Hello all, I have a DirectKS application with code based off the Microsoft sample but modified for much lower latency and wider (>stereo) output. My code works well with most soundcards, but there's a SoundMAX 6 channel embedded audio chip (presumably 5.1) that is giving me trouble. Here's what my diagnostic code returns to me: Filter SoundMAX Digital Audio has 1 Render Sink Pins Begin pin detail Filter SoundMAX Digital Audio Pin KSDATARANGE_AUDIO.DataRange: MajorFormat = {73647561-0000-0010-8000-00AA00389B71} SubFormat = {00000001-0000-0010-8000-00AA00389B71} Specifier = {05589F81-C356-11CE-BF01-00AA0055595A} MaximumChannels = 6 MinimumBitsPerSample = 8 MaximumBitsPerSample = 16 MinimumSampleFrequency = 100 MaximumSampleFrequency = 48000 MajorFormat is valid Subformat is valid Specifier is valid Channels, Bits per sample, and Frequency are valid Successfully set pin format Driver could not handle WAVE_FORMAT_EXTENSIBLE, trying WAVE_FORMAT_PCM Successfully set pin format Error - could not instantiate pin Filter SoundMAX Digital Audio Pin KSDATARANGE_AUDIO.DataRange: MajorFormat = {73647561-0000-0010-8000-00AA00389B71} SubFormat = {00000001-0000-0010-8000-00AA00389B71} Specifier = {518590A2-A184-11D0-8522-00C04FD9BAF3} MaximumChannels = 6 MinimumBitsPerSample = 8 MaximumBitsPerSample = 16 MinimumSampleFrequency = 100 MaximumSampleFrequency = 48000 MajorFormat is valid Subformat is valid Specifier is invalid Filter SoundMAX Digital Audio Pin KSDATARANGE_AUDIO.DataRange: MajorFormat = {73647561-0000-0010-8000-00AA00389B71} SubFormat = {00000000-0000-0000-0000-000000000000} Specifier = {05589F81-C356-11CE-BF01-00AA0055595A} MaximumChannels = 6 MinimumBitsPerSample = 8 MaximumBitsPerSample = 16 MinimumSampleFrequency = 100 MaximumSampleFrequency = 48000 MajorFormat is valid Subformat is valid Specifier is valid Channels, Bits per sample, and Frequency are valid Successfully set pin format Driver could not handle WAVE_FORMAT_EXTENSIBLE, trying WAVE_FORMAT_PCM Successfully set pin format Error - could not instantiate pin Filter SoundMAX Digital Audio Pin KSDATARANGE_AUDIO.DataRange: MajorFormat = {73647561-0000-0010-8000-00AA00389B71} SubFormat = {00000000-0000-0000-0000-000000000000} Specifier = {518590A2-A184-11D0-8522-00C04FD9BAF3} MaximumChannels = 6 MinimumBitsPerSample = 8 MaximumBitsPerSample = 16 MinimumSampleFrequency = 100 MaximumSampleFrequency = 48000 MajorFormat is valid Subformat is valid Specifier is invalid End pin detail As you can see, I try to open WAVE_FORMAT_EXTENSIBLE and if it fails I try WAVE_FORMAT_PCM (like the DirectKS sample). You can also see that I cannot ever successfully open a render sink pin although the preceeding set pin format is successful. My WAVEFORMATEXTENSIBLE struct upon open is: WAVEFORMATEXTENSIBLE wfx; wfx.Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE; wfx.Format.nChannels = pKSDATARANGE_AUDIO->MaximumChannels; // 6 in the SoundMAX case wfx.Format.nSamplesPerSec = 44100; wfx.Format.nBlockAlign = (hwBitDepth/8) * pKSDATARANGE_AUDIO->MaximumChannels; wfx.Format.nAvgBytesPerSec = wfx.Format.nSamplesPerSec * wfx.Format.nBlockAlign; wfx.Format.wBitsPerSample = hwBitDepth; wfx.Format.cbSize = sizeof(WAVEFORMATEXTENSIBLE)-sizeof(WAVEFORMATEX); wfx.Samples.wValidBitsPerSample = hwBitDepth; wfx.dwChannelMask = 0; wfx.SubFormat = KSDATAFORMAT_SUBTYPE_PCM; hwBitDepth is always either 16 or 32, but in the SoundMAX case its 16. Any ideas why I cannot instantiate this render sink pin? Is there something obvious I'm missing? Also, another question: Many WDM drivers allow me to just swap 2 data buffers into the render sink pin, but there's a few out there (Soundblaster Live! 5.1) that requires at least 3 buffers to prevent audio dropouts. Is there any way to know algorithmically, what the minimum is? Thanks, Mike Garrett ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.de/