rockbox/apps/plugins/mpegplayer/mpeg_misc.h
Daniel Stenberg 2acc0ac542 Updated our source code header to explicitly mention that we are GPL v2 or
later. We still need to hunt down snippets used that are not. 1324 modified
files...
http://www.rockbox.org/mail/archive/rockbox-dev-archive-2008-06/0060.shtml


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@17847 a1c6a512-1295-4272-9138-f99709370657
2008-06-28 18:10:04 +00:00

199 lines
6.4 KiB
C

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