User manual

AXIS P7210 Video Encoder

Video and Audio

• Compression. The compression level affe cts the image quality, bandwidth and ﬁle size of saved images; the lower the

compression, the higher the image quality with hig her bandwidth requirements and larger ﬁle sizes.

• Rotate image. If required, the image can be rotated.

• Maximum frame rate. To avoid bandwidth problems, the frame rate allowed to each viewe r ca n be li m ited .

• Overlay settings.See

Overlay, on page 16

Click Save to apply the new settings.

H.264

H.264, also known as MPEG-4 Part 10/AVC, is a video compression standard that provides high q uality video streams at low bit rates.

An H.264 video stream consists of different types of frames such as I-frames and P-frames. An I-frame is a complete image whe re as

P-frames only contain the differences from previous fram e s.

The GOV length is the number o f frames between two consecutive I-frames. Increasing the GOV length may save considerably o n

bandwidth requirements in some cases, but may also have an adverse affe ct on image q uality.

ThebitratecanbesetasVariable Bit Ra te (VBR) or Constant Bit Rate (CBR). VBR adjusts the bit rate according to the image

complexity, using up more bandw idth for incre ased activity in the ima ge , and less for lowe r ima ge activity. CBR allows you to s et a

ﬁxed Target bit rate that consumes a predictable amount of bandwidth. As the bit rate wo uld usually need to increase for increased

image activity, but in this case cannot, frame rate and image qualityareaffectednegatively.Topartly compensate for this, it is

possible to prioritize e ither frame rate or imag e q uality. Not setting a priority means that frame rate and image quality are equally

affected. You must save your settings before they c an tak e effec t.

The current bit rate can be set to appear as text overlay. To do this, select the Include text check box option under Overlay

Settings and enter the modiﬁer #b in the ﬁeld.

MJPEG

Sometimes the image size is large due to low light or complex scenery. Adjusting the m a ximum frame s ize helps to control the

bandwidth and storage used by the Motion JPEG video stream in these situations.

Setting the frame size to the Default setting

provides consistently good image quality at the expense of increased band width and storage usage in low light. Limiting the frame

size optimizes bandwidth and storage usage, but may give poor image quality. To prevent increased bandwidth and storage usage,

the ma ximum f ram e size should be set to an optimal value.

Quad stream

A Quad vie w displays images fr om all four channels on a single scree n ; where the image s from each came ra take up a quar ter of

the display area. It is possible to deﬁne settings for the video stream in qua d view.

Stream Proﬁles

Astreamproﬁle is a s

et of pre-conﬁgured stream settings including resolution, compression, frame rate and overlay settings.

Stream proﬁles can b e use d:

• When setting up recording using action rules, see

Events, on page 28

• When setting up a continuous recording, see

Continuous Recording, on page 32

• In the Live View page — select the stream proﬁ le from the Stream proﬁ le drop-down list.

Four pre-programmed stream pro ﬁles are ava ilab le for quick set up. Each pre -progr am m e d proﬁle has a d escriptive na m e, indicating

its purpose. If required, the pre-programmed stream proﬁles can be modiﬁed and ne w custom i zed stre am proﬁles can be created.

To create a new proﬁle or modify an existing proﬁle, g o to Setup > Video & A udio > Stream Proﬁles.

To select a default s t re am proﬁle for the Live View page, go to Setup > Live View Conﬁg.