[NUT-devel] max pts/distance stuff

[Oded Shimon]

On Fri, Mar 10, 2006 at 02:30:18PM +0100, Michael Niedermayer wrote:
> Hi
> 
> currenbtly we have
> "
> max_distance
>     max distance of syncpoints, the distance may only be larger if
>     there is no more than a single frame between the two syncpoints. This can
>     be used by the demuxer to detect damaged frame headers if the damage
>     results in too long of a chain
> 
>     syncpoints SHOULD be placed immediately before a keyframe if the
>     previous frame of the same stream was a non-keyframe, unless such
>     non-keyframe - keyframe transitions are very frequent
> 
>     SHOULD be set to <=32768
>     if the stored value is >65536 then max_distance MUST be set to 65536

Any chance we can increase this to 128kb?

> max_pts_distance
>     max absoloute difference of pts of new frame from last_pts in the
>     timebase of the stream, without a checksum after the frameheader
>     Note that last_pts is not necessarily the pts of the last frame
>     on the same stream, as it is altered by syncpoint timestamps.
> 
> max_frame_size
>     max frame size without a checksum after the frameheader.
>     MUST be <=4*max_distance. If stored value is bigger then
>     max_frame_size MUST be set to 4*max_distance 
> "
> 
> in the spec, 
> 
> there are several issues which need disscussion
> 1. no limit for max_pts_distance, users could set it to insane values and
>    cause troubble on the demuxer side, yes theres the time rescaling issue

I dislike it... You worry too much about broken muxers. :/

"SHOULD NOT be higher than 1/timebase" ....

> 2. max_frame_size limit is too large, its practically 256k, i think 64k or
>    less is more reasonable
> 3. what about droping one varaible and max_distance=max_frame_size?

Hmm... I used to be against this, but I think now you feel stronger about 
this than I do, so no real objection...

- ods15