Norimasa Okamoto
huffmancode to decode in real-time for motion-jpeg
Dependents: BaseJpegDecode_example SimpleJpegDecode_example Dumb_box_rev2
example code:
Import programBaseJpegDecode_example
BaseJpegDeocde exampe program
Last commit 27 Jan 2013 by 
Norimasa Okamoto
Import programSimpleJpegDecode_example
convert JPEG stream data to bitmap, BaseJpegDecode example program
Last commit 02 Feb 2013 by Norimasa Okamoto
Revision 2:5b1dd4e34857, committed 2012-10-30
- Comitter:
- va009039
- Date:
- Tue Oct 30 13:22:08 2012 +0000
- Parent:
- 1:bfbc18000cca
- Child:
- 3:a7547692071d
- Commit message:
- add inverseDCT
Changed in this revision
--- a/BaseJpegDecode.cpp Thu Oct 25 11:00:05 2012 +0000
+++ b/BaseJpegDecode.cpp Tue Oct 30 13:22:08 2012 +0000
@@ -71,8 +71,9 @@
{
m_block = 0;
m_scan = 0;
- m_old_DC_value[0] = 0;
- m_old_DC_value[1] = 0;
+ m_pre_DC_value[0] = 0;
+ m_pre_DC_value[1] = 0;
+ m_pre_DC_value[2] = 0;
m_bitpat.clear();
m_huff = NULL;
}
@@ -95,10 +96,10 @@
m_param1 = c<<8;
break;
case 2:
- width = m_param1 | c;
+ height = m_param1 | c;
break;
case 4:
- height = m_param1 | c;
+ width = m_param1 | c;
break;
case 7:
if (c == 0x22) {
@@ -202,18 +203,25 @@
DBG("%d %d %d %02x\n", m_huff->run, m_huff->value_size, m_huff->code_size, m_huff->code);
int value = pHD->getValue(m_huff, &m_bitpat);
if (tc == HT_DC) {
- value += m_old_DC_value[th];
+ int sc = 0; // Y
+ if (m_block == m_yblocks) {
+ sc = 1; // Cb
+ } else if (m_block == (m_yblocks+1)) {
+ sc = 2; // Cr
+ }
+ value += m_pre_DC_value[sc];
outputDC(m_mcu, m_block, value);
- m_old_DC_value[th] = value;
+ m_pre_DC_value[sc] = value;
m_scan++;
REPORT_CODE(report_scan_dc_count++);
} else { // AC
if (m_huff->value_size == 0 && m_huff->run == 0) { // EOB
DBG("AC EOB\n");
+ outputAC(m_mcu, m_block, 63, 0);
m_scan = 64;
} else {
for(int i = 0; i < m_huff->run; i++) {
- outputAC(m_mcu, m_block, m_scan, 0);
+ //outputAC(m_mcu, m_block, m_scan, 0);
m_scan++;
}
outputAC(m_mcu, m_block, m_scan, value);
--- a/BaseJpegDecode.h Thu Oct 25 11:00:05 2012 +0000
+++ b/BaseJpegDecode.h Tue Oct 30 13:22:08 2012 +0000
@@ -33,7 +33,7 @@
int m_block;
int m_scan;
Huff* m_huff;
- int m_old_DC_value[2];
+ int m_pre_DC_value[3];
BitPattern m_bitpat;
uint8_t m_mark;
HuffmanDecode* pHD;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/inverseDCT.cpp Tue Oct 30 13:22:08 2012 +0000
@@ -0,0 +1,130 @@
+#include "mbed.h"
+#include <math.h>
+#include "inverseDCT.h"
+
+#define PI 3.14159265
+
+const int zigzag[64] =
+ {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};
+
+int adjust(int value) {
+ value += 128;
+ if (value < 0) {
+ return 0;
+ } else if (value > 255) {
+ return 255;
+ }
+ return value;
+}
+
+#if DCT_USE_INT
+inverseDCT::inverseDCT()
+{
+ for(int x = 0; x < 8; x++) {
+ for(int u = 0; u < 8; u++) {
+ float value = cos((x*2+1)*u*PI/16);
+ m_cosxu[x*8+u] = value * 32;
+ }
+ }
+
+ for(int v = 0; v < 8; v++) {
+ for(int u = 0; u < 8; u++) {
+ float value = 1.0 / 4.0;
+ if (v == 0 && u == 0) {
+ value /= 2.0;
+ } else if (v == 0 || u == 0) {
+ value /= sqrt(2.0);
+ }
+ m_cucv[v*8+u] = value * 32;
+ }
+ }
+}
+
+void inverseDCT::inputBLOCK(int mcu, int block, int scan, int value)
+{
+ if (scan == 0) {
+ for(int i = 0; i < 64; i++) {
+ m_sum[i] = 0;
+ }
+ }
+
+ if (value != 0) {
+ int uv = zigzag[scan];
+ int u = uv % 8;
+ int v = uv / 8;
+ for(int y = 0; y < 8; y++) {
+ for(int x = 0; x < 8; x++) {
+ int t = m_cucv[uv] * value * m_cosxu[x*8+u] * m_cosxu[y*8+v] / 32 / 32;
+ m_sum[y*8+x] += t;
+ }
+ }
+ }
+
+ if (scan == 63) {
+ uint8_t result[64];
+ for(int i = 0; i < 64; i++) {
+ int value = m_sum[i] / 32;
+ result[i] = adjust(value);
+ }
+ outputBLOCK(mcu, block, result);
+ }
+}
+
+#else
+
+inverseDCT::inverseDCT()
+{
+}
+
+void inverseDCT::input(int mcu, int block, int scan, int value) {
+ if (scan == 0) {
+ for(int i = 0; i < 64; i++) {
+ m_s[i] = 0;
+ }
+ }
+ m_s[zigzag[scan]] = value;
+ if (scan == 63) {
+ calc(mcu, block, m_s);
+ }
+}
+
+void inverseDCT::calc(int mcu, int block, int s[]) {
+ for(int y = 0; y < 8; y++) {
+ for(int x = 0; x < 8; x++) {
+ float sum = 0.0;
+ for(int v = 0; v < 8; v++) {
+ float cv = 1.0;
+ if (v == 0) {
+ cv /= sqrt(2.0);
+ }
+ for(int u = 0; u < 8; u++) {
+ float cu = 1.0;
+ if (u == 0) {
+ cu /= sqrt(2.0);
+ }
+ int vu = v * 8 + u;
+ float cosxu = cos((x*2+1) * u * PI / 16);
+ float cosyv = cos((y*2+1) * v * PI / 16);
+ sum += cu * cv * s[vu] * cosxu * cosyv;
+ }
+ }
+ sum /= 4;
+ m_result[y*8+x] = adjust(sum);
+ }
+ }
+}
+#endif
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/inverseDCT.h Tue Oct 30 13:22:08 2012 +0000
@@ -0,0 +1,35 @@
+#ifndef INVERSE_DCT_H
+#define INVERSE_DCT_H
+
+#define DCT_USE_INT 1
+
+#ifdef DCT_USE_INT
+
+class inverseDCT {
+public:
+ inverseDCT();
+ void inputBLOCK(int mcu, int block, int scan, int value);
+ virtual void outputBLOCK(int mcu, int block, unsigned char* values) = 0;
+private:
+ int16_t m_sum[64];
+ int8_t m_cosxu[64];
+ int8_t m_cucv[64];
+};
+
+#else
+
+class inverseDCT {
+public:
+ inverseDCT();
+ void input(int mcu, int block, int scan, int value);
+ int m_result[64];
+private:
+ int m_sum[64];
+ void calc(int mcu, int block, int s[]);
+ int m_s[64];
+ void outputDot(int mcu, int block, int x, int y, int value);
+};
+
+#endif
+
+#endif // INVERSE_DCT_H
\ No newline at end of file