[NUT-devel] Info Packets

[Michael Niedermayer]

Hi

On Mon, Feb 20, 2006 at 06:22:34AM +0200, Oded Shimon wrote:
> On Sun, Feb 19, 2006 at 10:04:21PM +0100, Michael Niedermayer wrote:
> > Hi
> > 
> > On Sun, Feb 19, 2006 at 08:48:55PM +0200, Oded Shimon wrote:
> > > On Sun, Feb 19, 2006 at 07:15:17PM +0100, Michael Niedermayer wrote:
> > > > On Sun, Feb 19, 2006 at 07:04:02PM +0200, Oded Shimon wrote:
> > > > > On Sun, Feb 19, 2006 at 06:47:13PM +0200, Oded Shimon wrote:
> > > > > > On Sun, Feb 19, 2006 at 03:42:11PM +0100, Michael Niedermayer wrote:
> > > > > > > maybe a system we both would like is to add a list of streams and start/stop
> > > > > > > times at the top of every info packet, so that the packet applies to
> > > > > > > (streamX + StreamY + ... + StreamZ) at the time intervals 
> > > > > > > (startX..endX + startY..EndY + ... + startZ..EndZ)
> > > > > > > 
> > > > > > > and require that every 2 info packes with the same streams and intervalls be
> > > > > > > identical
> > > > > > > 
> > > > > > > that would avoid the chapter limitation your system introduces and it doesnt
> > > > > > > make info packets depend on each other which means simpler parsing and
> > > > > > > more error robustness
> > > > > > 
> > > > > > Do we really need the ability to specify regions smaller/seperate from
> > > > > > chapters? I fail to see the usefulness of this... Even mkv doesn't have 
> > > > > > such an ability, and they are the bloated tag-info experts...
> > > > > > Maybe we can make a 'chapterid=-1' or whatever that means it's not any 
> > > > > > chapter, it's some subregion. it has the disadvantage of having to allow 
> > > > > > several packets with the same "chapterid"..
> > > > > 
> > > > > Alternative, chapterid=-1,-2,... each subregion has a new id. (the only 
> > > > > reason negative values are special, they can overlap real chapters with 
> > > > > positive id's..)
> > > > > 
> > > > > This only works if we agree to dump the bitmask...
> > > > > 
> > > > > I preffer simplicity over compactness for the info packets...
> > > > 
> > > > i wont object against a single stream id and single start/stop time per info
> > > > packet as long as the overhead is not unreasonable
> > > > 
> > > > i am against your overlapping restrictions and negative chapter ids
> > > > 
> > > > 
> > > > packet: streamid=-1(all), startTime=0, len=sth_big, Title=foobar
> > > > packet: streamid=-1(all), startTime=0, len=123, Type="chapter", Title="Introduction"
> > > > packet: streamid=1, startTime=0, len=sth_big, Lang=mixed, PrimaryLang=eng
> > > > packet: streamid=1, startTime=100, len=50, Lang=ger
> > > 
> > > Hmm, you can do all this with the negative chapter ids, so what's the 
> > > problem?
> > 
> > negative chapter ids are an ugly hack
> 
> I somewhat agree... It reflects me failing to see the usefulness of 
> specifying subareas... It also confuses the player, it has several info 
> packets applying to the same region...
> 
> > and from where do we know the start/stop times of the chapters, iam
> > strongly against putting all chapter start/stop times in a single packet
> 
> I already gave up this, I said so in the other thread...
> 
> The idea I have in mind right now is:
> 
> packet: streamid=-1, chapterid=1, start=0, len=50, title=bla
> packet: streamid=-1, chapterid=2, start=50, len=30, title=whatever
> packet: streamid=-1, chapterid=-1, start=30, len=40, title=...
> 
> It's not very different from your idea of identifying packets by stream and 
> start/stop time... I suppose we can do that... Can you give a spec for how 
> to code it?

    stream_plus_1                       v
    start                               v
    len                                 v
    chapterid                           s
    count                               v
    for(i=0; i<count; i++{
        name                            vb
        value                           s
        if(value==-1){
            type= "UTF-8"
            value                       vb
        }else if(value==-2){
            type                        vb
            value                       vb
        }else if(value<-2){
            value.den= -value-2
            value.num                   s
        }
    }


stream_plus_1
    if zero then the packet applies to all streams

start/len
    are in the timebase of stream_plus_1 - 1 or msecs if stream_plus_1=0


[...]
-- 
Michael