Low video bitrate issue

[Paul M]

I am creating video lessons using Screencast-o-Matic Pro and a basic Logitech headset with a microphone. The issue is that I am getting a very low video bitrate between 150 kbps and 250 kbps. I need it to be at least 300 kbps since it is a minimum requirement of the website that hosts the videos. I believe that the ideal bitrate is 3000kbps to 5000 kbps.

I have been trying to increase the bitrate in different ways including re-recording them using SoM, then recording the audio separately but the bitrate is always low. I also used Handbrake to increase bitrate but the result was just a marginal increase.

I don't know whether the recording software is at fault or the audio output of the microphone or something else.

If SoM doesn't do the job for me, is there any other economical way of recording videos with a high bitrate?

A question for those who are familiar with Camtasia - if Camtasia(or other similarly priced software) is the solution does it offer the facility of choosing a high bitrate?

Any help would be appreciated.

[Baldrick]

You can't get better quality by using Handbrake. You must change it in Screencast.

But if you can't change the bitrate then try something else like the free OBS Studio (FREE and it worked okey when I tested it).

[Paul M]

Thanks for your response, Baldrick! Yes that seems to be quite true - Handbrake cannot increase bitrate substantially if it is not possible in the video.I did check out OBS Studio which seems good but since my comfort level is good with SoM I decided to stick with it after I got some more information about the issue and some possible solutions.

From another forum I learnt that the issue could be because I was using PowerPoint slides without much change in color throughout the video, and that could have caused the low bitrate.

For the time being, I'll mix in some form of demos in the low bitrate videos and see whether I can raise it above 300 kbps. When I checked the videos in my previous lessons that were approved by the site most of them had some form of demos, with the result that those videos had a bitrate above 300 kbps. I have completed audios for these videos so for these lessons I will leave it at that - if this trick raises the bitrate to what I need.

I'll also save them as .AVI files instead of .MP4 - I don't know why I have been going with .MP4 formats if saving as .AVI was possible.

In the future, I will also think of something else to make my slides themselves more colorful to bring in varying degrees of color spectrum and get a higher bitrate, at least above 300 kbps. Maybe use more colorful/ brighter slides than the dark grey ones that I am using for this presentation.

If these fixes work and I can continue using Screencast-o-Matic that will suffice for me. I don't want to upgrade to Camtasia because I have been happy with using SoM for about 2 years now, first with the free version and then the Pro version - previously for creating YouTube videos and now for online lessons. It may not have as many features as Camtasia and Sony Vegas but has enough editing features for my needs, is easy to use, never crashes(I heard Camtasia does) and the support is fast enough and helpful. In fact after I posted in this forum in a hurry to get some solution, I discovered that their response to my ticket was waiting in my email inbox.

The price difference when compared with the others is huge which makes SoM great value for money, at least for me.

I'll get back to working on my videos now, and if I have anything more to report I will post it here. Hopefully, someone will find my thread useful. There seems to be very little relevant information about bitrate issues on the web.

[jagabo]

If this is basically a slideshow you can arbitrarily force a higher bitrate in Handbrake by entering "keyint=1" (or some other small number) in the h.264 Extra Options field. If it's motion video you should be able to increase the file size and quality by setting the RF (rate factor) to a small value (move the slider to the right). Setting it to 1 should give you a gigantic file.

But reencoding your video will decrease the quality.

[Paul M]

If this is basically a slideshow you can arbitrarily force a higher bitrate in Handbrake by entering "keyint=1" (or some other small number) in the h.264 Extra Options field. If it's motion video you should be able to increase the file size and quality by setting the RF (rate factor) to a small value (move the slider to the right). Setting it to 1 should give you a gigantic file.

But reencoding your video will decrease the quality.

That seemed to work and it bumped up the bitrate to 8000 kbps. But the video quality is poor and a lot of what's on the screen is unclear.

Since I don't really need that high a bitrate, I'll try and experiment with Handbrake for a higher bitrate with an acceptable quality of videos that is at least viewable.

[jagabo]

If this is basically a slideshow you can arbitrarily force a higher bitrate in Handbrake by entering "keyint=1" (or some other small number) in the h.264 Extra Options field. If it's motion video you should be able to increase the file size and quality by setting the RF (rate factor) to a small value (move the slider to the right). Setting it to 1 should give you a gigantic file.

But reencoding your video will decrease the quality.

That seemed to work and it bumped up the bitrate to 8000 kbps.

Which one did you try?

But the video quality is poor and a lot of what's on the screen is unclear.

A rate factor below 10 should be indistinguishable from your source. Unless you have small colored text (or other small colored objects) and your source is RGB. The chroma subampling of of YV12 video (used in h.264 encoding) will blur colors a little. For example:

https://forum.videohelp.com/threads/319360-DVD-LAB-PRO-color-map?p=1977264&viewfull=1#post1977264

[Paul M]

Thanks for the tips Jagabo!

I entered keyint=1 and moved the slider a bit to 15 and then 18, giving my video a bitrate of about 7k and 4.5k respectively. But obviously it must have affected some other aspect of the video because when I uploaded both the edited videos to the site one by one, it still gave the same error.

The site's requirements are as follows:

- Video bit rate of at least 300 kbits/second (3000-5000 kbits/second is ideal)
- Videos should not be greater than 2GB in size
- Use .mp4, .mov, .avi, or .flv when exporting your video files
- Video compression format: H.264

The video with a bitrate of 4.5 kbps ticked off all the requirements but still did not get processed by the site, so now I am stuck.

[jagabo]

Are you using an unusual frame size? Try sticking with some of the standard frame sizes like 1920x1080, 1280x720, 640x480, etc. Or at least stick with mod 4 or mod 8 (integer multiples of 4 or 8).

[Paul M]

I edited 2 videos with mod 4 and slider set at 25, got good bit rates but site didn't accept it.

It looks like I'll have to create the videos all over again but fortunately I have audios for all of them so only need to go through the presentation once again. This time I think I'll try Camtasia which I believe has a trial for 30 days.

[poisondeathray]

What video site were you trying to upload to ?

What that the error message you got verbatim ? If not, post the rejection message

What does mediainfo view=>text say about one videos you uploaded ?

[jagabo]

Maybe they don't like all keyframes. Try "keyint=6:bframes=0".

[Paul M]

These videos are for Skillshare. Their tech specs are at this link:

http://help.skillshare.com/hc/en-us/articles/204543358-Technical-Specifications-Export...and-Uploading-

The error message is "low bitrate" or something to that effect - I can't see it now because I deleted all the 11 videos even the few that were accepted(although they had similar low bitrates, beats me how they got accepted), wanting to re-upload all the 11 videos again after running all of them through Handbrake to bump all of their bitrates.

This is the mediainfo screenshot for the last try with that one video(click to enlarge):



Between July and until last week, I had 2 courses uploaded that were similar - slides and a few online demos but there was no problem at all and both courses went live. They did have bitrates higher than 300 kbps though none had more than 450 kbps(but much below the "ideal" 3000-5000 kbps).

I am still unclear what the root cause could be, and the questions below are constantly running in my mind.

- Is it the recording software I am using? SoM does not seem to have a bitrate setting like Camtasia does.

- If I use a program that has a bitrate setting that I can adjust between the ideal bitrate of 3000-5000 kbps, will that solve my issue?

- Is it because I am recording mainly presentations? There are a few short demos in them but then a video introduction which had only one slide on the screen for 2 minutes was accepted by the site although the bitrate was only 185 kbps.( 5 out of the 11 videos did get accepted, all with low bitrates below 300 kbps).

Besides, all previous videos that were similar in nature (mostly slides and some demos) got accepted(but they had bitrates above 300 kbps).

I have also written to their support team and am in touch with SoM support.

Thanks for all of your help and tips on this thread.

[poisondeathray]

Very unlikely because of a bitrate issue

It's more likely because of the "weird" dimensions of 1266x942 .

Videos should be recorded at a resolution of 1280x720 or 1920x1080

16:9 Aspect Ratio for slides + video format

You have a 4:3 AR , so you should pillarbox it for 16:9 (add black borders to the left and right)

[Paul M]

I changed the AR by re-recording the videos with the SoM recording set at 720. SoM has 4 options - 480, 720, Active Window and Fullscreen. But I discovered(after the recordings were completed) that the width does not automatically adjust itself to 1280p using the setting, which says only "720". So the videos have a width of about 100p more or less than 1280p. As a result, instead of the AR showing as 16:9, I get 4:3 or 16:10 etc.

The pillarboxing looks odd and I don't know how it will be perceived by viewers. I guess it will be a part of learning through errors for me.

Anyway it was not of much use(re-recording and re-uploading them) because all except one faced the same issue, getting the low bitrate error although they had high bitrates that I got using Handbrake.

There are a total of 11 video uploads, out of which 5 show a low bitrate error now - down from 6 since one more got accepted after the Handbrake-enabled bump in bitrate. The ones that were accepted earlier neither have the minimum of 300 kbps as required nor the AR that has been stipulated by the site - and as pointed out above they are all having "weird" dimensions. That was my mistake the first time round since I kept adjusting the borders while recording, forgetting that it will change the AR.

I had written to Skillshare's support describing the problem that I am faced with and that I followed their instructions. They wrote back offering to upload one video from their end to see what happens. So I have sent them 1 video, and all I can do now is wait as far as these videos as concerned.

[poisondeathray]

Does Skillshare re-encode videos for distribution ?

The other things you can look at that may cause problems for some sites are VFR (variable frame rate) , and not web optimized (moov atom not at the beginning) .

In handbrake I think there is a CFR (constant frame rate) , and a web optimized tick box . VFR shouldn't cause a problems on flash or HTML5 platforms, but the moov atom issue will cause a video to not play until fully downloaded by the client

It would be unlikely for a minimum bitrate to be the culprit

[Paul M]

Ok, so here's my update. I received another email later saying that they are uploading that one video that I sent them. After about an hour I noticed that the video had shown up as processed. But I didn't get any email about why they thought the videos that I was uploading were returning an error.

So instead of sending them a reminder, I decided to try uploading all the videos again and voila they were all processed without any issue. I did try one of the videos which was not edited with Handbrake but it returned the same low bitrate error so I guess it was an issue with the bitrate at first. Why I say "at first" is because I had been clicking on the link next to error message while re-uploading the HB-edited videos. But it was only when I used the "upload" button right at the bottom of the page that all the videos were uploaded and processed without any issue.

So it was indeed an error on my part that prevented the videos from being processed after I made use of all the great tips in this thread.

I am grateful to poisondeathray and jagabo for their tips - actually I learnt a lot from all that was written in the posts. In fact I googled for more information about what was mentioned in those posts - and then I realized that video production and editing seems much more interesting than I thought!

Thanks again!