Macintosh-SW
/
fc8-compression
mirror of https://github.com/steve-chamberlin/fc8-compression.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Added block mode compression option

This commit is contained in:
steve-chamberlin 2016-05-09 16:18:00 -07:00
parent 54864236e9
commit 298e7dcb24
3 changed files with 182 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
compression.c
View File

@ -1,6 +1,25 @@
/*
* FC8 compression by Steve Chamberlin
* Derived from liblzg by Marcus Geelnard
* FC8 compression by Steve Chamberlin, 2016
* Some concepts and code derived from liblzg by Marcus Geelnard, 2010
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would
* be appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not
* be misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source
* distribution.
*/
#include <stdlib.h>
@ -61,12 +80,20 @@ const uint16_t _FC8_LENGTH_QUANT_LUT[257] = {
256 /* 256 */
};
uint32_t GetDecodedSize(const uint8_t *in)
uint32_t GetUInt32(const uint8_t *in)
{
return ((uint32_t)in[FC8_DECODED_SIZE_OFFSET]) << 24 |
((uint32_t)in[FC8_DECODED_SIZE_OFFSET+1]) << 16 |
((uint32_t)in[FC8_DECODED_SIZE_OFFSET+2]) << 8 |
((uint32_t)in[FC8_DECODED_SIZE_OFFSET+3]);
return ((uint32_t)in[0]) << 24 |
((uint32_t)in[1]) << 16 |
((uint32_t)in[2]) << 8 |
((uint32_t)in[3]);
}
void SetUInt32(uint8_t *in, uint32_t val)
{
in[0] = val >> 24;
in[1] = val >> 16;
in[2] = val >> 8;
in[3] = val;
}
typedef struct {
@ -338,6 +365,12 @@ uint32_t Encode(const uint8_t *in, uint32_t insize, uint8_t *out, uint32_t outsi
}
}
if (literalRunLength)
{
// terminate the final literal run, if any
*pRunLengthByte = literalRunLength-1;
}
// insert EOF
*dst++ = 0x40;
@ -352,11 +385,7 @@ uint32_t Encode(const uint8_t *in, uint32_t insize, uint8_t *out, uint32_t outsi
out[2] = '8';
out[3] = '_';
/* Decoded buffer size */
out[4] = insize >> 24;
out[5] = insize >> 16;
out[6] = insize >> 8;
out[7] = insize;
SetUInt32(out + FC8_DECODED_SIZE_OFFSET, insize);
/* Return size of compressed buffer */
return compressedSize;
@ -380,7 +409,7 @@ fail:
uint32_t Decode(const uint8_t *in, uint32_t insize, uint8_t *out, uint32_t outsize)
{
uint8_t *src, *inEnd, *dst, *outEnd, symbol, symbolType;
uint8_t *src, *dst, symbol, symbolType;
uint32_t i, length, offset;
/* Does the input buffer at least contain the header? */
@ -392,14 +421,12 @@ uint32_t Decode(const uint8_t *in, uint32_t insize, uint8_t *out, uint32_t outsi
return 0;
/* Get & check output buffer size */
if (outsize < GetDecodedSize(in))
if (outsize < GetUInt32(&in[FC8_DECODED_SIZE_OFFSET]))
return 0;
/* Initialize the byte streams */
src = (unsigned char *)in;
inEnd = ((unsigned char *)in) + insize;
dst = out;
outEnd = out + outsize;
/* Skip header information */
src += FC8_HEADER_SIZE;

143
fc8.c
View File

@ -1,6 +1,25 @@
/*
* FC8 compression by Steve Chamberlin
* Derived from liblzg by Marcus Geelnard
* FC8 compression by Steve Chamberlin, 2016
* Some concepts and code derived from liblzg by Marcus Geelnard, 2010
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would
* be appreciated but is not required.
*
* 2. Altered source versions must be plainly marked as such, and must not
* be misrepresented as being the original software.
*
* 3. This notice may not be removed or altered from any source
* distribution.
*/
#include <stdio.h>
@ -18,6 +37,7 @@ void ShowUsage(char *prgName)
{
fprintf(stderr, "Usage: %s [options] infile [outfile]\n", prgName);
fprintf(stderr, "Options:\n");
fprintf(stderr, " -b:NNN compress the input as multiple independent blocks of size NNN bytes\n");
fprintf(stderr, " -d decompress\n");
fprintf(stderr, "\nIf no output file is given, stdout is used for output.\n");
}
@ -31,6 +51,8 @@ int main(int argc, char **argv)
uint8_t *inBuf, *outBuf;
size_t fileSize;
uint8_t decompress = 0;
uint32_t blockSize = 0;
uint32_t i, numBlocks = 0;
int arg;
// Default arguments
@ -42,6 +64,12 @@ int main(int argc, char **argv)
{
if (strcmp("-d", argv[arg]) == 0)
decompress = 1;
else if (strncmp("-b", argv[arg], 2) == 0)
{
if (argv[arg][2] != ':')
ShowUsage(argv[0]);
blockSize = atoi(&argv[arg][3]);
}
else if (!inName)
inName = argv[arg];
else if (!outName)
@ -58,6 +86,11 @@ int main(int argc, char **argv)
return 0;
}
if (decompress && blockSize != 0)
{
fprintf(stderr, "Block size will be read from the input data, -b option ignored\n");
}
// Read input file
inBuf = (unsigned char*) 0;
inFile = fopen(inName, "rb");
@ -95,28 +128,118 @@ int main(int argc, char **argv)
if (decompress)
{
maxOutSize = GetDecodedSize(inBuf);
// determine blockSize and numBlocks
if (inBuf[0] != 'F' || inBuf[1] != 'C' || inBuf[2] != '8' || (inBuf[3] != '_' && inBuf[3] != 'b'))
{
fprintf(stderr, "Input is not an FC8 compressed file.\n");
return 0;
}
maxOutSize = GetUInt32(&inBuf[FC8_DECODED_SIZE_OFFSET]);
if (inBuf[3] == 'b')
{
blockSize = GetUInt32(&inBuf[FC8_BLOCK_SIZE_OFFSET]);
numBlocks = (maxOutSize + blockSize - 1) / blockSize;
fprintf(stderr, "Decompressing block format with %d byte blocks\n", blockSize);
}
else
{
blockSize = maxOutSize;
numBlocks = 1;
}
}
else
{
// Guess maximum size of compressed data in worst case
// Estimate the maximum size of compressed data in worst case
maxOutSize = inSize * 2;
if (blockSize != 0)
{
numBlocks = (inSize + blockSize - 1) / blockSize;
}
else
{
blockSize = inSize;
numBlocks = 1;
}
}
// Allocate memory for the output data
outBuf = (unsigned char*) malloc(maxOutSize);
if (outBuf)
{
// Compress/Decompress
if (decompress)
outSize = Decode(inBuf, inSize, outBuf, maxOutSize);
else
outSize = Encode(inBuf, inSize, outBuf, maxOutSize);
// If compressing block format, add the block header
if (!decompress && blockSize != inSize)
{
// Set header data
outBuf[0] = 'F';
outBuf[1] = 'C';
outBuf[2] = '8';
outBuf[3] = 'b';
// Uncompressed file size
SetUInt32(outBuf + FC8_DECODED_SIZE_OFFSET, inSize);
// block size
SetUInt32(outBuf + FC8_BLOCK_SIZE_OFFSET, blockSize);
// skip block header
outSize += FC8_BLOCK_HEADER_SIZE;
// skip block offsets
outSize += numBlocks * sizeof(uint32_t);
}
// process all the blocks
for (i=0; i<numBlocks; i++)
{
if (decompress)
{
uint32_t blockOffset = 0, processedBlockSize;
// decompressing block format?
if (blockSize != maxOutSize)
blockOffset = GetUInt32(&inBuf[FC8_BLOCK_HEADER_SIZE + sizeof(uint32_t) * i]);
processedBlockSize = Decode(inBuf + blockOffset, FC8_HEADER_SIZE, outBuf + blockSize * i, maxOutSize - blockSize * i);
// error?
if (processedBlockSize != blockSize)
{
outSize = 0;
break;
}
outSize += processedBlockSize;
}
else
{
uint32_t processedBlockSize = Encode(inBuf + blockSize * i, blockSize, outBuf + outSize, maxOutSize - outSize);
// error?
if (!processedBlockSize)
{
outSize = 0;
break;
}
// compressing block format?
if (blockSize != inSize)
{
// update the block offset in the block header
SetUInt32(&outBuf[FC8_BLOCK_HEADER_SIZE + sizeof(uint32_t) * i], outSize);
}
outSize += processedBlockSize;
}
}
// save result
if (outSize)
{
if (decompress)
fprintf(stderr, "Decompressed file is %d byte\n", outSize);
fprintf(stderr, "Decompressed file is %d bytes\n", outSize);
else
fprintf(stderr, "Result: %d bytes (%d%% of the original)\n", outSize, (100 * outSize) / inSize);

7
fc8.h
View File

@ -9,10 +9,15 @@
#define FC8_HEADER_SIZE 8
#define FC8_DECODED_SIZE_OFFSET 4
// for FC8b block format header
#define FC8_BLOCK_HEADER_SIZE 12
#define FC8_BLOCK_SIZE_OFFSET 8
uint32_t Encode(const uint8_t *in, uint32_t insize, uint8_t *out, uint32_t outsize);
uint32_t Decode(const uint8_t *in, uint32_t insize, uint8_t *out, uint32_t outsize);
uint32_t GetDecodedSize(const uint8_t *in);
uint32_t GetUInt32(const uint8_t *in);
void SetUInt32(uint8_t *in, uint32_t val);
#endif // _FC8_H_