Video artefacts when switching ofVideoPlayer pointers

bugs, errors
#1

Hey all,

I’m getting some strange video artefacts when switching between pointers to ofVideoPlayers. It’s usually a few frames from another video file, but can be garbage, which makes me think they are briefly pointing at the wrong place. This doesn’t happen when looping a single video.

This is happening both on OS X and Linux, the videos are H.264 mp4 files.

Class.h

vector<string>              mFiles;
vector<ofVideoPlayer*>      mPlayers;
ofVideoPlayer*              mPlayer;
int                         mFileIndex;

Class.cpp

void setup() {
    mFileIndex = 0;
    mPlayer = NULL;

    ofDirectory dir(VIDEO_PATH);
    if (dir.exists()) {
        dir.allowExt("mp4");
        dir.listDir();
        dir.sort();

        for(int i = 0; i < dir.numFiles(); ++i) {
            mFiles.push_back(dir.getPath(i);
            mPlayers.push_back(new ofVideoPlayer());
            mPlayers.back()->loadMovie(mFiles.back();
            mPlayers.back()->setLoopState(OF_LOOP_NONE);
        }
    }
    dir.close();

    mPlayer = mPlayers.at(mFileIndex);
}

void update() {
    if (mPlayer && mPlayer->isLoaded()) {

        mPlayer->update();

        if (mPlayer->getIsMovieDone()) {
            mFileIndex = (mFileIndex + 1) % mFiles.size();
            mPlayer = mPlayers.at(mFileIndex);
            mPlayer->play();
        }
    }
}

Any thoughts much appreciated,

Arthur C

#2

This garbage frame seems to occur on the 0th frame of the new player, so calling mPlayer->update() before mPlayer->play() does the trick.

Is this to be expected? The documentation implies that .play() should be called before .update()

#3

Did you edit your code after you figured it out? It looks like you do call .update() before you call .play() already… unless I’m missing something? I’m having a similar problem when switching between ofVideoPlayer objects: garbage frames when they app is first run, and then a flashframe from the middle of the video every time I switch back to it (when I’m trying to start the video over).

#4

In my code I called update on the old player, but not before calling play on the new player.

From what I remember, I may have still had issues as I ended up concatenating the videos and using a single video player in production.