f90cbcb652
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16194 a1c6a512-1295-4272-9138-f99709370657
197 lines
6.3 KiB
C
197 lines
6.3 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Miscellaneous helper API declarations
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*
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* Copyright (c) 2007 Michael Sevakis
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*
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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#ifndef MPEG_MISC_H
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#define MPEG_MISC_H
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/* Miscellaneous helpers */
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#ifndef ALIGNED_ATTR
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#define ALIGNED_ATTR(x) __attribute__((aligned(x)))
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#endif
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/* Generic states for when things are too simple to care about naming them */
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enum state_enum
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{
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state0 = 0,
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state1,
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state2,
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state3,
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state4,
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state5,
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state6,
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state7,
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state8,
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state9,
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};
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/* Macros for comparing memory bytes to a series of constant bytes in an
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efficient manner - evaluate to true if corresponding bytes match */
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#if defined (CPU_ARM)
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/* ARM must load 32-bit values at addres % 4 == 0 offsets but this data
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isn't aligned nescessarily, so just byte compare */
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#define CMP_3_CONST(_a, _b) \
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({ int _x; \
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asm volatile ( \
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"ldrb %[x], [%[a], #0] \n" \
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"eors %[x], %[x], %[b0] \n" \
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"ldreqb %[x], [%[a], #1] \n" \
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"eoreqs %[x], %[x], %[b1] \n" \
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"ldreqb %[x], [%[a], #2] \n" \
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"eoreqs %[x], %[x], %[b2] \n" \
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: [x]"=&r"(_x) \
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: [a]"r"(_a), \
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[b0]"i"(((_b) >> 24) & 0xff), \
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[b1]"i"(((_b) >> 16) & 0xff), \
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[b2]"i"(((_b) >> 8) & 0xff) \
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); \
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_x == 0; })
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#define CMP_4_CONST(_a, _b) \
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({ int _x; \
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asm volatile ( \
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"ldrb %[x], [%[a], #0] \n" \
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"eors %[x], %[x], %[b0] \n" \
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"ldreqb %[x], [%[a], #1] \n" \
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"eoreqs %[x], %[x], %[b1] \n" \
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"ldreqb %[x], [%[a], #2] \n" \
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"eoreqs %[x], %[x], %[b2] \n" \
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"ldreqb %[x], [%[a], #3] \n" \
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"eoreqs %[x], %[x], %[b3] \n" \
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: [x]"=&r"(_x) \
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: [a]"r"(_a), \
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[b0]"i"(((_b) >> 24) & 0xff), \
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[b1]"i"(((_b) >> 16) & 0xff), \
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[b2]"i"(((_b) >> 8) & 0xff), \
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[b3]"i"(((_b) ) & 0xff) \
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); \
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_x == 0; })
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#elif defined (CPU_COLDFIRE)
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/* Coldfire can just load a 32 bit value at any offset but ASM is not the
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best way to integrate this with the C code */
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#define CMP_3_CONST(a, b) \
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(((*(uint32_t *)(a) >> 8) == ((uint32_t)(b) >> 8)))
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#define CMP_4_CONST(a, b) \
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((*(uint32_t *)(a) == (b)))
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#else
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/* Don't know what this is - use bytewise comparisons */
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#define CMP_3_CONST(a, b) \
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(( ((a)[0] ^ (((b) >> 24) & 0xff)) | \
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((a)[1] ^ (((b) >> 16) & 0xff)) | \
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((a)[2] ^ (((b) >> 8) & 0xff)) ) == 0)
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#define CMP_4_CONST(a, b) \
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(( ((a)[0] ^ (((b) >> 24) & 0xff)) | \
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((a)[1] ^ (((b) >> 16) & 0xff)) | \
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((a)[2] ^ (((b) >> 8) & 0xff)) | \
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((a)[3] ^ (((b) ) & 0xff)) ) == 0)
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#endif /* CPU_* */
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/** Streams **/
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/* Convert PTS/DTS ticks to our clock ticks */
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#define TS_TO_TICKS(pts) ((uint64_t)CLOCK_RATE*(pts) / TS_SECOND)
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/* Convert our clock ticks to PTS/DTS ticks */
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#define TICKS_TO_TS(ts) ((uint64_t)TS_SECOND*(ts) / CLOCK_RATE)
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/* Convert timecode ticks to our clock ticks */
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#define TC_TO_TICKS(stamp) ((uint64_t)CLOCK_RATE*(stamp) / TC_SECOND)
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/* Convert our clock ticks to timecode ticks */
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#define TICKS_TO_TC(stamp) ((uint64_t)TC_SECOND*(stamp) / CLOCK_RATE)
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/* Convert timecode ticks to timestamp ticks */
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#define TC_TO_TS(stamp) ((stamp) / 600)
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/*
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* S = start position, E = end position
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*
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* pos:
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* initialize to search start position (S)
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*
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* len:
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* initialize to = ABS(S-E)
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* scanning = remaining bytes in scan direction
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*
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* dir:
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* scan direction; >= 0 == forward, < 0 == reverse
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*
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* margin:
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* amount of data to right of cursor - initialize by stream_scan_normalize
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*
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* data:
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* Extra data used/returned by the function implemented
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*
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* Forward scan:
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* S pos E
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* | *<-margin->| dir->
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* | |<--len--->|
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*
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* Reverse scan:
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* E pos S
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* |<-len->*<-margin->| <-dir
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* | | |
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*/
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struct stream_scan
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{
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off_t pos; /* Initial scan position (file offset) */
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ssize_t len; /* Maximum length of scan */
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off_t dir; /* Direction - >= 0; forward, < 0 backward */
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ssize_t margin; /* Used by function to track margin between position and data end */
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intptr_t data; /* */
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};
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#define SSCAN_REVERSE (-1)
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#define SSCAN_FORWARD 1
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/* Ensures direction is -1 or 1 and margin is properly initialized */
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void stream_scan_normalize(struct stream_scan *sk);
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/* Moves a scan cursor. If amount is positive, the increment is in the scan
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* direction, otherwise opposite the scan direction */
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void stream_scan_offset(struct stream_scan *sk, off_t by);
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/** Time helpers **/
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struct hms
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{
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unsigned int hrs;
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unsigned int min;
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unsigned int sec;
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unsigned int frac;
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};
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void ts_to_hms(uint32_t ts, struct hms *hms);
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void hms_format(char *buf, size_t bufsize, struct hms *hms);
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/** Maths **/
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/* Moving average */
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#define AVERAGE(var, x, count) \
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({ typeof (count) _c = (count); \
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((var) * (_c-1) + (x)) / (_c); })
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/* Multiply two unsigned 32-bit integers yielding a 64-bit result and
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* divide by another unsigned 32-bit integer to yield a 32-bit result.
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* Rounds to nearest with saturation. */
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uint32_t muldiv_uint32(uint32_t multiplicand,
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uint32_t multiplier,
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uint32_t divisor);
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#endif /* MPEG_MISC_H */
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