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<DIV>On 11/22/2013 7:47 PM, Don Moir wrote:</DIV>
<DIV> </DIV>
<DIV>>>>>Not sure what AV_PKT_FLAG_KEY is supposed to mean. The
assumption to me early on is it represented a key frame but not
necessarily.</DIV>
<DIV> </DIV>
<DIV>>>>>Is it not a application flag ?</DIV>
<DIV> </DIV>
<DIV>>>>>Seems for at least H264 it doesnt have much meaning to
application. If the packet dts value is in the stream index_entires then that
represents a key frame for sure ( hopefully :)</DIV>
<DIV> </DIV>
<DIV>>>>>What if there are no index_entries ? Whats a key packet
then and how to determine ?</DIV>
<DIV> </DIV>
<DIV>>>>>Just trying to clear up my own confusion with this.</DIV>
<DIV> </DIV>
<DIV><BR>>>>For h264, the key frame network abstraction unit of the
packet will be of type IDR, instant data refresh. <BR>>>>I believe NAL
type 5. </DIV>
<DIV> </DIV>
<DIV>>>>Thanks Andy. </DIV>
<DIV> </DIV>
<DIV>>>>Dont see that info in a packet. Only thing relevant that
changes is the flags member (0 or 1). Now frame may contain additional info
after decoding but it's documented that >>>AV_PKT_FLAG_KEY represents a
keyframe.</DIV>
<DIV> </DIV>
<DIV>>>>If it is for internal use, a different flag should have been
used the way I see it. So trying to understand what the real intended use of
AV_PKT_FLAG_KEY is.</DIV>
<DIV> </DIV>
<DIV><BR>>>Imagine H264 at HD resolution with 5 or 6 horizontal slices
where the key frame only equals one horizontal strip</DIV>
<DIV> </DIV>
<DIV>>Yeah I get that. It sure knows that a packet is a key packet when it
adds it to the index_entries but packet flag does not correspond. Seems like the
packet flag should >correspond to the index_entries. Yes or No ?</DIV>
<DIV> </DIV>
<DIV>I guess I still don't know what AV_PKT_FLAG_KEY is intended for but if
I set skip_frame to AVDISCARD_NONKEY, its a mess. I think some work has been
done on this. Think I remember seeing something somewhere. When I get a chance
will check new build. Mostly trying to get understanding
first.<BR></DIV></FONT></BODY></HTML>