svnno****@sourc*****
svnno****@sourc*****
2009年 8月 28日 (金) 01:25:51 JST
ForkRevision: 176
http://sourceforge.jp/projects/swfed/svn/view?view=rev&revision=176
Author: yoya
Date: 2009-08-28 01:25:51 +0900 (Fri, 28 Aug 2009)
Log Message:
-----------
- bitstream_getbits_signed を追加
- デバッグ用に bitstream_hexdump を追加
- エラー処理を実装途中
Modified Paths:
--------------
trunk/src/bitstream.c
trunk/src/bitstream.h
-------------- next part --------------
Modified: trunk/src/bitstream.c
===================================================================
--- trunk/src/bitstream.c 2009-08-27 16:20:13 UTC (rev 175)
+++ trunk/src/bitstream.c 2009-08-27 16:25:51 UTC (rev 176)
@@ -304,6 +304,21 @@
return bits;
}
+signed long
+bitstream_getbits_signed(bitstream_t *bs, int bit_width) {
+ int i;
+ int bit;
+ unsigned long bits = 0;
+ for (i=0 ; i < bit_width ; i++) {
+ bit = bitstream_getbit(bs);
+ if (bit == -1) {
+ return -1;
+ }
+ bits |= bit << (bit_width - 1 - i);
+ }
+ return bits;
+}
+
void
bitstream_align(bitstream_t *bs) {
if (bs->bit_offset > 0) {
@@ -362,16 +377,76 @@
bitstream_length(bitstream_t *bs) {
return bs->data_len;
}
+/*
+ * utility
+ */
-unsigned long
+
+
+extern signed long
+bitstream_unsigned2signed(unsigned long num, int size) {
+ unsigned long sig_bit = 1 << (size - 1);
+ if ((sig_bit & num) == 0) {
+ return (signed long) num;
+ } else {
+ unsigned long mask = sig_bit - 1;
+ return - ((num^mask) & mask) - 1;
+ }
+}
+
+extern unsigned long
+bitstream_signed2unsigned(signed long num, int size) { // XXX check me!
+ if (0 <= num){
+ return (unsigned long) num;
+ } else {
+ unsigned long sig_bit = 1 << (size - 1);
+ unsigned long mask = sig_bit - 1;
+ return - ((num^mask) & mask) - 1;
+ }
+}
+/*
+ * error handling
+ */
+
+int
+bitstream_iserror(bitstream_t *bs) {
+ (void) bs;
+ return 0;
+}
+
+void
+bitstream_printerror(bitstream_t *bs) {
+ (void) bs;
+}
+/*
+ * for debug
+ */
+
+void
bitstream_hexdump(bitstream_t *bs, int length) {
- unsigned long i;
- printf("%08lu: ", bs->byte_offset);
+ unsigned long i, j;
for ( i = bs->byte_offset ; i < bs->byte_offset + length ; i++) {
+ if ((i == bs->byte_offset) || (i%16) == 0) {
+ printf("%08lu: ", i);
+ if ((i%16) != 0) {
+ for( j = 0 ; j < (i%16) ; j++) {
+ printf(" ");
+ }
+ }
+ }
printf("%02x ", bs->data[i] & 0xff);
+ if ((i%16) == 7) {
+ printf(" ");
+ }
+ if ((i%16) == 15) {
+ printf("\n");
+ }
}
- printf("\n");
+ if ((i%16) != 0) {
+ printf("\n");
+ }
}
+
void
bitstream_print(bitstream_t *bs) {
printf("data=%p data_len=%lu data_alloc_len=%lu\n",
Modified: trunk/src/bitstream.h
===================================================================
--- trunk/src/bitstream.h 2009-08-27 16:20:13 UTC (rev 175)
+++ trunk/src/bitstream.h 2009-08-27 16:25:51 UTC (rev 176)
@@ -16,10 +16,16 @@
/* seek position */
unsigned long byte_offset;
unsigned long bit_offset;
+ /* error */
+ int error;
+
} bitstream_t;
#define BITSTREAM_DATA_LEN_MIN 0x100
+#define BITSTREAM_ERROR_NONE 0
+#define BITSTREAM_ERROR_NOMORE_DATA 1
+
extern bitstream_t *bitstream_open(void);
extern void bitstream_close(bitstream_t * bs);
@@ -46,6 +52,7 @@
extern int bitstream_getbit(bitstream_t *bs);
extern int bitstream_putbits(bitstream_t *bs, unsigned long bits, int bit_width);
extern unsigned long bitstream_getbits(bitstream_t *bs, int bit_width);
+extern signed long bitstream_getbits_signed(bitstream_t *bs, int bit_width);
extern void bitstream_align(bitstream_t *bs);
/* seeking */
@@ -61,8 +68,17 @@
extern unsigned char *bitstream_buffer(bitstream_t *bs, unsigned long byte_offset);
extern unsigned long bitstream_length(bitstream_t *bs);
-/* debug function */
-extern unsigned long bitstream_hexdump(bitstream_t *bs, int length);
+/* utility */
+
+extern signed long bitstream_unsigned2signed(unsigned long num, int size);
+extern unsigned long bitstream_signed2unsigned(signed long num, int size);
+
+/* error handling */
+extern int bitstream_iserror(bitstream_t *bs);
+extern void bitstream_printerror(bitstream_t *bs);
+
+/* for debug */
+extern void bitstream_hexdump(bitstream_t *bs, int length);
extern void bitstream_print(bitstream_t *bs);
#endif /* __BITSTREAM_H__ */