Let's take 3 types of components 1) Component must be moved to LOADED state for power savings - A 2) Component can achieve power savings when moved to IDLE or LOADED state - B 3) Component cannot achieve power savings in any state - C
Component A requires a well written App to call release() upon screen timeout. With a well writeen app, both component A and component B can benefit. There is nothing much we can do for component C in any case. With a not well written app (which does not call release()), platform can help take advantage of capabilities of component B. Question is can the platform framework help very well written component B when it is driven by not so well writeen App. Right now my component is see as the culprit as the platform continues to consume power even when playback has ended. The bad one here is really the app which was not well written to call release() upon idle screen timeout.I can save upto siginificant amount of power (in the range of 50 -100mA depending on the component). Startup latencies are not significantly variable. If a compoent impementation strictly adheres to the specs recommendation, state transitions should complete within a short amount of time (20ms recommended by the spec when transition invloves buffer exchange - Sec 3.2 of OMX IL 1.1.2). I don't think we are violating hardware abstraction here. Implicitly, it is better to build the platform to help well written component B do its best. Whether an IL client moves the component to IDLE or PAUSE should not matter much if the component implementation is compliant with the spec. Component A and C should continue to function even if IL client moves them to IDLE instead of PAUSE. State transition delays will be in the order of few milliseconds not noticable (I don't think there is noticable delay in skipping from end of one song to the next song with PV SW codecs on G1 - In this case, framwork is doing a complete unload and reload of of potentially the same component) Sending codec config upon reinitalizing (idle to executing transition): This is not needed for all types of media formats (for example for AAC ADTS and MP3). Formats which need this would use OMX_BUFFERFLAG_CODECCONFIG to signal config data. This is an implementation issue in IL client and OMX component. This is not an issue if both are spec compliant. My component would anyway cache configuration data the first time it is provided. If IL client does not provide it at the time of idle- >executing transition, it would reuse the configuration information provided at the very beginning. i.e., it would assume that there is no configuration change. At this time I am playing with an MP3 component which does not really require reconfiguration. Sec 3.2 The standards body identified the 20-millisecond timeout to be a reasonable response time for commands that may require buffer processing to be completed; the assumption here is that the longest buffer processing would be less than 30 milliseconds, which corresponds to 30-frames per second video. Sec 2.1.4 EXECUTING enables buffer processing to resume where the component left off. Transitioning from EXECUTING or PAUSED to IDLE will cause the context in which buffers were processed to be lost, which requires the start of a stream to be reintroduced. Transitioning from IDLE to LOADED will cause operational resources such as communication buffers to be lost. On Feb 8, 11:26 am, GregS <[email protected]> wrote: > Efficient power consumption is definitely worth pursuing. > Unfortunately, to my knowledge, the OpenMAX IL spec does not give any > guidelines on the expected power consumption in different states. > Therefore there may be some OpenMAX components that might even need to > be unloaded before there is any power consumption savings, others may > have saving when driven to idle, or maybe for some it doesn't matter > what state they are in (i.e., no power savings). Remember we're > trying to create something that works across many different hardware > platforms with different OpenMAX component implementations. Using > similar logic to what you describe, it could be argued that the > OpenMAX component implementation itself should handle the issues of > power efficiency when paused rather than requiring every OpenMAX IL > client that is interfacing with it to know the details of the power > consumption in different modes as well the start-up latencies so > proper tradeoffs could be made. The point of the OpenMAX IL interface > is to abstract hardware details. > > Of course all of this is a purely abstract discussion so far and I > realize we have to deal with non-ideal implementations. So in order > to assess the tradeoffs of changing the logic, it would be helpful to > understand if you have specific OpenMAX implementations of concern. > If so can you provide numbers on the power consumption of different > states? Part of the challenge of transitioning the component to the > idle state is that the codec configuration data would need to be > cached (not done today) so it could be used to reinitialize the state > of the OpenMAX component. In pause state the component keeps all the > configuration and state information so it isn't necessary to resend it > when starting playback again somewhere in the same clip. > > On Feb 6, 8:54 am, hdandroid <[email protected]> wrote: > > > > > You would expect a well written app to issue release(). There is no > > way to enforce this on all apps that run on the platform. > > There will always be an app that is not well written which would not > > call release(). > > > From a platform perspective, android platform can allow lower power > > consumption with both types of apps. This would require Opencore to > > move the component to Idle or loaded state at the end of playaback. I > > agree that this would result in additional buffer exchange as you > > mentioned. It is really small amount of work and it does not result in > > noticable delays and it is not perceivable by human ears (while > > playing the same clip again, user would experience the same delay that > > would result when he/she moves to the next song - this change is not > > perceivable) > > > Another case is music player app is put to background in PAUSE state > > (at the end of playback) and HW continues to consume power. In this > > case, well written app would call release() before going to > > background. Some apps (not well written) apps may not perform this > > operation. > > > I suggest that Opencore make this change (move to IDLE or LOADED at > > the end of playback) allowing underlying OMX Codecs to stay power > > friendly. This would allow the Android platform to stay power friendly > > for both types of Apps (well written and not well written ones) > > > On Feb 5, 10:55 pm, rktb <[email protected]> wrote: > > > > I see what you are referring to. But, I think moving the component to > > > PAUSE state might be preferable. > > > > First of all, where does this "Pause" come from? The PVPlayerEngine, > > > at the end of a playback of content, drives the engine to a Paused > > > state. This reduces the start up time if a same clip is being played > > > in a loop. With this objective, let us evaluate the possible states. > > > > By moving the component to IDLE state, the buffers have to be returned > > > to the node. When the playback restarts for the same clip, the buffers > > > have to be resend to the component. This seems to be a waste. > > > > By moving the component to LOADED state, all the buffers would have to > > > be freed. So, restarting the clip would mean re-allocating > > > buffers...which again seems to be a waste. > > > > If the application doesn't really want to consume any resources or > > > wants to reduce power consumption, it should not wait at the end of > > > the clip and should call mediaplayer->release(). > > > > -Ravi > > > > On Feb 5, 10:25 pm, hdandroid <[email protected]> wrote: > > > > > Can someone point me to the document? Is is somewhere on PV website or > > > > can I get it from git? > > > > I am pretty sure OpenCore is not tearing down the playback session - > > > > it continues to keep the component in PAUSE after the end of playback. > > > > > On Feb 5, 6:24 pm, Dave Sparks <[email protected]> wrote: > > > > > > When the app calls release, ultimately it will flow down to through > > > > > the framework to tear down the playback session. As Freepine points > > > > > out, the OMX decoder node in OpenCore is responsible for making the > > > > > appropriate calls to transistion the OMX component. There's an OMX > > > > > guide in the OpenCore docs that should help explain this. > > > > > > On Feb 5, 1:42 am, hdandroid <[email protected]> wrote: > > > > > > > I am not clear about the flow from the app's release() method to the > > > > > > OMX component. Isn't PV SW getting involved in changing OMX > > > > > > component > > > > > > state from PAUSE to IDLE or LOADED. > > > > > > > May be a better way to ask is who drives OMX Audio decoder's state > > > > > > transition when release() method is called. (I am assuming there is > > > > > > some kind of OMX IL client PV SW in android stack) > > > > > > > On Feb 4, 11:12 pm, Dave Sparks <[email protected]> wrote: > > > > > > > > OpenCore has no context to do this, this is managed through > > > > > > > application life cycle. > > > > > > > > The app is supposed to manage the resources by calling release() > > > > > > > on > > > > > > > the MediaPlayer. If the screen times out, then the app's onPause() > > > > > > > method will be called and it should call the release() method. If > > > > > > > the > > > > > > > app is not doing this - it's an app problem. > > > > > > > > On Feb 4, 10:26 pm, hdandroid <[email protected]> wrote: > > > > > > > > > At the end of audio playback, opencore framework places OMX > > > > > > > > audio > > > > > > > > decoder component in PAUSE state. User may not perform any > > > > > > > > operation > > > > > > > > after the end of playback (may be for several minutes). In case > > > > > > > > of HW > > > > > > > > audio decode, this will hold up resources and continue to drain > > > > > > > > current in PAUSE state. To avoid this from happening, opencore > > > > > > > > can > > > > > > > > either move the component to IDLE (or LOADED) state after > > > > > > > > completing > > > > > > > > playback of each song. This will allow the component to release > > > > > > > > HW > > > > > > > > resources and reduce power consumption > > > > > > > > > Is it a straight forward change to move the component to idle > > > > > > > > state > > > > > > > > instead of pause state at the end of playback? Any issues with > > > > > > > > this > > > > > > > > approach?- Hide quoted text - > > > > > > > > - Show quoted text -- Hide quoted text - > > > > > > - Show quoted text -- Hide quoted text - > > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "android-framework" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-framework?hl=en -~----------~----~----~----~------~----~------~--~---
