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authorVinod Koul2020-06-29 19:17:35 +0530
committerTakashi Iwai2020-07-07 11:53:27 +0200
commit2441bf4dbcb8196d994aa992b1be725a701589f2 (patch)
tree711ded6626ff7e444486b308c8fe477db4575af5 /Documentation/sound
parentd777587150bc12db82f3d3cd0b6f1a01f82e112a (diff)
ALSA: compress: document the compress audio state machine
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@opensource.cirrus.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20200629134737.105993-2-vkoul@kernel.org Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'Documentation/sound')
-rw-r--r--Documentation/sound/designs/compress-offload.rst51
1 files changed, 51 insertions, 0 deletions
diff --git a/Documentation/sound/designs/compress-offload.rst b/Documentation/sound/designs/compress-offload.rst
index ad4bfbdacc83..ad89af9b31c9 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_write() +----------+ |
+ | | ^ |
+ | | | compr_drain_notify() |
+ | | | or |
+ | | | compr_stop() |
+ | | | |
+ | | +----------+ |
+ | | | | |
+ | | | DRAIN | |
+ | | | | |
+ | | +----------+ |
+ | | ^ |
+ | | | |
+ | | | compr_drain() |
+ | | | |
+ | v | |
+ | +----------+ +----------+ |
+ | | | compr_start() | | compr_stop() |
+ | | PREPARE |------------------->| RUNNING |--------------------------+
+ | | | | | |
+ | +----------+ +----------+ |
+ | | | ^ |
+ | |compr_free() | | |
+ | | compr_pause() | | compr_resume() |
+ | | | | |
+ | v v | |
+ | +----------+ +----------+ |
+ | | | | | compr_stop() |
+ +--->| FREE | | PAUSE |---------------------------+
+ | | | |
+ +----------+ +----------+
+
Gapless Playback
================