GNOME Bugzilla – Bug 337009
props 'blocksize' and 'buffer-time' not functional in alsasrc
Last modified: 2006-05-14 10:52:06 UTC
Setting the properties blocksize and buffer-time doens't not effect the size of the buffers received on the src pad of alsasrc. I tested it using the following commandline and viewing the size of payloads on the UDP plackets using ethereal: gst-launch-0.10 alsasrc buffer_time=20000 ! "audio/x-raw-int, channels=1, rate=8000" ! udpsink host=SOME_IP or gst-launch-0.10 alsasrc blocksize=320 ! "audio/x-raw-int, channels=1, rate=8000" ! udpsink host=SOME_IP Since these props are inherited from the GstAudioSrc class, this bug might actually be there but i am not so sure about it.
buffer-time is the value of the internal audio buffer and should not affect the buffer size of the output buffers. blocksize does nothing for audio sources. latency-time affects the size of the buffers correctly. Note that not all sources might be able to adjust their latency-time, in the case of alsa dmix, that value is specified in the alsa configuration file and cannot be changed by an application.
If the blocksize parameter does nothing for audio sources, why it is possible to try to change this value (at least for alsasrc ) using the parameter of the element ? I think it may be confusing for a lot of people.
Because the blocksize parameter is provided by the BaseSrc base class, and there's no mechanism for sub-classes to disable it, even when they don't use it. Making it possible for sub-classes to do that sounds useful to me.