device-epd/lib/jpec/enc.cpp
Thomas Ballmann 22e8b6df19 #19
- switch to canvas for print screen functionality
- implement jpg encoder for print screen
2020-10-01 21:31:17 +02:00

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/**
* Copyright (c) 2012-2016 Moodstocks SAS
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "enc.h"
#include "huff.h"
#include "conf.h"
#include <Arduino.h>
#define JPEG_ENC_DEF_QUAL 93 /* default quality factor */
#define JPEC_ENC_HEAD_SIZ 330 /* header typical size in bytes */
#define JPEC_ENC_BLOCK_SIZ 30 /* 8x8 entropy coded block typical size in bytes */
/* Private function prototypes */
static void jpec_enc_init_dqt(jpec_enc_t *e);
static void jpec_enc_open(jpec_enc_t *e);
static void jpec_enc_close(jpec_enc_t *e);
static void jpec_enc_write_soi(jpec_enc_t *e);
static void jpec_enc_write_app0(jpec_enc_t *e);
static void jpec_enc_write_dqt(jpec_enc_t *e);
static void jpec_enc_write_sof0(jpec_enc_t *e);
static void jpec_enc_write_dht(jpec_enc_t *e);
static void jpec_enc_write_sos(jpec_enc_t *e);
static int jpec_enc_next_block(jpec_enc_t *e);
static void jpec_enc_block_dct(jpec_enc_t *e);
static void jpec_enc_block_quant(jpec_enc_t *e);
static void jpec_enc_block_zz(jpec_enc_t *e);
jpec_enc_t *jpec_enc_new(const uint8_t *img, uint16_t w, uint16_t h) {
// return jpec_enc_new2(img, w, h, JPEG_ENC_DEF_QUAL);
}
jpec_enc_t *jpec_enc_new2(const uint8_t *img, uint16_t w, uint16_t h, int q, jpec_enc_callback_t callback) {
//assert(img && w > 0 && !(w & 0x7) && h > 0 && !(h & 0x7));
jpec_enc_t *e = (jpec_enc_t *)malloc(sizeof(*e));
e->img = img;
e->w = w;
e->w8 = (((w-1)>>3)+1)<<3;
e->h = h;
e->qual = q;
e->bmax = (((w-1)>>3)+1) * (((h-1)>>3)+1);
e->bnum = -1;
e->bx = -1;
e->by = -1;
int bsiz = JPEC_ENC_HEAD_SIZ + e->bmax * JPEC_ENC_BLOCK_SIZ;
e->buf = jpec_buffer_new2(bsiz, callback);
e->hskel = (jpec_huff_skel_t*)malloc(sizeof(*e->hskel));
return e;
}
void jpec_enc_del(jpec_enc_t *e) {
assert(e);
if (e->buf) jpec_buffer_del(e->buf);
free(e->hskel);
free(e);
}
const uint8_t *jpec_enc_run(jpec_enc_t *e) {
assert(e);
jpec_enc_open(e);
while (jpec_enc_next_block(e)) {
jpec_enc_block_dct(e);
jpec_enc_block_quant(e);
jpec_enc_block_zz(e);
e->hskel->encode_block(e->hskel->opq, &e->block, e->buf);
}
jpec_enc_close(e);
return e->buf->stream;
}
/* Update the internal quantization matrix according to the asked quality */
static void jpec_enc_init_dqt(jpec_enc_t *e) {
assert(e);
float qualf = (float) e->qual;
float scale = (e->qual < 50) ? (50/qualf) : (2 - qualf/50);
for (int i = 0; i < 64; i++) {
int a = (int) ((float) jpec_qzr[i]*scale + 0.5);
a = (a < 1) ? 1 : ((a > 255) ? 255 : a);
e->dqt[i] = a;
}
}
static void jpec_enc_open(jpec_enc_t *e) {
assert(e);
jpec_huff_skel_init(e->hskel);
jpec_enc_init_dqt(e);
jpec_enc_write_soi(e);
jpec_enc_write_app0(e);
jpec_enc_write_dqt(e);
jpec_enc_write_sof0(e);
jpec_enc_write_dht(e);
jpec_enc_write_sos(e);
}
static void jpec_enc_close(jpec_enc_t *e) {
assert(e);
e->hskel->del(e->hskel->opq);
jpec_buffer_write_2bytes(e->buf, 0xFFD9); /* EOI marker */
}
static void jpec_enc_write_soi(jpec_enc_t *e) {
assert(e);
jpec_buffer_write_2bytes(e->buf, 0xFFD8); /* SOI marker */
}
static void jpec_enc_write_app0(jpec_enc_t *e) {
assert(e);
jpec_buffer_write_2bytes(e->buf, 0xFFE0); /* APP0 marker */
jpec_buffer_write_2bytes(e->buf, 0x0010); /* segment length */
jpec_buffer_write_byte(e->buf, 0x4A); /* 'J' */
jpec_buffer_write_byte(e->buf, 0x46); /* 'F' */
jpec_buffer_write_byte(e->buf, 0x49); /* 'I' */
jpec_buffer_write_byte(e->buf, 0x46); /* 'F' */
jpec_buffer_write_byte(e->buf, 0x00); /* '\0' */
jpec_buffer_write_2bytes(e->buf, 0x0101); /* v1.1 */
jpec_buffer_write_byte(e->buf, 0x00); /* no density unit */
jpec_buffer_write_2bytes(e->buf, 0x0001); /* X density = 1 */
jpec_buffer_write_2bytes(e->buf, 0x0001); /* Y density = 1 */
jpec_buffer_write_byte(e->buf, 0x00); /* thumbnail width = 0 */
jpec_buffer_write_byte(e->buf, 0x00); /* thumbnail height = 0 */
}
static void jpec_enc_write_dqt(jpec_enc_t *e) {
assert(e);
jpec_buffer_write_2bytes(e->buf, 0xFFDB); /* DQT marker */
jpec_buffer_write_2bytes(e->buf, 0x0043); /* segment length */
jpec_buffer_write_byte(e->buf, 0x00); /* table 0, 8-bit precision (0) */
for (int i = 0; i < 64; i++) {
jpec_buffer_write_byte(e->buf, e->dqt[jpec_zz[i]]);
}
}
static void jpec_enc_write_sof0(jpec_enc_t *e) {
assert(e);
jpec_buffer_write_2bytes(e->buf, 0xFFC0); /* SOF0 marker */
jpec_buffer_write_2bytes(e->buf, 0x000B); /* segment length */
jpec_buffer_write_byte(e->buf, 0x08); /* 8-bit precision */
jpec_buffer_write_2bytes(e->buf, e->h);
jpec_buffer_write_2bytes(e->buf, e->w);
jpec_buffer_write_byte(e->buf, 0x01); /* 1 component only (grayscale) */
jpec_buffer_write_byte(e->buf, 0x01); /* component ID = 1 */
jpec_buffer_write_byte(e->buf, 0x11); /* no subsampling */
jpec_buffer_write_byte(e->buf, 0x00); /* quantization table 0 */
}
static void jpec_enc_write_dht(jpec_enc_t *e) {
assert(e);
jpec_buffer_write_2bytes(e->buf, 0xFFC4); /* DHT marker */
jpec_buffer_write_2bytes(e->buf, 19 + jpec_dc_nb_vals); /* segment length */
jpec_buffer_write_byte(e->buf, 0x00); /* table 0 (DC), type 0 (0 = Y, 1 = UV) */
for (int i = 0; i < 16; i++) {
jpec_buffer_write_byte(e->buf, jpec_dc_nodes[i+1]);
}
for (int i = 0; i < jpec_dc_nb_vals; i++) {
jpec_buffer_write_byte(e->buf, jpec_dc_vals[i]);
}
jpec_buffer_write_2bytes(e->buf, 0xFFC4); /* DHT marker */
jpec_buffer_write_2bytes(e->buf, 19 + jpec_ac_nb_vals);
jpec_buffer_write_byte(e->buf, 0x10); /* table 1 (AC), type 0 (0 = Y, 1 = UV) */
for (int i = 0; i < 16; i++) {
jpec_buffer_write_byte(e->buf, jpec_ac_nodes[i+1]);
}
for (int i = 0; i < jpec_ac_nb_vals; i++) {
jpec_buffer_write_byte(e->buf, jpec_ac_vals[i]);
}
}
static void jpec_enc_write_sos(jpec_enc_t *e) {
assert(e);
jpec_buffer_write_2bytes(e->buf, 0xFFDA); /* SOS marker */
jpec_buffer_write_2bytes(e->buf, 8); /* segment length */
jpec_buffer_write_byte(e->buf, 0x01); /* nb. components */
jpec_buffer_write_byte(e->buf, 0x01); /* Y component ID */
jpec_buffer_write_byte(e->buf, 0x00); /* Y HT = 0 */
/* segment end */
jpec_buffer_write_byte(e->buf, 0x00);
jpec_buffer_write_byte(e->buf, 0x3F);
jpec_buffer_write_byte(e->buf, 0x00);
}
static int jpec_enc_next_block(jpec_enc_t *e) {
assert(e);
int rv = (++e->bnum >= e->bmax) ? 0 : 1;
if (rv) {
e->bx = (e->bnum << 3) % e->w8;
e->by = ( (e->bnum << 3) / e->w8 ) << 3;
}
return rv;
}
static uint8_t getPixel(jpec_enc_t *e, int16_t x, int16_t y) {
// uint8_t *ptr = &buffer[(x / 8) + y * ((WIDTH + 7) / 8)];
if ((x < 0) || (y < 0) || (x >= e->w) || (y >= e->h))
return 0;
uint8_t *ptr = (uint8_t *)&e->img[(x / 8) + y * ((e->w + 7) / 8)];
return ((*ptr) & (0x80 >> (x & 7))) != 0 ? 0xFF : 0;
}
static void jpec_enc_block_dct(jpec_enc_t *e) {
assert(e && e->bnum >= 0);
#define JPEC_BLOCK(col,row) getPixel(e, e->bx + col, e->by + row)
const float* coeff = jpec_dct;
float tmp[64];
for (int row = 0; row < 8; row++) {
/* NOTE: the shift by 256 allows resampling from [0 255] to [128 127] */
float s0 = (float) (JPEC_BLOCK(0, row) + JPEC_BLOCK(7, row) - 256);
float s1 = (float) (JPEC_BLOCK(1, row) + JPEC_BLOCK(6, row) - 256);
float s2 = (float) (JPEC_BLOCK(2, row) + JPEC_BLOCK(5, row) - 256);
float s3 = (float) (JPEC_BLOCK(3, row) + JPEC_BLOCK(4, row) - 256);
float d0 = (float) (JPEC_BLOCK(0, row) - JPEC_BLOCK(7, row));
float d1 = (float) (JPEC_BLOCK(1, row) - JPEC_BLOCK(6, row));
float d2 = (float) (JPEC_BLOCK(2, row) - JPEC_BLOCK(5, row));
float d3 = (float) (JPEC_BLOCK(3, row) - JPEC_BLOCK(4, row));
tmp[8 * row] = coeff[3]*(s0+s1+s2+s3);
tmp[8 * row + 1] = coeff[0]*d0+coeff[2]*d1+coeff[4]*d2+coeff[6]*d3;
tmp[8 * row + 2] = coeff[1]*(s0-s3)+coeff[5]*(s1-s2);
tmp[8 * row + 3] = coeff[2]*d0-coeff[6]*d1-coeff[0]*d2-coeff[4]*d3;
tmp[8 * row + 4] = coeff[3]*(s0-s1-s2+s3);
tmp[8 * row + 5] = coeff[4]*d0-coeff[0]*d1+coeff[6]*d2+coeff[2]*d3;
tmp[8 * row + 6] = coeff[5]*(s0-s3)+coeff[1]*(s2-s1);
tmp[8 * row + 7] = coeff[6]*d0-coeff[4]*d1+coeff[2]*d2-coeff[0]*d3;
}
for (int col = 0; col < 8; col++) {
float s0 = tmp[ col] + tmp[56 + col];
float s1 = tmp[ 8 + col] + tmp[48 + col];
float s2 = tmp[16 + col] + tmp[40 + col];
float s3 = tmp[24 + col] + tmp[32 + col];
float d0 = tmp[ col] - tmp[56 + col];
float d1 = tmp[ 8 + col] - tmp[48 + col];
float d2 = tmp[16 + col] - tmp[40 + col];
float d3 = tmp[24 + col] - tmp[32 + col];
e->block.dct[ col] = coeff[3]*(s0+s1+s2+s3);
e->block.dct[ 8 + col] = coeff[0]*d0+coeff[2]*d1+coeff[4]*d2+coeff[6]*d3;
e->block.dct[16 + col] = coeff[1]*(s0-s3)+coeff[5]*(s1-s2);
e->block.dct[24 + col] = coeff[2]*d0-coeff[6]*d1-coeff[0]*d2-coeff[4]*d3;
e->block.dct[32 + col] = coeff[3]*(s0-s1-s2+s3);
e->block.dct[40 + col] = coeff[4]*d0-coeff[0]*d1+coeff[6]*d2+coeff[2]*d3;
e->block.dct[48 + col] = coeff[5]*(s0-s3)+coeff[1]*(s2-s1);
e->block.dct[56 + col] = coeff[6]*d0-coeff[4]*d1+coeff[2]*d2-coeff[0]*d3;
}
#undef JPEC_BLOCK
}
static void jpec_enc_block_quant(jpec_enc_t *e) {
assert(e && e->bnum >= 0);
for (int i = 0; i < 64; i++) {
e->block.quant[i] = (int) (e->block.dct[i]/e->dqt[i]);
}
}
static void jpec_enc_block_zz(jpec_enc_t *e) {
assert(e && e->bnum >= 0);
e->block.len = 0;
for (int i = 0; i < 64; i++) {
if ((e->block.zz[i] = e->block.quant[jpec_zz[i]])) e->block.len = i + 1;
}
}