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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.
Playback control
After you've defined the input and outputs for a context, you can send it playback commands.
mmr_list_change()
Set a new playlist

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.
      - 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.
        mmr_list_change()
        Set a new playlist
        mmr_play()
        Start playing
        mmr_seek()
        Seek to a position
        mmr_speed_set()
        Set the play speed
        mmr_stop()
        Stop playing
    - 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_list_change()

Set a new playlist

Synopsis:

#include <mm/renderer.h>

int mmr_list_change(mmr_context_t *ctxt,
                    const char *url,
                    int delta)

Arguments:

ctxt: A context handle
url: The URL of a new playlist
delta: The difference in the current track's position in the two lists

Library:

mmrndclient

Description:

Set a new playlist without interrupting playback. This function can be used only during playback of a playlist (including when it's paused, but not stopped).

The new playlist must contain the currently playing track at position n+delta, where n is its position on the old playlist and delta is the difference in its position in the two lists. This last value is signed, so it can be negative.

Returns:

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

Common errors returned by this function and recommended follow-up actions are:

MMR_ERROR_INVALID_STATE: The context was stopped when not playing. The playback might have reached the end of the old playlist and so it was too late to switch playlists without interrupting playback. To fix, attach the new playlist as an input, seek to the beginning of the appropriate track, and start playback.
MMR_ERROR_INVALID_PARAMETER: The indicated location in the new list (n + delta) is out of range or refers to a different URL. This error could be caused by a stale delta value, which results when the track you thought was playing just ended and a different track is playing now. To fix, recompute the difference between the position of the current track on the two lists.

Page updated: March 12, 2026