Ronald S. Bultje wrote:
Hi,
On Fri, Apr 29, 2011 at 12:45 PM, Clément Bœsch<ubi...@gmail.com> wrote:
On Fri, Apr 29, 2011 at 07:27:26AM +0200, Vladimir Pantelic wrote:
On 04/28/2011 05:10 PM, Ronald S. Bultje wrote:
>Hi,
>
>On Thu, Apr 28, 2011 at 3:05 PM, Clément Bœsch<ubi...@gmail.com> wrote:
>>This patch allows users to be notified about track switch on a continuous
>>audio stream. The A-V statusbar mess up a bit the printing sometimes, I
>>don't know how I should handle that. Also, I wonder if there is an
>>performance issue looping on every metadata that often.
>
>Seems like a case where introducing a "metadata_changed" message
>somewhere would help. Maybe in AVPacket.side_data? :-).
This is not really simple to handle when you are in the metadata scope:
metadata functions don't have access the AVPacket, it would require a few
changes.
since metadata can change out-of-band, what pkt would you attach it to?
why not make a simple counter in metadata that increases on each change,
then users don't have to md5sum it to know if it was modified?
I tried that, but it would require an API modification, and actually it
does not work for a simple reason: the metadata allocation is completely
destroyed and a new one is created on track switch. So you might have the
same amount of "update count" (which is actually the same value as the
count field) while it's total different values.
But, the good news is that since it's a different pointer, we can just
based the code on this. Of course, this is assuming all other continuous
streams demuxers won't add new fields and purges the old ones, but it
looks improbable because of the complexity.
New simpler patch attached.
Not that I'm completely against this patch, after all it's only
metadata (don't take that badly Anton), but the update wouldn't
reflect when it took effect. I think that is what side_data is for. In
fact, I believe metatadata should be moved entirely into side-data
when it updates midstream, just like palettes.
again, to what stream do you attach this? user might have discarded some
streams but still be interested in metadata updates.
Or you add another metadata stream, moving libav further towards
"everything is a stream" :)
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