java得到amr的播放时长duration

来源：互联网发布：无锡ntt数据有限公司编辑：程序博客网时间：2024/06/07 22:04
/**     * 得到amr的时长     *      * @param file     * @return     * @throws IOException     */    public static long getAmrDuration(File file) throws IOException {        long duration = -1;        int[] packedSize = { 12, 13, 15, 17, 19, 20, 26, 31, 5, 0, 0, 0, 0, 0, 0, 0 };        RandomAccessFile randomAccessFile = null;        try {            randomAccessFile = new RandomAccessFile(file, "rw");            long length = file.length();//文件的长度            int pos = 6;//设置初始位置            int frameCount = 0;//初始帧数            int packedPos = -1;            /////////////////////////////////////////////////////            byte[] datas = new byte[1];//初始数据值            while (pos <= length) {                randomAccessFile.seek(pos);                if (randomAccessFile.read(datas, 0, 1) != 1) {                    duration = length > 0 ? ((length - 6) / 650) : 0;                    break;                }                packedPos = (datas[0] >> 3) & 0x0F;                pos += packedSize[packedPos] + 1;                frameCount++;            }            /////////////////////////////////////////////////////            duration += frameCount * 20;//帧数*20        } finally {            if (randomAccessFile != null) {                randomAccessFile.close();            }        }        return duration;    }