[FFmpeg-devel] [PATCH] RTP depacketizer for AMR

Martin Storsjö martin
Wed Jan 27 16:15:50 CET 2010


On Wed, 27 Jan 2010, Michael Niedermayer wrote:

> > I also tried returning all frames at once, but ffmpeg.c gives the 
> > "Multiple frames in a packet from stream" error message (but works fine 
> > except for that).
> is there a meassureable difference in speed between returning all and
> spliting? Spliting is preferred but if there are speed advantages then
> we might think about detecting the cases where spliting is unneeded and
> avoid it. (its unneeded when decoding, needed when doing stream copy)

Splitting it within the RTP depacketizer needs one extra memcpy compared 
to returning all data at once, but I guess the same copy would have to be 
done in a parser instead (for the stream copy case) if we don't split them 

As for the speed difference, I don't really think it's measurable. The 
data amount for AMR is very low anyway (around 1,6 KB/s), so one extra 
memcpy of that amount isn't bad. And splitting may have to be done at some 
point anyway.

// Martin

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