On Tue, 21 Dec 2004 00:01:03 +0800, Tj <[EMAIL PROTECTED]> wrote: > Marcus Metzler wrote:
> For my broadcasts, what immediately comes after 0x00 0x00 0x00 0xbd is > not 0x80. It's some arbitary number which follows no apparant pattern to > me.. That is PES header's length field. For AC3 with the DVD header Mr Metzler talked about the first byte os PES _payload_ is 0x80 - 0x87. Description of PES packet can be found at ISO 13838-1 or ITU-T H.222.0, they are the same document. If you do not have access to those you can see for example http://dvd.sourceforge.net/dvdinfo/pes-hdr.html . > There will be a problem for me if I call "startcode = get_byte > (&s->pb)", decrement the len var and then realised I did not get the > range I want. because at the end of this function, I assign pstart_code > to whatever comes after 0x00 0x00 0x00 0xbd, which appears to be random > (not tested throughly). > Everything else in myth expects a 0x80 after 0x00 0x00 0x00 0xbd, but my > mythbox doesn't do that, causing mythfrontend to crash as it's not > expecting that as a startcode. No it does not, it expects 0x80 after PES header. Read mpegps_read_pes_header carefully, before the line "if (startcode == 0x1bd) {" the PES header is eaten away and "startcode = get_byte(&s->pb);" three lines after reads the first byte of the payload. > Without seeing 0x80, I can't really be sure that the private stream I'm > handling is actually AC3 rite? How save is it to skip this block of You can make a good estimate by looking if the first two bytes of PES payload are AC3 frame start (0x0b 0x77). > Is this a computer hardware, TV antenna issue or software issue? Is this > a bad packet caused by a faulty/lousy antenna? I'd guess software. I'll try to look into it. - Juha -- Madness takes it's toll. Please have exact change.
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