players.c

来自「Windows NT声卡驱动VXD」· C语言 代码 · 共 581 行 · 第 1/2 页

#include "esd-server.h"
#include <errno.h>

/*******************************************************************/
/* globals */
esd_player_t *esd_players_list = NULL;
esd_player_t *esd_recorder = NULL;
esd_player_t *esd_monitor_list = NULL;

/*******************************************************************/
/* for debugging purposes, dump the list of the clients and data */
void dump_players()
{
    esd_player_t *player = esd_players_list;

    if ( !esdbg_trace ) return;

    while ( player != NULL ) {
	printf( "-%02d- player: [%p]\n", 
		player->source_id, player );
	player = player->next;
    }
    return;
}

/*******************************************************************/
/* deallocate memory for the player */
void free_player( esd_player_t *player )
{
    esd_sample_t *sample;

    /* see if we need to do any housekeeping */
    if ( ( player->format & ESD_MASK_MODE ) == ESD_STREAM ) {
	/* TODO: erase client should be independent of players */
	erase_client( player->parent );
    } else if ( ( player->format & ESD_MASK_MODE ) == ESD_SAMPLE ) {
	sample = (esd_sample_t *) (player->parent);
	sample->ref_count--;
	esd_playing_samples--;

	ESDBG_TRACE( printf( "<%02d> free player: [%p] refs=%d erase?=%d samps=%d\n", 
			     player->source_id, player, sample->ref_count, 
			     sample->erase_when_done, esd_playing_samples ); );

	if ( sample->erase_when_done && !sample->ref_count ) {
	    ESDBG_TRACE( printf( "<%02d> free_player: erasing sample\n", 
				 sample->sample_id ); );

	    erase_sample( sample->sample_id, 0 );
	}
    }

    /* free any memory allocated with the player */
    free( player->data_buffer );

    /* free the player memory itself */
    free( player );

    return;
}

/*******************************************************************/
/* add a complete new player into the list of players at head */
void add_player( esd_player_t *player )
{
    /* printf ( "adding player %p\n", new_player ); */
    if ( !player ) {
	ESDBG_TRACE( printf( "<NIL> can't add non-existent player!\n" ); );
	return;
    }

    player->next = esd_players_list;
    esd_players_list = player;
    return;
}

/*******************************************************************/
/* erase a player from the player list */
void erase_player( esd_player_t *player )
{
    esd_player_t *previous = NULL;
    esd_player_t *current = esd_players_list;

    /* iterate until we hit a NULL */
    while ( current != NULL )
    {
	/* see if we hit the target player */
	if ( current == player ) {
	    if( previous != NULL ){
		/* we are deleting in the middle of the list */
		previous->next = current->next;
	    } else { 
		/* we are deleting the head of the list */
		esd_players_list = current->next;
	    }

	    /* TODO: delete if needed */

	    free_player( player );

	    return;
	}

	/* iterate through the list */
	previous = current;
	current = current->next;
    }

    /* hmm, we didn't find the desired player, just get on with life */
    ESDBG_TRACE( printf( "-%02d- player not found\n", player->source_id ); );
    return;
}


/*******************************************************************/
/* erase a monitor from the monitor list */
void erase_monitor( esd_player_t *monitor )
{
    esd_player_t *previous = NULL;
    esd_player_t *current = esd_monitor_list;

    /* iterate until we hit a NULL */
    while ( current != NULL )
    {
	/* see if we hit the target monitor */
	if ( current == monitor ) {
	    if( previous != NULL ){
		/* we are deleting in the middle of the list */
		previous->next = current->next;
	    } else { 
		/* we are deleting the head of the list */
		esd_monitor_list = current->next;
	    }

	    /* TODO: delete if needed */
	    free_player( monitor );

	    return;
	}

	/* iterate through the list */
	previous = current;
	current = current->next;
    }

    /* hmm, we didn't find the desired monitor, just get on with life */
    ESDBG_TRACE( printf( "-%02d- monitor not found\n", monitor->source_id ); );
    return;
}


/*******************************************************************/
/* write block of data from client, return < 0 to have it erased */
int write_player( esd_player_t *player, void *src_buffer, int src_length, 
		  int src_rate, int src_format )
{
    fd_set wr_fds;
    int length = 0, actual = 0, can_write = 0;
    struct timeval timeout;
    char message[ 100 ];
    short data, *pos; /* used for swapping */
    esd_client_t *client;
    short *buffer;

    /* use select to prevent blocking clients that are ready */
    timeout.tv_sec = 0;
    timeout.tv_usec = 0;
    FD_ZERO( &wr_fds );
    FD_SET( player->source_id, &wr_fds );
    
    /* if the data is ready, read a block */
    can_write = select( player->source_id + 1, 
			NULL, &wr_fds, NULL, &timeout ) ;
    if ( can_write > 0 )
    {
	/* translate the data */
	length = player->translate_func( player->data_buffer, 
					 player->buffer_length, 
					 player->rate, 
					 player->format, 
					 src_buffer, 
					 src_length, 
					 src_rate, 
					 src_format );

	/* endian swap multi-byte data if we need to */
	client = (esd_client_t *) (player->parent);
	if ( client->swap_byte_order 
	     && ( (player->format & ESD_MASK_BITS) == ESD_BITS16 ) )
	{
	    printf( "swapping...\n" );
	    buffer = (short*) player->data_buffer;
	    for ( pos = buffer 
		      ; pos < buffer + length / sizeof(short)
		      ; pos += sizeof(short) )
	    {
		data = swap_endian_16( (*pos) );
		*pos = data;
	    }
	}

	/* write out the data */
	ESD_WRITE_BIN( player->source_id, player->data_buffer, 
		       player->buffer_length, length, "str rd" );

    } else if ( can_write < 0 ) {
	sprintf( message, "error writing client (%d)\n", 
		 player->source_id );
	perror( message );
	return -1;
    }

    /* check for end of stream */
    if ( length < 0 ) return -1;
    if ( length == 0 ) return 0;
 
    return actual;
}

/*******************************************************************/
/* read block of data from client, return < 0 to have it erased */
int read_player( esd_player_t *player )
{
    fd_set rd_fds;
    int actual = 0, actual_2nd = 0, can_read = 0;
    struct timeval timeout;
    char message[ 100 ];
    short data, *pos; /* used for swapping */
    esd_client_t *client;
    short *buffer;

    switch( player->format & ESD_MASK_MODE ) {
    case ESD_STREAM:
	/* use select to prevent blocking clients that are ready */
	timeout.tv_sec = 0;
	timeout.tv_usec = 0;
	FD_ZERO( &rd_fds );
	FD_SET( player->source_id, &rd_fds );

	/* if the data is ready, read a block */
	can_read = select( player->source_id + 1, 
			   &rd_fds, NULL, NULL, &timeout ) ;
	if ( can_read > 0 )
	{
	    ESD_READ_BIN( player->source_id, player->data_buffer, 
			  player->buffer_length, actual, "str rd" );

	    /* check for end of stream */
	    if ( actual == 0 
		 || ( actual < 0 && errno != EAGAIN && errno != EINTR ) )
		return -1;
 
	    /* more data, save how much we got */
	    player->actual_length = actual;

	    /* endian swap multi-byte data if we need to */
	    client = (esd_client_t *) (player->parent);
	    if ( client->swap_byte_order 
		 && ( (player->format & ESD_MASK_BITS) == ESD_BITS16 ) )
	    {
		printf( "swapping...\n" );
		buffer = (short*) player->data_buffer;
		for ( pos = buffer 
			  ; pos < buffer + actual / sizeof(short)
			  ; pos += sizeof(short) )
		{
		    data = swap_endian_16( (*pos) );
		    *pos = data;
		}
	    }

	} else if ( can_read < 0 ) {
	    sprintf( message, "error reading client (%d)\n", 
		     player->source_id );
	    perror( message );
	    return -1;
	}

	break;

    case ESD_SAMPLE:

	/* printf( "player [%p], pos = %d, format = 0x%08x\n", 
		player, player->last_pos, player->format ); */
	
	/* only keep going if we didn't want to stop looping */
	if ( ( player->last_pos ) == 0 &&
	    ( ( ((esd_sample_t*)player->parent)->format & ESD_MASK_FUNC ) 
	      == ESD_STOP ) ) 
	{