Welcome to Bro.adca.st streaming platform!

About our bandwidth limiter and how to prevent your stream to get flagged

We had many complaints today about channels being flagged that were not exceeding the maximum bitrate. If this happened to you also, and your channel or channels have been flagged even when you are using a lower bandwidth than maximum allowed of 500kbps, the reason may be the encoding method that you are using.

You will need to check the method in which your stream is being encoded and change it to a proper mode in order to fix the issue.


The following list explain the available methods:


VBR (Variable Bit Rate)

VBR encoding method allows the user to specify a bitrate range — a minimum and/or maximum allowed bitrate. The minimum and maximum allowed bitrate set bounds in which the bitrate may vary.

On encoding software like xSplit, you can choose to use VBR mode and the limit for maximum bitrate, but in FMLE (Flash Media Live Encoder) the limit is set on minimum bitrate, so your streams may go way beyond the selected bitrate and this is most likely the reason of you channel being flagged. You can check this on FMLE by ticking the "Auto Adjust" setting and then the configure button aside.

This encoding method is not recommended on our platform unless you are encoding from FFmpeg where you can pass the parameter "-maxrate 450k" or in XSplit where you can choose the maximum bitrate using VBR Mode.


ABR (Average Bit Rate)

ABR refer to a form of VBR, which provides something of a "running average", with the end goal that the stream matches this bitrate "overall on average" (so basically, if it gets a lot of black frames, which cost very little, it will encode them with less than the requested bitrate, but then the next few seconds of (non-black) frames it will encode at very high quality, to bring the average back in line). On encoding software like FFmpeg, this is the default method.

This method is not recommended at all on our platform, cause the fluctuations on the bitrate will get your channels flagged and banned.


CBR (Constant Bit Rate)

CBR encoding allows the user to specify a constant bitrate. CBR is useful for streaming multimedia content on limited capacity platforms like ours since it is the maximum bit rate that matters, not the average, so CBR should be used to take advantage of all of the capacity.

This method is the recommended and most safe method to publish your streams to Bro.adca.st.


A quick summary of this post:

If you are using XSplit, you can choose any available mode (CBR or VBR) but you'll need to adjust the video bitrate or max bitrate to 400k. Make sure your VBV (Video buffering) is also set to 400k when streaming on both modes.

If the encoder of your choice is FFmpeg or avconv, or any similar GUI software based in FFmpeg, you'll need to set the parameters -maxrate 400k -bufsize 400k to the target stream. Example ffmpeg command: ffmpeg -i INPUT -c:v libx264 -vb 400k -maxrate 400k -bufsize 400k -ab 32k -ar 11025 -ac 2 -c:a aac -strict experimental -f flv rtmp://origin.bro.adca.st:1935/liverepeater/xxStreamfieldxx;

If your software is FMLE (Flash Media Live Encoder) you need to keep the "Auto Adjust" setting OFF, and set the video bitrate to 400 Kbps, while the audio settings should be: ACC, Mono, 11025 hz, 32 Kbps.

If you are using any other encoder try to adjust its settings to any of the above CBR or VBR configurations, or give us a Skype Chat and we will help you accomplish the task.


Happy Streaming!