Using liveadder

Oly olymk2 at gmail.com
Wed May 8 15:56:33 PDT 2013


I guess multiple pipelines would be an option, wonder what latency that may
have creating loading converting. Also does not seem that efficient seems
the ideal would be to load convert and reuse the converted audio from
memory. I do plan on storing the output at some point. For now best I can
describe is like a mobile phone / guitar app that mixes the notes together
but the notes are audio files that should give a good idea of the sort of
pipeline I am after :)
On 8 May 2013 23:44, "John Westing" <john.blank.westing at gmail.com> wrote:

> liveadder is what it is, I simply don't understand how to use it. The
> pipeline examples I showed above were just proof-of-concept to explain my
> problem, my target configuration is RTP and combining multiple streams. and
> I don't understand why liveadder can't play the pipelines I have above? In
> my pipeline example I configured the timestamps and durations to be exact,
> and starting from 0, what timestamp information does liveadder expect to be
> able to pass audio through it? Also Olivier while I have your attention, I
> was able somehow to get liveadder to pass audio with an RTP stream,
> however, when I started the second stream liveadder only passed the first
> stream I started, even when I paused the first and only played the second,
> it only allows the first stream through in all cases. I can see that
> liveadder negotiates caps with both of its sink pads, data is getting to
> it, it just doesn't get passed to alsasink for the second stream.
>
> Oly, not exactly sure what your idea was for a final application, but
> couldn't you just have a program that listens for key strokes and invokes
> pipelines when key pressed events are received? ex: gst-launch filesrc
> location=soundforAkey.wav ! wavparse ! alsasink. You could write a
> gstreamer app to create the pipelines or invoke gst-launch using system().
> Multiple instances of alsasink in different processes will mix the sounds
> automatically (on my platform). You can send signals to the processes to
> stop them and start over, or seek to the beginning if you can support
> seeking. Just my thoughts, maybe I've under estimated the difficulty of
> your problem.
>
>
>
> On Wed, May 8, 2013 at 5:44 PM, Oly <olymk2 at gmail.com> wrote:
>
>> Well what i was trying to achieve was in essence to load in several
>> samples and mix them in real time with low latency, best example i can give
>> is to hit a key on the keyboard and the sound plays instantly press it
>> again and it starts same sound from start, hit a different key and its
>> mixed into the other sample.
>>
>> From the time i spent looking into this it seemed mixer and live adder
>> are the way to go but i could be wrong there are a lot of plugins, they are
>> short samples think wav or aiff samples and could be left in memory because
>> the samples will not change once the program is running.
>>
>>
>> On Wed, May 8, 2013 at 10:34 PM, Olivier Crête <
>> olivier.crete at collabora.com> wrote:
>>
>>> On Wed, 2013-05-08 at 21:09 +0100, Oly wrote:
>>> > I would be interested in an answer to this i asked a similar question
>>> > a while back and have still not figured it out, i tend to agree it
>>> > feels like liveaddr is just broke adder seems to work but everthing
>>> > goes strange when i switch possibly something i am doing but there is
>>> > a lack of information for liveaddr.
>>>
>>> Liveadder has been designed for live sparse streams (like the ones you
>>> get from RTP). If your sparse stream has GAP events in the gaps, just
>>> use regular adder. If not (and you have a good reason not to have GAP
>>> events), then I guess we could try to fix up liveadder.
>>>
>>> --
>>> Olivier Crête
>>> olivier.crete at collabora.com
>>>
>>> _______________________________________________
>>> gstreamer-devel mailing list
>>> gstreamer-devel at lists.freedesktop.org
>>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>>
>>
>>
>> _______________________________________________
>> gstreamer-devel mailing list
>> gstreamer-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>>
>>
>
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/gstreamer-devel/attachments/20130508/f2a3697e/attachment.html>


More information about the gstreamer-devel mailing list