Re: [Multi channel on Jelly Bean] Support multi channel through HDMI port on Jelly Bean 4.1

[jrc src]

Hello

Any idea of how volume is controlled/handled in direct output thread?

always full?

jrc

On Thursday, April 25, 2013 6:18:51 AM UTC+5:30, David Kim wrote:

Dear Eric,

Thank you very much for your very clear and detail explanation.

Best Regards,

On Wednesday, April 17, 2013 5:58:30 AM UTC+9, Eric Laurent wrote:

David,

Mutlichannel audio uses a DirectoutputThread.

The DirectOutputThread is selected if an AudioTrack is opened with a channel mask indicating 5.1 AND the audio HAL has reported an output profile in audio_policy.conf with direct output flag set and a compatible channel mask or "dynamic" channel mask. In case of "dynamic" channel mask, the audio HAL is queried after the HDMI sink is connected for the actual number of channels supported.

The output of the down mixer is stereo only and mixed with other tracks by MixerThread.

Thanks.

Eric.

On Sunday, April 14, 2013 8:04:40 PM UTC-7, David Kim wrote:

Dear experts,

I would like to ask some questions about multi channel supporting on JellyBean. Please give your advice for my questions.

According to Google, multi channel audio can be supported from JB 4.1 as follows

'Multichannel audio : Android 4.1 supports multichannel audio on devices that have hardware multichannel audio out through the HDMI port.'

- When I connect a TV which can support multi channel through HDMI port, what is the audio path in the audioflinger?

- In case of that, which thread is using for? DirectOutputThread or MixerThread?

- Which use cases we are using the DirectOutputThread for?

- Is the output of Downmixer in the MixerThread 2-channel stereo only?

Thank you in advance.