[linux-audio-dev] Linux Alsa Audio over 1394 - a Thesis

[Martijn Sipkema]

[...]
> The bottom level packets are sent at fixed time intervals (obviously,
> corresponding to the frame clock of the bus), but these packets are tiny
> and you get millions of them per second. A useful packet of audio data
> will be made up of a bunch of these.
> 
> According to the mLAN spec you need a buffer of around ~250us (depending
> on format) to collate the packets.

Still there is no guarantee that 10 packets always have exactly the same
number of samples. You say the mLAN spec says you need a buffer of
around ~250us. Note that is doesn't say a buffer of a number of frames.
The bottom line is these packets are sent at regular time intervals, not
at a fixed number of frames and thus JACK should support this by
allowing non-const (frames) callbacks IMHO.

--ms