Showing a mp4 in my app

SGaist · 12 Feb 2020, 20:19

Can you play your video directly with GStreamer from the command line ?

MichRX7 · S SGaist 12 Feb 2020, 19:30

@SGaist said in Showing a mp4 in my app:

Can you play your video directly with GStreamer from the command line ?

Yes, using:
gst-launch-1.0 playbin uri=file:///home/pi/Videos/tomtiph.mp4

or

gst-play-1.0 /home/pi/Videos/tomtiph.mp4

both those commands play the video

SGaist · 12 Feb 2020, 21:57

Good.

Then as next step, I would build and run the Media Player Example.

MichRX7 · 12 Feb 2020, 23:09

@SGaist said in Showing a mp4 in my app:

Good.

Then as next step, I would build and run the Media Player Example.

I have, it won't play the mp4 videos, but it will play the mov video saved direct from an iPhone just like my other videowidget.

SGaist · wrote on 12 Feb 2020, 22:38

What are the specifications of that video ?

MichRX7 · wrote on 12 Feb 2020, 23:09

@MichRX7 said in Showing a mp4 in my app:

@SGaist said in Showing a mp4 in my app:

Good.

Then as next step, I would build and run the Media Player Example.

I have, it won't play the mp4 videos, but it will play the mov video saved direct from an iPhone just like my other videowidget.

File Type MPEG-4 Video
Total Size 5.8 MiB

JKSH · 13 Feb 2020, 04:31

@SGaist recommended this earlier; it's still worth doing: Check the error signal. It could provide some clues as to why your video isn't playing.

Also, try connecting the status/state change signals and see what you get:

connect(player, QOverload<QMediaPlayer::Error>::of(&QMediaPlayer::error), [=](QMediaPlayer::Error error)
{
    qDebug() << "Error:" << error << player->errorString();
});

connect(player, &QMediaPlayer::mediaStatusChanged, [=](QMediaPlayer::MediaStatus status)
{
    qDebug() << "Media Status:" << status;
}

connect(player,, &QMediaPlayer::stateChanged, [=](QMediaPlayer::State state)
{
    qDebug() << "State:" << state;
}

MichRX7 · 13 Feb 2020, 05:17

@JKSH

Thank you for the reply. I placed these in the file. When I do the first connect throws this issue:
/tmp/VisualGDB/c/projects/LinuxProject1/MainWindow.cpp:35: error: reference to non-static member function must be called; did you mean to call it with no arguments?

The 2nd and 3rd connect's throw an error unless I put ); after the closing } for each connect.

I can't build the file until I figure out the issue with the first connect is. If I comment it out and place the ); after the 2nd and 3rd connects I can build the file, but I don't see any errors in the debug window in QT Creator if that is where I should be seeing issues.

MichRX7 · wrote on 13 Feb 2020, 04:48

When I run the build after commenting out the first connect that is giving me an issue I do see this in the debugger:
GStreamer; Unable to pause - "file:///home/pi/Videos/tomtiff.mp4"
Media Status: QMediaPlayer::LoadingMedia
GStreamer; Unable to pause - "file:///home/pi/Videos/tomtiff.mp4"
mediaStatus: QMediaPlayer::LoadingMedia error: QMediaPlayer::NoError

Media Status: QMediaPlayer::InvalidMedia
Error: "Resource not found."

If I switch the file name to the known working MOV file and run the build I do not see this information or anything like it in the debugger.

JKSH · 13 Feb 2020, 05:25

@MichRX7 said in Showing a mp4 in my app:

error: reference to non-static member function must be called; did you mean to call it with no arguments?

Remember to include the & inside of()

The 2nd and 3rd connect's throw an error unless I put ); after the closing } for each connect.

Oops! I've edited the post to fix the syntax

MichRX7 · 13 Feb 2020, 05:28

@JKSH said in Showing a mp4 in my app:

@MichRX7 said in Showing a mp4 in my app:

error: reference to non-static member function must be called; did you mean to call it with no arguments?

Remember to include the & inside of()

I copied it right from the page, this is what I have in my code that is throwing that error:
connect(player, QOverloadQMediaPlayer::Error::of(&QMediaPlayer::error), [=](QMediaPlayer::Error error)
{
qDebug() << "Error:" << error << player->errorString;
});

JKSH · wrote on 13 Feb 2020, 05:28

@MichRX7 said in Showing a mp4 in my app:

qDebug() << "Error:" << error << player->errorString;

Found it: errorString() needs parentheses

MichRX7 · 13 Feb 2020, 06:13

Well, there is a lot of output, not sure if you want to see all of it.

But, on the MOV file that plays correctly I see this near the end (after pressing the button to create the videowidget and play):
Thread 18 created.

~"[New Thread 0x8d0fc390 (LWP 17529)]\n"
[New Thread 0x8d0fc390 (LWP 17529)]
*running,thread-id="18"
dNOTE: INFERIOR STILL RUNNING IN STATE InferiorRunOk.

Media Status: QMediaPlayer::BufferedMedia

=thread-created,id="19",group-id="i1"
Thread 19 created.
~"[New Thread 0x8bbff390 (LWP 17530)]\n"
[New Thread 0x8bbff390 (LWP 17530)]
*running,thread-id="19"
dNOTE: INFERIOR STILL RUNNING IN STATE InferiorRunOk.

~"[Thread 0x8bbff390 (LWP 17530) exited]\n"
[Thread 0x8bbff390 (LWP 17530) exited]
=thread-exited,id="19",group-id="i1"
Thread 19 in group i1 exited.

In the MOV that won't play I see:
Thread 21 created.

~"[New Thread 0x8ddf2390 (LWP 17432)]\n"
[New Thread 0x8ddf2390 (LWP 17432)]
*running,thread-id="21"
dNOTE: INFERIOR STILL RUNNING IN STATE InferiorRunOk.

Media Status: QMediaPlayer::BufferedMedia

QWidget::paintEngine: Should no longer be called
QWidget::paintEngine: Should no longer be called

In the MP4 that doesn't play:
Thread 21 created.

~"[New Thread 0x8dbff390 (LWP 17705)]\n"
[New Thread 0x8dbff390 (LWP 17705)]
*running,thread-id="21"
dNOTE: INFERIOR STILL RUNNING IN STATE InferiorRunOk.

Media Status: QMediaPlayer::BufferedMedia

QWidget::paintEngine: Should no longer be called
QWidget::paintEngine: Should no longer be called

If you want to see the full debug section from when I hit the button to here I can paste it, but it is VERY long.

JKSH · wrote on 13 Feb 2020, 06:13

@MichRX7 said in Showing a mp4 in my app:

Well, there is a lot of output, not sure if you want to see all of it.

...

 Thread 18 created.
>~"[New Thread 0x8d0fc390 (LWP 17529)]\n"
 [New Thread 0x8d0fc390 (LWP 17529)]
>*running,thread-id="18"
dNOTE: INFERIOR STILL RUNNING IN STATE InferiorRunOk.

Looks like you ran it in the Debugger.

Run it normally (click "Run" instead of "Start Debugging" and you should see a lot less output.

MichRX7 · wrote on 13 Feb 2020, 06:22

Ok, here is the MP4 when I just run:
01:16:58: Starting /tmp/VisualGDB/c/projects/LinuxProject1/Debug/LinuxProject1...
qt5ct: using qt5ct plugin
qt5ct: D-Bus global menu: no
Media Status: QMediaPlayer::LoadingMedia
State: QMediaPlayer::PlayingState
mediaStatus: QMediaPlayer::LoadingMedia error: QMediaPlayer::NoError
Media Status: QMediaPlayer::BufferedMedia
01:17:08: /tmp/VisualGDB/c/projects/LinuxProject1/Debug/LinuxProject1 exited with code 0

MOV file that plays as I expect:
01:18:52: Starting /tmp/VisualGDB/c/projects/LinuxProject1/Debug/LinuxProject1...
qt5ct: using qt5ct plugin
qt5ct: D-Bus global menu: no
Media Status: QMediaPlayer::LoadingMedia
State: QMediaPlayer::PlayingState
mediaStatus: QMediaPlayer::LoadingMedia error: QMediaPlayer::NoError
Media Status: QMediaPlayer::BufferedMedia
01:19:07: /tmp/VisualGDB/c/projects/LinuxProject1/Debug/LinuxProject1 exited with code 0

MOV file that doesn't play (just get black window like MP4 file)
01:20:36: Starting /tmp/VisualGDB/c/projects/LinuxProject1/Debug/LinuxProject1...
qt5ct: using qt5ct plugin
qt5ct: D-Bus global menu: no
Media Status: QMediaPlayer::LoadingMedia
State: QMediaPlayer::PlayingState
mediaStatus: QMediaPlayer::LoadingMedia error: QMediaPlayer::NoError
Media Status: QMediaPlayer::BufferedMedia
QWidget::paintEngine: Should no longer be called
QWidget::paintEngine: Should no longer be called
QWidget::paintEngine: Should no longer be called
QWidget::paintEngine: Should no longer be called
01:20:49: /tmp/VisualGDB/c/projects/LinuxProject1/Debug/LinuxProject1 exited with code 0

MichRX7 · 13 Feb 2020, 08:57

Go figure, if I take the MOV that won't play into my video editor and export it as a WMV it plays.
Same goes with the MP4, convert it to WMV and it plays.

Maybe there is an issue with my video software and MP4/MOV? Just odd that I can play them from the command line, but not from within my QT app.

JKSH · 13 Feb 2020, 11:30

@MichRX7 said in Showing a mp4 in my app:

Go figure, if I take the MOV that won't play into my video editor and export it as a WMV it plays.
Same goes with the MP4, convert it to WMV and it plays.

Maybe there is an issue with my video software and MP4/MOV? Just odd that I can play them from the command line, but not from within my QT app.

Sounds like the video codecs aren't being loaded/used correctly in your Qt app.

What version of Qt are you using? What version of OS?

qt5ct: using qt5ct plugin

How did you install Qt?

mediaStatus: QMediaPlayer::LoadingMedia error: QMediaPlayer::NoError

Hmm... nothing in the log jumps out to me, unfortunately.

QWidget::paintEngine: Should no longer be called

This looks somewhat ominous; I'm not sure if this is a clue or not. https://stackoverflow.com/questions/45537627/qwidgetpaintengine-should-no-longer-be-called-appears-when-using-qmediaplay

MichRX7 · 13 Feb 2020, 21:48

@JKSH

I am on a Rpi4 running Raspbian GNU/Linux 10 (buster).
I am running Qt Creator 4.8.2 Based on Qt 5.11.3 (GCC 8.3.0, 32 bit)

I tried to install 5.14.1, but failed gloriously (lol). I will give it a try again some day, but wanted to try writing actual code. I believe the 5.11.3 came with Raspbian buster.

JKSH · 14 Feb 2020, 12:48

@MichRX7 said in Showing a mp4 in my app:

I tried to install 5.14.1, but failed gloriously (lol). I will give it a try again some day, but wanted to try writing actual code. I believe the 5.11.3 came with Raspbian buster.

When you're ready to try again, see https://www.tal.org/tutorials/building-qt-512-raspberry-pi as a good place to start.

For now, have a look at the list of multimedia dependencies in the link above. I wonder if the Raspbian's copy of the Qt5Multimedia library was built with all of those in place?

MichRX7 · 14 Feb 2020, 12:56

@JKSH

Yes, thank you for all your help and thank you for the insight from everyone on this thread. Right now just trying to do a proof of concept to show some people, and if I can get it to reliably show the wmv files that'll be fine for now.

I actually did try that page, and replaced 5.12.7 with 5.14.1. And it was my plan to try and figure out (using that page) what I did wrong when I'm ready to try again.