Re: Linux DVB Explained..
Hi Patrick, Thanks for some clarifications, they are invaluable. On 19 November 2012 10:52, Patrick Boettcher pboettc...@kernellabs.com wrote: Hi Richard, --- The hardware I am using has 6 TS data inputs, 4 tuners (linked to TS inputs) and hardware PID filters and I am trying to establish the relationship of dmx and dmxdev. Before understanding the relationship you need to know where, in the end, you want your TS-packets. In user-space? Sent to a hardware-decoder? Somewhere else? All of that? HTH a litte bit, -- Patrick A brief description of the hardware platform : The device is a Dual Core ARM A9 SoC with 8 TS inputs (each TS channel has a dedicated PID filter) . There are 8 MPEG decoders and two live video surfaces. All TS channels can go to a mpeg decoder directly OR can be placed in a ringbuffer so that it can be sent to userspace (DVR perhaps) My aim is to create a skeleton DVB device (that works with my hardware) with documentation so that others dont have to learn the lessons I have :D It sounds easy, but I doubt it is.. Richard -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Linux DVB Explained..
Hi Richard, I can maybe answer some of your questions with semi-complete answers in the hope it helps you further. On Saturday 17 November 2012 13:35:18 Richard wrote: struct dvb_demux : This has a start_feed and a stop feed. What feed is this? ... the RAW 188 byte packets from the device perhaps? start/stop_feed are callbacks in the dvb_demux-device (which is represented with dvb/adapterX/demuxX by your driver) which have to be filled in by the driver which implements and controls the HW-demux. E.g: (from dmxdev.c) when a user is issuing the DMX_ADD_PID ioctl (which marks the request of a certain PID from the TS currently received) the start_feed-callback is called. It tells the driver that the TS-packets identified with PID are expected via e.g. the dvrX device. So the driver has to instruct its internal demux to have them pass the filter. What is the main purpose of this structure? struct dmx_demux : This structure holds the frontend device struct and contains the .fops for read/write. Is this the main interface when using the /dev/dvb/adapterX/demux ? /dvr? I'm not sure to get what you want to know here. adapter = dvb_register_adapter() : Register a new DVB device adapter (called once) dvb_dmx_init(dvbdemux); // Called once per Demux chain? dvb_dmxdev_init(); // Called once per demux chain ? same as above --- The hardware I am using has 6 TS data inputs, 4 tuners (linked to TS inputs) and hardware PID filters and I am trying to establish the relationship of dmx and dmxdev. Before understanding the relationship you need to know where, in the end, you want your TS-packets. In user-space? Sent to a hardware-decoder? Somewhere else? All of that? HTH a litte bit, -- Patrick -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Linux DVB Explained..
Apologies Mauro, I accidentailly bumped the 'Send' whilst typing your name. The message is addressed to Mauro and All, On 17 November 2012 13:35, Richard tuxbox.g...@gmail.com wrote: Hi Mau, I have started documenting a HOWTO on making a linuxDVB device and would like to know what the following is used for struct dvb_demux : This has a start_feed and a stop feed. What feed is this? ... the RAW 188 byte packets from the device perhaps? What is the main purpose of this structure? struct dmx_demux : This structure holds the frontend device struct and contains the .fops for read/write. Is this the main interface when using the /dev/dvb/adapterX/demux ? /dvr? So far... adapter = dvb_register_adapter() : Register a new DVB device adapter (called once) dvb_dmx_init(dvbdemux); // Called once per Demux chain? dvb_dmxdev_init(); // Called once per demux chain ? same as above --- The hardware I am using has 6 TS data inputs, 4 tuners (linked to TS inputs) and hardware PID filters and I am trying to establish the relationship of dmx and dmxdev. Any clarification is most welcome Best Regards, Richard To add more queries, What is the purpose of dmx_frontend and dvb_frontend The word 'frontend' seems to be sending me in a loop. Its usually FE-Tuner-Demod-PID Filter- TS Data so I am at a loss where dmx_frontend goes Richard -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
