X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=driver.c;h=6a7a8ec82d01996cdd83ea511575e6a65a76afc4;hb=9d2d4ff08d760e0abd83d2cea03c77d5b752a400;hp=08b684a0715162f058a12fe920c7e9c4fb90fd62;hpb=823f82d1e860f1260c483ef544c4e9532132c7e8;p=fjl diff --git a/driver.c b/driver.c index 08b684a..6a7a8ec 100644 --- a/driver.c +++ b/driver.c @@ -1,16 +1,21 @@ #include +#include #include #include "bytesource.h" #include "choice.h" #include "dehuff.h" +#include "idct.h" #include "input.h" +#include "zigzag.h" struct jpeg_image { unsigned precision; unsigned width, height; unsigned num_components; unsigned hsample[256], vsample[256], qtable[256]; + uint32_t qvalues[256][DCTSIZE2]; + void* idct_data[256]; }; ssize_t stdio_read(void* userdata, uint8_t* buf, size_t count) @@ -18,14 +23,47 @@ ssize_t stdio_read(void* userdata, uint8_t* buf, size_t count) return fread(buf, 1, count, (FILE*)userdata); } +void read_dqt(struct byte_source* source, struct jpeg_image* image) +{ + unsigned len = read_uint16(byte_source_input_func, source); + assert(len >= 67); + uint8_t precision_table = read_uint8(byte_source_input_func, source); + int precision = precision_table >> 4; // 0 = 8 bits, otherwise 16 bits. + int table = precision_table & 0x0f; + + if (image->idct_data[table] != NULL) { + idct_choice_free(image->idct_data[table]); + } + + if (precision != 0) { + assert(len == 131); + fprintf(stderr, "Quantization table %u: 16 bits/entry\n", table); + } else { + assert(len == 67); + fprintf(stderr, "Quantization table %u: 8 bits/entry\n", table); + } + + for (unsigned i = 0; i < 64; ++i) { + if (precision != 0) { + image->qvalues[table][unzigzag[i]] = + read_uint16(byte_source_input_func, source); + } else { + image->qvalues[table][unzigzag[i]] = + read_uint8(byte_source_input_func, source); + } + } + + image->idct_data[table] = idct_choice_alloc(image->qvalues[table]); +} + void read_sof(struct byte_source* source, struct jpeg_image* image) { unsigned len = read_uint16(byte_source_input_func, source); assert(len >= 8); image->precision = read_uint8(byte_source_input_func, source); assert(image->precision == 8); - image->width = read_uint16(byte_source_input_func, source); image->height = read_uint16(byte_source_input_func, source); + image->width = read_uint16(byte_source_input_func, source); image->num_components = read_uint8(byte_source_input_func, source); len -= 8; @@ -84,51 +122,77 @@ void read_scan(struct byte_source* source, struct jpeg_image* image, huffman_tab struct bit_source bits; init_bit_source(&bits, byte_source_input_func, source); + + // Some debugging code. + assert(image->width % 8 == 0); + int y_stride = image->width; + uint8_t* y_row_data = (uint8_t*)malloc(y_stride * DCTSIZE * image->vsample[1]); + assert(y_row_data != NULL); + int xb = 0; for ( ;; ) { for (unsigned c = 0; c < num_components; ++c) { unsigned cn = component_num[c]; - unsigned nc = image->vsample[cn] * image->hsample[cn]; - for (unsigned n = 0; n < nc; ++n) { - const struct huffman_table* dc_table = &((*tables)[DC_CLASS][dc_huffman_table[c]]); - const struct huffman_table* ac_table = &((*tables)[AC_CLASS][ac_huffman_table[c]]); - - // decode DC component - unsigned dc_category = read_huffman_symbol(dc_table, &bits); - possibly_refill(&bits, dc_category); - last_dc[c] += extend(read_bits(&bits, dc_category), dc_category); - - // printf("dc=%d ac=", last_dc[c]); - putchar(last_dc[c]); - - // decode AC components - int zz[63] = { 0 }; - for (unsigned i = 0; i < 63; ++i) { - unsigned rs = read_huffman_symbol(ac_table, &bits); - unsigned r = rs >> 4; - unsigned s = rs & 0xf; - - if (rs == 0x00) { - /* end of block */ - break; + assert(image->idct_data[image->qtable[cn]] != NULL); + + for (unsigned local_yb = 0; local_yb < image->vsample[cn]; ++local_yb) { + for (unsigned local_xb = 0; local_xb < image->hsample[cn]; ++local_xb) { + const struct huffman_table* dc_table = &((*tables)[DC_CLASS][dc_huffman_table[c]]); + const struct huffman_table* ac_table = &((*tables)[AC_CLASS][ac_huffman_table[c]]); + + // decode DC component + unsigned dc_category = read_huffman_symbol(dc_table, &bits); + possibly_refill(&bits, dc_category); + last_dc[c] += extend(read_bits(&bits, dc_category), dc_category); + + int16_t coeff[DCTSIZE2] = { 0 }; + coeff[0] = last_dc[c]; + + // decode AC components + for (unsigned i = 1; i < DCTSIZE2; ++i) { + unsigned rs = read_huffman_symbol(ac_table, &bits); + unsigned r = rs >> 4; + unsigned s = rs & 0xf; + + if (rs == 0x00) { + /* end of block */ + break; + } + if (rs == 0xf0) { + /* 16 zero coefficients */ + i += 15; + continue; + } + + possibly_refill(&bits, s); + coeff[unzigzag[i]] = extend(read_bits(&bits, s), s); + + i += r; } - if (rs == 0xf0) { - /* 16 zero coefficients */ - i += 15; + + uint8_t pixdata[DCTSIZE2]; + idct_choice(coeff, image->idct_data[image->qtable[cn]], pixdata); + + if (cn != 1) { continue; } - possibly_refill(&bits, s); - - i += r; - zz[i] = extend(read_bits(&bits, s), s); - } - - for (unsigned i = 0; i < 63; ++i) { - putchar(zz[i]); - //printf("%d ", zz[i]); + for (int y = 0; y < DCTSIZE; ++y) { + memcpy(y_row_data + (local_yb * DCTSIZE + y) * y_stride + (xb + local_xb) * DCTSIZE, + pixdata + y * DCTSIZE, + DCTSIZE); + } } - //printf("\n"); + } + + if (cn != 1) { + continue; + } + + xb += image->hsample[cn]; + if (xb * DCTSIZE == y_stride) { + fwrite(y_row_data, y_stride * DCTSIZE * image->vsample[cn], 1, stdout); + xb = 0; } } } @@ -155,6 +219,7 @@ void skip_segment(struct byte_source* source) int main(void) { struct jpeg_image jpeg; + memset(&jpeg, 0, sizeof(jpeg)); init_choices(); struct byte_source source; @@ -192,9 +257,11 @@ int main(void) /* comment */ case 0xff: /* ignore */ + skip_segment(&source); + break; case 0xdb: /* DQT */ - skip_segment(&source); + read_dqt(&source, &jpeg); break; case 0xc0: /* SOF0 (baseline DCT, Huffman encoded) */