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QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
Multimedia
Multimedia Renderer
Multimedia Renderer API
The multimedia renderer API exposes the data types and functions you can use to connect to mm-renderer, create contexts, configure inputs and outputs, control playback, and process events.
Events
The mm-renderer service can report events so you can monitor and react to changes in playback activity, input and output attachments, and any errors that occur.
mmr_metadata_split()
Get metadata properties of a single track or image inside the input file

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics tool suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running QNX Neutrino 7.1.
- Quickstart Guide
- OS Components & Operations
- Audio & Graphics API
- Multimedia
  - Adding Multimedia to Target Images
  - Multimedia Renderer
    - Multimedia Renderer: Capabilities and Architecture
      The multimedia rendering service, mm-renderer, allows multimedia applications to play audio and video content from files and devices.
    - Configuring and Starting mm-renderer
      The multimedia renderer is a connection-based service that runs on the target system and allows media applications to control and monitor playback activity through API calls.
    - Playing and Recording Media Content
      The mm-renderer service lets you play audio and video tracks, and record audio content. You can select a file or streaming server as the input, and the appropriate hardware devices or rendering service for the outputs. During playback, mm-renderer manages the media flow based on commands.
    - Multimedia Renderer API
      The multimedia renderer API exposes the data types and functions you can use to connect to mm-renderer, create contexts, configure inputs and outputs, control playback, and process events.
      - Function safety
        Function safety refers to whether or not it's safe to use the multimedia renderer API functions in certain situations.
      - Connection management
        Your client application must connect to mm-renderer before it can do anything with the service.
      - Context management
        Each mm-renderer context manages a separate media flow independently of other contexts. The media flow is defined by the input and the outputs, and can be configured by parameters.
      - Error information
        The mm-renderer service stores information about any error that occurs when an API call is made. This information includes a code for the mm-renderer error type and other data specific to either the media protocol used or the underlying POSIX error.
      - Events
        The mm-renderer service can report events so you can monitor and react to changes in playback activity, input and output attachments, and any errors that occur.
        mmr_event_arm()
        Set a sigevent to deliver when a new mm-renderer event becomes available
        mmr_event_data_set()
        Set user data for the dictionary returned with the last event
        mmr_event_get()
        Get the next available event
        mmr_event_t
        Information about an mm-renderer event
        mmr_event_type_t
        The mm-renderer events reported by the API
        mmr_event_wait()
        Wait until an event is available
        mmr_metadata_split()
        Get metadata properties of a single track or image inside the input file
        mmr_state_t
        The context states
      - Input configuration
        You can attach an input to the context by naming the URL of a track or playlist stored on a media device or in the local filesystem. The acceptable URL formats vary with the input type. For some formats, you can include parameters in the URL string, to specify settings such as the audio sampling rate.
      - Output configuration
        You must attach an output to the context before attaching the input. An output is specified by a URL. The acceptable URL format depends on the output type, which can be an audio device, video device, subpicture (for delivering subtitles), or file. For video and subpicture outputs, the URL string can configure the output window.
      - Playback control
        After you've defined the input and outputs for a context, you can send it playback commands.
    - Dictionary Object API
  - Multimedia Streaming Server
  - Multimedia Test Utilities
  - OpenMAX AL Additions
- Networking Middleware
- Programming
- Sensor Framework
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX Neutrino RTOS system and developers who want to create a QNX Neutrino resource manager free from vulnerabilities.
- Utilities & Libraries
QNX Hypervisor
The QNX Hypervisor allows you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

mmr_metadata_split()

Get metadata properties of a single track or image inside the input file

Synopsis:

#include <mm/renderer/events.h>

strm_dict_t* mmr_metadata_split(strm_dict_t const *md,
                                const char *type,
                                unsigned idx)

Arguments:

md: A handle to a dictionary containing a complete metadata set read from a METADATA event. The function doesn't consume the handle, so the caller can keep using it afterwards.
type: The media properties to look for in the metadata. For information about audio, video, or subpicture tracks, use audio, video, or subpicture. For artwork, use image.
idx: The zero-based index of the dictionary entry from which to extract metadata. This index corresponds to the input track or image for which you're retrieving properties.

Library:

mmrndclient

Description:

This function examines the metadata set stored in the md dictionary and extracts the properties indicated by type from the entry stored at idx. These properties are parsed into key-value pairs and put into a new dictionary, and a handle to this dictionary is returned.

When you receive a METADATA event through mmr_event_get(), the data field in the returned structure stores a dictionary containing the metadata properties of the attached input or a track referenced by it (e.g., a playlist entry). The dictionary's handle can be passed into mmr_metadata_split() to read properties of audio, video, and subpicture tracks, and artwork inside the input.

The following properties are stored in the new dictionary, based on the value of type:


Type	Properties
audio	`sample_rate`, `channels`, `bitrate`, `fourcc`, and `lang`
image	`width`, `height`, `mime`, and `type`
subpicture	Same as for video, except `frame_rate` isn't present
video	`frame_rate`, `bitrate`, `width`, `height`, `pixel_width`, `pixel_height`, `fourcc`, and `lang`

For information about reading these values in the dictionary, see the Dictionary Object API reference.

Returns:

A handle to a new dictionary containing the parsed properties on success, or NULL if no metadata properties are found or an error occurs. In the latter case, check errno, which can be one of:

ENOENT, if no properties were found
EINVAL, if either md or type is a null pointer or has an invalid value
ENOMEM, if there's not enough memory

Page updated: March 12, 2026