Microsoft KB Archive/308928

= The MCI_PLAY Command Returns No Response for Five or More Seconds =

Article ID: 308928

Article Last Modified on 10/27/2006

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APPLIES TO


 * Microsoft Windows XP Home Edition
 * Microsoft Windows XP Professional

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This article was previously published under Q308928



SYMPTOMS
When an MCI_PLAY command is sent by the mciSendCommand function to a CD-ROM device, some CD-ROM devices do not respond for five or more seconds.



CAUSE
In Windows XP, digital audio playback is enabled by installing a filter driver named Redbook.sys in the CD-ROM device driver stack. This driver emulates audio playback operations by reading the data from the audio CD digitally and sending it to kernel streaming. This works well, but MCI seems to send a PAUSE_AUDIO request between tracks, then sends a seek to reposition the head in the optical drive, and then sends a PLAY_AUDIO command to resume audio. Redbook.sys, when it finishes a previous PLAY_AUDIO command, sets its internal state to &quot;not playing.&quot; Then, when the PAUSE_AUDIO request occurs, Redbook.sys does not handle this request because it is not playing audio at the time, and sends it down the remainder of the device stack.

When this command is sent down the device stack, some drives (not all) report ABORTED_COMMAND at the ATAPI layer because the drive is not playing audio. This error is automatically (and correctly) retried by the upper layers (Cdrom.sys, in this case) with a one-second pause to allow the drive's firmware to recover from this sort of error. Windows believes the ABORTED_COMMAND response to be a very serious error, which should not be reported by drives in normal operation, including getting commands that are invalid at a given point in time. This command is therefore sent six times, with a one-second pause between each, resulting in a five-second delay.



RESOLUTION
To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to Obtain the Latest Windows XP Service Pack

The English version of this fix should have the following file attributes or later:   Date         Time   Version      Size    File name 01-Oct-2001 21:55  5.1.2600.14  55,936  Redbook.sys



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows XP Service Pack 1.



MORE INFORMATION
The following CD-ROM devices are known to exhibit the problem that is described in this article:

Goldstar LG CRD-8400B

Kyushu-Matsushita UJDA330 CD-RW

NEC 8500A CD-RW

TEAC CD-W28E CD-RW

TEAC CD-224E CD-ROM

Keywords: kbhotfixserver kbqfe kbbug kbfix kboswin2000fix kbwinxpsp1fix KB308928

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