Don't play mp3

[Mihaill]

Hi!
How play audio?
If I do this:

QMediaPlayer m_player;
m_player.setSource(QUrl(m_lastPath));
QAudioOutput *audioOutput = new QAudioOutput;
m_player.setAudioOutput(audioOutput);
m_player.play();

Then I get eoor:

[mp3 @ 000001E640C19B00] Could not find codec parameters for stream 1 (Video: png, none): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, mp3, from 'C:/Users/Admin/AppData/Local/Temp/MM terminal.GtMcrE.mp3':
  Metadata:
    artist          : Sound Clip
    title           : Военно-морской сигнал тревоги 
    encoder         : Lavf56.40.101
    date            : 2020
  Duration: 00:00:08.39, start: 0.011995, bitrate: 130 kb/s
  Stream #0:0: Audio: mp3 (mp3float), 44100 Hz, stereo, fltp, 128 kb/s
      Metadata:
        encoder         : LAME3.97 
      Side data:
        replaygain: track gain - -10.600000, track peak - unknown, album gain - unknown, album peak - unknown, 
  Stream #0:1: Video: png, none, 90k tbr, 90k tbn (attached pic)
      Metadata:
        title           : Album cover
        comment         : Cover (front)

In qt5 audio player was normal work with this file.

[Mihaill]

it's work with vlc

#pragma once

#include <QObject>
#include <vlc/vlc.h>
#include <QString>
#include <QUrl>
#include <QTimer>

class VlcAudioPlayer : public QObject
{
    Q_OBJECT
public:
    explicit VlcAudioPlayer(QObject* parent = nullptr);
    ~VlcAudioPlayer();

    // Запустить воспроизведение аудиофайла по локальному пути
    bool play(const QString& filePath);

    // Остановить воспроизведение
    void stop();

    // Проверить, играет ли сейчас аудио
    bool isPlaying() const;

signals:
    void started();
    void stopped();
    void finished();

private slots:
    void checkPlayback();

private:
    libvlc_instance_t* m_instance = nullptr;
    libvlc_media_player_t* m_mediaPlayer = nullptr;
    QTimer m_timer;
};

#include "VlcAudioPlayer.h"
#include <QDebug>

VlcAudioPlayer::VlcAudioPlayer(QObject* parent)
    : QObject(parent)
{
    const char* args[] = { "--no-xlib" };
    m_instance = libvlc_new(1, args);
    if (!m_instance) {
        qWarning() << "Failed to create libVLC instance";
    }

    m_mediaPlayer = nullptr;

    // Таймер для проверки состояния воспроизведения
    connect(&m_timer, &QTimer::timeout, this, &VlcAudioPlayer::checkPlayback);
    m_timer.setInterval(200); // проверять каждые 200 мс
}

VlcAudioPlayer::~VlcAudioPlayer()
{
    if (m_mediaPlayer) {
        libvlc_media_player_stop(m_mediaPlayer);
        libvlc_media_player_release(m_mediaPlayer);
    }
    if (m_instance) {
        libvlc_release(m_instance);
    }
}

bool VlcAudioPlayer::play(const QString& filePath)
{
    if (!m_instance) {
        qWarning() << "libVLC instance is null";
        return false;
    }

    // Если уже играет, остановим
    if (isPlaying()) {
        stop();
    }

    // Преобразуем путь в URI
    QUrl url = QUrl::fromLocalFile(filePath);
    QString uri = url.toString();

    libvlc_media_t* media = libvlc_media_new_location(m_instance, uri.toUtf8().constData());
    if (!media) {
        qWarning() << "Failed to create media from URI:" << uri;
        return false;
    }

    if (m_mediaPlayer) {
        libvlc_media_player_stop(m_mediaPlayer);
        libvlc_media_player_release(m_mediaPlayer);
        m_mediaPlayer = nullptr;
    }

    m_mediaPlayer = libvlc_media_player_new_from_media(media);
    libvlc_media_release(media);

    if (!m_mediaPlayer) {
        qWarning() << "Failed to create media player";
        return false;
    }

    if (libvlc_media_player_play(m_mediaPlayer) != 0) {
        qWarning() << "Failed to start playback";
        libvlc_media_player_release(m_mediaPlayer);
        m_mediaPlayer = nullptr;
        return false;
    }

    emit started();
    m_timer.start();

    return true;
}

void VlcAudioPlayer::stop()
{
    if (m_mediaPlayer && isPlaying()) {
        libvlc_media_player_stop(m_mediaPlayer);
        emit stopped();
    }
    m_timer.stop();
}

bool VlcAudioPlayer::isPlaying() const
{
    if (!m_mediaPlayer)
        return false;
    return libvlc_media_player_is_playing(m_mediaPlayer) != 0;
}

void VlcAudioPlayer::checkPlayback()
{
    if (!m_mediaPlayer) {
        m_timer.stop();
        return;
    }

    if (!isPlaying()) {
        m_timer.stop();
        emit finished();
    }
}

[jsulm]

@Mihaill Add error handling to your code to see whether there are any errors (https://doc.qt.io/archives/qt-5.15/qmediaplayer.html#error-1)
Also connect a slot to https://doc.qt.io/archives/qt-5.15/qmediaplayer.html#stateChanged and see which state changes you have.

I hope m_player is not a local variable which gets destroyed when its scope is gone...

"Then I get eoor:" - I don't see any errors related to audio playback.

[Mihaill]

@jsulm
m_player is variable in my class
m_player dont emited signal error()
m_player change status on QMediaPlayer::LoadingMedia
after I get error in consol:

[mp3 @ 00000165A7B5A100] Could not find codec parameters for stream 1 (Video: png, none): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, mp3, from 'C:/Users/Admin/AppData/Local/Temp/MM terminal.cRcedC.mp3':
  Metadata:
    artist          : Sound Clip
    title           : Военно-морской сигнал тревоги 
    encoder         : Lavf56.40.101
    date            : 2020
  Duration: 00:00:08.39, start: 0.011995, bitrate: 130 kb/s
  Stream #0:0: Audio: mp3 (mp3float), 44100 Hz, stereo, fltp, 128 kb/s
      Metadata:
        encoder         : LAME3.97 
      Side data:
        replaygain: track gain - -10.600000, track peak - unknown, album gain - unknown, album peak - unknown, 
  Stream #0:1: Video: png, none, 90k tbr, 90k tbn (attached pic)
      Metadata:
        title           : Album cover
        comment         : Cover (front)

after:
m_player change status on QMediaPlayer::LoadedMedia
m_player change status on QMediaPlayer::BufferingMedia
m_player change status on QMediaPlayer::BufferedMedia

[Mihaill]

@jsulm
after QMediaPlayer::BufferedMedia m_player have:

[25.07.2025 17:00:27.476 UTC+03:00][D]: -----m_player.duration() 8385

[25.07.2025 17:00:27.478 UTC+03:00][D]: -----m_player.hasAudio() true

[25.07.2025 17:00:27.479 UTC+03:00][D]: -----m_player.hasVideo() false

[25.07.2025 17:00:27.479 UTC+03:00][D]: -----m_player.position() 0

but m_player don't started

[JoeCFD]

try the following to see if it works or not
QT_MEDIA_BACKEND=gstreamer ./your_application

I guess you are using Qt6 and its default backend is FFmpeg. And check if you have installed FFmpeg.

Multimedia module in Qt5 uses gstreamer.

[Mihaill]

@JoeCFD said in Don't play mp3:

I guess you are using Qt6 and its default backend is FFmpeg. And check if you have installed FFmpeg.

My computer have ffmpeg version 2024-10-07. And another mp3 is work. But me need play all possible mp3.
And ffplay can play my file

[JonB]

@Mihaill
Qt cannot help if perchance ffmpeg cannot play some mp3 file. Have you tried the ffmpeg directly on the problem file? I do not see anywhere reported that ffmpeg cannot play certain mp3 files

Why are some MP3 files not playing?

If you find MP3 files are not playing on Windows, Android, or iOS, that may be caused by various reasons, including MP3 file corruption, incomplete downloading/transmission, code issues, hardware problems, unsupported media players, or computer viruses.17 Feb 2025

[Mihaill]

@JonB but ffmpeg can play my file

[JonB]

@Mihaill
OIC, I misunderstood. Can only think: check the command line you use from ffmpeg explicitly when it works against the command line being executed from Qt? Check it is using the same ffmpeg executable from Qt as you use from command line?

[Mihaill]

@JonB In command lyne I test this ile like this:

ffplay alarm.mp3

In qt console after QMediaPlayer::LoadingMedia I get this error:

[mp3 @ 00000174EAE75600] Could not find codec parameters for stream 1 (Video: png, none): unspecified size
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, mp3, from 'C:/QtProjects/qsingleteleshell/BModules/mmTerminal/sounds/alarm.mp3':
  Metadata:
    artist          : Sound Clip
    title           : Военно-морской сигнал тревоги 
    encoder         : Lavf56.40.101
    date            : 2020
  Duration: 00:00:08.39, start: 0.011995, bitrate: 130 kb/s
  Stream #0:0: Audio: mp3 (mp3float), 44100 Hz, stereo, fltp, 128 kb/s
      Metadata:
        encoder         : LAME3.97 
      Side data:
        replaygain: track gain - -10.600000, track peak - unknown, album gain - unknown, album peak - unknown, 
  Stream #0:1: Video: png, none, 90k tbr, 90k tbn (attached pic)
      Metadata:
        title           : Album cover
        comment         : Cover (front)

[Mihaill]

I find in log this text : Using Qt multimedia with FFmpeg version 7.1 LGPL version 2.1 or later

[Mihaill]

it's work with vlc

#pragma once

#include <QObject>
#include <vlc/vlc.h>
#include <QString>
#include <QUrl>
#include <QTimer>

class VlcAudioPlayer : public QObject
{
    Q_OBJECT
public:
    explicit VlcAudioPlayer(QObject* parent = nullptr);
    ~VlcAudioPlayer();

    // Запустить воспроизведение аудиофайла по локальному пути
    bool play(const QString& filePath);

    // Остановить воспроизведение
    void stop();

    // Проверить, играет ли сейчас аудио
    bool isPlaying() const;

signals:
    void started();
    void stopped();
    void finished();

private slots:
    void checkPlayback();

private:
    libvlc_instance_t* m_instance = nullptr;
    libvlc_media_player_t* m_mediaPlayer = nullptr;
    QTimer m_timer;
};

#include "VlcAudioPlayer.h"
#include <QDebug>

VlcAudioPlayer::VlcAudioPlayer(QObject* parent)
    : QObject(parent)
{
    const char* args[] = { "--no-xlib" };
    m_instance = libvlc_new(1, args);
    if (!m_instance) {
        qWarning() << "Failed to create libVLC instance";
    }

    m_mediaPlayer = nullptr;

    // Таймер для проверки состояния воспроизведения
    connect(&m_timer, &QTimer::timeout, this, &VlcAudioPlayer::checkPlayback);
    m_timer.setInterval(200); // проверять каждые 200 мс
}

VlcAudioPlayer::~VlcAudioPlayer()
{
    if (m_mediaPlayer) {
        libvlc_media_player_stop(m_mediaPlayer);
        libvlc_media_player_release(m_mediaPlayer);
    }
    if (m_instance) {
        libvlc_release(m_instance);
    }
}

bool VlcAudioPlayer::play(const QString& filePath)
{
    if (!m_instance) {
        qWarning() << "libVLC instance is null";
        return false;
    }

    // Если уже играет, остановим
    if (isPlaying()) {
        stop();
    }

    // Преобразуем путь в URI
    QUrl url = QUrl::fromLocalFile(filePath);
    QString uri = url.toString();

    libvlc_media_t* media = libvlc_media_new_location(m_instance, uri.toUtf8().constData());
    if (!media) {
        qWarning() << "Failed to create media from URI:" << uri;
        return false;
    }

    if (m_mediaPlayer) {
        libvlc_media_player_stop(m_mediaPlayer);
        libvlc_media_player_release(m_mediaPlayer);
        m_mediaPlayer = nullptr;
    }

    m_mediaPlayer = libvlc_media_player_new_from_media(media);
    libvlc_media_release(media);

    if (!m_mediaPlayer) {
        qWarning() << "Failed to create media player";
        return false;
    }

    if (libvlc_media_player_play(m_mediaPlayer) != 0) {
        qWarning() << "Failed to start playback";
        libvlc_media_player_release(m_mediaPlayer);
        m_mediaPlayer = nullptr;
        return false;
    }

    emit started();
    m_timer.start();

    return true;
}

void VlcAudioPlayer::stop()
{
    if (m_mediaPlayer && isPlaying()) {
        libvlc_media_player_stop(m_mediaPlayer);
        emit stopped();
    }
    m_timer.stop();
}

bool VlcAudioPlayer::isPlaying() const
{
    if (!m_mediaPlayer)
        return false;
    return libvlc_media_player_is_playing(m_mediaPlayer) != 0;
}

void VlcAudioPlayer::checkPlayback()
{
    if (!m_mediaPlayer) {
        m_timer.stop();
        return;
    }

    if (!isPlaying()) {
        m_timer.stop();
        emit finished();
    }
}