SiliconDust HDHomeRun Manual de usuario descargar pdf (Pagina 11)

The HDHomeRun hardware uses the digital center frequency to tune a channel.

For ATSC/US-QAM operation the Windows BDA system uses the NTSC video carrier frequency.

The HDHomeRun BDA driver will add 1.75MHz to the requested frequency to convert the

requested frequency into the digital center frequency needed by the hardware.

For DVBT/DVBC operation the Windows BDA system uses the digital center frequency. The BDA

driver will pass the requested frequency directly to the hardware.

Program/PID filtering:

The HDHomeRun supports hardware PID filtering. When used this reduces the network bandwidth

to that of the sub-channel being watched/recorded. This is useful for US-QAM as the HDHomeRun

will stream 80Mbps of network traffic if both tuners are streaming unfiltered.

There are three options for using the hardware PID filter support - filtering by program number,

custom PID handling, or built in Windows PID handling.

Filter by program number:

The HDHomeRun driver supports a custom IHDHomeRun_ProgramFilter interface to allow the BDA

application to select a program (sub-channel) of interest. The HDHomeRun will automatically

detect the required PIDs and set the PID filter appropriately.

The API consists of two functions - put_ProgramNumber and get_ProgramNumber.

1) Locate the KSNODE_BDA_PID_FILTER node of the HDHomeRun tuner.

2) Get the IHDHomeRun_ProgramFilter interface.

3) Set the program number (1-65535) by calling put_ProgramNumber. To pass all programs

unfiltered pass 0 as the program number. To disable program filtering and return to PID

filtering pass -1 as the program number.

Custom PID handling:

The HDHomeRun driver supports the Microsoft IMPEG2PIDMap interface for configuring the

hardware PID filter.

4) Locate the KSNODE_BDA_PID_FILTER node of the HDHomeRun tuner.

5) Get the IMPEG2PIDMap interface.

6) Call MapPID and UnmapPID APIs are needed.

For ATSC, typically the application will set he PID filter to PAT(0x0000) + PSIP(0x1FFB) on a

channel change.

Once the PAT has been detected and processed the application will enable the PMT PIDs identified

in the PAT.

Then, once the desired PMT has been detected and processed the application will enable the ES

PIDs (audio and video) identified in the PMT.

Built in Windows PID handling:

XP: The Windows BDA system supports the PID filtering APIs but does not set the PID filter.

XP + MCE 2005: The Windows BDA system supports the PID filtering APIs and will set the PID

filter automatically when using the standard Windows BDA components.

Vista: The Windows BDA system supports the PID filtering APIs and will attempt to set the PID

1 2 ... 6 7 8 9 10 11 12 13 14 15 16 ... 23 24

Sin comentarios

SiliconDust HDHomeRun Manual de usuario Pagina 11