[linux-dvb] Keep bitrates below 10Mbps...

Manu Abraham abraham.manu at gmail.com
Sat Oct 29 12:01:15 CEST 2005


Josef Wolf wrote:

>On Sat, Oct 29, 2005 at 10:37:12AM +0400, Manu Abraham wrote:
>
>Thanks for your reply!
>
>  
>
>>>- Most of the time the bitrate on the video-pid is quite low (about
>>>2000..3500 TS packets per second, which gives something below 7MBps).
>>>But sometimes (every 10..20 minutes) the bitrate raises dramatically[2]
>>>for a couple of seconds (sometimes just one second, sometimes up to 20
>>>seconds) and comes down again to the 2000..3500 range.  I really don't
>>>understand what is going on here.  How come this dramatic raise without
>>>increase in the motion or in picture-details?  Is this raise really
>>>caused by the video stream?
>>>      
>>>
>>Since the TS is constituted of more than the Video ES, the bandwidth 
>>occupied might very well depend on other factors.
>>    
>>
>
>Sorry,  I should have stated more clearly that this bitrate-raise is only
>on the video-pid (pid 101).
>
>  
>
>>I remember Johannes once saying that the EIT rate on the German Das 
>>Erste is quite high.
>>    
>>
>
>But isn't the EIT on a completely different PID?  Thus the EIT should
>have no impact on this raise.
>
>  
>

Sorry, I thought you were looking at the transport stream.

>>>I would like to try this recoding (TS->PS).  Extracting PES from the TS
>>>is not really a probem.  But unfortunately, I could not find any
>>>description how PS streams are to be constructed.  Any pointers?
>>>      
>>>
>>You can probably, check out replex from the Metzler bros, 
>>http://www.metzlerbros.org/dvb
>>    
>>
>
>I'll take a look at it.  But since I need to do it on the fly (since I want
>live-streams) I'll probably need to roll my own.
>
>  
>

A TS2PS can take a little bit of CPU power, another option was 
dvbstream, it had a ts2ps conversion, i don't know whether it is still 
there.
Once Nico had plans to remove it. If it is removed, you can check for 
some older versions.

>I found a description in iso13818-1 section 2.5, but this is somewhat hard
>to read =:)  Are any more comprehensive descriptions avalable?
>
>  
>

I think compared to other documents (eventhough not directly related, 
EN50221 and friends), 13818-1 is far better.


Manu





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