Re: blob metadata (was: Images ?)

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Re: blob metadata (was: Images ?)

by Stephen Sinclair :: Rate this Message:

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The idea occurred to me once that it certainly would be nice to be
able to send meta data with blobs so that they could be interpreted
correctly.  This could include applications like streaming audio data
-- you would want information about sample rate, compression, etc.
Another use case for meta data would be for sending things like
matrices: row/column information would be necessary.  (Right now I am
sending matrices as lists of 9 or 16 floats)

Well, for the former case (images, sound files), the internet is
fortunately already well-populated with standards for file types:
e.g, http://en.wikipedia.org/wiki/MIME

I suppose you could even just send a message with two blobs: a MIME
header and a file.  Of course, it might not fit in a UDP message, so
you might want to use TCP, and in that case, perhaps you also might as
well be using HTTP instead of OSC... but I digress.

For the problem of sending metadata about vector/matrix formats, I
have no solution except to define application-specific standards.
(i.e., my receiver "knows" that a certain message has a 3x3 matrix as
its 9 arguments.)  Does anyone know if there are any existing metadata
standards for identifying mathematical data structures?


Steve


On Thu, Mar 5, 2009 at 3:07 AM, Gaspard Bucher <gaspard@...> wrote:

> I am not sure I see any cross-application use case where it would be
> needed to have a common picture format. Most of the cases I see are
> image processing applications in which cases you need a lossless
> compression (not some jpg or png). Personally I could use a special
> compressed blob with some meta-data on the size and number of layers
> (multi-plane matrix).
>
> Gaspard
>
> On Thu, Mar 5, 2009 at 8:37 AM, Xavier Miller <xavier.miller@...> wrote:
>> Hello,
>>
>> In our application, we plan to send images in OSC messages. Is already a
>> type tag defined ? I think it should be interesting to define one, which
>> is not "blob".
>>
>> Something like "p" (picture), then the image format (bmp, xpm, png,
>> jpg... / dimensions), then the image blob itself.
>>
>> Kind regards,
>> Xavier Miller.
>> _______________________________________________
>> OSC_dev mailing list
>> OSC_dev@...
>> http://lists.create.ucsb.edu/mailman/listinfo/osc_dev
>>
> _______________________________________________
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> OSC_dev@...
> http://lists.create.ucsb.edu/mailman/listinfo/osc_dev
>
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Re: blob metadata (was: Images ?)

by Andy W. Schmeder-2 :: Rate this Message:

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The OSC 1.1 revision (which is coming soon) has a provision for  
annotating a blob with a MIME type.  There is also an n-dimensional  
matrix format in row-major order.

However these are mostly a stop-gap measure to prevent people from  
going crazy with new types. OSC will likely never reach the full-blown  
sophistication of something like XMLSchema when it comes to defining  
arbitrary structured data types.



On Mar 5, 2009, at 10:33 AM, Stephen Sinclair wrote:

> Well, for the former case (images, sound files), the internet is
> fortunately already well-populated with standards for file types:
> e.g, http://en.wikipedia.org/wiki/MIME

---

Andy W. Schmeder
andy [at] cnmat.berkeley.edu

Programmer/Analyst II
Research Group
Center for New Music and Audio Technologies
University of California at Berkeley
http://cnmat.berkeley.edu





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Parent Message unknown Re: blob metadata (was: Images ?)

by salsaman-3 :: Rate this Message:

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Huh...? This makes no sense at all to me - the "C" in OSC stands for
*control* - in other words it is a control channel, not a data channel...!

To me it is far more logical to send any data out of band, but for example
you could enclose this with a "sending data" / "data-received","checksum"
exchange.

This is exactly what I am doing with LiVES - OSC is control only, actual
video and audio data are sent via other routes (e.g. video/audio jack,
ogg)

There are various advantages to splitting this way, for example you can
more easily interlace/multiplex your data, you can send control messages
during the data transfer (for example a restart/cancel, volume change,
etc), also the command channels are kept quieter, thus more responsive.

Seems a bit lazy to me to want to send control and data all on the same
channel.


Just my opinion...

Salsaman.
http://lives.sourceforge.net



On Thu, March 5, 2009 19:33, Stephen Sinclair wrote:

> The idea occurred to me once that it certainly would be nice to be
> able to send meta data with blobs so that they could be interpreted
> correctly.  This could include applications like streaming audio data
> -- you would want information about sample rate, compression, etc.
> Another use case for meta data would be for sending things like
> matrices: row/column information would be necessary.  (Right now I am
> sending matrices as lists of 9 or 16 floats)
>
> Well, for the former case (images, sound files), the internet is
> fortunately already well-populated with standards for file types:
> e.g, http://en.wikipedia.org/wiki/MIME
>
> I suppose you could even just send a message with two blobs: a MIME
> header and a file.  Of course, it might not fit in a UDP message, so
> you might want to use TCP, and in that case, perhaps you also might as
> well be using HTTP instead of OSC... but I digress.
>
> For the problem of sending metadata about vector/matrix formats, I
> have no solution except to define application-specific standards.
> (i.e., my receiver "knows" that a certain message has a 3x3 matrix as
> its 9 arguments.)  Does anyone know if there are any existing metadata
> standards for identifying mathematical data structures?
>
>
> Steve
>
>
> On Thu, Mar 5, 2009 at 3:07 AM, Gaspard Bucher <gaspard@...> wrote%3

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Re: blob metadata (was: Images ?)

by Xavier Miller :: Rate this Message:

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Hello,

In the lighting domain, we transmit images to the control console by
using one protocol, the same that controls our media server (that
protocol is CITP/MSEX running on ArtNet).

When you control video devices, it would be nice to see on the
controller what you do, so that you don't need to be anymore along your
computer.

A VJ can for example go to the dancing floor playing with hiss iPhone
and controlling his VJ software there, in place of being stuck near his
computer, far away from the crowd.

In my case, transmitting images though OSC is a real need. And I will do
for my application. Up to the OSC controllers to support it or not.
Using more than one protocol to transmit so little data (thumnails, not
full HD videos) is overkill, even more for little controllers as iPhones.


Kind regards,
Xavier.

salsaman@... a écrit :

> Huh...? This makes no sense at all to me - the "C" in OSC stands for
> *control* - in other words it is a control channel, not a data channel...!
>
> To me it is far more logical to send any data out of band, but for example
> you could enclose this with a "sending data" / "data-received","checksum"
> exchange.
>
> This is exactly what I am doing with LiVES - OSC is control only, actual
> video and audio data are sent via other routes (e.g. video/audio jack,
> ogg)
>
> There are various advantages to splitting this way, for example you can
> more easily interlace/multiplex your data, you can send control messages
> during the data transfer (for example a restart/cancel, volume change,
> etc), also the command channels are kept quieter, thus more responsive.
>
> Seems a bit lazy to me to want to send control and data all on the same
> channel.
>
>
> Just my opinion...
>
> Salsaman.
> http://lives.sourceforge.net
>
>
>
> On Thu, March 5, 2009 19:33, Stephen Sinclair wrote:
>> The idea occurred to me once that it certainly would be nice to be
>> able to send meta data with blobs so that they could be interpreted
>> correctly.  This could include applications like streaming audio data
>> -- you would want information about sample rate, compression, etc.
>> Another use case for meta data would be for sending things like
>> matrices: row/column information would be necessary.  (Right now I am
>> sending matrices as lists of 9 or 16 floats)
>>
>> Well, for the former case (images, sound files), the internet is
>> fortunately already well-populated with standards for file types:
>> e.g, http://en.wikipedia.org/wiki/MIME
>>
>> I suppose you could even just send a message with two blobs: a MIME
>> header and a file.  Of course, it might not fit in a UDP message, so
>> you might want to use TCP, and in that case, perhaps you also might as
>> well be using HTTP instead of OSC... but I digress.
>>
>> For the problem of sending metadata about vector/matrix formats, I
>> have no solution except to define application-specific standards.
>> (i.e., my receiver "knows" that a certain message has a 3x3 matrix as
>> its 9 arguments.)  Does anyone know if there are any existing metadata
>> standards for identifying mathematical data structures?
>>
>>
>> Steve
>>
>>
>> On Thu, Mar 5, 2009 at 3:07 AM, Gaspard Bucher <gaspard@...> wrote%3
>
> _______________________________________________
> OSC_dev mailing list
> OSC_dev@...
> http://lists.create.ucsb.edu/mailman/listinfo/osc_dev
_______________________________________________
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Re: blob metadata (was: Images ?)

by IOhannes m zmölnig :: Rate this Message:

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Xavier Miller wrote:
> Using more than one protocol to transmit so little data (thumnails, not
> full HD videos) is overkill, even more for little controllers as iPhones.

how does a conceptual overkill relate to the limited calculating power
of an iPhone?

i do understand your need, and do not really agree with salsamans rather
orthodox view about "control" vs. data (e.g. we are all using hyperTEXT
each day to transmit media data)

but i really find it a bad idea to reserve an entire type for your
thumbnails: you still have the problem of the actual image-format stored
in the block and if you don't want to fix this in your type as well
(c'mon let's fight: i'd go for ppm) you would have to parse the
image-data in order to understand how to interpret it.


i like the idea of attaching a mime-type to the blob.

fgmasdr
IOhannes


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smime.p7s (4K) Download Attachment

Re: blob metadata (was: Images ?)

by Xavier Miller :: Rate this Message:

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No problem. As nobody here seems to have a standard, I will do something
in my side.

Kind regards,
Xavier Miller.

IOhannes m zmoelnig a écrit :

> Xavier Miller wrote:
>> Using more than one protocol to transmit so little data (thumnails, not
>> full HD videos) is overkill, even more for little controllers as iPhones.
>
> how does a conceptual overkill relate to the limited calculating power
> of an iPhone?
>
> i do understand your need, and do not really agree with salsamans rather
> orthodox view about "control" vs. data (e.g. we are all using hyperTEXT
> each day to transmit media data)
>
> but i really find it a bad idea to reserve an entire type for your
> thumbnails: you still have the problem of the actual image-format stored
> in the block and if you don't want to fix this in your type as well
> (c'mon let's fight: i'd go for ppm) you would have to parse the
> image-data in order to understand how to interpret it.
>
>
> i like the idea of attaching a mime-type to the blob.
>
> fgmasdr
> IOhannes
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> OSC_dev mailing list
> OSC_dev@...
> http://lists.create.ucsb.edu/mailman/listinfo/osc_dev
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