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Diffstat (limited to 'apps/plugins/jpeg/jpeg_decoder.c')
-rw-r--r--apps/plugins/jpeg/jpeg_decoder.c1538
1 files changed, 0 insertions, 1538 deletions
diff --git a/apps/plugins/jpeg/jpeg_decoder.c b/apps/plugins/jpeg/jpeg_decoder.c
deleted file mode 100644
index c90bff8..0000000
--- a/apps/plugins/jpeg/jpeg_decoder.c
+++ /dev/null
@@ -1,1538 +0,0 @@
-/***************************************************************************
-* __________ __ ___.
-* Open \______ \ ____ ____ | | _\_ |__ _______ ___
-* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
-* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
-* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
-* \/ \/ \/ \/ \/
-* $Id$
-*
-* JPEG image viewer
-* (This is a real mess if it has to be coded in one single C file)
-*
-* File scrolling addition (C) 2005 Alexander Spyridakis
-* Copyright (C) 2004 Jörg Hohensohn aka [IDC]Dragon
-* Heavily borrowed from the IJG implementation (C) Thomas G. Lane
-* Small & fast downscaling IDCT (C) 2002 by Guido Vollbeding JPEGclub.org
-*
-* This program is free software; you can redistribute it and/or
-* modify it under the terms of the GNU General Public License
-* as published by the Free Software Foundation; either version 2
-* of the License, or (at your option) any later version.
-*
-* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
-* KIND, either express or implied.
-*
-****************************************************************************/
-
-#include "plugin.h"
-
-#include "jpeg_decoder.h"
-
-/* for portability of below JPEG code */
-#define MEMSET(p,v,c) rb->memset(p,v,c)
-#define MEMCPY(d,s,c) rb->memcpy(d,s,c)
-#define INLINE static inline
-#define ENDIAN_SWAP16(n) n /* only for poor little endian machines */
-
-/**************** begin JPEG code ********************/
-
-INLINE unsigned range_limit(int value)
-{
-#if CONFIG_CPU == SH7034
- unsigned tmp;
- asm ( /* Note: Uses knowledge that only low byte of result is used */
- "mov #-128,%[t] \n"
- "sub %[t],%[v] \n" /* value -= -128; equals value += 128; */
- "extu.b %[v],%[t] \n"
- "cmp/eq %[v],%[t] \n" /* low byte == whole number ? */
- "bt 1f \n" /* yes: no overflow */
- "cmp/pz %[v] \n" /* overflow: positive? */
- "subc %[v],%[v] \n" /* %[r] now either 0 or 0xffffffff */
- "1: \n"
- : /* outputs */
- [v]"+r"(value),
- [t]"=&r"(tmp)
- );
- return value;
-#elif defined(CPU_COLDFIRE)
- asm ( /* Note: Uses knowledge that only the low byte of the result is used */
- "add.l #128,%[v] \n" /* value += 128; */
- "cmp.l #255,%[v] \n" /* overflow? */
- "bls.b 1f \n" /* no: return value */
- "spl.b %[v] \n" /* yes: set low byte to appropriate boundary */
- "1: \n"
- : /* outputs */
- [v]"+d"(value)
- );
- return value;
-#elif defined(CPU_ARM)
- asm ( /* Note: Uses knowledge that only the low byte of the result is used */
- "add %[v], %[v], #128 \n" /* value += 128 */
- "cmp %[v], #255 \n" /* out of range 0..255? */
- "mvnhi %[v], %[v], asr #31 \n" /* yes: set all bits to ~(sign_bit) */
- : /* outputs */
- [v]"+r"(value)
- );
- return value;
-#else
- value += 128;
-
- if ((unsigned)value <= 255)
- return value;
-
- if (value < 0)
- return 0;
-
- return 255;
-#endif
-}
-
-/* IDCT implementation */
-
-
-#define CONST_BITS 13
-#define PASS1_BITS 2
-
-
-/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
-* causing a lot of useless floating-point operations at run time.
-* To get around this we use the following pre-calculated constants.
-* If you change CONST_BITS you may want to add appropriate values.
-* (With a reasonable C compiler, you can just rely on the FIX() macro...)
-*/
-#define FIX_0_298631336 2446 /* FIX(0.298631336) */
-#define FIX_0_390180644 3196 /* FIX(0.390180644) */
-#define FIX_0_541196100 4433 /* FIX(0.541196100) */
-#define FIX_0_765366865 6270 /* FIX(0.765366865) */
-#define FIX_0_899976223 7373 /* FIX(0.899976223) */
-#define FIX_1_175875602 9633 /* FIX(1.175875602) */
-#define FIX_1_501321110 12299 /* FIX(1.501321110) */
-#define FIX_1_847759065 15137 /* FIX(1.847759065) */
-#define FIX_1_961570560 16069 /* FIX(1.961570560) */
-#define FIX_2_053119869 16819 /* FIX(2.053119869) */
-#define FIX_2_562915447 20995 /* FIX(2.562915447) */
-#define FIX_3_072711026 25172 /* FIX(3.072711026) */
-
-
-
-/* Multiply an long variable by an long constant to yield an long result.
-* For 8-bit samples with the recommended scaling, all the variable
-* and constant values involved are no more than 16 bits wide, so a
-* 16x16->32 bit multiply can be used instead of a full 32x32 multiply.
-* For 12-bit samples, a full 32-bit multiplication will be needed.
-*/
-#define MULTIPLY16(var,const) (((short) (var)) * ((short) (const)))
-
-
-/* Dequantize a coefficient by multiplying it by the multiplier-table
-* entry; produce an int result. In this module, both inputs and result
-* are 16 bits or less, so either int or short multiply will work.
-*/
-/* #define DEQUANTIZE(coef,quantval) (((int) (coef)) * (quantval)) */
-#define DEQUANTIZE MULTIPLY16
-
-/* Descale and correctly round an int 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) (((x) + (1l << ((n)-1))) >> (n))
-
-
-
-/*
-* Perform dequantization and inverse DCT on one block of coefficients,
-* producing a reduced-size 1x1 output block.
-*/
-void idct1x1(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line)
-{
- (void)skip_line; /* unused */
- *p_byte = range_limit(inptr[0] * quantptr[0] >> 3);
-}
-
-
-
-/*
-* Perform dequantization and inverse DCT on one block of coefficients,
-* producing a reduced-size 2x2 output block.
-*/
-void idct2x2(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line)
-{
- int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
- unsigned char* outptr;
-
- /* Pass 1: process columns from input, store into work array. */
-
- /* Column 0 */
- tmp4 = DEQUANTIZE(inptr[8*0], quantptr[8*0]);
- tmp5 = DEQUANTIZE(inptr[8*1], quantptr[8*1]);
-
- tmp0 = tmp4 + tmp5;
- tmp2 = tmp4 - tmp5;
-
- /* Column 1 */
- tmp4 = DEQUANTIZE(inptr[8*0+1], quantptr[8*0+1]);
- tmp5 = DEQUANTIZE(inptr[8*1+1], quantptr[8*1+1]);
-
- tmp1 = tmp4 + tmp5;
- tmp3 = tmp4 - tmp5;
-
- /* Pass 2: process 2 rows, store into output array. */
-
- /* Row 0 */
- outptr = p_byte;
-
- outptr[0] = range_limit((int) DESCALE(tmp0 + tmp1, 3));
- outptr[1] = range_limit((int) DESCALE(tmp0 - tmp1, 3));
-
- /* Row 1 */
- outptr = p_byte + skip_line;
-
- outptr[0] = range_limit((int) DESCALE(tmp2 + tmp3, 3));
- outptr[1] = range_limit((int) DESCALE(tmp2 - tmp3, 3));
-}
-
-
-
-/*
-* Perform dequantization and inverse DCT on one block of coefficients,
-* producing a reduced-size 4x4 output block.
-*/
-void idct4x4(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line)
-{
- int tmp0, tmp2, tmp10, tmp12;
- int z1, z2, z3;
- int * wsptr;
- unsigned char* outptr;
- int ctr;
- int workspace[4*4]; /* buffers data between passes */
-
- /* Pass 1: process columns from input, store into work array. */
-
- wsptr = workspace;
- for (ctr = 0; ctr < 4; ctr++, inptr++, quantptr++, wsptr++)
- {
- /* Even part */
-
- tmp0 = DEQUANTIZE(inptr[8*0], quantptr[8*0]);
- tmp2 = DEQUANTIZE(inptr[8*2], quantptr[8*2]);
-
- tmp10 = (tmp0 + tmp2) << PASS1_BITS;
- tmp12 = (tmp0 - tmp2) << PASS1_BITS;
-
- /* Odd part */
- /* Same rotation as in the even part of the 8x8 LL&M IDCT */
-
- z2 = DEQUANTIZE(inptr[8*1], quantptr[8*1]);
- z3 = DEQUANTIZE(inptr[8*3], quantptr[8*3]);
-
- z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
- tmp0 = DESCALE(z1 + MULTIPLY16(z3, - FIX_1_847759065), CONST_BITS-PASS1_BITS);
- tmp2 = DESCALE(z1 + MULTIPLY16(z2, FIX_0_765366865), CONST_BITS-PASS1_BITS);
-
- /* Final output stage */
-
- wsptr[4*0] = (int) (tmp10 + tmp2);
- wsptr[4*3] = (int) (tmp10 - tmp2);
- wsptr[4*1] = (int) (tmp12 + tmp0);
- wsptr[4*2] = (int) (tmp12 - tmp0);
- }
-
- /* Pass 2: process 4 rows from work array, store into output array. */
-
- wsptr = workspace;
- for (ctr = 0; ctr < 4; ctr++)
- {
- outptr = p_byte + (ctr*skip_line);
- /* Even part */
-
- tmp0 = (int) wsptr[0];
- tmp2 = (int) wsptr[2];
-
- tmp10 = (tmp0 + tmp2) << CONST_BITS;
- tmp12 = (tmp0 - tmp2) << CONST_BITS;
-
- /* Odd part */
- /* Same rotation as in the even part of the 8x8 LL&M IDCT */
-
- z2 = (int) wsptr[1];
- z3 = (int) wsptr[3];
-
- z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
- tmp0 = z1 + MULTIPLY16(z3, - FIX_1_847759065);
- tmp2 = z1 + MULTIPLY16(z2, FIX_0_765366865);
-
- /* Final output stage */
-
- outptr[0] = range_limit((int) DESCALE(tmp10 + tmp2,
- CONST_BITS+PASS1_BITS+3));
- outptr[3] = range_limit((int) DESCALE(tmp10 - tmp2,
- CONST_BITS+PASS1_BITS+3));
- outptr[1] = range_limit((int) DESCALE(tmp12 + tmp0,
- CONST_BITS+PASS1_BITS+3));
- outptr[2] = range_limit((int) DESCALE(tmp12 - tmp0,
- CONST_BITS+PASS1_BITS+3));
-
- wsptr += 4; /* advance pointer to next row */
- }
-}
-
-
-
-/*
-* Perform dequantization and inverse DCT on one block of coefficients.
-*/
-void idct8x8(unsigned char* p_byte, int* inptr, int* quantptr, int skip_line)
-{
- long tmp0, tmp1, tmp2, tmp3;
- long tmp10, tmp11, tmp12, tmp13;
- long z1, z2, z3, z4, z5;
- int * wsptr;
- unsigned char* outptr;
- int ctr;
- int workspace[64]; /* buffers data between passes */
-
- /* Pass 1: process columns from input, store into work array. */
- /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
-
- wsptr = workspace;
- for (ctr = 8; ctr > 0; ctr--)
- {
- /* Due to quantization, we will usually find that many of the input
- * coefficients are zero, especially the AC terms. We can exploit this
- * by short-circuiting the IDCT calculation for any column in which all
- * the AC terms are zero. In that case each output is equal to the
- * DC coefficient (with scale factor as needed).
- * With typical images and quantization tables, half or more of the
- * column DCT calculations can be simplified this way.
- */
-
- if ((inptr[8*1] | inptr[8*2] | inptr[8*3]
- | inptr[8*4] | inptr[8*5] | inptr[8*6] | inptr[8*7]) == 0)
- {
- /* AC terms all zero */
- int dcval = DEQUANTIZE(inptr[8*0], quantptr[8*0]) << PASS1_BITS;
-
- wsptr[8*0] = wsptr[8*1] = wsptr[8*2] = wsptr[8*3] = wsptr[8*4]
- = wsptr[8*5] = wsptr[8*6] = wsptr[8*7] = dcval;
- inptr++; /* advance pointers to next column */
- quantptr++;
- wsptr++;
- continue;
- }
-
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = DEQUANTIZE(inptr[8*2], quantptr[8*2]);
- z3 = DEQUANTIZE(inptr[8*6], quantptr[8*6]);
-
- z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY16(z3, - FIX_1_847759065);
- tmp3 = z1 + MULTIPLY16(z2, FIX_0_765366865);
-
- z2 = DEQUANTIZE(inptr[8*0], quantptr[8*0]);
- z3 = DEQUANTIZE(inptr[8*4], quantptr[8*4]);
-
- tmp0 = (z2 + z3) << CONST_BITS;
- tmp1 = (z2 - z3) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
-
- /* Odd part per figure 8; the matrix is unitary and hence its
- transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. */
-
- tmp0 = DEQUANTIZE(inptr[8*7], quantptr[8*7]);
- tmp1 = DEQUANTIZE(inptr[8*5], quantptr[8*5]);
- tmp2 = DEQUANTIZE(inptr[8*3], quantptr[8*3]);
- tmp3 = DEQUANTIZE(inptr[8*1], quantptr[8*1]);
-
- z1 = tmp0 + tmp3;
- z2 = tmp1 + tmp2;
- z3 = tmp0 + tmp2;
- z4 = tmp1 + tmp3;
- z5 = MULTIPLY16(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
-
- tmp0 = MULTIPLY16(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp1 = MULTIPLY16(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY16(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
- tmp3 = MULTIPLY16(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
- z1 = MULTIPLY16(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- z2 = MULTIPLY16(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- z3 = MULTIPLY16(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z4 = MULTIPLY16(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
-
- z3 += z5;
- z4 += z5;
-
- tmp0 += z1 + z3;
- tmp1 += z2 + z4;
- tmp2 += z2 + z3;
- tmp3 += z1 + z4;
-
- /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
-
- wsptr[8*0] = (int) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
- wsptr[8*7] = (int) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
- wsptr[8*1] = (int) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
- wsptr[8*6] = (int) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
- wsptr[8*2] = (int) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
- wsptr[8*5] = (int) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
- wsptr[8*3] = (int) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
- wsptr[8*4] = (int) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
-
- inptr++; /* advance pointers to next column */
- quantptr++;
- wsptr++;
- }
-
- /* Pass 2: process rows from work array, store into output array. */
- /* Note that we must descale the results by a factor of 8 == 2**3, */
- /* and also undo the PASS1_BITS scaling. */
-
- wsptr = workspace;
- for (ctr = 0; ctr < 8; ctr++)
- {
- outptr = p_byte + (ctr*skip_line);
- /* Rows of zeroes can be exploited in the same way as we did with columns.
- * However, the column calculation has created many nonzero AC terms, so
- * the simplification applies less often (typically 5% to 10% of the time).
- * On machines with very fast multiplication, it's possible that the
- * test takes more time than it's worth. In that case this section
- * may be commented out.
- */
-
-#ifndef NO_ZERO_ROW_TEST
- if ((wsptr[1] | wsptr[2] | wsptr[3]
- | wsptr[4] | wsptr[5] | wsptr[6] | wsptr[7]) == 0)
- {
- /* AC terms all zero */
- unsigned char dcval = range_limit((int) DESCALE((long) wsptr[0],
- PASS1_BITS+3));
-
- outptr[0] = dcval;
- outptr[1] = dcval;
- outptr[2] = dcval;
- outptr[3] = dcval;
- outptr[4] = dcval;
- outptr[5] = dcval;
- outptr[6] = dcval;
- outptr[7] = dcval;
-
- wsptr += 8; /* advance pointer to next row */
- continue;
- }
-#endif
-
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = (long) wsptr[2];
- z3 = (long) wsptr[6];
-
- z1 = MULTIPLY16(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY16(z3, - FIX_1_847759065);
- tmp3 = z1 + MULTIPLY16(z2, FIX_0_765366865);
-
- tmp0 = ((long) wsptr[0] + (long) wsptr[4]) << CONST_BITS;
- tmp1 = ((long) wsptr[0] - (long) wsptr[4]) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
-
- /* Odd part per figure 8; the matrix is unitary and hence its
- * transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively. */
-
- tmp0 = (long) wsptr[7];
- tmp1 = (long) wsptr[5];
- tmp2 = (long) wsptr[3];
- tmp3 = (long) wsptr[1];
-
- z1 = tmp0 + tmp3;
- z2 = tmp1 + tmp2;
- z3 = tmp0 + tmp2;
- z4 = tmp1 + tmp3;
- z5 = MULTIPLY16(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
-
- tmp0 = MULTIPLY16(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp1 = MULTIPLY16(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY16(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
- tmp3 = MULTIPLY16(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
- z1 = MULTIPLY16(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- z2 = MULTIPLY16(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- z3 = MULTIPLY16(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z4 = MULTIPLY16(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
-
- z3 += z5;
- z4 += z5;
-
- tmp0 += z1 + z3;
- tmp1 += z2 + z4;
- tmp2 += z2 + z3;
- tmp3 += z1 + z4;
-
- /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
-
- outptr[0] = range_limit((int) DESCALE(tmp10 + tmp3,
- CONST_BITS+PASS1_BITS+3));
- outptr[7] = range_limit((int) DESCALE(tmp10 - tmp3,
- CONST_BITS+PASS1_BITS+3));
- outptr[1] = range_limit((int) DESCALE(tmp11 + tmp2,
- CONST_BITS+PASS1_BITS+3));
- outptr[6] = range_limit((int) DESCALE(tmp11 - tmp2,
- CONST_BITS+PASS1_BITS+3));
- outptr[2] = range_limit((int) DESCALE(tmp12 + tmp1,
- CONST_BITS+PASS1_BITS+3));
- outptr[5] = range_limit((int) DESCALE(tmp12 - tmp1,
- CONST_BITS+PASS1_BITS+3));
- outptr[3] = range_limit((int) DESCALE(tmp13 + tmp0,
- CONST_BITS+PASS1_BITS+3));
- outptr[4] = range_limit((int) DESCALE(tmp13 - tmp0,
- CONST_BITS+PASS1_BITS+3));
-
- wsptr += 8; /* advance pointer to next row */
- }
-}
-
-
-
-/* JPEG decoder implementation */
-
-/* Preprocess the JPEG JFIF file */
-int process_markers(unsigned char* p_src, long size, struct jpeg* p_jpeg)
-{
- unsigned char* p_bytes = p_src;
- int marker_size; /* variable length of marker segment */
- int i, j, n;
- int ret = 0; /* returned flags */
-
- p_jpeg->p_entropy_end = p_src + size;
-
- while (p_src < p_bytes + size)
- {
- if (*p_src++ != 0xFF) /* no marker? */
- {
- p_src--; /* it's image data, put it back */
- p_jpeg->p_entropy_data = p_src;
- break; /* exit marker processing */
- }
-
- switch (*p_src++)
- {
- case 0xFF: /* Fill byte */
- ret |= FILL_FF;
- case 0x00: /* Zero stuffed byte - entropy data */
- p_src--; /* put it back */
- continue;
-
- case 0xC0: /* SOF Huff - Baseline DCT */
- {
- ret |= SOF0;
- marker_size = *p_src++ << 8; /* Highbyte */
- marker_size |= *p_src++; /* Lowbyte */
- n = *p_src++; /* sample precision (= 8 or 12) */
- if (n != 8)
- {
- return(-1); /* Unsupported sample precision */
- }
- p_jpeg->y_size = *p_src++ << 8; /* Highbyte */
- p_jpeg->y_size |= *p_src++; /* Lowbyte */
- p_jpeg->x_size = *p_src++ << 8; /* Highbyte */
- p_jpeg->x_size |= *p_src++; /* Lowbyte */
-
- n = (marker_size-2-6)/3;
- if (*p_src++ != n || (n != 1 && n != 3))
- {
- return(-2); /* Unsupported SOF0 component specification */
- }
- for (i=0; i<n; i++)
- {
- p_jpeg->frameheader[i].ID = *p_src++; /* Component info */
- p_jpeg->frameheader[i].horizontal_sampling = *p_src >> 4;
- p_jpeg->frameheader[i].vertical_sampling = *p_src++ & 0x0F;
- p_jpeg->frameheader[i].quanttable_select = *p_src++;
- if (p_jpeg->frameheader[i].horizontal_sampling > 2
- || p_jpeg->frameheader[i].vertical_sampling > 2)
- return -3; /* Unsupported SOF0 subsampling */
- }
- p_jpeg->blocks = n;
- }
- break;
-
- case 0xC1: /* SOF Huff - Extended sequential DCT*/
- case 0xC2: /* SOF Huff - Progressive DCT*/
- case 0xC3: /* SOF Huff - Spatial (sequential) lossless*/
- case 0xC5: /* SOF Huff - Differential sequential DCT*/
- case 0xC6: /* SOF Huff - Differential progressive DCT*/
- case 0xC7: /* SOF Huff - Differential spatial*/
- case 0xC8: /* SOF Arith - Reserved for JPEG extensions*/
- case 0xC9: /* SOF Arith - Extended sequential DCT*/
- case 0xCA: /* SOF Arith - Progressive DCT*/
- case 0xCB: /* SOF Arith - Spatial (sequential) lossless*/
- case 0xCD: /* SOF Arith - Differential sequential DCT*/
- case 0xCE: /* SOF Arith - Differential progressive DCT*/
- case 0xCF: /* SOF Arith - Differential spatial*/
- {
- return (-4); /* other DCT model than baseline not implemented */
- }
-
- case 0xC4: /* Define Huffman Table(s) */
- {
- unsigned char* p_temp;
-
- ret |= DHT;
- marker_size = *p_src++ << 8; /* Highbyte */
- marker_size |= *p_src++; /* Lowbyte */
-
- p_temp = p_src;
- while (p_src < p_temp+marker_size-2-17) /* another table */
- {
- int sum = 0;
- i = *p_src & 0x0F; /* table index */
- if (i > 1)
- {
- return (-5); /* Huffman table index out of range */
- }
- else if (*p_src++ & 0xF0) /* AC table */
- {
- for (j=0; j<16; j++)
- {
- sum += *p_src;
- p_jpeg->hufftable[i].huffmancodes_ac[j] = *p_src++;
- }
- if(16 + sum > AC_LEN)
- return -10; /* longer than allowed */
-
- for (; j < 16 + sum; j++)
- p_jpeg->hufftable[i].huffmancodes_ac[j] = *p_src++;
- }
- else /* DC table */
- {
- for (j=0; j<16; j++)
- {
- sum += *p_src;
- p_jpeg->hufftable[i].huffmancodes_dc[j] = *p_src++;
- }
- if(16 + sum > DC_LEN)
- return -11; /* longer than allowed */
-
- for (; j < 16 + sum; j++)
- p_jpeg->hufftable[i].huffmancodes_dc[j] = *p_src++;
- }
- } /* while */
- p_src = p_temp+marker_size - 2; /* skip possible residue */
- }
- break;
-
- case 0xCC: /* Define Arithmetic coding conditioning(s) */
- return(-6); /* Arithmetic coding not supported */
-
- case 0xD8: /* Start of Image */
- case 0xD9: /* End of Image */
- case 0x01: /* for temp private use arith code */
- break; /* skip parameterless marker */
-
-
- case 0xDA: /* Start of Scan */
- {
- ret |= SOS;
- marker_size = *p_src++ << 8; /* Highbyte */
- marker_size |= *p_src++; /* Lowbyte */
-
- n = (marker_size-2-1-3)/2;
- if (*p_src++ != n || (n != 1 && n != 3))
- {
- return (-7); /* Unsupported SOS component specification */
- }
- for (i=0; i<n; i++)
- {
- p_jpeg->scanheader[i].ID = *p_src++;
- p_jpeg->scanheader[i].DC_select = *p_src >> 4;
- p_jpeg->scanheader[i].AC_select = *p_src++ & 0x0F;
- }
- p_src += 3; /* skip spectral information */
- }
- break;
-
- case 0xDB: /* Define quantization Table(s) */
- {
- ret |= DQT;
- marker_size = *p_src++ << 8; /* Highbyte */
- marker_size |= *p_src++; /* Lowbyte */
- n = (marker_size-2)/(QUANT_TABLE_LENGTH+1); /* # of tables */
- for (i=0; i<n; i++)
- {
- int id = *p_src++; /* ID */
- if (id >= 4)
- {
- return (-8); /* Unsupported quantization table */
- }
- /* Read Quantisation table: */
- for (j=0; j<QUANT_TABLE_LENGTH; j++)
- p_jpeg->quanttable[id][j] = *p_src++;
- }
- }
- break;
-
- case 0xDD: /* Define Restart Interval */
- {
- marker_size = *p_src++ << 8; /* Highbyte */
- marker_size |= *p_src++; /* Lowbyte */
- p_jpeg->restart_interval = *p_src++ << 8; /* Highbyte */
- p_jpeg->restart_interval |= *p_src++; /* Lowbyte */
- p_src += marker_size-4; /* skip segment */
- }
- break;
-
- case 0xDC: /* Define Number of Lines */
- case 0xDE: /* Define Hierarchical progression */
- case 0xDF: /* Expand Reference Component(s) */
- case 0xE0: /* Application Field 0*/
- case 0xE1: /* Application Field 1*/
- case 0xE2: /* Application Field 2*/
- case 0xE3: /* Application Field 3*/
- case 0xE4: /* Application Field 4*/
- case 0xE5: /* Application Field 5*/
- case 0xE6: /* Application Field 6*/
- case 0xE7: /* Application Field 7*/
- case 0xE8: /* Application Field 8*/
- case 0xE9: /* Application Field 9*/
- case 0xEA: /* Application Field 10*/
- case 0xEB: /* Application Field 11*/
- case 0xEC: /* Application Field 12*/
- case 0xED: /* Application Field 13*/
- case 0xEE: /* Application Field 14*/
- case 0xEF: /* Application Field 15*/
- case 0xFE: /* Comment */
- {
- marker_size = *p_src++ << 8; /* Highbyte */
- marker_size |= *p_src++; /* Lowbyte */
- p_src += marker_size-2; /* skip segment */
- }
- break;
-
- case 0xF0: /* Reserved for JPEG extensions */
- case 0xF1: /* Reserved for JPEG extensions */
- case 0xF2: /* Reserved for JPEG extensions */
- case 0xF3: /* Reserved for JPEG extensions */
- case 0xF4: /* Reserved for JPEG extensions */
- case 0xF5: /* Reserved for JPEG extensions */
- case 0xF6: /* Reserved for JPEG extensions */
- case 0xF7: /* Reserved for JPEG extensions */
- case 0xF8: /* Reserved for JPEG extensions */
- case 0xF9: /* Reserved for JPEG extensions */
- case 0xFA: /* Reserved for JPEG extensions */
- case 0xFB: /* Reserved for JPEG extensions */
- case 0xFC: /* Reserved for JPEG extensions */
- case 0xFD: /* Reserved for JPEG extensions */
- case 0x02: /* Reserved */
- default:
- return (-9); /* Unknown marker */
- } /* switch */
- } /* while */
-
- return (ret); /* return flags with seen markers */
-}
-
-
-void default_huff_tbl(struct jpeg* p_jpeg)
-{
- static const struct huffman_table luma_table =
- {
- {
- 0x00,0x01,0x05,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,0x00,0x00,
- 0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B
- },
- {
- 0x00,0x02,0x01,0x03,0x03,0x02,0x04,0x03,0x05,0x05,0x04,0x04,0x00,0x00,0x01,0x7D,
- 0x01,0x02,0x03,0x00,0x04,0x11,0x05,0x12,0x21,0x31,0x41,0x06,0x13,0x51,0x61,0x07,
- 0x22,0x71,0x14,0x32,0x81,0x91,0xA1,0x08,0x23,0x42,0xB1,0xC1,0x15,0x52,0xD1,0xF0,
- 0x24,0x33,0x62,0x72,0x82,0x09,0x0A,0x16,0x17,0x18,0x19,0x1A,0x25,0x26,0x27,0x28,
- 0x29,0x2A,0x34,0x35,0x36,0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,0x49,
- 0x4A,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68,0x69,
- 0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x83,0x84,0x85,0x86,0x87,0x88,0x89,
- 0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,
- 0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,0xC3,0xC4,0xC5,
- 0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,0xE1,0xE2,
- 0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,
- 0xF9,0xFA
- }
- };
-
- static const struct huffman_table chroma_table =
- {
- {
- 0x00,0x03,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x00,0x00,0x00,
- 0x00,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B
- },
- {
- 0x00,0x02,0x01,0x02,0x04,0x04,0x03,0x04,0x07,0x05,0x04,0x04,0x00,0x01,0x02,0x77,
- 0x00,0x01,0x02,0x03,0x11,0x04,0x05,0x21,0x31,0x06,0x12,0x41,0x51,0x07,0x61,0x71,
- 0x13,0x22,0x32,0x81,0x08,0x14,0x42,0x91,0xA1,0xB1,0xC1,0x09,0x23,0x33,0x52,0xF0,
- 0x15,0x62,0x72,0xD1,0x0A,0x16,0x24,0x34,0xE1,0x25,0xF1,0x17,0x18,0x19,0x1A,0x26,
- 0x27,0x28,0x29,0x2A,0x35,0x36,0x37,0x38,0x39,0x3A,0x43,0x44,0x45,0x46,0x47,0x48,
- 0x49,0x4A,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0x63,0x64,0x65,0x66,0x67,0x68,
- 0x69,0x6A,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0x82,0x83,0x84,0x85,0x86,0x87,
- 0x88,0x89,0x8A,0x92,0x93,0x94,0x95,0x96,0x97,0x98,0x99,0x9A,0xA2,0xA3,0xA4,0xA5,
- 0xA6,0xA7,0xA8,0xA9,0xAA,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,0xB8,0xB9,0xBA,0xC2,0xC3,
- 0xC4,0xC5,0xC6,0xC7,0xC8,0xC9,0xCA,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,0xD8,0xD9,0xDA,
- 0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,0xE8,0xE9,0xEA,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,0xF8,
- 0xF9,0xFA
- }
- };
-
- MEMCPY(&p_jpeg->hufftable[0], &luma_table, sizeof(luma_table));
- MEMCPY(&p_jpeg->hufftable[1], &chroma_table, sizeof(chroma_table));
-
- return;
-}
-
-/* Compute the derived values for a Huffman table */
-void fix_huff_tbl(int* htbl, struct derived_tbl* dtbl)
-{
- int p, i, l, si;
- int lookbits, ctr;
- char huffsize[257];
- unsigned int huffcode[257];
- unsigned int code;
-
- dtbl->pub = htbl; /* fill in back link */
-
- /* Figure C.1: make table of Huffman code length for each symbol */
- /* Note that this is in code-length order. */
-
- p = 0;
- for (l = 1; l <= 16; l++)
- { /* all possible code length */
- for (i = 1; i <= (int) htbl[l-1]; i++) /* all codes per length */
- huffsize[p++] = (char) l;
- }
- huffsize[p] = 0;
-
- /* Figure C.2: generate the codes themselves */
- /* Note that this is in code-length order. */
-
- code = 0;
- si = huffsize[0];
- p = 0;
- while (huffsize[p])
- {
- while (((int) huffsize[p]) == si)
- {
- huffcode[p++] = code;
- code++;
- }
- code <<= 1;
- si++;
- }
-
- /* Figure F.15: generate decoding tables for bit-sequential decoding */
-
- p = 0;
- for (l = 1; l <= 16; l++)
- {
- if (htbl[l-1])
- {
- dtbl->valptr[l] = p; /* huffval[] index of 1st symbol of code length l */
- dtbl->mincode[l] = huffcode[p]; /* minimum code of length l */
- p += htbl[l-1];
- dtbl->maxcode[l] = huffcode[p-1]; /* maximum code of length l */
- }
- else
- {
- dtbl->maxcode[l] = -1; /* -1 if no codes of this length */
- }
- }
- dtbl->maxcode[17] = 0xFFFFFL; /* ensures huff_DECODE terminates */
-
- /* Compute lookahead tables to speed up decoding.
- * First we set all the table entries to 0, indicating "too long";
- * then we iterate through the Huffman codes that are short enough and
- * fill in all the entries that correspond to bit sequences starting
- * with that code.
- */
-
- MEMSET(dtbl->look_nbits, 0, sizeof(dtbl->look_nbits));
-
- p = 0;
- for (l = 1; l <= HUFF_LOOKAHEAD; l++)
- {
- for (i = 1; i <= (int) htbl[l-1]; i++, p++)
- {
- /* l = current code's length, p = its index in huffcode[] & huffval[]. */
- /* Generate left-justified code followed by all possible bit sequences */
- lookbits = huffcode[p] << (HUFF_LOOKAHEAD-l);
- for (ctr = 1 << (HUFF_LOOKAHEAD-l); ctr > 0; ctr--)
- {
- dtbl->look_nbits[lookbits] = l;
- dtbl->look_sym[lookbits] = htbl[16+p];
- lookbits++;
- }
- }
- }
-}
-
-
-/* zag[i] is the natural-order position of the i'th element of zigzag order.
- * If the incoming data is corrupted, decode_mcu could attempt to
- * reference values beyond the end of the array. To avoid a wild store,
- * we put some extra zeroes after the real entries.
- */
-static const int zag[] =
-{
- 0, 1, 8, 16, 9, 2, 3, 10,
- 17, 24, 32, 25, 18, 11, 4, 5,
- 12, 19, 26, 33, 40, 48, 41, 34,
- 27, 20, 13, 6, 7, 14, 21, 28,
- 35, 42, 49, 56, 57, 50, 43, 36,
- 29, 22, 15, 23, 30, 37, 44, 51,
- 58, 59, 52, 45, 38, 31, 39, 46,
- 53, 60, 61, 54, 47, 55, 62, 63,
- 0, 0, 0, 0, 0, 0, 0, 0, /* extra entries in case k>63 below */
- 0, 0, 0, 0, 0, 0, 0, 0
-};
-
-void build_lut(struct jpeg* p_jpeg)
-{
- int i;
- fix_huff_tbl(p_jpeg->hufftable[0].huffmancodes_dc,
- &p_jpeg->dc_derived_tbls[0]);
- fix_huff_tbl(p_jpeg->hufftable[0].huffmancodes_ac,
- &p_jpeg->ac_derived_tbls[0]);
- fix_huff_tbl(p_jpeg->hufftable[1].huffmancodes_dc,
- &p_jpeg->dc_derived_tbls[1]);
- fix_huff_tbl(p_jpeg->hufftable[1].huffmancodes_ac,
- &p_jpeg->ac_derived_tbls[1]);
-
- /* build the dequantization tables for the IDCT (De-ZiZagged) */
- for (i=0; i<64; i++)
- {
- p_jpeg->qt_idct[0][zag[i]] = p_jpeg->quanttable[0][i];
- p_jpeg->qt_idct[1][zag[i]] = p_jpeg->quanttable[1][i];
- }
-
- for (i=0; i<4; i++)
- p_jpeg->store_pos[i] = i; /* default ordering */
-
- /* assignments for the decoding of blocks */
- if (p_jpeg->frameheader[0].horizontal_sampling == 2
- && p_jpeg->frameheader[0].vertical_sampling == 1)
- { /* 4:2:2 */
- p_jpeg->blocks = 4;
- p_jpeg->x_mbl = (p_jpeg->x_size+15) / 16;
- p_jpeg->x_phys = p_jpeg->x_mbl * 16;
- p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8;
- p_jpeg->y_phys = p_jpeg->y_mbl * 8;
- p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */
- p_jpeg->mcu_membership[1] = 0;
- p_jpeg->mcu_membership[2] = 1;
- p_jpeg->mcu_membership[3] = 2;
- p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */
- p_jpeg->tab_membership[1] = 0;
- p_jpeg->tab_membership[2] = 1;
- p_jpeg->tab_membership[3] = 1;
- p_jpeg->subsample_x[0] = 1;
- p_jpeg->subsample_x[1] = 2;
- p_jpeg->subsample_x[2] = 2;
- p_jpeg->subsample_y[0] = 1;
- p_jpeg->subsample_y[1] = 1;
- p_jpeg->subsample_y[2] = 1;
- }
- if (p_jpeg->frameheader[0].horizontal_sampling == 1
- && p_jpeg->frameheader[0].vertical_sampling == 2)
- { /* 4:2:2 vertically subsampled */
- p_jpeg->store_pos[1] = 2; /* block positions are mirrored */
- p_jpeg->store_pos[2] = 1;
- p_jpeg->blocks = 4;
- p_jpeg->x_mbl = (p_jpeg->x_size+7) / 8;
- p_jpeg->x_phys = p_jpeg->x_mbl * 8;
- p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16;
- p_jpeg->y_phys = p_jpeg->y_mbl * 16;
- p_jpeg->mcu_membership[0] = 0; /* Y1=Y2=0, U=1, V=2 */
- p_jpeg->mcu_membership[1] = 0;
- p_jpeg->mcu_membership[2] = 1;
- p_jpeg->mcu_membership[3] = 2;
- p_jpeg->tab_membership[0] = 0; /* DC, DC, AC, AC */
- p_jpeg->tab_membership[1] = 0;
- p_jpeg->tab_membership[2] = 1;
- p_jpeg->tab_membership[3] = 1;
- p_jpeg->subsample_x[0] = 1;
- p_jpeg->subsample_x[1] = 1;
- p_jpeg->subsample_x[2] = 1;
- p_jpeg->subsample_y[0] = 1;
- p_jpeg->subsample_y[1] = 2;
- p_jpeg->subsample_y[2] = 2;
- }
- else if (p_jpeg->frameheader[0].horizontal_sampling == 2
- && p_jpeg->frameheader[0].vertical_sampling == 2)
- { /* 4:2:0 */
- p_jpeg->blocks = 6;
- p_jpeg->x_mbl = (p_jpeg->x_size+15) / 16;
- p_jpeg->x_phys = p_jpeg->x_mbl * 16;
- p_jpeg->y_mbl = (p_jpeg->y_size+15) / 16;
- p_jpeg->y_phys = p_jpeg->y_mbl * 16;
- p_jpeg->mcu_membership[0] = 0;
- p_jpeg->mcu_membership[1] = 0;
- p_jpeg->mcu_membership[2] = 0;
- p_jpeg->mcu_membership[3] = 0;
- p_jpeg->mcu_membership[4] = 1;
- p_jpeg->mcu_membership[5] = 2;
- p_jpeg->tab_membership[0] = 0;
- p_jpeg->tab_membership[1] = 0;
- p_jpeg->tab_membership[2] = 0;
- p_jpeg->tab_membership[3] = 0;
- p_jpeg->tab_membership[4] = 1;
- p_jpeg->tab_membership[5] = 1;
- p_jpeg->subsample_x[0] = 1;
- p_jpeg->subsample_x[1] = 2;
- p_jpeg->subsample_x[2] = 2;
- p_jpeg->subsample_y[0] = 1;
- p_jpeg->subsample_y[1] = 2;
- p_jpeg->subsample_y[2] = 2;
- }
- else if (p_jpeg->frameheader[0].horizontal_sampling == 1
- && p_jpeg->frameheader[0].vertical_sampling == 1)
- { /* 4:4:4 */
- /* don't overwrite p_jpeg->blocks */
- p_jpeg->x_mbl = (p_jpeg->x_size+7) / 8;
- p_jpeg->x_phys = p_jpeg->x_mbl * 8;
- p_jpeg->y_mbl = (p_jpeg->y_size+7) / 8;
- p_jpeg->y_phys = p_jpeg->y_mbl * 8;
- p_jpeg->mcu_membership[0] = 0;
- p_jpeg->mcu_membership[1] = 1;
- p_jpeg->mcu_membership[2] = 2;
- p_jpeg->tab_membership[0] = 0;
- p_jpeg->tab_membership[1] = 1;
- p_jpeg->tab_membership[2] = 1;
- p_jpeg->subsample_x[0] = 1;
- p_jpeg->subsample_x[1] = 1;
- p_jpeg->subsample_x[2] = 1;
- p_jpeg->subsample_y[0] = 1;
- p_jpeg->subsample_y[1] = 1;
- p_jpeg->subsample_y[2] = 1;
- }
- else
- {
- /* error */
- }
-
-}
-
-
-/*
-* These functions/macros provide the in-line portion of bit fetching.
-* Use check_bit_buffer to ensure there are N bits in get_buffer
-* before using get_bits, peek_bits, or drop_bits.
-* check_bit_buffer(state,n,action);
-* Ensure there are N bits in get_buffer; if suspend, take action.
-* val = get_bits(n);
-* Fetch next N bits.
-* val = peek_bits(n);
-* Fetch next N bits without removing them from the buffer.
-* drop_bits(n);
-* Discard next N bits.
-* The value N should be a simple variable, not an expression, because it
-* is evaluated multiple times.
-*/
-
-INLINE void check_bit_buffer(struct bitstream* pb, int nbits)
-{
- if (pb->bits_left < nbits)
- { /* nbits is <= 16, so I can always refill 2 bytes in this case */
- unsigned char byte;
-
- byte = *pb->next_input_byte++;
- if (byte == 0xFF) /* legal marker can be byte stuffing or RSTm */
- { /* simplification: just skip the (one-byte) marker code */
- pb->next_input_byte++;
- }
- pb->get_buffer = (pb->get_buffer << 8) | byte;
-
- byte = *pb->next_input_byte++;
- if (byte == 0xFF) /* legal marker can be byte stuffing or RSTm */
- { /* simplification: just skip the (one-byte) marker code */
- pb->next_input_byte++;
- }
- pb->get_buffer = (pb->get_buffer << 8) | byte;
-
- pb->bits_left += 16;
- }
-}
-
-INLINE int get_bits(struct bitstream* pb, int nbits)
-{
- return ((int) (pb->get_buffer >> (pb->bits_left -= nbits))) & (BIT_N(nbits)-1);
-}
-
-INLINE int peek_bits(struct bitstream* pb, int nbits)
-{
- return ((int) (pb->get_buffer >> (pb->bits_left - nbits))) & (BIT_N(nbits)-1);
-}
-
-INLINE void drop_bits(struct bitstream* pb, int nbits)
-{
- pb->bits_left -= nbits;
-}
-
-/* re-synchronize to entropy data (skip restart marker) */
-void search_restart(struct bitstream* pb)
-{
- pb->next_input_byte--; /* we may have overread it, taking 2 bytes */
- /* search for a non-byte-padding marker, has to be RSTm or EOS */
- while (pb->next_input_byte < pb->input_end &&
- (pb->next_input_byte[-2] != 0xFF || pb->next_input_byte[-1] == 0x00))
- {
- pb->next_input_byte++;
- }
- pb->bits_left = 0;
-}
-
-/* Figure F.12: extend sign bit. */
-#define HUFF_EXTEND(x,s) ((x) < extend_test[s] ? (x) + extend_offset[s] : (x))
-
-static const int extend_test[16] = /* entry n is 2**(n-1) */
-{
- 0, 0x0001, 0x0002, 0x0004, 0x0008, 0x0010, 0x0020, 0x0040, 0x0080,
- 0x0100, 0x0200, 0x0400, 0x0800, 0x1000, 0x2000, 0x4000
-};
-
-static const int extend_offset[16] = /* entry n is (-1 << n) + 1 */
-{
- 0, ((-1)<<1) + 1, ((-1)<<2) + 1, ((-1)<<3) + 1, ((-1)<<4) + 1,
- ((-1)<<5) + 1, ((-1)<<6) + 1, ((-1)<<7) + 1, ((-1)<<8) + 1,
- ((-1)<<9) + 1, ((-1)<<10) + 1, ((-1)<<11) + 1, ((-1)<<12) + 1,
- ((-1)<<13) + 1, ((-1)<<14) + 1, ((-1)<<15) + 1
-};
-
-/* Decode a single value */
-INLINE int huff_decode_dc(struct bitstream* bs, struct derived_tbl* tbl)
-{
- int nb, look, s, r;
-
- check_bit_buffer(bs, HUFF_LOOKAHEAD);
- look = peek_bits(bs, HUFF_LOOKAHEAD);
- if ((nb = tbl->look_nbits[look]) != 0)
- {
- drop_bits(bs, nb);
- s = tbl->look_sym[look];
- check_bit_buffer(bs, s);
- r = get_bits(bs, s);
- s = HUFF_EXTEND(r, s);
- }
- else
- { /* slow_DECODE(s, HUFF_LOOKAHEAD+1)) < 0); */
- long code;
- nb=HUFF_LOOKAHEAD+1;
- check_bit_buffer(bs, nb);
- code = get_bits(bs, nb);
- while (code > tbl->maxcode[nb])
- {
- code <<= 1;
- check_bit_buffer(bs, 1);
- code |= get_bits(bs, 1);
- nb++;
- }
- if (nb > 16) /* error in Huffman */
- {
- s=0; /* fake a zero, this is most safe */
- }
- else
- {
- s = tbl->pub[16 + tbl->valptr[nb] + ((int) (code - tbl->mincode[nb])) ];
- check_bit_buffer(bs, s);
- r = get_bits(bs, s);
- s = HUFF_EXTEND(r, s);
- }
- } /* end slow decode */
- return s;
-}
-
-INLINE int huff_decode_ac(struct bitstream* bs, struct derived_tbl* tbl)
-{
- int nb, look, s;
-
- check_bit_buffer(bs, HUFF_LOOKAHEAD);
- look = peek_bits(bs, HUFF_LOOKAHEAD);
- if ((nb = tbl->look_nbits[look]) != 0)
- {
- drop_bits(bs, nb);
- s = tbl->look_sym[look];
- }
- else
- { /* slow_DECODE(s, HUFF_LOOKAHEAD+1)) < 0); */
- long code;
- nb=HUFF_LOOKAHEAD+1;
- check_bit_buffer(bs, nb);
- code = get_bits(bs, nb);
- while (code > tbl->maxcode[nb])
- {
- code <<= 1;
- check_bit_buffer(bs, 1);
- code |= get_bits(bs, 1);
- nb++;
- }
- if (nb > 16) /* error in Huffman */
- {
- s=0; /* fake a zero, this is most safe */
- }
- else
- {
- s = tbl->pub[16 + tbl->valptr[nb] + ((int) (code - tbl->mincode[nb])) ];
- }
- } /* end slow decode */
- return s;
-}
-
-
-#ifdef HAVE_LCD_COLOR
-
-/* JPEG decoder variant for YUV decoding, into 3 different planes */
-/* Note: it keeps the original color subsampling, even if resized. */
-int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel[3],
- int downscale, void (*pf_progress)(int current, int total))
-{
- struct bitstream bs; /* bitstream "object" */
- int block[64]; /* decoded DCT coefficients */
-
- int width, height;
- int skip_line[3]; /* bytes from one line to the next (skip_line) */
- int skip_strip[3], skip_mcu[3]; /* bytes to next DCT row / column */
-
- int i, x, y; /* loop counter */
-
- unsigned char* p_line[3] = {p_pixel[0], p_pixel[1], p_pixel[2]};
- unsigned char* p_byte[3]; /* bitmap pointer */
-
- void (*pf_idct)(unsigned char*, int*, int*, int); /* selected IDCT */
- int k_need; /* AC coefficients needed up to here */
- int zero_need; /* init the block with this many zeros */
-
- int last_dc_val[3] = {0, 0, 0}; /* or 128 for chroma? */
- int store_offs[4]; /* memory offsets: order of Y11 Y12 Y21 Y22 U V */
- int restart = p_jpeg->restart_interval; /* MCUs until restart marker */
-
- /* pick the IDCT we want, determine how to work with coefs */
- if (downscale == 1)
- {
- pf_idct = idct8x8;
- k_need = 64; /* all */
- zero_need = 63; /* all */
- }
- else if (downscale == 2)
- {
- pf_idct = idct4x4;
- k_need = 25; /* this far in zig-zag to cover 4*4 */
- zero_need = 27; /* clear this far in linear order */
- }
- else if (downscale == 4)
- {
- pf_idct = idct2x2;
- k_need = 5; /* this far in zig-zag to cover 2*2 */
- zero_need = 9; /* clear this far in linear order */
- }
- else if (downscale == 8)
- {
- pf_idct = idct1x1;
- k_need = 0; /* no AC, not needed */
- zero_need = 0; /* no AC, not needed */
- }
- else return -1; /* not supported */
-
- /* init bitstream, fake a restart to make it start */
- bs.next_input_byte = p_jpeg->p_entropy_data;
- bs.bits_left = 0;
- bs.input_end = p_jpeg->p_entropy_end;
-
- width = p_jpeg->x_phys / downscale;
- height = p_jpeg->y_phys / downscale;
- for (i=0; i<3; i++) /* calculate some strides */
- {
- skip_line[i] = width / p_jpeg->subsample_x[i];
- skip_strip[i] = skip_line[i]
- * (height / p_jpeg->y_mbl) / p_jpeg->subsample_y[i];
- skip_mcu[i] = width/p_jpeg->x_mbl / p_jpeg->subsample_x[i];
- }
-
- /* prepare offsets about where to store the different blocks */
- store_offs[p_jpeg->store_pos[0]] = 0;
- store_offs[p_jpeg->store_pos[1]] = 8 / downscale; /* to the right */
- store_offs[p_jpeg->store_pos[2]] = width * 8 / downscale; /* below */
- store_offs[p_jpeg->store_pos[3]] = store_offs[1] + store_offs[2]; /* r+b */
-
- for(y=0; y<p_jpeg->y_mbl && bs.next_input_byte <= bs.input_end; y++)
- {
- for (i=0; i<3; i++) /* scan line init */
- {
- p_byte[i] = p_line[i];
- p_line[i] += skip_strip[i];
- }
- for (x=0; x<p_jpeg->x_mbl; x++)
- {
- int blkn;
-
- /* Outer loop handles each block in the MCU */
- for (blkn = 0; blkn < p_jpeg->blocks; blkn++)
- { /* Decode a single block's worth of coefficients */
- int k = 1; /* coefficient index */
- int s, r; /* huffman values */
- int ci = p_jpeg->mcu_membership[blkn]; /* component index */
- int ti = p_jpeg->tab_membership[blkn]; /* table index */
- struct derived_tbl* dctbl = &p_jpeg->dc_derived_tbls[ti];
- struct derived_tbl* actbl = &p_jpeg->ac_derived_tbls[ti];
-
- /* Section F.2.2.1: decode the DC coefficient difference */
- s = huff_decode_dc(&bs, dctbl);
-
- last_dc_val[ci] += s;
- block[0] = last_dc_val[ci]; /* output it (assumes zag[0] = 0) */
-
- /* coefficient buffer must be cleared */
- MEMSET(block+1, 0, zero_need*sizeof(block[0]));
-
- /* Section F.2.2.2: decode the AC coefficients */
- for (; k < k_need; k++)
- {
- s = huff_decode_ac(&bs, actbl);
- r = s >> 4;
- s &= 15;
-
- if (s)
- {
- k += r;
- check_bit_buffer(&bs, s);
- r = get_bits(&bs, s);
- block[zag[k]] = HUFF_EXTEND(r, s);
- }
- else
- {
- if (r != 15)
- {
- k = 64;
- break;
- }
- k += r;
- }
- } /* for k */
- /* In this path we just discard the values */
- for (; k < 64; k++)
- {
- s = huff_decode_ac(&bs, actbl);
- r = s >> 4;
- s &= 15;
-
- if (s)
- {
- k += r;
- check_bit_buffer(&bs, s);
- drop_bits(&bs, s);
- }
- else
- {
- if (r != 15)
- break;
- k += r;
- }
- } /* for k */
-
- if (ci == 0)
- { /* Y component needs to bother about block store */
- pf_idct(p_byte[0]+store_offs[blkn], block,
- p_jpeg->qt_idct[ti], skip_line[0]);
- }
- else
- { /* chroma */
- pf_idct(p_byte[ci], block, p_jpeg->qt_idct[ti],
- skip_line[ci]);
- }
- } /* for blkn */
- p_byte[0] += skip_mcu[0]; /* unrolled for (i=0; i<3; i++) loop */
- p_byte[1] += skip_mcu[1];
- p_byte[2] += skip_mcu[2];
- if (p_jpeg->restart_interval && --restart == 0)
- { /* if a restart marker is due: */
- restart = p_jpeg->restart_interval; /* count again */
- search_restart(&bs); /* align the bitstream */
- last_dc_val[0] = last_dc_val[1] =
- last_dc_val[2] = 0; /* reset decoder */
- }
- } /* for x */
- if (pf_progress != NULL)
- pf_progress(y, p_jpeg->y_mbl-1); /* notify about decoding progress */
- } /* for y */
-
- return 0; /* success */
-}
-#else /* !HAVE_LCD_COLOR */
-
-/* a JPEG decoder specialized in decoding only the luminance (b&w) */
-int jpeg_decode(struct jpeg* p_jpeg, unsigned char* p_pixel[1], int downscale,
- void (*pf_progress)(int current, int total))
-{
- struct bitstream bs; /* bitstream "object" */
- int block[64]; /* decoded DCT coefficients */
-
- int width, height;
- int skip_line; /* bytes from one line to the next (skip_line) */
- int skip_strip, skip_mcu; /* bytes to next DCT row / column */
-
- int x, y; /* loop counter */
-
- unsigned char* p_line = p_pixel[0];
- unsigned char* p_byte; /* bitmap pointer */
-
- void (*pf_idct)(unsigned char*, int*, int*, int); /* selected IDCT */
- int k_need; /* AC coefficients needed up to here */
- int zero_need; /* init the block with this many zeros */
-
- int last_dc_val = 0;
- int store_offs[4]; /* memory offsets: order of Y11 Y12 Y21 Y22 U V */
- int restart = p_jpeg->restart_interval; /* MCUs until restart marker */
-
- /* pick the IDCT we want, determine how to work with coefs */
- if (downscale == 1)
- {
- pf_idct = idct8x8;
- k_need = 64; /* all */
- zero_need = 63; /* all */
- }
- else if (downscale == 2)
- {
- pf_idct = idct4x4;
- k_need = 25; /* this far in zig-zag to cover 4*4 */
- zero_need = 27; /* clear this far in linear order */
- }
- else if (downscale == 4)
- {
- pf_idct = idct2x2;
- k_need = 5; /* this far in zig-zag to cover 2*2 */
- zero_need = 9; /* clear this far in linear order */
- }
- else if (downscale == 8)
- {
- pf_idct = idct1x1;
- k_need = 0; /* no AC, not needed */
- zero_need = 0; /* no AC, not needed */
- }
- else return -1; /* not supported */
-
- /* init bitstream, fake a restart to make it start */
- bs.next_input_byte = p_jpeg->p_entropy_data;
- bs.bits_left = 0;
- bs.input_end = p_jpeg->p_entropy_end;
-
- width = p_jpeg->x_phys / downscale;
- height = p_jpeg->y_phys / downscale;
- skip_line = width;
- skip_strip = skip_line * (height / p_jpeg->y_mbl);
- skip_mcu = (width/p_jpeg->x_mbl);
-
- /* prepare offsets about where to store the different blocks */
- store_offs[p_jpeg->store_pos[0]] = 0;
- store_offs[p_jpeg->store_pos[1]] = 8 / downscale; /* to the right */
- store_offs[p_jpeg->store_pos[2]] = width * 8 / downscale; /* below */
- store_offs[p_jpeg->store_pos[3]] = store_offs[1] + store_offs[2]; /* r+b */
-
- for(y=0; y<p_jpeg->y_mbl && bs.next_input_byte <= bs.input_end; y++)
- {
- p_byte = p_line;
- p_line += skip_strip;
- for (x=0; x<p_jpeg->x_mbl; x++)
- {
- int blkn;
-
- /* Outer loop handles each block in the MCU */
- for (blkn = 0; blkn < p_jpeg->blocks; blkn++)
- { /* Decode a single block's worth of coefficients */
- int k = 1; /* coefficient index */
- int s, r; /* huffman values */
- int ci = p_jpeg->mcu_membership[blkn]; /* component index */
- int ti = p_jpeg->tab_membership[blkn]; /* table index */
- struct derived_tbl* dctbl = &p_jpeg->dc_derived_tbls[ti];
- struct derived_tbl* actbl = &p_jpeg->ac_derived_tbls[ti];
-
- /* Section F.2.2.1: decode the DC coefficient difference */
- s = huff_decode_dc(&bs, dctbl);
-
- if (ci == 0) /* only for Y component */
- {
- last_dc_val += s;
- block[0] = last_dc_val; /* output it (assumes zag[0] = 0) */
-
- /* coefficient buffer must be cleared */
- MEMSET(block+1, 0, zero_need*sizeof(block[0]));
-
- /* Section F.2.2.2: decode the AC coefficients */
- for (; k < k_need; k++)
- {
- s = huff_decode_ac(&bs, actbl);
- r = s >> 4;
- s &= 15;
-
- if (s)
- {
- k += r;
- check_bit_buffer(&bs, s);
- r = get_bits(&bs, s);
- block[zag[k]] = HUFF_EXTEND(r, s);
- }
- else
- {
- if (r != 15)
- {
- k = 64;
- break;
- }
- k += r;
- }
- } /* for k */
- }
- /* In this path we just discard the values */
- for (; k < 64; k++)
- {
- s = huff_decode_ac(&bs, actbl);
- r = s >> 4;
- s &= 15;
-
- if (s)
- {
- k += r;
- check_bit_buffer(&bs, s);
- drop_bits(&bs, s);
- }
- else
- {
- if (r != 15)
- break;
- k += r;
- }
- } /* for k */
-
- if (ci == 0)
- { /* only for Y component */
- pf_idct(p_byte+store_offs[blkn], block, p_jpeg->qt_idct[ti],
- skip_line);
- }
- } /* for blkn */
- p_byte += skip_mcu;
- if (p_jpeg->restart_interval && --restart == 0)
- { /* if a restart marker is due: */
- restart = p_jpeg->restart_interval; /* count again */
- search_restart(&bs); /* align the bitstream */
- last_dc_val = 0; /* reset decoder */
- }
- } /* for x */
- if (pf_progress != NULL)
- pf_progress(y, p_jpeg->y_mbl-1); /* notify about decoding progress */
- } /* for y */
-
- return 0; /* success */
-}
-#endif /* !HAVE_LCD_COLOR */
-
-/**************** end JPEG code ********************/
generated by cgit v1.1 at 2026-04-25 16:04:08 +0000