Hi Rolf, You are correct that the EN300468 doesnot talk about adaptation field because it is oriented towards DVB standard.Adaptation field concept comes in MPEG2 Transport streams.I will send you the code for review once it is ready.
I have some clips as I mentioned in my first mail, where the 5th byte after the header gives the info about the offset of the setion.My query is that does the real time stream has the same syntax or not because you must have tested your code on them.Pl. find below a PAT packet which explains what I meant. <--------------------188 bytes-------------------------------------------------------------> 47 40 00 10 00 00 B0 11 00 01 C1 00 00 00 00 E0 10 00 01 E0 64 F3 1E 15 01 FF...........FF Regards, Sheetal Pandey -----Original Message----- From: Rolf Hakenes [mailto:[EMAIL PROTECTED]] Sent: Sunday, February 16, 2003 4:27 PM To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED] Subject: Re: SI_PARSER.C ISSUE Hi, sorry for this late reply, but I have been on a business trip last week. You are right. The si_parser.c code does not take care of adaptation fields at the moment. As far as I know, adaptation fields are only relevant for the MPEG stream layer (like the video, audio or SI stream), whereas si_parser.c deals with MPEG system information (SI) layer only. In my point of view this is another (higher) protocol layer. I think the driver code deals with the adaptation fields during filtering the sections out of the MPEG data stream, because I never had any problems with that. If I did something wrong, I would be very happy to integrate or fix that within the code. Please send your corrected si_parser.c to me, so that I could have a look at it. Additionally, I do not see any adaptation fields defined in EN 300468, beside the notice, that instead of using stuffing tables to fill unsused data stream regions, the adaptation mechanism could be used for this purpose as well. But that is quite obvious, as stuffing tables are the stuffing mechanism provided by the DVB-SI protocol layer, adaptation fields are the stuffing mechanism provided by the underlying protocol layer, and of course you are free to use either of them to stuff your data... Geetings, Rolf > > Hi Rolf, > > I want to bring under your notice some of the points that I had found out > during the development.I am referring the document > DVB-SI_info-en_300468v010401p for extracting various tables from TS > clips.This document can be downloaded from etsi.org which is an official > site for DVB documents. > > Pl. see that my findings are based on above document which talks about the > syntax of MPEG2 TS. > I found that the code si_parser.c doesnot take care of the ADAPTATION FIELD > CONTROL bits.To explain a little further, in the header there are two > adptation field control bits which has following options: > > 1.01-no adptation field,payload only > 2.10-adaptation field only,no payload > 3.11-adaptation field followed by payload > 4.00-reserved for future use. > > Since the code need to be general it should take care of all the four > options.The presence of an adaptation field is indicated by the adaptation > field control bits in a transport stream packet.If present,the adaptation > field directly follows the 4 Byte packet header,before any user payload > data.This is the case with the clips I have. > > I had modified the si_parser.c to consider these bits.I would highly > appreciate if you can comment on this. > > Regards, > Sheetal Pandey > ************************************************************************** This email (including any attachments) is intended for the sole use of the intended recipient/s and may contain material that is CONFIDENTIAL AND PRIVATE COMPANY INFORMATION. Any review or reliance by others or copying or distribution or forwarding of any or all of the contents in this message is STRICTLY PROHIBITED. If you are not the intended recipient, please contact the sender by email and delete all copies; your cooperation in this regard is appreciated. ************************************************************************** -- Info: To unsubscribe send a mail to [EMAIL PROTECTED] with "unsubscribe linux-dvb" as subject.
