Revision be18dbc36026ee929a7b2dd098b85d09daa4b116 authored by hudson@kremvax on 17 October 2009, 19:49:58 UTC, committed by hudson@kremvax on 17 October 2009, 19:49:58 UTC
1 parent eea235a
timecode.c
/** \file SMPTE timecode analyzer for the audio port
*/
#ifndef __ARM__
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <arpa/inet.h> // for ntohl
#define con_printf(font,...) /* Nothing */
unsigned offset;
#else
#include "dryos.h"
#include "tasks.h"
#include "audio.h"
#include "bmp.h"
#include "config.h"
#include "menu.h"
#define printf(fmt,...) /* Nothing */
#endif
#include <stdint.h>
// SMTPE timecode frame
static uint8_t smpte_frame[ 8 ];
// Returns 1 if there is a new frame available
static int
tc_sample(
int16_t sample
)
{
static uint32_t last_transition;
// Hold onto the last bit for hysteris
static int bit = 0;
static int bit_count = 0;
static uint32_t word = 0;
static uint32_t raw_word = 0;
static int synced = 0;
static int byte_count = 0;
// Use some hysteris to avoid zero crosing errors
int old_bit = bit;
if( sample > 1000 )
bit = 0;
else
if( sample < -1000 )
bit = 1;
static int x, y = 32;
// Record any transition to help reconstruct the clock
if( bit == old_bit )
return 0;
#ifdef __ARM__
unsigned (*read_clock)(void) = (void*) 0xff9948d8;
unsigned now = read_clock();
#else
unsigned now = offset;
#endif
int delta = now - last_transition;
last_transition = now;
// Timer is only 24 bits?
delta &= 0x00FFFFFF;
#if 0 //def __ARM__
bmp_printf( FONT_SMALL, x, y, "%02x ", delta );
x += 3 * 8;
if( x > 700 )
{
x = 0;
y += 12;
if( y > 400 )
{
y = 32;
msleep( 2000 );
}
}
bit_count = 0;
return 0;
#endif
int new_bit;
static unsigned last_bit;
//printf( "%08x delta %x\n", offset, delta );
#ifdef __ARM__
// These deltas are in timer ticks
// Timer == 500 MHz? 0xD0 ==> 2400 Hz, 0x1A0 => 1200 Hz
#define ONE_LEN 0xD0
#define ZERO_LEN 0x1A0
#define EPS 0x30
#else
// These are in byte offsets in the file
#define ZERO_LEN 0x25
#define ONE_LEN 0x12
#define EPS 0x04
#endif
if( ZERO_LEN-EPS < delta && delta < ZERO_LEN+EPS )
{
// Full bit width
new_bit = 0;
} else
if( ONE_LEN-EPS < delta && delta < ONE_LEN+EPS )
{
// Skip the second transition if we're short
if( ++last_bit & 1 )
return 0;
last_bit = 0;
new_bit = 1;
} else {
bmp_printf(
FONT(FONT_SMALL,COLOR_RED,0),
delta < ONE_LEN ? 10 :
delta > ZERO_LEN ? 210 :
110,
300,
"%04x",
delta
);
printf( "%08x: bad delta %x\n", offset, delta );
// Lost sync somewhere
synced = 0;
word = 0;
return 0;
}
word = (word << 1) | new_bit;
//printf( " %04x\n", word & 0xFFFF );
//return 0;
// Check for SMPTE sync signal
if( !synced )
{
if( (word & 0xFFFF) == 0x3FFD )
{
//fprintf( stderr, "%x: Got sync!\n", offset );
printf( "\n%08x: synced", offset );
synced = 1;
word = 1;
byte_count = 0;
}
return 0;
}
// We are locked; wait until we have 8 bits then write it
if( (word & 0x100) == 0 )
return 0;
//printf( " %02x", word & 0xFF );
// Reverse the word since we bit banged it in the wrong order
word = 0
| ( word & 0x01 ) << 7
| ( word & 0x02 ) << 5
| ( word & 0x04 ) << 3
| ( word & 0x08 ) << 1
| ( word & 0x10 ) >> 1
| ( word & 0x20 ) >> 3
| ( word & 0x40 ) >> 5
| ( word & 0x80 ) >> 7
;
#ifdef __ARM__
//con_printf( FONT_SMALL, "%02x ", word );
#endif
smpte_frame[ byte_count++ ] = word;
word = 1;
if( byte_count < 8 )
return 0;
// We have a complete frame
synced = 0;
return 1;
}
#ifndef __ARM__
struct au_hdr
{
uint32_t magic;
uint32_t offset;
uint32_t len;
uint32_t encoding;
uint32_t rate;
uint32_t channels;
};
int main( int argc, char ** argv )
{
const char * filename = argc > 1 ? argv[1] : "timecode.au";
int fd = open( filename, O_RDONLY );
if( fd < 0 )
{
perror( filename );
return -1;
}
struct au_hdr hdr;
offset = read( fd, &hdr, sizeof(hdr) );
hdr.magic = ntohl( hdr.magic );
hdr.offset = ntohl( hdr.offset );
hdr.len = ntohl( hdr.len );
hdr.encoding = ntohl( hdr.encoding );
hdr.rate = ntohl( hdr.rate );
hdr.channels = ntohl( hdr.channels );
fprintf( stderr,
"magic=%08x encoding=%x\n",
hdr.magic,
hdr.encoding
);
if( hdr.magic != 0x2e736e64
|| hdr.encoding != 3 )
{
fprintf( stderr, "Bad magic or unsupported format!\n" );
return -1;
}
uint16_t sample;
uint32_t last_transition = 0;
// Seek to the start of the data
while( offset < hdr.offset )
offset += read( fd, &sample, 1 );
while( offset < hdr.len )
{
ssize_t rc = read( fd, &sample, sizeof(sample) );
offset += rc;
if( rc < 1 )
break;
sample = ntohs( sample );
// Convert to an unsigned value
sample += 32768;
if( tc_sample( sample ) == 0 )
continue;
printf( "%08x", offset );
int i;
for( i=0 ; i<8 ; i++ )
printf( " %02x", smpte_frame[ i ] );
// Decode it:
#define BCD_BITS(x) \
(smpte_frame[x/8] & 0xF)
int f = BCD_BITS(0) + 10 * (BCD_BITS(8) & 0x3);
int s = BCD_BITS(16) + 10 * (BCD_BITS(24) & 0x7);
int m = BCD_BITS(32) + 10 * BCD_BITS(40);
int h = BCD_BITS(48) + 10 * (BCD_BITS(56) & 0x3);
printf( ": %02d:%02d:%02d.%02d\n", h, m, s, f );
}
return 0;
}
#else
static void
process_timecode( void )
{
while( !gui_menu_task )
{
int sample = audio_read_level( 0 );
if( tc_sample( sample ) == 0 )
continue;
// Print a timecode result!
// Decode it:
#define BCD_BITS(x) \
(smpte_frame[x/8] & 0xF)
int f = BCD_BITS(0) + 10 * (BCD_BITS(8) & 0x3);
int s = BCD_BITS(16) + 10 * (BCD_BITS(24) & 0x7);
int m = BCD_BITS(32) + 10 * BCD_BITS(40);
int h = BCD_BITS(48) + 10 * (BCD_BITS(56) & 0x3);
#if 0
bmp_printf(
FONT(FONT_LARGE,COLOR_WHITE,COLOR_BLUE),
180, 150,
" \n"
" SMPTE LTC \n"
" %02d:%02d:%02d.%02d \n"
" \n",
h, m, s, f
);
#else
bmp_printf(
FONT_HUGE,
0, 150,
//23456789012
//hh:mm:ss.ff \n
" SMTPE LTC: \n"
" %02d:%02d:%02d.%02d ",
h, m, s, f
);
#endif
}
}
static struct semaphore * timecode_sem;
static void
timecode_unlock( void * priv )
{
gui_stop_menu();
give_semaphore( timecode_sem );
}
static struct menu_entry timecode_menu[] = {
{
.display = menu_print,
.priv = "Jam timecode",
.select = timecode_unlock,
},
};
static void
tc_task( void )
{
timecode_sem = create_named_semaphore( "timecode", 0 );
menu_add( "Debug", timecode_menu, COUNT(timecode_menu) );
while(1)
{
take_semaphore( timecode_sem, 0 );
process_timecode();
}
}
TASK_CREATE( __FILE__, tc_task, 0, 0x18, 0x1000 );
#endif
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