[vlc] Re: H263 over RTP

[jogging song]

Hi, Chris
     There are three RFCs about h.263 packet, that is RFC 2190, RFC2429 and
RFC4629. Doe vlc support all these three RFCs?

thanks in advance.
Jogging

On 3/6/07, chris.2.dobbs at bt.com <chris.2.dobbs at bt.com> wrote:
>
>  All,
> If anyone is interested I have managed to get VLC to playback file based
> H263 video remotely over RTP (as a non-encapsulated elementary stream).
>
> I had trouble getting this to work as I couldn't figure out how to
> transpose the file based H263 records into RFC4629 RTP packets. I finally
> managed to reverse engineer to live555 code (which includes an H263 streamer
> module) and this is what u have to do:
>
> Many thanks to Ross Finlayson BTW who prodded me in the right direction
> several times...
>
> The following does not detail all the RTP field setups as they are not
> crucial to getting this to work, things like sequence number and time stamps
> are taken as read…
>
> 1. Read 5 bytes first (from file based H263 data) , this gives you a
> starting frame of reference.
>     Create 1st RTP packet and set the M bit to 1
>     Create and add to RTP payload the 2 byte H263 header and set the P bit
> to 1 (zero rest out)
>
>     copy the 5 byte record  into the RTP payload body (after the H263
> header).
>
>     Send it
>
> 2. Read as much as u can from file without blowing your MTU , in my case
> this is 1500 so I chose 1436 (like the live555 code)
>
>     Create new RTP packet + new 2 byte H263 header
>     Scan newly read in H263 record for occurance of end of frame marker -
> this is two consectutive bytes of zeros (00 00).
>
>
>     pseudo code follows:
>
>      IF eof frame marker found:
>                This record contains an end of frame so set the RTP M bit
> to 1 and  set the H263 header P bit to 0, then copy to RTP payload (after
> H263 header)
>
>             the record data  up to but NOT including the "0000". Store
> remainder in temp.
>             The next record read will therefore be a new start of frame.
>
>     IF eof frame marker not found:
>                IF previous record read contained an end of frame marker
>                            prefix the this packet with any remainder
> stored in temp and set the P bit to 1
>                            and the M bit to 0.
>                            Need to make sure at this point that we don't
> blow the MTU.
>                ELSE
>                            Set RTP M bit to 0 and H263 P bit to 0 and copy
> whole record into RTP payload(after the H263 header).
>
>     Send it !
>
> 3. Repeat 2 until EOF
>
> To get a remote vlc to read this stream, create an sdp file like this
>
>  v=0
> o=- 7776 3 IN IP4 10.215.130.112
> s=Test H263 stream
> i=Parameters for the session streamed by "ChipsAhoyH263"
> t=0 0
> m=video 7776 RTP/AVP 98
> a=rtpmap:98 H263-1998/90000
> a=fmtp:98 profile=0; level=40
> b=TIAS:2048000
>
> Where 7776 is the port you are streaming out to from above steps.
> Save as say c:\testH263.sdp
>
> Start vlc like this:
>
> Vlc -vvv *file://c:\testH263.sdp*
>
> Start the stream and u should see video.
>
> I guess I should have figured all this out from the various RFC's but to
> actually implement was not exactly straightforward - no where could I find
> info on how to look for the end of frame marker ("0000") which is the key to
> the whole thing!
>
> Hope this helps as it drove me nuts...
> -Chris
>
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