ENC-200™ H.264 Encoder
User Guide V1.8
19
3.4.2
Menu: Encoder / Video
Figure 7 shows the ‘Encoder / Video’ page of the ENC-200™ encoder and Table 7 describes it.
Figure 7: ‘Encoder / Video’ page of the ENC-200™ encoder
Settings:
Description:
Codec:
Displays the video codec of the output stream. (Read only)
Profile:
Specifies the used H.264 profile. You can choose between:
Baseline
Main
Bitrate:
Specifies the video bitrate in kBit/s of the output stream.
Intra Frame Interval:
Specifies the interval of the intra frames. Intra frames (= I-Frames)
are total independently coded frames which are used as
references frames.
Additional Information about P-Frames and GOP length:
At the ENC-200™ the data volume of a P-Frame amounts
between 5% and 20% of an I-Frame. If is assumed of an average
data volume of 10%, it means that for one I-Frame or ten P-
Frames the same data volume is needed. The H.264 standard
allows long GOPs. The ENC-200™ limits the GOP length to 500
frames. More P-Frames at the same data rate means also a better
quality. But more P-Frames have also two disadvantages: 1) The
decoder can start the decoding process not till then the decoder
get an I-Frame. That means at a GOP of 500 frames, the decoder
waits in worst case 20 seconds before a picture can be displayed.
2) The result of this is also, that at occurrence of network errors
(high packet loss), Frame gaps of up to 20 seconds can occur. So,
the lower the P-Frames, the higher are the robustness and the
faster can be switched the streams.
Deinterlacing:
Enables / Disables deinterlacing.
Input:
Specifies the video input which is available on the Sub-D 26-pin
connector or on the BNC connector of the front panel.
SDI (via BNC on the front panel; note here chapter 4.5)
CVBS(BNC) (via BNC on the front panel; note chapter 4.5)
CVBS (via breakout cable)
