device.c

python的多媒体包,可以实现很多漂亮的功能哦

                }
            }
        }
    }

    free( (void*) fd );
    FreeLibrary( hASPI );
    _dvdcss_error( dvdcss, "unable to get haid and target (aspi)" );
    return -1;
}
#endif

/*****************************************************************************
 * Seek commands.
 *****************************************************************************/

#if defined( WIN32 )
static int win2k_seek( dvdcss_t dvdcss, int i_blocks )
{
    LARGE_INTEGER li_seek;

#ifndef INVALID_SET_FILE_POINTER
#   define INVALID_SET_FILE_POINTER ((DWORD)-1)
#endif

    if( dvdcss->i_pos == i_blocks )
    {
        /* We are already in position */
        return i_blocks;
    }

    li_seek.QuadPart = (LONGLONG)i_blocks * DVDCSS_BLOCK_SIZE;

    li_seek.LowPart = SetFilePointer( (HANDLE) dvdcss->i_fd,
                                      li_seek.LowPart,
                                      &li_seek.HighPart, FILE_BEGIN );
    if( (li_seek.LowPart == INVALID_SET_FILE_POINTER)
        && GetLastError() != NO_ERROR)
    {
        dvdcss->i_pos = -1;
        return -1;
    }

    dvdcss->i_pos = (int)( li_seek.QuadPart / DVDCSS_BLOCK_SIZE );

    return dvdcss->i_pos;
}

static int aspi_seek( dvdcss_t dvdcss, int i_blocks )
{
    int i_old_blocks;
    char sz_buf[ DVDCSS_BLOCK_SIZE ];
    struct w32_aspidev *fd = (struct w32_aspidev *) dvdcss->i_fd;

    if( dvdcss->i_pos == i_blocks )
    {
        /* We are already in position */
        return i_blocks;
    }

    i_old_blocks = fd->i_blocks;
    fd->i_blocks = i_blocks;

    if( aspi_read_internal( dvdcss->i_fd, sz_buf, 1 ) == -1 )
    {
        fd->i_blocks = i_old_blocks;
        dvdcss->i_pos = -1;
        return -1;
    }

    (fd->i_blocks)--;

    dvdcss->i_pos = fd->i_blocks;

    return dvdcss->i_pos;
}
#else

static int libc_seek( dvdcss_t dvdcss, int i_blocks )
{
    off_t   i_seek;

    if( dvdcss->i_pos == i_blocks )
    {
        /* We are already in position */
        return i_blocks;
    }

    i_seek = lseek( dvdcss->i_read_fd,
                    (off_t)i_blocks * (off_t)DVDCSS_BLOCK_SIZE, SEEK_SET );

    if( i_seek < 0 )
    {
        _dvdcss_error( dvdcss, strerror(errno) );
        dvdcss->i_pos = -1;
        return i_seek;
    }

    dvdcss->i_pos = i_seek / DVDCSS_BLOCK_SIZE;

    return dvdcss->i_pos;
}

#endif

/*****************************************************************************
 * Read commands.
 *****************************************************************************/
#if defined( WIN32 )
static int win2k_read ( dvdcss_t dvdcss, void *p_buffer, int i_blocks )
{
    int i_bytes;

    if( !ReadFile( (HANDLE) dvdcss->i_fd, p_buffer,
              i_blocks * DVDCSS_BLOCK_SIZE,
              (LPDWORD)&i_bytes, NULL ) )
    {
        dvdcss->i_pos = -1;
        return -1;
    }

    dvdcss->i_pos += i_bytes / DVDCSS_BLOCK_SIZE;
    return i_bytes / DVDCSS_BLOCK_SIZE;
}

static int aspi_read ( dvdcss_t dvdcss, void *p_buffer, int i_blocks )
{
    int i_read = aspi_read_internal( dvdcss->i_fd, p_buffer, i_blocks );

    if( i_read < 0 )
    {
        dvdcss->i_pos = -1;
        return i_read;
    }

    dvdcss->i_pos += i_read;
    return i_read;
}
#else

static int libc_read ( dvdcss_t dvdcss, void *p_buffer, int i_blocks )
{
    off_t i_ret;

    i_ret = read( dvdcss->i_read_fd, p_buffer,
                  (off_t)i_blocks * DVDCSS_BLOCK_SIZE );

    if( i_ret < 0 )
    {
        _dvdcss_error( dvdcss, "read error" );
        dvdcss->i_pos = -1;
        return i_ret;
    }

    /* Handle partial reads */
    if( i_ret != (off_t)i_blocks * DVDCSS_BLOCK_SIZE )
    {
        int i_seek;

        dvdcss->i_pos = -1;
        i_seek = libc_seek( dvdcss, i_ret / DVDCSS_BLOCK_SIZE );
        if( i_seek < 0 )
        {
            return i_seek;
        }

        /* We have to return now so that i_pos isn't clobbered */
        return i_ret / DVDCSS_BLOCK_SIZE;
    }

    dvdcss->i_pos += i_ret / DVDCSS_BLOCK_SIZE;
    return i_ret / DVDCSS_BLOCK_SIZE;
}

#endif

/*****************************************************************************
 * Readv commands.
 *****************************************************************************/
static int libc_readv ( dvdcss_t dvdcss, struct iovec *p_iovec, int i_blocks )
{
#if defined( WIN32 )
    int i_index, i_len, i_total = 0;
    unsigned char *p_base;
    int i_bytes;

    for( i_index = i_blocks;
         i_index;
         i_index--, p_iovec++ )
    {
        i_len  = p_iovec->iov_len;
        p_base = p_iovec->iov_base;

        if( i_len <= 0 )
        {
            continue;
        }

        i_bytes = read( dvdcss->i_fd, p_base, i_len );

        if( i_bytes < 0 )
        {
            /* One of the reads failed, too bad.
             * We won't even bother returning the reads that went ok,
             * and as in the posix spec the file postition is left
             * unspecified after a failure */
            dvdcss->i_pos = -1;
            return -1;
        }

        i_total += i_bytes;

        if( i_bytes != i_len )
        {
            /* We reached the end of the file or a signal interrupted
             * the read. Return a partial read. */
            int i_seek;

            dvdcss->i_pos = -1;
            i_seek = win2k_seek( dvdcss, i_total / DVDCSS_BLOCK_SIZE );
            if( i_seek < 0 )
            {
                return i_seek;
            }

            /* We have to return now so that i_pos isn't clobbered */
            return i_total / DVDCSS_BLOCK_SIZE;
        }
    }

    dvdcss->i_pos += i_total / DVDCSS_BLOCK_SIZE;
    return i_total / DVDCSS_BLOCK_SIZE;
#else
    int i_read = readv( dvdcss->i_read_fd, p_iovec, i_blocks );

    if( i_read < 0 )
    {
        dvdcss->i_pos = -1;
        return i_read;
    }

    dvdcss->i_pos += i_read / DVDCSS_BLOCK_SIZE;
    return i_read / DVDCSS_BLOCK_SIZE;
#endif
}

#if defined( WIN32 )
/*****************************************************************************
 * win_readv: vectored read using ReadFile for Win2K and ASPI for win9x
 *****************************************************************************/
static int win_readv ( dvdcss_t dvdcss, struct iovec *p_iovec, int i_blocks )
{
    int i_index;
    int i_blocks_read, i_blocks_total = 0;

    /* Check the size of the readv temp buffer, just in case we need to
     * realloc something bigger */
    if( dvdcss->i_readv_buf_size < i_blocks * DVDCSS_BLOCK_SIZE )
    {
        dvdcss->i_readv_buf_size = i_blocks * DVDCSS_BLOCK_SIZE;

        if( dvdcss->p_readv_buffer ) free( dvdcss->p_readv_buffer );

        /* Allocate a buffer which will be used as a temporary storage
         * for readv */
        dvdcss->p_readv_buffer = malloc( dvdcss->i_readv_buf_size );
        if( !dvdcss->p_readv_buffer )
        {
            _dvdcss_error( dvdcss, " failed (readv)" );
            dvdcss->i_pos = -1;
            return -1;
        }
    }

    for( i_index = i_blocks; i_index; i_index-- )
    {
        i_blocks_total += p_iovec[i_index-1].iov_len;
    }

    if( i_blocks_total <= 0 ) return 0;

    i_blocks_total /= DVDCSS_BLOCK_SIZE;

    if( WIN2K )
    {
        unsigned long int i_bytes;
        if( !ReadFile( (HANDLE)dvdcss->i_fd, dvdcss->p_readv_buffer,
                       i_blocks_total * DVDCSS_BLOCK_SIZE, &i_bytes, NULL ) )
        {
            /* The read failed... too bad.
             * As in the posix spec the file postition is left
             * unspecified after a failure */
            dvdcss->i_pos = -1;
            return -1;
        }
        i_blocks_read = i_bytes / DVDCSS_BLOCK_SIZE;
    }
    else /* Win9x */
    {
        i_blocks_read = aspi_read_internal( dvdcss->i_fd,
                                            dvdcss->p_readv_buffer,
                                            i_blocks_total );
        if( i_blocks_read < 0 )
        {
            /* See above */
            dvdcss->i_pos = -1;
            return -1;
        }
    }

    /* We just have to copy the content of the temp buffer into the iovecs */
    for( i_index = 0, i_blocks_total = i_blocks_read;
         i_blocks_total > 0;
         i_index++ )
    {
        memcpy( p_iovec[i_index].iov_base,
                dvdcss->p_readv_buffer + (i_blocks_read - i_blocks_total)
                                           * DVDCSS_BLOCK_SIZE,
                p_iovec[i_index].iov_len );
        /* if we read less blocks than asked, we'll just end up copying
         * garbage, this isn't an issue as we return the number of
         * blocks actually read */
        i_blocks_total -= ( p_iovec[i_index].iov_len / DVDCSS_BLOCK_SIZE );
    }

    dvdcss->i_pos += i_blocks_read;
    return i_blocks_read;
}

static int aspi_read_internal( int i_fd, void *p_data, int i_blocks )
{
    HANDLE hEvent;
    struct SRB_ExecSCSICmd ssc;
    struct w32_aspidev *fd = (struct w32_aspidev *) i_fd;

    /* Create the transfer completion event */
    hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );
    if( hEvent == NULL )
    {
        return -1;
    }

    memset( &ssc, 0, sizeof( ssc ) );

    ssc.SRB_Cmd         = SC_EXEC_SCSI_CMD;
    ssc.SRB_Flags       = SRB_DIR_IN | SRB_EVENT_NOTIFY;
    ssc.SRB_HaId        = LOBYTE( fd->i_sid );
    ssc.SRB_Target      = HIBYTE( fd->i_sid );
    ssc.SRB_SenseLen    = SENSE_LEN;

    ssc.SRB_PostProc = (LPVOID) hEvent;
    ssc.SRB_BufPointer  = p_data;
    ssc.SRB_CDBLen      = 12;

    ssc.CDBByte[0]      = 0xA8; /* RAW */
    ssc.CDBByte[2]      = (UCHAR) (fd->i_blocks >> 24);
    ssc.CDBByte[3]      = (UCHAR) (fd->i_blocks >> 16) & 0xff;
    ssc.CDBByte[4]      = (UCHAR) (fd->i_blocks >> 8) & 0xff;
    ssc.CDBByte[5]      = (UCHAR) (fd->i_blocks) & 0xff;

    /* We have to break down the reads into 64kb pieces (ASPI restriction) */
    if( i_blocks > 32 )
    {
        ssc.SRB_BufLen = 32 * DVDCSS_BLOCK_SIZE;
        ssc.CDBByte[9] = 32;
        fd->i_blocks  += 32;

        /* Initiate transfer */
        ResetEvent( hEvent );
        fd->lpSendCommand( (void*) &ssc );

        /* transfer the next 64kb (aspi_read_internal is called recursively)
         * We need to check the status of the read on return */
        if( aspi_read_internal( i_fd,
                                (uint8_t*) p_data + 32 * DVDCSS_BLOCK_SIZE,
                                i_blocks - 32) < 0 )
        {
            return -1;
        }
    }
    else
    {
        /* This is the last transfer */
        ssc.SRB_BufLen   = i_blocks * DVDCSS_BLOCK_SIZE;
        ssc.CDBByte[9]   = (UCHAR) i_blocks;
        fd->i_blocks += i_blocks;

        /* Initiate transfer */
        ResetEvent( hEvent );
        fd->lpSendCommand( (void*) &ssc );

    }

    /* If the command has still not been processed, wait until it's finished */
    if( ssc.SRB_Status == SS_PENDING )
    {
        WaitForSingleObject( hEvent, INFINITE );
    }
    CloseHandle( hEvent );

    /* check that the transfer went as planned */
    if( ssc.SRB_Status != SS_COMP )
    {
      return -1;
    }

    return i_blocks;
}
#endif