ entropy->cinfo = cinfo;
+ entropy->gather_statistics = gather_statistics;
+
+ is_DC_band = (cinfo->Ss == 0);
+
+ /* We assume jcmaster.c already validated the scan parameters. */
+
+ /* Select execution routines */
+ if (cinfo->Ah == 0) {
+ if (is_DC_band)
+ entropy->pub.encode_mcu = encode_mcu_DC_first;
+ else
+ entropy->pub.encode_mcu = encode_mcu_AC_first;
+ if (jsimd_can_encode_mcu_AC_first_prepare())
+ entropy->AC_first_prepare = jsimd_encode_mcu_AC_first_prepare;
+ else
+ entropy->AC_first_prepare = encode_mcu_AC_first_prepare;
+ } else {
+ if (is_DC_band)
+ entropy->pub.encode_mcu = encode_mcu_DC_refine;
+ else {
+ entropy->pub.encode_mcu = encode_mcu_AC_refine;
+ if (jsimd_can_encode_mcu_AC_refine_prepare())
+ entropy->AC_refine_prepare = jsimd_encode_mcu_AC_refine_prepare;
+ else
+ entropy->AC_refine_prepare = encode_mcu_AC_refine_prepare;
+ /* AC refinement needs a correction bit buffer */
+ if (entropy->bit_buffer == NULL)
+ entropy->bit_buffer = (char *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ MAX_CORR_BITS * sizeof(char));
+ }
+ }
+ if (gather_statistics)
+ entropy->pub.finish_pass = finish_pass_gather_phuff;
+ else
+ entropy->pub.finish_pass = finish_pass_phuff;
+
+ /* Only DC coefficients may be interleaved, so cinfo->comps_in_scan = 1
+ * for AC coefficients.
+ */
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ /* Initialize DC predictions to 0 */
+ entropy->last_dc_val[ci] = 0;
+ /* Get table index */
+ if (is_DC_band) {
+ if (cinfo->Ah != 0) /* DC refinement needs no table */
+ continue;
+ tbl = compptr->dc_tbl_no;
+ } else {
+ entropy->ac_tbl_no = tbl = compptr->ac_tbl_no;
+ }
+ if (gather_statistics) {
+ /* Check for invalid table index */
+ /* (make_c_derived_tbl does this in the other path) */
+ if (tbl < 0 || tbl >= NUM_HUFF_TBLS)
+ ERREXIT1(cinfo, JERR_NO_HUFF_TABLE, tbl);
+ /* Allocate and zero the statistics tables */
+ /* Note that jpeg_gen_optimal_table expects 257 entries in each table! */
+ if (entropy->count_ptrs[tbl] == NULL)
+ entropy->count_ptrs[tbl] = (long *)
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ 257 * sizeof(long));
+ memset(entropy->count_ptrs[tbl], 0, 257 * sizeof(long));
+ } else {
+ /* Compute derived values for Huffman table */
+ /* We may do this more than once for a table, but it's not expensive */
+ jpeg_make_c_derived_tbl(cinfo, is_DC_band, tbl,
+ &entropy->derived_tbls[tbl]);
+ }
+ }
+
+ /* Initialize AC stuff */
+ entropy->EOBRUN = 0;
+ entropy->BE = 0;
+
+ /* Initialize bit buffer to empty */
+ entropy->put_buffer = 0;
+ entropy->put_bits = 0;
+
+ /* Initialize restart stuff */
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num = 0;
+}
+
+
+/* Outputting bytes to the file.
+ * NB: these must be called only when actually outputting,
+ * that is, entropy->gather_statistics == FALSE.
+ */
+
+/* Emit a byte */
+#define emit_byte(entropy, val) { \
+ *(entropy)->next_output_byte++ = (JOCTET)(val); \
+ if (--(entropy)->free_in_buffer == 0) \
+ dump_buffer(entropy); \
+}
+
+
+LOCAL(void)
+dump_buffer(phuff_entropy_ptr entropy)
+/* Empty the output buffer; we do not support suspension in this module. */
+{
+ struct jpeg_destination_mgr *dest = entropy->cinfo->dest;
+
+ if (!(*dest->empty_output_buffer) (entropy->cinfo))
+ ERREXIT(entropy->cinfo, JERR_CANT_SUSPEND);
+ /* After a successful buffer dump, must reset buffer pointers */
+ entropy->next_output_byte = dest->next_output_byte;
+ entropy->free_in_buffer = dest->free_in_buffer;
+}
+
+
+/* Outputting bits to the file */
+
+/* Only the right 24 bits of put_buffer are used; the valid bits are
+ * left-justified in this part. At most 16 bits can be passed to emit_bits
+ * in one call, and we never retain more than 7 bits in put_buffer
+ * between calls, so 24 bits are sufficient.
+ */
+
+LOCAL(void)
+emit_bits(phuff_entropy_ptr entropy, unsigned int code, int size)
+/* Emit some bits, unless we are in gather mode */
+{
+ /* This routine is heavily used, so it's worth coding tightly. */
+ register size_t put_buffer = (size_t)code;
+ register int put_bits = entropy->put_bits;
+
+ /* if size is 0, caller used an invalid Huffman table entry */
+ if (size == 0)
+ ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE);
+
+ if (entropy->gather_statistics)
+ return; /* do nothing if we're only getting stats */
+
+ put_buffer &= (((size_t)1) << size) - 1; /* mask off any extra bits in code */
+
+ put_bits += size; /* new number of bits in buffer */
+
+ put_buffer <<= 24 - put_bits; /* align incoming bits */
+
+ put_buffer |= entropy->put_buffer; /* and merge with old buffer contents */
+
+ while (put_bits >= 8) {
+ int c = (int)((put_buffer >> 16) & 0xFF);
+
+ emit_byte(entropy, c);
+ if (c == 0xFF) { /* need to stuff a zero byte? */
+ emit_byte(entropy, 0);
+ }
+ put_buffer <<= 8;
+ put_bits -= 8;
+ }
+
+ entropy->put_buffer = put_buffer; /* update variables */
+ entropy->put_bits = put_bits;
+}
+
+
+LOCAL(void)
+flush_bits(phuff_entropy_ptr entropy)
+{
+ emit_bits(entropy, 0x7F, 7); /* fill any partial byte with ones */
+ entropy->put_buffer = 0; /* and reset bit-buffer to empty */
+ entropy->put_bits = 0;
+}
+
+
+/*
+ * Emit (or just count) a Huffman symbol.
+ */
+
+LOCAL(void)
+emit_symbol(phuff_entropy_ptr entropy, int tbl_no, int symbol)
+{
+ if (entropy->gather_statistics)
+ entropy->count_ptrs[tbl_no][symbol]++;
+ else {
+ c_derived_tbl *tbl = entropy->derived_tbls[tbl_no];
+ emit_bits(entropy, tbl->ehufco[symbol], tbl->ehufsi[symbol]);
+ }
+}
+
+
+/*
+ * Emit bits from a correction bit buffer.
+ */
+
+LOCAL(void)
+emit_buffered_bits(phuff_entropy_ptr entropy, char *bufstart,
+ unsigned int nbits)
+{
+ if (entropy->gather_statistics)
+ return; /* no real work */
+
+ while (nbits > 0) {
+ emit_bits(entropy, (unsigned int)(*bufstart), 1);
+ bufstart++;
+ nbits--;
+ }
+}
+
+
+/*
+ * Emit any pending EOBRUN symbol.
+ */
+
+LOCAL(void)
+emit_eobrun(phuff_entropy_ptr entropy)
+{
+ register int temp, nbits;
+
+ if (entropy->EOBRUN > 0) { /* if there is any pending EOBRUN */
+ temp = entropy->EOBRUN;
+ nbits = JPEG_NBITS_NONZERO(temp) - 1;
+ /* safety check: shouldn't happen given limited correction-bit buffer */
+ if (nbits > 14)
+ ERREXIT(entropy->cinfo, JERR_HUFF_MISSING_CODE);
+
+ emit_symbol(entropy, entropy->ac_tbl_no, nbits << 4);
+ if (nbits)
+ emit_bits(entropy, entropy->EOBRUN, nbits);
+
+ entropy->EOBRUN = 0;
+
+ /* Emit any buffered correction bits */
+ emit_buffered_bits(entropy, entropy->bit_buffer, entropy->BE);
+ entropy->BE = 0;
+ }
+}
+
+
+/*
+ * Emit a restart marker & resynchronize predictions.
+ */
+
+LOCAL(void)
+emit_restart(phuff_entropy_ptr entropy, int restart_num)
+{
+ int ci;
+
+ emit_eobrun(entropy);
+
+ if (!entropy->gather_statistics) {
+ flush_bits(entropy);
+ emit_byte(entropy, 0xFF);
+ emit_byte(entropy, JPEG_RST0 + restart_num);
+ }
+
+ if (entropy->cinfo->Ss == 0) {
+ /* Re-initialize DC predictions to 0 */
+ for (ci = 0; ci < entropy->cinfo->comps_in_scan; ci++)
+ entropy->last_dc_val[ci] = 0;
+ } else {
+ /* Re-initialize all AC-related fields to 0 */
+ entropy->EOBRUN = 0;
+ entropy->BE = 0;
+ }
+}
+
+
+/*
+ * MCU encoding for DC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+METHODDEF(boolean)
+encode_mcu_DC_first(j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+ register int temp, temp2, temp3;
+ register int nbits;
+ int blkn, ci;
+ int Al = cinfo->Al;
+ JBLOCKROW block;
+ jpeg_component_info *compptr;
+ ISHIFT_TEMPS
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+ /* Encode the MCU data blocks */
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ block = MCU_data[blkn];
+ ci = cinfo->MCU_membership[blkn];
+ compptr = cinfo->cur_comp_info[ci];
+
+ /* Compute the DC value after the required point transform by Al.
+ * This is simply an arithmetic right shift.
+ */
+ temp2 = IRIGHT_SHIFT((int)((*block)[0]), Al);
+
+ /* DC differences are figured on the point-transformed values. */
+ temp = temp2 - entropy->last_dc_val[ci];
+ entropy->last_dc_val[ci] = temp2;
+
+ /* Encode the DC coefficient difference per section G.1.2.1 */
+
+ /* This is a well-known technique for obtaining the absolute value without
+ * a branch. It is derived from an assembly language technique presented
+ * in "How to Optimize for the Pentium Processors", Copyright (c) 1996,
+ * 1997 by Agner Fog.
+ */
+ temp3 = temp >> (CHAR_BIT * sizeof(int) - 1);
+ temp ^= temp3;
+ temp -= temp3; /* temp is abs value of input */
+ /* For a negative input, want temp2 = bitwise complement of abs(input) */
+ temp2 = temp ^ temp3;
+
+ /* Find the number of bits needed for the magnitude of the coefficient */
+ nbits = JPEG_NBITS(temp);
+ /* Check for out-of-range coefficient values.
+ * Since we're encoding a difference, the range limit is twice as much.
+ */
+ if (nbits > MAX_COEF_BITS + 1)
+ ERREXIT(cinfo, JERR_BAD_DCT_COEF);
+
+ /* Count/emit the Huffman-coded symbol for the number of bits */
+ emit_symbol(entropy, compptr->dc_tbl_no, nbits);
+
+ /* Emit that number of bits of the value, if positive, */
+ /* or the complement of its magnitude, if negative. */
+ if (nbits) /* emit_bits rejects calls with size 0 */
+ emit_bits(entropy, (unsigned int)temp2, nbits);
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * Data preparation for encode_mcu_AC_first().
+ */
+
+#define COMPUTE_ABSVALUES_AC_FIRST(Sl) { \
+ for (k = 0; k < Sl; k++) { \
+ temp = block[jpeg_natural_order_start[k]]; \
+ if (temp == 0) \
+ continue; \
+ /* We must apply the point transform by Al. For AC coefficients this \
+ * is an integer division with rounding towards 0. To do this portably \
+ * in C, we shift after obtaining the absolute value; so the code is \
+ * interwoven with finding the abs value (temp) and output bits (temp2). \
+ */ \
+ temp2 = temp >> (CHAR_BIT * sizeof(int) - 1); \
+ temp ^= temp2; \
+ temp -= temp2; /* temp is abs value of input */ \
+ temp >>= Al; /* apply the point transform */ \
+ /* Watch out for case that nonzero coef is zero after point transform */ \
+ if (temp == 0) \
+ continue; \
+ /* For a negative coef, want temp2 = bitwise complement of abs(coef) */ \
+ temp2 ^= temp; \
+ values[k] = (UJCOEF)temp; \
+ values[k + DCTSIZE2] = (UJCOEF)temp2; \
+ zerobits |= ((size_t)1U) << k; \
+ } \
+}
+
+METHODDEF(void)
+encode_mcu_AC_first_prepare(const JCOEF *block,
+ const int *jpeg_natural_order_start, int Sl,
+ int Al, UJCOEF *values, size_t *bits)
+{
+ register int k, temp, temp2;
+ size_t zerobits = 0U;
+ int Sl0 = Sl;
+
+#if SIZEOF_SIZE_T == 4
+ if (Sl0 > 32)
+ Sl0 = 32;
+#endif
+
+ COMPUTE_ABSVALUES_AC_FIRST(Sl0);
+
+ bits[0] = zerobits;
+#if SIZEOF_SIZE_T == 4
+ zerobits = 0U;
+
+ if (Sl > 32) {
+ Sl -= 32;
+ jpeg_natural_order_start += 32;
+ values += 32;
+
+ COMPUTE_ABSVALUES_AC_FIRST(Sl);
+ }
+ bits[1] = zerobits;
+#endif
+}
+
+/*
+ * MCU encoding for AC initial scan (either spectral selection,
+ * or first pass of successive approximation).
+ */
+
+#define ENCODE_COEFS_AC_FIRST(label) { \
+ while (zerobits) { \
+ r = count_zeroes(&zerobits); \
+ cvalue += r; \
+label \
+ temp = cvalue[0]; \
+ temp2 = cvalue[DCTSIZE2]; \
+ \
+ /* if run length > 15, must emit special run-length-16 codes (0xF0) */ \
+ while (r > 15) { \
+ emit_symbol(entropy, entropy->ac_tbl_no, 0xF0); \
+ r -= 16; \
+ } \
+ \
+ /* Find the number of bits needed for the magnitude of the coefficient */ \
+ nbits = JPEG_NBITS_NONZERO(temp); /* there must be at least one 1 bit */ \
+ /* Check for out-of-range coefficient values */ \
+ if (nbits > MAX_COEF_BITS) \
+ ERREXIT(cinfo, JERR_BAD_DCT_COEF); \
+ \
+ /* Count/emit Huffman symbol for run length / number of bits */ \
+ emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + nbits); \
+ \
+ /* Emit that number of bits of the value, if positive, */ \
+ /* or the complement of its magnitude, if negative. */ \
+ emit_bits(entropy, (unsigned int)temp2, nbits); \
+ \
+ cvalue++; \
+ zerobits >>= 1; \
+ } \
+}
+
+METHODDEF(boolean)
+encode_mcu_AC_first(j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+ register int temp, temp2;
+ register int nbits, r;
+ int Sl = cinfo->Se - cinfo->Ss + 1;
+ int Al = cinfo->Al;
+ UJCOEF values_unaligned[2 * DCTSIZE2 + 15];
+ UJCOEF *values;
+ const UJCOEF *cvalue;
+ size_t zerobits;
+ size_t bits[8 / SIZEOF_SIZE_T];
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+#ifdef WITH_SIMD
+ cvalue = values = (UJCOEF *)PAD((JUINTPTR)values_unaligned, 16);
+#else
+ /* Not using SIMD, so alignment is not needed */
+ cvalue = values = values_unaligned;
+#endif
+
+ /* Prepare data */
+ entropy->AC_first_prepare(MCU_data[0][0], jpeg_natural_order + cinfo->Ss,
+ Sl, Al, values, bits);
+
+ zerobits = bits[0];
+#if SIZEOF_SIZE_T == 4
+ zerobits |= bits[1];
+#endif
+
+ /* Emit any pending EOBRUN */
+ if (zerobits && (entropy->EOBRUN > 0))
+ emit_eobrun(entropy);
+
+#if SIZEOF_SIZE_T == 4
+ zerobits = bits[0];
+#endif
+
+ /* Encode the AC coefficients per section G.1.2.2, fig. G.3 */
+
+ ENCODE_COEFS_AC_FIRST((void)0;);
+
+#if SIZEOF_SIZE_T == 4
+ zerobits = bits[1];
+ if (zerobits) {
+ int diff = ((values + DCTSIZE2 / 2) - cvalue);
+ r = count_zeroes(&zerobits);
+ r += diff;
+ cvalue += r;
+ goto first_iter_ac_first;
+ }
+
+ ENCODE_COEFS_AC_FIRST(first_iter_ac_first:);
+#endif
+
+ if (cvalue < (values + Sl)) { /* If there are trailing zeroes, */
+ entropy->EOBRUN++; /* count an EOB */
+ if (entropy->EOBRUN == 0x7FFF)
+ emit_eobrun(entropy); /* force it out to avoid overflow */
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * MCU encoding for DC successive approximation refinement scan.
+ * Note: we assume such scans can be multi-component, although the spec
+ * is not very clear on the point.
+ */
+
+METHODDEF(boolean)
+encode_mcu_DC_refine(j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+ register int temp;
+ int blkn;
+ int Al = cinfo->Al;
+ JBLOCKROW block;
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+ /* Encode the MCU data blocks */
+ for (blkn = 0; blkn < cinfo->blocks_in_MCU; blkn++) {
+ block = MCU_data[blkn];
+
+ /* We simply emit the Al'th bit of the DC coefficient value. */
+ temp = (*block)[0];
+ emit_bits(entropy, (unsigned int)(temp >> Al), 1);
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * Data preparation for encode_mcu_AC_refine().
+ */
+
+#define COMPUTE_ABSVALUES_AC_REFINE(Sl, koffset) { \
+ /* It is convenient to make a pre-pass to determine the transformed \
+ * coefficients' absolute values and the EOB position. \
+ */ \
+ for (k = 0; k < Sl; k++) { \
+ temp = block[jpeg_natural_order_start[k]]; \
+ /* We must apply the point transform by Al. For AC coefficients this \
+ * is an integer division with rounding towards 0. To do this portably \
+ * in C, we shift after obtaining the absolute value. \
+ */ \
+ temp2 = temp >> (CHAR_BIT * sizeof(int) - 1); \
+ temp ^= temp2; \
+ temp -= temp2; /* temp is abs value of input */ \
+ temp >>= Al; /* apply the point transform */ \
+ if (temp != 0) { \
+ zerobits |= ((size_t)1U) << k; \
+ signbits |= ((size_t)(temp2 + 1)) << k; \
+ } \
+ absvalues[k] = (UJCOEF)temp; /* save abs value for main pass */ \
+ if (temp == 1) \
+ EOB = k + koffset; /* EOB = index of last newly-nonzero coef */ \
+ } \
+}
+
+METHODDEF(int)
+encode_mcu_AC_refine_prepare(const JCOEF *block,
+ const int *jpeg_natural_order_start, int Sl,
+ int Al, UJCOEF *absvalues, size_t *bits)
+{
+ register int k, temp, temp2;
+ int EOB = 0;
+ size_t zerobits = 0U, signbits = 0U;
+ int Sl0 = Sl;
+
+#if SIZEOF_SIZE_T == 4
+ if (Sl0 > 32)
+ Sl0 = 32;
+#endif
+
+ COMPUTE_ABSVALUES_AC_REFINE(Sl0, 0);
+
+ bits[0] = zerobits;
+#if SIZEOF_SIZE_T == 8
+ bits[1] = signbits;
+#else
+ bits[2] = signbits;
+
+ zerobits = 0U;
+ signbits = 0U;
+
+ if (Sl > 32) {
+ Sl -= 32;
+ jpeg_natural_order_start += 32;
+ absvalues += 32;
+
+ COMPUTE_ABSVALUES_AC_REFINE(Sl, 32);
+ }
+
+ bits[1] = zerobits;
+ bits[3] = signbits;
+#endif
+
+ return EOB;
+}
+
+
+/*
+ * MCU encoding for AC successive approximation refinement scan.
+ */
+
+#define ENCODE_COEFS_AC_REFINE(label) { \
+ while (zerobits) { \
+ idx = count_zeroes(&zerobits); \
+ r += idx; \
+ cabsvalue += idx; \
+ signbits >>= idx; \
+label \
+ /* Emit any required ZRLs, but not if they can be folded into EOB */ \
+ while (r > 15 && (cabsvalue <= EOBPTR)) { \
+ /* emit any pending EOBRUN and the BE correction bits */ \
+ emit_eobrun(entropy); \
+ /* Emit ZRL */ \
+ emit_symbol(entropy, entropy->ac_tbl_no, 0xF0); \
+ r -= 16; \
+ /* Emit buffered correction bits that must be associated with ZRL */ \
+ emit_buffered_bits(entropy, BR_buffer, BR); \
+ BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ \
+ BR = 0; \
+ } \
+ \
+ temp = *cabsvalue++; \
+ \
+ /* If the coef was previously nonzero, it only needs a correction bit. \
+ * NOTE: a straight translation of the spec's figure G.7 would suggest \
+ * that we also need to test r > 15. But if r > 15, we can only get here \
+ * if k > EOB, which implies that this coefficient is not 1. \
+ */ \
+ if (temp > 1) { \
+ /* The correction bit is the next bit of the absolute value. */ \
+ BR_buffer[BR++] = (char)(temp & 1); \
+ signbits >>= 1; \
+ zerobits >>= 1; \
+ continue; \
+ } \
+ \
+ /* Emit any pending EOBRUN and the BE correction bits */ \
+ emit_eobrun(entropy); \
+ \
+ /* Count/emit Huffman symbol for run length / number of bits */ \
+ emit_symbol(entropy, entropy->ac_tbl_no, (r << 4) + 1); \
+ \
+ /* Emit output bit for newly-nonzero coef */ \
+ temp = signbits & 1; /* ((*block)[jpeg_natural_order_start[k]] < 0) ? 0 : 1 */ \
+ emit_bits(entropy, (unsigned int)temp, 1); \
+ \
+ /* Emit buffered correction bits that must be associated with this code */ \
+ emit_buffered_bits(entropy, BR_buffer, BR); \
+ BR_buffer = entropy->bit_buffer; /* BE bits are gone now */ \
+ BR = 0; \
+ r = 0; /* reset zero run length */ \
+ signbits >>= 1; \
+ zerobits >>= 1; \
+ } \
+}
+
+METHODDEF(boolean)
+encode_mcu_AC_refine(j_compress_ptr cinfo, JBLOCKROW *MCU_data)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+ register int temp, r, idx;
+ char *BR_buffer;
+ unsigned int BR;
+ int Sl = cinfo->Se - cinfo->Ss + 1;
+ int Al = cinfo->Al;
+ UJCOEF absvalues_unaligned[DCTSIZE2 + 15];
+ UJCOEF *absvalues;
+ const UJCOEF *cabsvalue, *EOBPTR;
+ size_t zerobits, signbits;
+ size_t bits[16 / SIZEOF_SIZE_T];
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Emit restart marker if needed */
+ if (cinfo->restart_interval)
+ if (entropy->restarts_to_go == 0)
+ emit_restart(entropy, entropy->next_restart_num);
+
+#ifdef WITH_SIMD
+ cabsvalue = absvalues = (UJCOEF *)PAD((JUINTPTR)absvalues_unaligned, 16);
+#else
+ /* Not using SIMD, so alignment is not needed */
+ cabsvalue = absvalues = absvalues_unaligned;
+#endif
+
+ /* Prepare data */
+ EOBPTR = absvalues +
+ entropy->AC_refine_prepare(MCU_data[0][0], jpeg_natural_order + cinfo->Ss,
+ Sl, Al, absvalues, bits);
+
+ /* Encode the AC coefficients per section G.1.2.3, fig. G.7 */
+
+ r = 0; /* r = run length of zeros */
+ BR = 0; /* BR = count of buffered bits added now */
+ BR_buffer = entropy->bit_buffer + entropy->BE; /* Append bits to buffer */
+
+ zerobits = bits[0];
+#if SIZEOF_SIZE_T == 8
+ signbits = bits[1];
+#else
+ signbits = bits[2];
+#endif
+ ENCODE_COEFS_AC_REFINE((void)0;);
+
+#if SIZEOF_SIZE_T == 4
+ zerobits = bits[1];
+ signbits = bits[3];
+
+ if (zerobits) {
+ int diff = ((absvalues + DCTSIZE2 / 2) - cabsvalue);
+ idx = count_zeroes(&zerobits);
+ signbits >>= idx;
+ idx += diff;
+ r += idx;
+ cabsvalue += idx;
+ goto first_iter_ac_refine;
+ }
+
+ ENCODE_COEFS_AC_REFINE(first_iter_ac_refine:);
+#endif
+
+ r |= (int)((absvalues + Sl) - cabsvalue);
+
+ if (r > 0 || BR > 0) { /* If there are trailing zeroes, */
+ entropy->EOBRUN++; /* count an EOB */
+ entropy->BE += BR; /* concat my correction bits to older ones */
+ /* We force out the EOB if we risk either:
+ * 1. overflow of the EOB counter;
+ * 2. overflow of the correction bit buffer during the next MCU.
+ */
+ if (entropy->EOBRUN == 0x7FFF ||
+ entropy->BE > (MAX_CORR_BITS - DCTSIZE2 + 1))
+ emit_eobrun(entropy);
+ }
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+
+ /* Update restart-interval state too */
+ if (cinfo->restart_interval) {
+ if (entropy->restarts_to_go == 0) {
+ entropy->restarts_to_go = cinfo->restart_interval;
+ entropy->next_restart_num++;
+ entropy->next_restart_num &= 7;
+ }
+ entropy->restarts_to_go--;
+ }
+
+ return TRUE;
+}
+
+
+/*
+ * Finish up at the end of a Huffman-compressed progressive scan.
+ */
+
+METHODDEF(void)
+finish_pass_phuff(j_compress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+
+ entropy->next_output_byte = cinfo->dest->next_output_byte;
+ entropy->free_in_buffer = cinfo->dest->free_in_buffer;
+
+ /* Flush out any buffered data */
+ emit_eobrun(entropy);
+ flush_bits(entropy);
+
+ cinfo->dest->next_output_byte = entropy->next_output_byte;
+ cinfo->dest->free_in_buffer = entropy->free_in_buffer;
+}
+
+
+/*
+ * Finish up a statistics-gathering pass and create the new Huffman tables.
+ */
+
+METHODDEF(void)
+finish_pass_gather_phuff(j_compress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy = (phuff_entropy_ptr)cinfo->entropy;
+ boolean is_DC_band;
+ int ci, tbl;
+ jpeg_component_info *compptr;
+ JHUFF_TBL **htblptr;
+ boolean did[NUM_HUFF_TBLS];
+
+ /* Flush out buffered data (all we care about is counting the EOB symbol) */
+ emit_eobrun(entropy);
+
+ is_DC_band = (cinfo->Ss == 0);
+
+ /* It's important not to apply jpeg_gen_optimal_table more than once
+ * per table, because it clobbers the input frequency counts!
+ */
+ memset(did, 0, sizeof(did));
+
+ for (ci = 0; ci < cinfo->comps_in_scan; ci++) {
+ compptr = cinfo->cur_comp_info[ci];
+ if (is_DC_band) {
+ if (cinfo->Ah != 0) /* DC refinement needs no table */
+ continue;
+ tbl = compptr->dc_tbl_no;
+ } else {
+ tbl = compptr->ac_tbl_no;
+ }
+ if (!did[tbl]) {
+ if (is_DC_band)
+ htblptr = &cinfo->dc_huff_tbl_ptrs[tbl];
+ else
+ htblptr = &cinfo->ac_huff_tbl_ptrs[tbl];
+ if (*htblptr == NULL)
+ *htblptr = jpeg_alloc_huff_table((j_common_ptr)cinfo);
+ jpeg_gen_optimal_table(cinfo, *htblptr, entropy->count_ptrs[tbl]);
+ did[tbl] = TRUE;
+ }
+ }
+}
+
+
+/*
+ * Module initialization routine for progressive Huffman entropy encoding.
+ */
+
+GLOBAL(void)
+jinit_phuff_encoder(j_compress_ptr cinfo)
+{
+ phuff_entropy_ptr entropy;
+ int i;
+
+ entropy = (phuff_entropy_ptr)
+ (*cinfo->mem->alloc_small) ((j_common_ptr)cinfo, JPOOL_IMAGE,
+ sizeof(phuff_entropy_encoder));
+ cinfo->entropy = (struct jpeg_entropy_encoder *)entropy;
+ entropy->pub.start_pass = start_pass_phuff;
+
+ /* Mark tables unallocated */
+ for (i = 0; i < NUM_HUFF_TBLS; i++) {
+ entropy->derived_tbls[i] = NULL;
+ entropy->count_ptrs[i] = NULL;
+ }
+ entropy->bit_buffer = NULL; /* needed only in AC refinement scan */
+}
+
+#endif /* C_PROGRESSIVE_SUPPORTED */