From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from rouge.crans.org ([138.231.136.3]:57970 "EHLO rouge.crans.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753744AbZCTJI3 (ORCPT ); Fri, 20 Mar 2009 05:08:29 -0400 Message-ID: <49C35D3D.7070300@crans.org> Date: Fri, 20 Mar 2009 10:09:17 +0100 From: Brice Dubost MIME-Version: 1.0 To: linux-media@vger.kernel.org CC: linux-dvb@linuxtv.org Subject: Re: [linux-dvb] Weird TS Stream from DMX_SET_PES_FILTER References: <1002969792.105131237502284915.JavaMail.root@email> In-Reply-To: <1002969792.105131237502284915.JavaMail.root@email> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Bob Ingraham wrote: > Hello, > > I've been using the Linux DVB API to grab DBV-S MPEG2 video packets using a TechniSat S2 card. > > But something seems odd about DMX_SET_PES_FILTER. > > It returns a TS packets for my pid just fine, but by MPEG2 frames have no PES headers! The raw compressed MPEG2 frames just immediately follow the TS/adapation-field headers directly. > > When I wrote my TS packet decoder, I was expecting to have to decode PES headers after the TS header. But instead I found the raw compressed frames. > > They decode fine (with ffmpeg's libavcodec mpeg2 decoder,) and they look fine when rendered using SDL. > > But besides my own program, I can't get vlc or mplayer to decode this stream. Both vlc and mplayer sense a TS stream, but then they never render anything because, I suspect, that they can't find PES headers. > > So, two questions: > > 1. Am I crazy or is DMX_SET_PES_FILTER returning a non-standard TS stream? > > 2. Is there a way to receive a compliant MPEG-TS (or MPEG2-PS,) stream? > > 3. Should I use DMX_SET_FILTER instead? > > 4. If so, what goes in the filter/mask members of the dmx_filter_t struct? > > > Thanks, > Bob > > PS: I use the following to filter on my video stream pid (0x1344): > > struct dmx_pes_filter_params f; > > memset(&f, 0, sizeof(f)); > f.pid = (uint16_t) pid; > f.input = DMX_IN_FRONTEND; > f.output = DMX_OUT_TS_TAP; > f.pes_type = DMX_PES_OTHER; > f.flags = DMX_IMMEDIATE_START; > > Hello, I use exactly the same parameters and I get a raw mpeg2-TS stream (ie packet of 188 bytes with the TS headers as defined in the mpeg2-ts norm) If you want your stream to be read with VLC you need also the PAT and the PMT pids. If you want the sound you'll need also the PCR pid. I don't know how to get the PES headers Hope this information will help you Regards -- Brice