[PATCH v4 1/3] ALSA: compress: document the compress audio state machine
From: Vinod Koul
Date: Mon Jun 29 2020 - 17:38:41 EST
So we had some discussions of the stream states, so I thought it is a
good idea to document the state transitions, so add it documentation
Reviewed-by: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
---
.../sound/designs/compress-offload.rst | 51 +++++++++++++++++++
1 file changed, 51 insertions(+)
diff --git a/Documentation/sound/designs/compress-offload.rst b/Documentation/sound/designs/compress-offload.rst
index ad4bfbdacc83..b6e9025ae105 100644
--- a/Documentation/sound/designs/compress-offload.rst
+++ b/Documentation/sound/designs/compress-offload.rst
@@ -151,6 +151,57 @@ Modifications include:
- Addition of encoding options when required (derived from OpenMAX IL)
- Addition of rateControlSupported (missing in OpenMAX AL)
+State Machine
+=============
+
+The compressed audio stream state machine is described below ::
+
+ +----------+
+ | |
+ | OPEN |
+ | |
+ +----------+
+ |
+ |
+ | compr_set_params()
+ |
+ v
+ compr_free() +----------+
+ +------------------------------------| |
+ | | SETUP |
+ | +------------------------>| |<-------------------------+
+ | | compr_drain_notify() +----------+ |
+ | | or | |
+ | | compr_stop() | |
+ | | | compr_write() |
+ | | | |
+ | | v |
+ | | +----------+ |
+ | | | | compr_free() |
+ | | | PREPARE |---------------> A |
+ | | | | |
+ | | +----------+ |
+ | | | |
+ | | | |
+ | | | compr_start() |
+ | | | |
+ | | v |
+ | +----------+ +----------+ |
+ | | | compr_drain() | | compr_stop() |
+ | | DRAIN |<-------------------| RUNNING |--------------------------+
+ | | | | | |
+ | +----------+ +----------+ |
+ | | ^ |
+ | A | | |
+ | | compr_pause() | | compr_resume() |
+ | | | | |
+ | v v | |
+ | +----------+ +----------+ |
+ | | | | | compr_stop() |
+ +--->| FREE | | PAUSE |---------------------------+
+ | | | |
+ +----------+ +----------+
+
Gapless Playback
================
--
2.26.2