First commit: Working cdplayer for linux using tinyalsa

cdplayer.c

@@ -0,0 +1,130 @@
+#include <fcntl.h> 
+#include <unistd.h>
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <linux/cdrom.h>
+#include <tinyalsa/pcm.h>
+
+#define FRAMES 1
+
+#define SIZE CD_FRAMESIZE_RAW
+#define PERIOD 1024
+#define COUNT 2
+
+struct cdrom_read_audio sr;
+
+void forward( int signum )
+{
+	sr.addr.lba+=3600;
+}
+
+void backward( int signum )
+{
+	sr.addr.lba-=3600;
+}
+
+void weite_err( char * s )
+{
+	char * p;
+	p=s;
+	while( *p )
+		++p;
+	write( STDERR_FILENO, p, p-s );
+}
+
+int main( int argc, char * argv[] )
+{
+	int fdi, card=0, device=0;
+	struct pcm * pcm;
+	struct pcm_config config;
+	char *msg, buff[SIZE*FRAMES];
+	struct sigaction f_action, b_action;
+
+	if( argc < 2 )
+	{
+		weite_err( "Usage: " );
+		weite_err( argv[0] );
+		weite_err( " /dev/sr0 (<card>) (<device>)" );
+		goto err0;
+	}
+
+	if( (fdi=open( argv[1] , O_RDONLY | O_NONBLOCK )) < 0 )
+	{
+		weite_err( "couldn't open input device " );
+		weite_err( argv[1] );
+		weite_err( " \n" );
+		goto err0;
+	}
+
+	switch( ioctl( fdi, CDROM_DRIVE_STATUS, 0 ) )
+	{
+	case CDS_NO_DISC:
+		weite_err( "No disk\n" );
+		goto err1;
+	case CDS_DRIVE_NOT_READY:
+		weite_err( "Drive not ready\n" );
+		goto err1;
+	case CDS_TRAY_OPEN:
+		weite_err( "Tray open\n" );
+		goto err1;
+	case -1:
+		weite_err( "Error\n" );
+		goto err1;
+	}
+
+	switch( argc )
+	{
+	case 4:
+		device = *argv[3] - '0';
+	case 3:
+		card = *argv[2] - '0';
+	}
+
+	/* Prepare signals */
+	{
+		f_action.sa_handler = forward ; 
+		b_action.sa_handler = backward ; 
+
+		sigaddset( &f_action.sa_mask, SIGUSR1 ); 
+		sigaddset( &b_action.sa_mask, SIGUSR2 ); 
+		sigaction( SIGUSR1, &f_action, NULL );
+		sigaction( SIGUSR2, &b_action, NULL );
+	}
+
+	/* config pcm */
+	{
+		config.channels = 2;
+		config.rate = 44100;
+		config.format = PCM_FORMAT_S16_LE;
+
+		config.period_size = PERIOD;
+		config.period_count = COUNT;
+		config.start_threshold = PERIOD;
+		config.silence_threshold = PERIOD*COUNT;
+		config.stop_threshold = PERIOD*COUNT;
+	}
+
+	/* config sr */
+	{
+		sr.buf = buff;
+		sr.nframes = FRAMES;
+		sr.addr_format = CDROM_LBA;
+	}
+
+	pcm = pcm_open( card, device, PCM_OUT , &config );
+
+	sr.addr.lba=0;
+	while( ioctl( fdi, CDROMREADAUDIO, &sr ) != -1 )
+	{
+		pcm_writei( pcm, buff, SIZE*FRAMES/4 );
+		sr.addr.lba+=FRAMES; 
+	}
+
+	pcm_close( pcm );
+	close( fdi );
+	return 0;
+err1:
+	close( fdi );
+err0:
+	return 1;
+}