how to get media file information.

saber

i want to get properties of video and audio file.
like what is the frame rate , bit rate ,format ,all the bits and pices .
how can i get this information??

Diracsbracket

@saber
Hi,
Did you have a look at the following example?
https://doc.qt.io/qt-5.10/qtmultimedia-multimediawidgets-player-player-cpp.html

It uses the QMediaMetaData namespace:
http://doc.qt.io/qt-5/qmediametadata.html#details

saber

@Diracsbracket
yes .
but don't know how to use that .

Diracsbracket

@saber said in how to get media file information.:

but don't know how to use that

This is a minimal example you can try out:
(based on: http://qt.shoutwiki.com/wiki/Using_Qt_Mobility_to_get_metadata_from_media_files)

Define player as a class member:

private:
    QMediaPlayer *m_player;

In your code:

   m_player = new QMediaPlayer(this);
  connect(m_player, SIGNAL(mediaStatusChanged(QMediaPlayer::MediaStatus)), this, SLOT(onMediaStatusChanged(QMediaPlayer::MediaStatus)));

   m_player->setMedia(QUrl::fromLocalFile("C:\\yourMovie.avi"));

Define the onMediaStatusChanged slot e.g. as follows:

void MainWindow::onMediaStatusChanged(QMediaPlayer::MediaStatus status)
{
    if (status == QMediaPlayer::LoadedMedia)
        GetMetaData(m_player);
}

The GetMetaData() method lists all available metadata:

void MainWindow::GetMetaData(QMediaPlayer *player)
{
   // Get the list of keys there is metadata available for
   QStringList metadatalist = player->availableMetaData();

   // Get the size of the list
   int list_size = metadatalist.size();

   //qDebug() << player->isMetaDataAvailable() << list_size;

   // Define variables to store metadata key and value
   QString metadata_key;
   QVariant var_data;

   for (int indx = 0; indx < list_size; indx++)
   {
     // Get the key from the list
     metadata_key = metadatalist.at(indx);

     // Get the value for the key
     var_data = player->metaData(metadata_key);

    qDebug() << metadata_key << var_data.toString();
   }
 }

The output on a sample .avi movie on my system is:

"AudioBitRate" "128000"
"AudioCodec" "MPEG Audio Layer-3 (MP3)"
"ChannelCount" "2"
"Copyright" "SaM"
"Duration" "5069876"
"PixelAspectRatio" ""
"Resolution" ""
"SampleRate" "48000"
"VideoBitRate" "1028056"
"VideoCodec" "MPEG-4 part 2 Video (MP4V)"
"VideoFrameRate" "24"

saber

@Diracsbracket
thank you very much.

some questions
why we not getting Resolution,PixelAspectRatio ??

and we ONLY get the metadata what is Available??

Diracsbracket

@saber said in how to get media file information.:

Resolution,PixelAspectRatio

Probably because this info is not available in the AVI header (maybe not part of the AVI specs?).

@saber said in how to get media file information.:

and we ONLY get the metadata what is Available

You could probably use the metaData() method to query by key all the possible/relevant
keys defined in the QMediaMetaData namespace, and check if it returns something valid?

QVariant metaData(const QString &key) const;

Also keep in mind that Qt's Multimedia framework is not as complete as some of the specialized libraries out there.

saber

@Diracsbracket thanks.

this way can i get image info??
if yes , how to get that?

some of the specialized libraries out there.

please give me some suggestion.

Diracsbracket

@saber said in how to get media file information.:

this way can i get image info

It doesn't seem to work for images (as tested from the minimal example I posted above...)

But, from searching on this forum (or on Google), the answer for pictures is given here:
https://forum.qt.io/topic/83259/get-metadata-date-taken-location-from-photo-jpeg/2
https://github.com/mayanklahiri/easyexif

@saber said in how to get media file information.:

please give me some suggestion

Have a look at:
http://en.cppreference.com/w/cpp/links/libs

saber

@Diracsbracket
hi .
i found a library called mediainfo .here is the github
it has a example made by qt.
but i don't understand how to build it or use it as a lib.
can you help?

and i tried this but not getting the duration.

m_player->metaData(QMediaMetaData::Duration).toString();

just giving me this "QVariant(Invalid)"

SGaist

@saber, that's a question you should ask to the mediainfo authors. At least you should explain exactly what is happening to you.

Diracsbracket

@saber said in how to get media file information.:

can you help?

As @SGaist suggested, I'm affraid that you will have to ask the authors of that library, as I haven't tried that one yet :-(.

@saber said in how to get media file information.:

just giving me this "QVariant(Invalid)"

Since QMediaMetaData::Duration is a qint64 as per http://doc.qt.io/qt-5/qmediametadata.html, maybe try as follows:

QString::number(m_player->metaData(QMediaMetaData::Duration))

Diracsbracket

This post is deleted!

saber

@Diracsbracket
Thanks, mediainfo builds fine in my linux system.
i want it as a lib(exclude all the gui and extra pieces) so it will be easer to include it in my project.
i wanted to make a function that will take the file path >> send it to that lib >>lib will give the all the mediainfo.
but i have no idea or programming skills to do that .so if you want the same ,please modify the mideainfo to a library.
thanks

Diracsbracket

@saber said in how to get media file information.:

i want it as a lib

MediaInfoLib IS the lib. I thought this would have been clear enough...
MediaInfo is just an application using it. Study that example to learn how to use it.

saber

@Diracsbracket

oh!ok.
can you show me the lib folder?
and how to include it in .pro .
an example will be great!!

Diracsbracket

@saber said in how to get media file information.:

can you show me the lib folder?
and how to include it in .pro .
an example will be great!!

As I wrote. Study the example. You said MediaInfo builds correctly on your system, so you have access to all the info you need, since it builds perfectly in Qt Creator. Don't expect everything to be done for you...
Good luck!

saber

after long works i made an app with mediainfo as backend.
here is the app CoreInfo.
thanks.