goldendict-ng/multimediaaudioplayer.cc
Igor Kushnir 9aa3c44d4e Add QMediaPlayer internal player back end (Qt5 only)
* add config and GUI support for internal player back end switching;
* make FFmpeg player disabling option consistent with other similar
  qmake options by using CONFIG;
* add a new qmake option that disables Qt Multimedia player. This is
  useful for GNU/Linux distributions where Qt WebKit and Qt Multimedia
  packages depend on different GStreamer versions and don't work
  correctly when combined in one application.

The existing FFmpeg+libao internal player back end has a relatively
low-level implementation, which is difficult to understand and improve.
There are at least 3 open internal player issues:
  1) many GNU/Linux users have to edit their libao configuration file to
     make Goldendict's internal player work (issue #412);
  2) libao's pulseaudio plugin does not support 32-bit audio, which
     means that many MediaWiki pronunciations don't work with the most
     popular GNU/Linux audio driver (issue #949);
  3) Ffmpeg::DecoderContext uses deprecated FFmpeg APIs, which causes
     compiler warnings and means that this internal player back end
     may not compile with a future FFmpeg library version (issue #978).

The Qt Multimedia back end implementation uses the highest-level
Qt audio API and is very simple.
This new back end works flawlessly on my GNU/Linux machine.
I'm not making it the default back end because I don't know how well
it will work on other platforms with different configurations.
2018-03-30 17:10:33 +03:00

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1.2 KiB
C++

/* This file is (c) 2018 Igor Kushnir <igorkuo@gmail.com>
* Part of GoldenDict. Licensed under GPLv3 or later, see the LICENSE file */
#ifdef MAKE_QTMULTIMEDIA_PLAYER
#include <QByteArray>
#include <QMediaContent>
#include "multimediaaudioplayer.hh"
MultimediaAudioPlayer::MultimediaAudioPlayer() :
player( 0, QMediaPlayer::StreamPlayback )
{
typedef void( QMediaPlayer::* ErrorSignal )( QMediaPlayer::Error );
connect( &player, static_cast< ErrorSignal >( &QMediaPlayer::error ),
this, &MultimediaAudioPlayer::onMediaPlayerError );
}
QString MultimediaAudioPlayer::play( const char * data, int size )
{
stop();
audioBuffer.setData( data, size );
if( !audioBuffer.open( QIODevice::ReadOnly ) )
return tr( "Couldn't open audio buffer for reading." );
player.setMedia( QMediaContent(), &audioBuffer );
player.play();
return QString();
}
void MultimediaAudioPlayer::stop()
{
player.setMedia( QMediaContent() ); // Forget about audioBuffer.
audioBuffer.close();
audioBuffer.setData( QByteArray() ); // Free memory.
}
void MultimediaAudioPlayer::onMediaPlayerError()
{
emit error( player.errorString() );
}
#endif // MAKE_QTMULTIMEDIA_PLAYER