mirror of
https://github.com/genodelabs/genode.git
synced 2025-01-04 04:54:12 +00:00
4d442bca30
This patch reduces the number of exception types by facilitating globally defined exceptions for common usage patterns shared by most services. In particular, RPC functions that demand a session-resource upgrade not longer reflect this condition via a session-specific exception but via the 'Out_of_ram' or 'Out_of_caps' types. Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable', 'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args', 'Service::Unavailable', and 'Local_service::Factory::Denied' types have been replaced by the single 'Service_denied' exception type defined in 'session/session.h'. This consolidation eases the error handling (there are fewer exceptions to handle), alleviates the need to convert exceptions along the session-creation call chain, and avoids possible aliasing problems (catching the wrong type with the same name but living in a different scope). |
||
|---|---|---|
| .. | ||
| mixer.cc | ||
| README | ||
| target.mk | ||
The mixer component implements a simple Audio_out session mixer. Input packets from multiple sources are mixed together into one output packet. The mixer can be tested by executing the 'repos/os/run/mixer.run' run script. Configuration ============= The mixer gets its configuration via a ROM module called 'mixer.config'. The following configuration snippet illustrates its structure: ! <config> ! <default out_volume="75" volume="25" muted="0"/> ! <channel_list> ! <channel type="input" label="client" number="0" volume="75" muted="1"/> ! <channel type="input" label="client" number="1" volume="15" muted="1"/> ! <channel type="output" label="master" number="0" volume="100" muted="0"/> ! <channel type="output" label="master" number="1" volume="100" muted="0"/> ! </channel_list> ! </config> The '<default>' node is used to set up the initial settings for new clients. According to this configuration every new client will start with a volume level set to 25 and is not muted. The initial output volume level is set to 75 (the volume level ranges from 0 to 100). The '<channel_list>' node contains all (pre-)configured channels. Each '<channel>' node has several mandatory attributes: 'type' specifies its type and is either 'input' or 'output', the 'label' attribute contains the label of a client for an input node and the label 'master' for an output node, 'number' specifies the channel number (0 for left and 1 for right), the 'volume' attribute sets the volume level and 'muted' marks the channel as muted. In addition, there are optional read-only channel attributes which are mainly used by the channel list report. Channel list report =================== The mixer reports all available channels in its 'channel_list' report. The report contains a `<channel_list>' node that is similar to the one used in the 'mixer.config': ! <channel_list> ! <channel type="input" label="client0" name="left" number="0" active="1" volume="100" muted="0"/> ! <channel type="input" label="client0" name="right" number="1" active="1" volume="100" muted="0"/> ! <channel type="input" label="client1" name="left" number="0" active="0" volume="25" muted="0"/> ! <channel type="input" label="client1" name="right" number="1" active="0" volume="25" muted="0"/> ! <channel type="output" label="master" name="left" number="0" active="1" volume="100" muted="0"/> ! <channel type="output" label="master" name="right" number="1" active="1" volume="100" muted="0"/> ! </channel_list> Each channel node features all mandatory attributes as well as a few optional ones. The 'name' attribute contains the name of the channel. It is the alphanumeric description of the numeric 'number' attribute. The 'active' attribute indicates whether a channel is currently playing or not. A 'channel_list' report may by used to create a new configuration for the mixer. Every time the available channels change, e.g. when a new client appears, a new report is generated by the mixer. In return this report can then be used to configure the volume level of the new client. A new report is also generated after a new configuration has been applied by the mixer.