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- Bartosz: we can get raw streams (unmixed streams) by bipassing the Android framework mixer.
- Applications can request for this, but by defaults all internal streams are going through the framework mixer.
- There is also the Android Audio API which is used for low latency streams that allows us to get raw streams.
- Gunnar:Unknown User (bartoszbialek)please add your comments in the page Android and System Level Audio
- Suhasini: what about the Network audio devices? can we use the device outbus for direct access of raw streams?
- Piotr: in summary, this API is used to handle adressable ports not for use of raw streams
- Bartosz: this is used for Android to capture external streams and represent them as internal streams but the audio path is longer (more latency)
- Raw Streams are both input and output streams
- Gunnar: when we talk about Raw streams do we want to take into consideration compressed streams
- Wassim: this is a link for the data format https://source.android.com/devices/audio/data_formats
- Piotr: the PCM format is mostly used and since we are starting with a generic solution, might as well not extend it beyond this scope
Other investigation topics
- Gunnar: what about the codecs?
- Piotr: multimedia framework is doing this and it's not part of the Audio HAL
- Bartosz: Android controls whether we want to take the stream and decoded using the CPU or not (this is called Offloading)applications can request for this
Thursday 09 April - 11:30am CET (AUDIO_HAL_CW15)
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