From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:55358 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751801Ab2KSKwr (ORCPT ); Mon, 19 Nov 2012 05:52:47 -0500 Received: by mail-wg0-f44.google.com with SMTP id dr13so2755257wgb.1 for ; Mon, 19 Nov 2012 02:52:46 -0800 (PST) From: Patrick Boettcher To: Richard Cc: linux-media@vger.kernel.org Subject: Re: Linux DVB Explained.. Date: Mon, 19 Nov 2012 11:52:43 +0100 Message-ID: <1603480.BOCkXrJCoo@dibcom294> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: 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