this is my simple html to play a single video :
<video id="video_Div" controls> <source src="room.mp4" type="video/mp4 "> Your browser does not support the video tag</video>
but it did not play . but when using another .mp4 videos ,”221.mp4″ it works and plays without any problems
why not all mp4 video works or played in chrome browser ?
I’m using chrome browser
The answer to your question ‘why not all mp4 video works or played in chrome browser?’ – i.e. why one mp4 video will work but another may not, is to do with MP4 itself.
MP4 is a container specification – it provides a mechanism to contain video, audio and data streams in a single ‘wrapper’ or container format.
It can support many different audio and video formats within the MP4 container and this is the reason for the behaviour you are seeing. Your browser and device will typically have a set of video and audio encoding it can support and if the MP4 container’s streams are using these it will be able to play the video. If not it won’t be able to play the video.
Note that even if you know the video encoding format, a codec like h.264, h.265, vp9 etc, there may still be subset of the functionality, or profiles, for a given codec which are and are not supported.
You can see the more detail and information on different supported types in a number of places, but this link from Mozilla is a good place for an up to dat view: https://developer.mozilla.org/en-US/docs/Web/Media/Formats/Video_codecs
As mentioned in the comments to your question, you can see what encoding your video has by using tools like ffprobe:https://ffmpeg.org/ffprobe.html. An example output might look like the example below. This tells you the video stream ‘0’ is using the ‘main’ profile of the H.264 codec, for example:
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/bbb_PCM_48_16.mp4': Metadata: major_brand : qt minor_version : 0 compatible_brands: qt creation_time : 2019-09-19T20:37:29.000000Z timecode : 00:00:00:00 Duration: 00:00:48.00, start: 0.000000, bitrate: 5042 kb/s Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 853x480, 3503 kb/s, 24 fps, 24 tbr, 600 tbn, 1200 tbc (default) Metadata: creation_time : 2019-09-19T20:37:29.000000Z handler_name : Core Media Video encoder : H.264 Stream #0:1(eng): Data: none (tmcd / 0x64636D74) (default) Metadata: creation_time : 2019-09-19T20:37:29.000000Z handler_name : Core Media Time Code timecode : 00:00:00:00 Stream #0:2(und): Audio: pcm_s16be (lpcm / 0x6D63706C), 48000 Hz, stereo, s16, 1536 kb/s (default) Metadata: creation_time : 2019-09-19T20:37:29.000000Z handler_name : Core Media Audio