HTTP Pseudo-Streaming bug, the video is slow, and lag

Discussion in 'Bug Reports' started by redstrike, Aug 8, 2011.

  1. redstrike

    redstrike Member

  2. NiteWave

    NiteWave Administrator

    have you tried this video on other web server like apache?

    this will give us more info.

    update:
    I tried this video on LAN with 256K Outbound Bandwidth (bytes/sec) limit, and JWPlayer 5.7(http://developer.longtailvideo.com/trac/export/1942/trunk/fl5/player.swf), seek working fine.
    not sure if the file name will cause any problem, I renamed it to video.mp4 before testing.
    Last edited: Aug 8, 2011
  3. meto

    meto New Member

    I had same problem on KVM, under OpenVZ everything was fine. Are you using any sort of virtualisation?
  4. redstrike

    redstrike Member

    No. I don't use Apache. Seeking time is ok, but the video's frame starting lagging, not smooth. i have tried to rename the file for long time ago but it's not working. Can you show me your mp4 link?

    I am using a VPS with 768 MB RAM. Is it the bottleneck? But another videos work correctly (after seek time, it's play normally, not lag in frame). Maybe, i don't know which virtualization software is used by my VPS provider, but it can be KVM.
    Last edited: Aug 8, 2011
  5. meto

    meto New Member

    It could be due to some kind of IO buffering in KVM, dont really know, I just went with OpenVZ. Which VPS provider do you use then?
  6. redstrike

    redstrike Member

    My VPS Provider told me that they are using something similar to Parallels Virtuozzo. I hope this is not LiteSpeed's bug.
  7. NiteWave

    NiteWave Administrator

    it's in a LAN. I just created a test.html:
    Code:
    <embed
          flashvars="file=video.mp4&provider=http&http.startparam=start"
          width="876" height="480"
          src="player.swf"
          allowfullscreen="true"
          allowscriptaccess="always"
          wmode="transparent"
    />
    
    the video.mp4 is the "problem" mp4, player.swf is JWPlayer 5.7 as mentioned before.

    can you access test.html on your server and see if same problem.
  8. redstrike

    redstrike Member

  9. NiteWave

    NiteWave Administrator

    got it ... I think it's bit rate / bandwidth issue.
    when your bandwidth is wide enough, you can host high bit rate videos;
    otherwise only low bit rate video can play smoothly.

    the video itself has no problem.
  10. redstrike

    redstrike Member

    I have converted those files using VBR-2 pass method. The bit rate of each scene is high and low in a dynamic way. You mean the overall bit rate (file size) or the bit rate per second ?

    I see, i have checked another videos. It show that the videos which over 26 MB is laggy, below 25 MB is ok.

    But i think another issue is the frame rates of those videos. 29.97 fps, 30 pfs is better than 25 fps? And how much banwidth is enough for streaming videos with quality over 360p (480p, 720p)? I don't sure about this situation...

    Update: I have re-converted the video to a new version which has preset similar to Youtube's 480p: http://www.youtube.com/watch?v=kypfWa6b_7g The framerates from 25 pfs to 24 pfs. At: http://www.raphay.com/test1.html

    But it's still not working. Was CPU of server the bottleneck?
    Last edited: Aug 8, 2011
  11. redstrike

    redstrike Member

  12. NiteWave

    NiteWave Administrator

    Hi, it's quite fast to me at the moment.

    it's a network speed issue --- the download speed between the server and browser. if download speed slow, the video have to keep buffering to be able to play.
  13. redstrike

    redstrike Member

    I think you misunderstand me. I means everything working, buffering ok, but the video frames become unstable, slow than loading in the normal way. Please open the video by your windows media player, or sth elese and compare it 1 to 1 with the video on the browser which has been seeking time.

    In my opinion, maybe it's file issue, or flash player or web server.
    Last edited: Aug 8, 2011
  14. NiteWave

    NiteWave Administrator

    you mean "slow motion" ? i.e., original video is 30 frames/second, but playing with 20 frames/s, or 10 frames/s. so looks like slower than normal. if it's the case, I haven't experienced it yet.

    do the video play normally without seek? it's normal in my random seek tests.

    to prevent a single IP consuming too many bandwidth, maybe you can try limit the Outbound Bandwidth to 256K(or 364K, 128K etc), to see if any improvement.

    Server->Security->Outbound Bandwidth (bytes/sec)
  15. redstrike

    redstrike Member

    Yes, NiteWave. I mean "slow motion". The video play normally without seek, but after seek the motion is slow than normal a little.

    UPDATE:
    I re-converted the video to 2 different presets by using another softwares. It's work now. Thanks for your support.
    Last edited: Aug 9, 2011
  16. NiteWave

    NiteWave Administrator

    Thanks for your update. can you specify what's the root cause? so others can learn from your experience.
  17. redstrike

    redstrike Member

    I tested by using another softwares. The root cause is the original video's frames rate, i met 2 cases both of them has 24 fps. The 29.97 fps video is suitable for internet streaming than any others.

    Then, Encoder software is the another issue with them. I usually use TMPGEnc with the preset optimize for small size but high quality (it need more computing power). Last night, i have tested by using Adobe Media Encoder with the same preset with TMPGEnc... it's end up like TMGPEnc. In some encoder for common user like AVS Video Converter, the quality of result can't be compared to 2 of above but the video end up is OK.

    Maybe this is the bottneck of mp4. So, Youtube doesn't use mp4 for preset 480p of their video. I usually see the FLV.

    I suggest the Pseudo-Streaming FLV feature for LiteSpeed.
    Last edited: Aug 10, 2011
  18. NiteWave

    NiteWave Administrator

    not sure if the video is ok when upload to youtube ?

    litespeed has supported Pseudo-Streaming FLV earlier than mp4. it's simpler than mp4.
  19. redstrike

    redstrike Member

    I downloaded the original mp4 720p from Youtube. Everything is ok with Youtube.

    Do i need a tool to move the medata of FLV to the start of file, like MP4? Can you suggest me? After conversation, we need to do a minor step to make our video can be streaming in Pseudo way. I have tried to download the FLV from Youtube, but i can't Pseudo streaming that FLV?
  20. NiteWave

    NiteWave Administrator

    I used a tool flvtool++ from facebook:
    http://mirror.facebook.net/facebook/flvtool /
    and working well.

    rename the flv file with suffix .flv. it looks video file downloaded from youtube without .mp4, .flv suffix

    random seek to mp4 has more overhead of CPU, memory at the server side than flv. so if .flv is ok, better to use .flv to reduce the server overhead.
    Last edited: Aug 10, 2011

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