Qt Mobility: Multimedia / Audio – Introduction

In this module, developers will learn how to make a guitar tuner application by using the audio classes of the Multimedia module of the Qt Mobility APIs.

Multimedia API

The Multimedia API provides classes for a wide range of multimedia use cases, including the following:

• Playback of audio and video from local files, network URIs, or application-provided buffers;
• Radio playback;
• Playlist management;
• Low-latency audio playback and recording;
• Camera functionality (still capture, video recording, and viewfinder preview).

In this hands-on lab, the low-level QAudioInput and QAudioOutput classes are used to generate and analyse voice.

Quite a few examples and demonstrations already exist that show how the classes of the Multimedia module of the Qt Mobility APIs can be used. For example:

• Slide show, which demonstrates how to display images and video;
• Player, which demonstrates how to change the hue, saturation, brightness, and contrast of the video being watched;
• Audio Recorder example, which demonstrates how to choose the codec and the audio source, and record the audio into a file.

Other examples can be found in the examples and demos folders of the Qt Mobility project's base repository.

The QAudioInput and QAudioOutput classes are present both in Qt (in a module QtMultimedia) and in Qt Mobility (in a module Multimedia), since they were released in the Qt 4.6.2 technology preview as part of the QtMultimedia module. After that, it was decided that the Multimedia module should be one of the Qt Mobility modules. Thus, the rest of the Multimedia classes are not present in Qt, and they are only available in Multimedia.

Qt Mobility APIs

Qt Mobility Project delivers a set of new Qt APIs with features that are well known in the world of mobile devices, particularly mobile phones. For more information about the features of Qt Mobility Project, see the Qt Mobility Project Reference Documentation page.