1. M4V format
   M4V is a standard video file format created by Apple. This format is used by iPod, iPhone and PlayStation Portable, and it is based on the second edition of MPEG-4 encoding. The video coding adopts H264 or H264/AVC, and the audio coding adopts AAC. Using H264 high-definition coding, compared to traditional On2 VP6, H263, Divx, etc., it can achieve higher definition with a smaller volume. The M4V format is also known as Apple’s Video Podcast format. It is a special type of MP4, M4V is the representative application of MP4 format HD
2. MP4 format
   MP4 is a set of compression coding standards for audio and video information, formulated by the “Moving Picture Experts Group” (MPEG) under the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) , The first edition was adopted in October 1998, and the second edition was adopted in December 1999. The main uses of the MPEG-4 format are online streaming, CD-ROM, voice transmission (video telephony), and TV broadcasting

Three, identify the specific format of the video,
use phpsh to encode and view here

$f = new finfo
=> finfo {#2339}
$f->file(‘/tmp/5s_video.mp4’, FILEINFO_MIME_TYPE);
=> “video/mp4”

$f->file(‘/tmp/杀手篇.mp4’, FILEINFO_MIME_TYPE);
=> “video/x-m4v”