.flv-stutter hell!

[oivind]

I've been struggling with stutters in my online .flv-videos. I have also been struggling finding an answer despite posting on various video editing forums for some six months now. Maybe successful stutter free flv-encoding is a secret within the community?

After reading a selection of articles and posts on this topic, many claim that low bitrate is key to stutter free playback. I have now succeeded reducing the file size to 3741 KB with a data rate of 921 kbps. However, the online .flv-video is still stuttering!

Most of the times the movie will play back without stutter locally. The stuttering starts when attempting playback of the same file from the server.

Another thing that really has me scratching my head is that the stutters appear erratically. That is, my videos are set up to replay automatically. The first playback may stutter, and then the next one will not stutter at all. The stutters also appear at different stages throughout the video.There is no obvious pattern and file size does not seem to affect this behavior at all.

The video file in question: http://www.serpent3d.net/Showroom4.html


Data on the video file:

Format: .flv (H.264)
Frame rate: 30fps
Data rate: 921 kbps
Total bitrate: 921 kbps (no audio)


One of the most useful articles on the subject is «Avoiding judder in motion graphics» by Rick Gerard. http://kb2.adobe.com/community/publishing/908/cpsid_90843.html. He states that a lot of movement in the scene can produce judder, and the only way around it is adding motion blur and increasing frame rates. I have tried both methods, but still struggle with stuttering.

I have no ambitions becoming an engineer within the field of video-editing! I am simply looking for a well-documented way of safely encoding the videos for stutter free online playback. With the .flv-format being the dominating way of encoding online videos, one should think that this knowledge is out there, although I haven’t had any luck so far…

[jagabo]

How much stutter are you seeing? Not quite totally smooth? Like one repeated frame now and then? Half second long pauses? Worse? It's pretty smooth here. Occasionally an extra frame.

I downloaded the file and it was 8 MB, 2217 kbps according to MediaInfo.

[hech54]

The video file in question

I don't see any studdering AT ALL in that video.
So......:
a. get a newer computer
b. get an older computer(like mine)
c. you are doing nothing but spamming here(at videohelp).

[Baldrick]

One thread is enough. I deleted your other thread.

It plays fine here too.

[oivind]

How much stutter are you seeing? Not quite totally smooth? Like one repeated frame now and then? Half second long pauses? Worse? It's pretty smooth here. Occasionally an extra frame.

I downloaded the file and it was 8 MB, 2217 kbps according to MediaInfo.

Thank you very much for your reply. Exactly, not quite totally smooth - one dropped frame now and then for every other playback or so. The FLV player is configured for automatic playback. I know it isn't too bad, but I want it better! Is there any good reason why I shouldn't be able to completely eliminate the problem?

[oivind]

The video file in question

I don't see any studdering AT ALL in that video.
So......:
a. get a newer computer
b. get an older computer(like mine)
c. you are doing nothing but spamming here(at videohelp).

I apologise for the multiple posts, however I found it rather strange that nobody (here and elsewhere) seemed to have any real knowledge and insight explaining or providing solutions to the .flv stutter problem. The stutter problem is widely reported, but no real solutions are given.

[oivind]

One thread is enough. I deleted your other thread.

It plays fine here too.

Thank you for reporting back! Did you watch the video more than once? The reason for my question being that the FLV player is set up for automatic playback. Here, on my computer, the stutter problem will vary from playback to playback.

I do apologise for the double posting. I have been struggling with this problem for quite som time, and guess I was running out of patience...

[jagabo]

The animation is too slow and boring. And 2200 kbps (not the 921 kbps you claimed) is a waste of bandwidth. You should discard every other frame, keep the frame rate at 30 fps, and encode with a lower bitrate.

[AlanHK]

I apologise for the multiple posts, however I found it rather strange that nobody (here and elsewhere) seemed to have any real knowledge and insight explaining or providing solutions to the .flv stutter problem. The stutter problem is widely reported, but no real soltions are given.

It may or may not be related, but Youtube videos can stutter due to them using HTML5.

If your server is doing that, it may be the problem.

See eg here: http://my.opera.com/community/forums/topic.dml?id=1211952&t=1344059871

On Youtube you can fix it by going to http://www.youtube.com/html5 and turning off the HTML5 player.

[oivind]

The animation is too slow and boring. And 2200 kbps (not the 921 kbps you claimed) is a waste of bandwidth. You should discard every other frame, keep the frame rate at 30 fps, and encode with a lower bitrate.

I appreciate your comments.

Yes, there are currently two alternate files that I use for testing purposes. For the past 24 hours, I've been pointing to the larger of the two (usb4.flv). The 821 kbps file (usb2.flv) is now back in action, but I can't see much difference in playback between the two.

Lower bitrate doesn't seem to cut it alone... When it comes to discarding every other frame, I am little unsure what you are refering to. I use Adobe Media Encoder.

I would agree that the piece comes across a little dry and boring. However, that is NOT the issue here. I am simply trying to establish a safe and tested encoding routine for .flv-files to publish with the embedded FLV player on my website. Hence the title of the thread... As soon as I get this annoying and time consuming issue sorted out, I can get back focusing on the creative proceess. Not much point in posting a staggering video if you're unable to stream it smoothly! Or what do you think!?

[jagabo]

One of the most useful articles on the subject is «Avoiding judder in motion graphics» by Rick Gerard. http://kb2.adobe.com/community/publishing/908/cpsid_90843.html. He states that a lot of movement in the scene can produce judder, and the only way around it is adding motion blur and increasing frame rates. I have tried both methods, but still struggle with stuttering.

That has nothing to do with your problem. The fact that the file plays locally just fine, and that it's much smoother the second time through on the web page (after it's cached locally) indicates a problem with the streaming. The player is pausing every now and then, causing littler jerks. Not enough read ahead buffering or something like that. Or there is some kind of playback incompatibility with the file, stream server, and/or embedded flash player. Try using fewer (or none at all) B frames?

[oivind]

One of the most useful articles on the subject is «Avoiding judder in motion graphics» by Rick Gerard. http://kb2.adobe.com/community/publishing/908/cpsid_90843.html. He states that a lot of movement in the scene can produce judder, and the only way around it is adding motion blur and increasing frame rates. I have tried both methods, but still struggle with stuttering.

That has nothing to do with your problem. The fact that the file plays locally just fine, and that it's much smoother the second time through on the web page (after it's cached locally) indicates a problem with the streaming. The player is pausing every now and then, causing littler jerks. Not enough read ahead buffering or something like that. Or there is some kind of playback incompatibility with the file, stream server, and/or embedded flash player. Try using fewer (or none at all) B frames?

Thank you very much for pointing me to important information. I will have a thorough look at that now and report back as soon as the results are coming in...

[oivind]

One of the most useful articles on the subject is «Avoiding judder in motion graphics» by Rick Gerard. http://kb2.adobe.com/community/publishing/908/cpsid_90843.html. He states that a lot of movement in the scene can produce judder, and the only way around it is adding motion blur and increasing frame rates. I have tried both methods, but still struggle with stuttering.

That has nothing to do with your problem. The fact that the file plays locally just fine, and that it's much smoother the second time through on the web page (after it's cached locally) indicates a problem with the streaming. The player is pausing every now and then, causing littler jerks. Not enough read ahead buffering or something like that. Or there is some kind of playback incompatibility with the file, stream server, and/or embedded flash player. Try using fewer (or none at all) B frames?

I just followed your instructions, rendering using profile to «High» and then «Baseline». These settings should use less B-frames (2 and 0) as oppsed profile setting «Main» which use 3. Both of the new renders now appear healed from the stutter-problem.

I used Level 3.2 for both of the new renders. Is there some additional performance (stability) gain by adjusting this value further for my 960*540 .flv-movie?

It will be interesting applying these settings to another video which actually has been stuttering worse than the one in this post.

I will carry out some further testing and return with the results.

[oivind]

I have been testing video streaming for a few days, but changes in encoding does not improve online playback performance at all. The stuttering is still a problem!

Please find the test video and detailed findings here: http://www.serpent3d.net/serpent_test.html

[poisondeathray]

The reason is it's buffering. This is a bandwidth issue. You need to pay for more server bandwidth or set a larger initial delay (so the buffer can build)

The reason why people suggest lowering the bitrate may help is that there is less chance of exceeding the network connection. But this doesn't address the real problem

[oivind]

The reason is it's buffering. This is a bandwidth issue. You need to pay for more server bandwidth or set a larger initial delay (so the buffer can build)

The reason why people suggest lowering the bitrate may help is that there is less chance of exceeding the network connection

Thanks for the ultra quick reply: The buffer is set to 6 seconds. Any other setting (lower or higher) makes the video stutter more. All other information is readily available on the test page.

[poisondeathray]

If you use a different host (with large bandwidth), you will see it doesn't stutter

[oivind]

If you use a different host (with large bandwidth), you will see it doesn't stutter

I have been suspecting that for a long time, however it seems strange that the stuttering varies even after the file has been fully downloaded to the cache of local machine. As I've stated before: There is next to no stuttering when the same file is played back from the original file locally.

Regardless: I've been struggling with this issue for more than half a year now. Most likely I will be changing host very soon!

[poisondeathray]

If you use a different host (with large bandwidth), you will see it doesn't stutter

I have been suspecting that for a long time, however it seems strange that the stuttering varies even after the file has been fully downloaded to the local machine. As I've stated before: There is next to no stuttering when the same file is played back locally.

Indeed that is strange. I don't see the problem when it's been downloaded. Can you try on a different machine ?

Clearly there is a bandwidth and buffering issue (it even says so as it's stuttering). But if you're referring to this other problem, I don't see it. It might be a local flash configuration issue