[mythtv] [PATCH] DVB fixes

[Augusto Cardoso]

Hi!



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On 12/21/2003 at 3:32 AM Kenneth Aafløy wrote:
...
>
>But none of those had a cam attached, right?
>
>The problem is that the cam is sent a program map table, which I have
>to wait for in dvbcam. This will then skip some content in the stream,
>because the cam won't let data through untill it knows what to decode,
>and has verified the card ws stream content.
>
>I'm also pretty sure that all info in the PS is contained in the TS
>packets, and not generated by libdvbdev. Because TS is merely a wrapper
>for the PS, which just needs unpacking.
>

You're right, I'm not running with a CAM. What you do is to fix the dvbrecorder.cpp and enable the wait_for_seqstart. Without CAM, the you don't need the wait_for_seqstart.

Please change the default for wait_for_seqstart to true and please commit these changes because some of them do fix a couple of crashes.

...
>
>Nothing audio/video related is stored in 1ba (pack_start), it's stored
>in a program map with startcode 1bc (look at libavformat/mpeg.c). It's
>merely an indicator of the start of a group of packets, iirc.
>

The muxrate is necessary and it's calculated from the video and audio data. This has to do more with avsync and the timing model of MPEG. Please note that some players and some implementation don't use this.

The 00 00 01 BA and 00 00 01 BB aren't present in the TS stream. They are currently generated in the libdvbdev. Please look at the code if you don't believe me. This is in ctools.c "cwrite_ps". There is a whole sequence of events that starts in transform.c and will eventually get to "cwrite_ps".

	Augusto