java mp4parser获取GPS位置

Question

亲爱的大家：，
我正在做一个新项目，需要从MP4视频中获取GPS位置。下面是我尝试过的代码，但是得到了空指针异常

File videoFile = new File(videoFilePath);
if (!videoFile.exists()) {
    throw new FileNotFoundException("File " + videoFilePath + " not exists");
}
if (!videoFile.canRead()) {
    throw new IllegalStateException("No read permissions to file " + videoFilePath);
}
IsoFile isoFile = new IsoFile(videoFilePath);
AppleNameBox nam = Path.getPath(isoFile, "/moov[0]/udta[0]/meta[0]/ilst/©xyz");
String xml = nam.getValue();

谢谢，
Om

Answer 1

这个代码对我有用。当没有位置标签时，它会给出NPE

private String readVideoLocation(String fullFilePath) throws Exception {
    File videoFile = new File(fullFilePath);
    if (!videoFile.exists()) {
        throw new FileNotFoundException("File " + fullFilePath + " not exists");
    }

    if (!videoFile.canRead()) {
        throw new IllegalStateException("No read permissions to file " + fullFilePath);
    }

    FileDataSourceImpl fileDataSource = new FileDataSourceImpl(fullFilePath); 
    IsoFile isoFile = new IsoFile(fileDataSource);

    AppleGPSCoordinatesBox locBox = Path.getPath(isoFile, "/moov[0]/udta[0]/meta[0]/ilst/©xyz");
    String xml = locBox.getValue();
    isoFile.close();
    return xml;
}