Messages in this thread | | | Date | Thu, 9 May 2024 13:13:34 +0200 | Subject | Re: [PATCH v15 00/16] Add audio support in v4l2 framework | From | Jaroslav Kysela <> |
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On 09. 05. 24 12:44, Shengjiu Wang wrote: >>> mem2mem is just like the decoder in the compress pipeline. which is >>> one of the components in the pipeline. >> >> I was thinking of loopback with endpoints using compress streams, >> without physical endpoint, something like: >> >> compress playback (to feed data from userspace) -> DSP (processing) -> >> compress capture (send data back to userspace) >> >> Unless I'm missing something, you should be able to process data as fast >> as you can feed it and consume it in such case. >> > > Actually in the beginning I tried this, but it did not work well. > ALSA needs time control for playback and capture, playback and capture > needs to synchronize. Usually the playback and capture pipeline is > independent in ALSA design, but in this case, the playback and capture > should synchronize, they are not independent.
The core compress API core no strict timing constraints. You can eventually0 have two half-duplex compress devices, if you like to have really independent mechanism. If something is missing in API, you can extend this API (like to inform the user space that it's a producer/consumer processing without any relation to the real time). I like this idea.
Jaroslav
-- Jaroslav Kysela <perex@perex.cz> Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
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