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author | toma <toma@283d02a7-25f6-0310-bc7c-ecb5cbfe19da> | 2009-11-25 17:56:58 +0000 |
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committer | toma <toma@283d02a7-25f6-0310-bc7c-ecb5cbfe19da> | 2009-11-25 17:56:58 +0000 |
commit | bcb704366cb5e333a626c18c308c7e0448a8e69f (patch) | |
tree | f0d6ab7d78ecdd9207cf46536376b44b91a1ca71 /kopete/libkopete/avdevice/sonix_compress.cpp | |
download | tdenetwork-bcb704366cb5e333a626c18c308c7e0448a8e69f.tar.gz tdenetwork-bcb704366cb5e333a626c18c308c7e0448a8e69f.zip |
Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.
BUG:215923
git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdenetwork@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da
Diffstat (limited to 'kopete/libkopete/avdevice/sonix_compress.cpp')
-rw-r--r-- | kopete/libkopete/avdevice/sonix_compress.cpp | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/kopete/libkopete/avdevice/sonix_compress.cpp b/kopete/libkopete/avdevice/sonix_compress.cpp new file mode 100644 index 00000000..400635c4 --- /dev/null +++ b/kopete/libkopete/avdevice/sonix_compress.cpp @@ -0,0 +1,180 @@ +#include "sonix_compress.h" + +#define CLAMP(x) ((x)<0?0:((x)>255)?255:(x)) + +typedef struct { + int is_abs; + int len; + int val; + int unk; +} code_table_t; + + +/* local storage */ +static code_table_t table[256]; +static int init_done = 0; + +/* global variable */ +int sonix_unknown = 0; + +/* + sonix_decompress_init + ===================== + pre-calculates a locally stored table for efficient huffman-decoding. + + Each entry at index x in the table represents the codeword + present at the MSB of byte x. + +*/ +void sonix_decompress_init(void) +{ + int i; + int is_abs, val, len, unk; + + for (i = 0; i < 256; i++) { + is_abs = 0; + val = 0; + len = 0; + unk = 0; + if ((i & 0x80) == 0) { + /* code 0 */ + val = 0; + len = 1; + } + else if ((i & 0xE0) == 0x80) { + /* code 100 */ + val = +4; + len = 3; + } + else if ((i & 0xE0) == 0xA0) { + /* code 101 */ + val = -4; + len = 3; + } + else if ((i & 0xF0) == 0xD0) { + /* code 1101 */ + val = +11; + len = 4; + } + else if ((i & 0xF0) == 0xF0) { + /* code 1111 */ + val = -11; + len = 4; + } + else if ((i & 0xF8) == 0xC8) { + /* code 11001 */ + val = +20; + len = 5; + } + else if ((i & 0xFC) == 0xC0) { + /* code 110000 */ + val = -20; + len = 6; + } + else if ((i & 0xFC) == 0xC4) { + /* code 110001xx: unknown */ + val = 0; + len = 8; + unk = 1; + } + else if ((i & 0xF0) == 0xE0) { + /* code 1110xxxx */ + is_abs = 1; + val = (i & 0x0F) << 4; + len = 8; + } + table[i].is_abs = is_abs; + table[i].val = val; + table[i].len = len; + table[i].unk = unk; + } + + sonix_unknown = 0; + init_done = 1; +} + + +/* + sonix_decompress + ================ + decompresses an image encoded by a SN9C101 camera controller chip. + + IN width + height + inp pointer to compressed frame (with header already stripped) + OUT outp pointer to decompressed frame + + Returns 0 if the operation was successful. + Returns <0 if operation failed. + +*/ +int sonix_decompress(int width, int height, unsigned char *inp, unsigned char *outp) +{ + int row, col; + int val; + int bitpos; + unsigned char code; + unsigned char *addr; + + if (!init_done) { + /* do sonix_decompress_init first! */ + return -1; + } + + bitpos = 0; + for (row = 0; row < height; row++) { + + col = 0; + + /* first two pixels in first two rows are stored as raw 8-bit */ + if (row < 2) { + addr = inp + (bitpos >> 3); + code = (addr[0] << (bitpos & 7)) | (addr[1] >> (8 - (bitpos & 7))); + bitpos += 8; + *outp++ = code; + + addr = inp + (bitpos >> 3); + code = (addr[0] << (bitpos & 7)) | (addr[1] >> (8 - (bitpos & 7))); + bitpos += 8; + *outp++ = code; + + col += 2; + } + + while (col < width) { + /* get bitcode from bitstream */ + addr = inp + (bitpos >> 3); + code = (addr[0] << (bitpos & 7)) | (addr[1] >> (8 - (bitpos & 7))); + + /* update bit position */ + bitpos += table[code].len; + + /* update code statistics */ + sonix_unknown += table[code].unk; + + /* calculate pixel value */ + val = table[code].val; + if (!table[code].is_abs) { + /* value is relative to top and left pixel */ + if (col < 2) { + /* left column: relative to top pixel */ + val += outp[-2*width]; + } + else if (row < 2) { + /* top row: relative to left pixel */ + val += outp[-2]; + } + else { + /* main area: average of left pixel and top pixel */ + val += (outp[-2] + outp[-2*width]) / 2; + } + } + + /* store pixel */ + *outp++ = CLAMP(val); + col++; + } + } + + return 0; +} |