Android开发Android开发Android技术知识

Android获取Camera录制的视频的地理位置

2018-07-15  本文已影响16人  blingbling_5a3f

前段时间在做视频播放器的时候碰到一个新需求:需要将视频的地理位置显示在视频的详情里面。第一反应就是每一个视频文件都可以记录下来一些信息,这些信息里面包含了经纬度等等,就像照片的ExifInterface类一样。于是就去查看了MediaRecorder类,便发现了这个类里面有public void setLocation(float latitude, float longitude)这么个方法可以给录制的视频设置经纬度。

/**
     * Set and store the geodata (latitude and longitude) in the output file.
     * This method should be called before prepare(). The geodata is
     * stored in udta box if the output format is OutputFormat.THREE_GPP
     * or OutputFormat.MPEG_4, and is ignored for other output formats.
     * The geodata is stored according to ISO-6709 standard.
     *
     * @param latitude latitude in degrees. Its value must be in the
     * range [-90, 90].
     * @param longitude longitude in degrees. Its value must be in the
     * range [-180, 180].
     *
     * @throws IllegalArgumentException if the given latitude or
     * longitude is out of range.
     *
     */
    public void setLocation(float latitude, float longitude) {
        int latitudex10000  = (int) (latitude * 10000 + 0.5);
        int longitudex10000 = (int) (longitude * 10000 + 0.5);

        if (latitudex10000 > 900000 || latitudex10000 < -900000) {
            String msg = "Latitude: " + latitude + " out of range.";
            throw new IllegalArgumentException(msg);
        }
        if (longitudex10000 > 1800000 || longitudex10000 < -1800000) {
            String msg = "Longitude: " + longitude + " out of range";
            throw new IllegalArgumentException(msg);
        }

        setParameter("param-geotag-latitude=" + latitudex10000);
        setParameter("param-geotag-longitude=" + longitudex10000);
    }

所以说明视频文件里面是存储了经纬度的,现在的关键就是找到对应的API去获取视频文件存储的经纬度。回忆以前获取视频的某一帧图像使用的是MediaMetadataRetriever类,通过这个对象是否也可以获取一些别的信息呢?创建mediaMetadataRetriever对象后发现了这么个方法:mediaMetadataRetriever.extractMetadata(int keyCode);看见这个方法名就感觉找到了(提炼出元数据),现在还需要一个关键的keyCode。于是进入到这个类里面浏览源码,发现了一大堆的key:

/**
     * The metadata key to retrieve the numeric string describing the
     * order of the audio data source on its original recording.
     */
    public static final int METADATA_KEY_CD_TRACK_NUMBER = 0;
    /**
     * The metadata key to retrieve the information about the album title
     * of the data source.
     */
    public static final int METADATA_KEY_ALBUM           = 1;
    /**
     * The metadata key to retrieve the information about the artist of
     * the data source.
     */
    public static final int METADATA_KEY_ARTIST          = 2;
    /**
     * The metadata key to retrieve the information about the author of
     * the data source.
     */
    public static final int METADATA_KEY_AUTHOR          = 3;
    /**
     * The metadata key to retrieve the information about the composer of
     * the data source.
     */
    public static final int METADATA_KEY_COMPOSER        = 4;
    /**
     * The metadata key to retrieve the date when the data source was created
     * or modified.
     */
    public static final int METADATA_KEY_DATE            = 5;
    /**
     * The metadata key to retrieve the content type or genre of the data
     * source.
     */
    public static final int METADATA_KEY_GENRE           = 6;
    /**
     * The metadata key to retrieve the data source title.
     */
    public static final int METADATA_KEY_TITLE           = 7;
    /**
     * The metadata key to retrieve the year when the data source was created
     * or modified.
     */
    public static final int METADATA_KEY_YEAR            = 8;
    /**
     * The metadata key to retrieve the playback duration of the data source.
     */
    public static final int METADATA_KEY_DURATION        = 9;
    /**
     * The metadata key to retrieve the number of tracks, such as audio, video,
     * text, in the data source, such as a mp4 or 3gpp file.
     */
    public static final int METADATA_KEY_NUM_TRACKS      = 10;
    /**
     * The metadata key to retrieve the information of the writer (such as
     * lyricist) of the data source.
     */
    public static final int METADATA_KEY_WRITER          = 11;
    /**
     * The metadata key to retrieve the mime type of the data source. Some
     * example mime types include: "video/mp4", "audio/mp4", "audio/amr-wb",
     * etc.
     */
    public static final int METADATA_KEY_MIMETYPE        = 12;
    /**
     * The metadata key to retrieve the information about the performers or
     * artist associated with the data source.
     */
    public static final int METADATA_KEY_ALBUMARTIST     = 13;
    /**
     * The metadata key to retrieve the numberic string that describes which
     * part of a set the audio data source comes from.
     */
    public static final int METADATA_KEY_DISC_NUMBER     = 14;
    /**
     * The metadata key to retrieve the music album compilation status.
     */
    public static final int METADATA_KEY_COMPILATION     = 15;
    /**
     * If this key exists the media contains audio content.
     */
    public static final int METADATA_KEY_HAS_AUDIO       = 16;
    /**
     * If this key exists the media contains video content.
     */
    public static final int METADATA_KEY_HAS_VIDEO       = 17;
    /**
     * If the media contains video, this key retrieves its width.
     */
    public static final int METADATA_KEY_VIDEO_WIDTH     = 18;
    /**
     * If the media contains video, this key retrieves its height.
     */
    public static final int METADATA_KEY_VIDEO_HEIGHT    = 19;
    /**
     * This key retrieves the average bitrate (in bits/sec), if available.
     */
    public static final int METADATA_KEY_BITRATE         = 20;
    /**
     * This key retrieves the language code of text tracks, if available.
     * If multiple text tracks present, the return value will look like:
     * "eng:chi"
     * @hide
     */
    public static final int METADATA_KEY_TIMED_TEXT_LANGUAGES      = 21;
    /**
     * If this key exists the media is drm-protected.
     * @hide
     */
    public static final int METADATA_KEY_IS_DRM          = 22;
    /**
     * This key retrieves the location information, if available.
     * The location should be specified according to ISO-6709 standard, under
     * a mp4/3gp box "@xyz". Location with longitude of -90 degrees and latitude
     * of 180 degrees will be retrieved as "-90.0000+180.0000", for instance.
     */
    public static final int METADATA_KEY_LOCATION        = 23;
    /**
     * This key retrieves the video rotation angle in degrees, if available.
     * The video rotation angle may be 0, 90, 180, or 270 degrees.
     */
    public static final int METADATA_KEY_VIDEO_ROTATION = 24;
    /**
     * This key retrieves the original capture framerate, if it's
     * available. The capture framerate will be a floating point
     * number.
     */
    public static final int METADATA_KEY_CAPTURE_FRAMERATE = 25;

这里我所需要的仅仅是:public static final int METADATA_KEY_LOCATION = 23;

/**
     * 获取视频保存的地理位置信息
     *
     * @return +22.000+119.999
     */
    public static String getVideoLocationInfo(String path) {
        MediaMetadataRetriever metadataRetriever = new MediaMetadataRetriever();
        try {
            metadataRetriever.setDataSource(path);
        } catch (Exception e) {
            e.printStackTrace();
            return "";
        }
        return metadataRetriever.extractMetadata(MediaMetadataRetriever.METADATA_KEY_LOCATION);
    }

返回的经纬度格式:+22.000+119.999,这里需要将经度部分和纬度部分分割开来。

String s = getVideoLocationInfo(videoPath);
        if(!TextUtils.isEmpty(s)){
                char[]chars=s.toCharArray();
                String latitude=null;
                String longitude=null;
                for(int i=0;i<chars.length;i++){
        if((chars[i]=='+'||chars[i]=='-')&&i>0){
        latitude=s.substring(0,i);
        longitude=s.substring(i,chars.length);
        break;
        }
        }
        double dLat=Double.parseDouble(latitude);
        double dLon=Double.parseDouble(longitude);
        }

最后通过Geocoder解析出经纬度对应的具体城市位置:

@WorkerThread
    private static void getAddress(Activity a, double latitude, double longitude, final TextView localeTxt) {
        Geocoder geocoder = new Geocoder(a);
        final StringBuilder stringBuilder = new StringBuilder();
        try {
            //根据经纬度获取地理位置信息
            List<Address> addresses = geocoder.getFromLocation(latitude, longitude, 1);
            if (addresses.size() > 0) {
                Address address = addresses.get(0);
                String countryName = address.getCountryName();//国家
                String adminArea = address.getAdminArea();//省份
                String locality = address.getLocality();//市
                String subLocality = address.getSubLocality();//区
                String thoroughfare = address.getThoroughfare();//街道
                if (!TextUtils.isEmpty(countryName)) {
                    stringBuilder.append(countryName).append(a.getResources().getString(R.string.divide));
                }
                if (!TextUtils.isEmpty(adminArea)) {
                    stringBuilder.append(adminArea).append(a.getResources().getString(R.string.divide));
                }
                if (!TextUtils.isEmpty(locality)) {
                    stringBuilder.append(locality).append(a.getResources().getString(R.string.divide));
                }
                if (!TextUtils.isEmpty(subLocality)) {
                    stringBuilder.append(subLocality).append(a.getResources().getString(R.string.divide));
                }
                if (!TextUtils.isEmpty(thoroughfare)) {
                    stringBuilder.append(thoroughfare).append(a.getResources().getString(R.string.divide));
                }
                stringBuilder.deleteCharAt(stringBuilder.lastIndexOf(a.getResources().getString(R.string.divide)));
            }
        } catch (IOException e) {
            e.printStackTrace();
            a.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    localeTxt.setVisibility(View.GONE);
                }
            });
        }
        final String s = stringBuilder.toString();
        if (!TextUtils.isEmpty(s)) {
            a.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    localeTxt.setText(s);
                }
            });
        } else {
            a.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    localeTxt.setVisibility(View.GONE);
                }
            });
        }
    }
上一篇下一篇

猜你喜欢

热点阅读