I have overrided the default data intersection handler. I can output 8 channel PCM actually. But I don't know why "Max Number of Channels" is always 2. From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Matthew van Eerde Sent: Friday, December 28, 2012 12:43 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Re: Max Number of Channels of a HDMI device Since you support more than two channels, you also need to override the default data intersection handler. http://msdn.microsoft.com/en-us/library/windows/hardware/ff536252(v=vs.8 5).aspx The current implementation of the port driver's default handler is limited in the types of data ranges that it can handle: * Only PCM data formats * Only mono and stereo audio streams An adapter driver that supports non-PCM or multichannel formats should implement a proprietary data-intersection handler instead of relying on the port driver to handle data intersections for these formats. From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of JimiYeh@xxxxxxxxxx Sent: Wednesday, December 26, 2012 11:55 PM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Max Number of Channels of a HDMI device Hi all, I am trying to write a WaveRT driver for HDMI on window7. I need to report my data range according to the HDMI sink device (Ex: monitor, amplifier, ...). When I attached the amplifier which can support 8 channel, The control panel will show the information about the amplifier. I can see the correct sample size range, frequency range except "Max number of Channels". "Max Number of Channels" is 2. I have checked my data range in my code. I'm sure I set the MaximumChannels is 8. if(myELD->GetFormatSupport(LPCM)) { DataRangeAudio[LPCM].DataRange.FormatSize = sizeof(KSDATARANGE_AUDIO); DataRangeAudio[LPCM].DataRange.Flags = 0; DataRangeAudio[LPCM].DataRange.SampleSize = 0; DataRangeAudio[LPCM].DataRange.Reserved = 0; DataRangeAudio[LPCM].DataRange.MajorFormat = KSDATAFORMAT_TYPE_AUDIO; DataRangeAudio[LPCM].DataRange.SubFormat = KSDATAFORMAT_SUBTYPE_PCM; DataRangeAudio[LPCM].DataRange.Specifier = KSDATAFORMAT_SPECIFIER_WAVEFORMATEX; DataRangeAudio[LPCM].MaximumChannels = myELD->GetFormatMaxChannel(LPCM); DOUT(DBGJimi, ("Max Channel : %d", DataRangeAudio[LPCM].MaximumChannels)); // the debug message is 8 DataRangeAudio[LPCM].MinimumBitsPerSample = myELD->GetFormatMinBitDepth(LPCM); DataRangeAudio[LPCM].MaximumBitsPerSample = myELD->GetFormatMaxBitDepth(LPCM); DataRangeAudio[LPCM].MinimumSampleFrequency = myELD->GetFormatMinFrequency(LPCM); DOUT(DBGJimi, ("Min rate : %d", DataRangeAudio[LPCM].MinimumSampleFrequency)); DataRangeAudio[LPCM].MaximumSampleFrequency = myELD->GetFormatMaxFrequency(LPCM); DOUT(DBGJimi, ("Max rate : %d", DataRangeAudio[LPCM].MaximumSampleFrequency)); pKsDataRange[DataRangeIndex] = reinterpret_cast<KSDATARANGE*>(&DataRangeAudio[LPCM]); DataRangeIndex++; } Thank you. Best Regards, Jimi