Set track parameters.


#include <mm/renderer.h>
int mmr_track_parameters( mmr_context_t *ctxt, 
                          unsigned index, 
                          strm_dict_t *parms )


A context handle.
Zero to set the default parameters, or an index within the current playlist window.
A dictionary object containing the parameters to set (handle gets consumed by this call, even on failure), or NULL to reset the parameters to their default values.




Set track parameters. This function can be used only when the input type is "playlist".

The index specifies the track to which these parameters are applied. This value must be within range of the current playlist window, or the function call fails. An index of zero specifies default parameters that are given to any new track that enters the playlist window.

Some plugins used by mm-renderer can change track parameter values if the provided values are not acceptable for the attached input. You can examine the track parameter settings returned through the Event API to see which values were accepted and which ones were changed (see mmr_event_data.html).

When the input URL starts with audio:, you can set one of the following parameters:

Classify the audio track based on its content (voice, ring tones, video chat, etc.). This parameter provides a shortcut for setting the audio type, thereby simplifying your client code. By using this parameter, you can avoid making the multiple Audio Manager API calls required to obtain an audio manager handle and then use that handle to set the audio type.

The audio type is specified as a string, whose value is one of the audio types defined by the AUDIO_TYPE_NAMES set of string constants, which is documented in the Audio Manager Library reference.
Associate an audio manager handle with the audio stream managed by the current context. This parameter lets you control multiple audio stream settings. To obtain a value for this parameter, call the audio_manager_get_handle() API function, passing in the desired audio type. You can then use this handle to change the audio type and other audio stream characteristics through the Audio Manager API. Refer to the audio routing functions described in the Audio Manager Library reference for more information.


Zero on success, -1 on failure (use mmr_error_info()).


QNX Neutrino

Interrupt handler No
Signal handler No
Thread Yes


See the mmr_output_parameters() examples for demos on how to set each of the audio_type and audioman_handle parameters.