I don't think we should restrict any use case, but the focus should be to 
optimize performance in common cases.

To clarify my all-intra comment, I did indeed mean a test config of all intra 
frames (like jct-vc), but the primary purpose of those results would be a 
separate data point for general intra efficiency in all use cases, not 
specifically for an all-intra use case, which I agree is rather rare outside 
some professional applications.

Mo



On Mar 16, 2015, at 3:14 AM, Mohammed Raad 
<[email protected]<mailto:[email protected]>> wrote:

Are there any use-cases besides web streaming and communication that is being 
considered for this effort? If people are thinking of using a new codec for 
something like digital cinema then an all intra case makes sense.

Mohammed

On Sun, Mar 15, 2015 at 11:06 PM, Harald Alvestrand 
<[email protected]<mailto:[email protected]>> wrote:
(side note: I *hate* the current setting of Thunderbird where it doesn't
wrap lines before replying - it interferes destructively with Mo's
Outlook settings that send plain text with extremely long lines...
apologies for the broken result.)


Den 15. mars 2015 17:54, skrev Mo Zanaty (mzanaty):
> I don't have good stats, but I'm sure it's much longer than all current test 
> sequences, which tend to be only a few seconds due to uncompressed video size 
> constraints.
>
> It is important to understand intra efficiency during a stream switch, 
> recovery, join, random access, etc. Perhaps we can just test All-Intra 
> configs as a separate data point for this rather than mixing periodic intra.
>

By "All-Intra", do you mean streams with only I-frames? I think they are
probably too unrealistic to tell us much except the still image
performance. Even adding 3 p-frames after the i-frame will
*significantly* increase compression of the video stream.

But it would indeed be nice to have specific data on how the encoding
efficiency varies with recovery point interval. There should be some
point where the average efficiency is not significantly affected by
regular I-frames, because the I-frame size is small compared to the
accumulated p-frames (but the bumpy bitrate caused by large I-frames
could still cause interesting effects in bandwidth-constrained situations.)

> Mo
>
>
>
> On Mar 15, 2015, at 10:07 AM, Timothy B. Terriberry 
> <[email protected]<mailto:[email protected]>> wrote:
>
> Mo Zanaty (mzanaty) wrote:
>> Another reason for testing with periodic intra is the recent rise in RTP 
>> mixers which switch rather than transcode media. Setting the intra interval 
>> to the average active speaker switching time gives a good estimate of 
>> real-world codec efficiency in these topologies.
>
> Do either you or Harald have some statistics with which to estimate that time?
>
> _______________________________________________
> video-codec mailing list
> [email protected]<mailto:[email protected]>
> https://www.ietf.org/mailman/listinfo/video-codec
>
> _______________________________________________
> video-codec mailing list
> [email protected]<mailto:[email protected]>
> https://www.ietf.org/mailman/listinfo/video-codec
>

_______________________________________________
video-codec mailing list
[email protected]<mailto:[email protected]>
https://www.ietf.org/mailman/listinfo/video-codec



--
Mohammed Raad, PhD.
Partner
RAADTECH CONSULTING
P.O. Box 113
Warrawong
NSW 2502 Australia
Phone: +61 414451478
Email: [email protected]<mailto:[email protected]>
_______________________________________________
video-codec mailing list
[email protected]<mailto:[email protected]>
https://www.ietf.org/mailman/listinfo/video-codec
_______________________________________________
video-codec mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/video-codec

Reply via email to