video_bitrate can also be set from the web interface under camera settings. For most purposes it can be lowered down to 3Mbit/s. You can also edit the default in the /etc file if required.xab wrote:Check /etc/raspimjpeg , find the line with "video_bitrate" and then modify the number, by default it should be 17Mbit/ssknic wrote:Hi, I play with raspberry pi as cam using rpi cam web interface. Using default settings and watching live video from pi it consumes 18Mbit/s of bandwitch. This is pretty much and on mobile internet it is not possible. How to lower this bandwitch to 3Mbit/s? Thanks
However this bit rate affects video recordings and their playback from the download screen. It does not affect the live video main screen as this is obtained from the mjpeg feed.
There are a number of factors affecting the live previews; width, divider, quality. These can all be controlled from the web interface. In addition you can choose between default streaming where it is fetching a sequence of jpegs or a true mjpeg stream. This doesn't fundamentally change the bandwidth but the mjpeg stream has less to and fro with the web server so may be smoother.
Width controls the size of the mjpeg images generated and will have a significant impact on bandwidth. It also controls the size on the display. By default it is 512px. If you can live with say 384 then that should halves the bandwidth.
Quality is the jpeg compression factor (0-100). Lower numbers give better compression at the expense of quality. It is set to 25 by default which gives pretty good compression and not too much degradation. YOu could try lowering it to say 15 which will significantly lower sizes further but you will start to see some degradation. Lowe than this it will start to get bad.
Divider is the rate at which new data is fetched. It is the video fps (default 25) divided by 'Divider'. Nominally that would mean it is trying to update at 25fps but in practice other delays lower this a bit. Increasing the divider lowers the fetch frame rate so 3 would give a nominal rate of 8fps. This will also have a dramatic effect on bandwidth.
Edit: Using width=384, Q=15, Divider=3 I got about 1.5Mbit/s usage