User Manual v.2
QVidium
®
QVENC4K™ UHD/HEVC Video Encoder
Copyright 2023 QVidium
®
Technologies, Inc.
Page 19 of 43
Note:
Be aware that the user interface will not warn you if you try to enter a bit rate beyond the
operating limits of the encoder. For more details on the range of
encoding bit rates
, please
see
Appendix C
(Section 7.2). For more information on the various
video parameters
(Frame Rate,
Encoding, Format, Resolution, etc.) please
see
Appendix A
(Section 7.1). For UHD or HD video,
you can select either HEVC (H.265) or MPEG4-AVC (H.264)
Video Encoding
.
2.2.1 Basic Encoding Parameters
All the basic parameters you normally would need to set when creating a new encoding profile are
grouped together under the
Profiles
menu when editing or creating a profile, as shown in Figure 7,
above. Below is a description of these basic video and audio encoding settings:
Input: BNC or SFP
. Default is
BNC
. The QVENC4K has 2 video inputs capable of SDI rates from
HD-SDI and 3G-SDI through 12G-SDI. You can select between SFP input or BNC input from a
75 Ohm coaxial cable. SFP allow you to insert one of any standard SFP form-factor modules.
Usually this is to allow for a fiber-optic SDI feed, which is very useful for accommodating long
cable spans.
Video Size: Auto
,
1920x1080
,
1280x720
,
960x540
,
854x480
,
640x360
, and
480x270
. Default is
Auto
. The QVENC4K has in internal video scalar. Setting resolution to “
Auto
” retains the
resolution of the SDI signal. Otherwise, the scalar downscales or upscales the resolution to the
selected value.
Note:
The QVENC4K cannot de-interlace an interlaced signal, nor can it
create interlaced video from progressive. When presented with interlaced video, it will
automatically upscale the video before encoding it.
Video Encoding: HEVC
(H.265) or
H264
(H.264/MPEG4-AVC). Default is
HEVC
. You can select
between HEVC/H.265 encoding and MPEG4-AVC/H.264 (Main profile). HEVC requires about
one-half 1/2) to one-third (1/3) of the bit rate for comparable video quality versus H.264 for
UHD/4K video because it uses a much larger block size. The video encoding format of the
output IP stream is 8-bit, 4:2:0.
Vide Frame Rate: Full
or
Half
. Default is
Full
. This setting allows you to reduce the frame rate to
one-half of the original Standard video frame rates are normally 59.94 fps. or 50 fps. Halving
the frame rate allows for half the stream bit rate.
Video Bit Rate:
Defaut is
7,500
Kbps (7.5 Mbps). This sets the total output stream bit rate in
kilobits per second (Kbps). The QVENC4K sets an internal video bit rate by subtracting the
audio bit rate from the Stream Bit Rate and setting an additional margin for IP packetization.
For all stream modes, the output bit rate should not exceed this value. However, there may be
a variation in output bit rate of up to about 5% over the value you set. If the bit rate is too low
for the video content you have, then you can expect to see pixelization and blurring of the
image for scenes with high motion. The minimum bit rate is set to 500Kbps (500). The
maximum bit rate is 60Mbps (60000) per stream.
Vide GOP:
Default is
15
. This sets the Group-of-Pictures (GOP) value. Each GOP begins with an
I-Frame (aka. Key-Frame) which is essentially a JPEG snapshot, followed by P (Predictive)
Frames and B (Bidirectional) Frames to create a full GOP. A larger GOP can decrease the
overall required bit rate, at the expense of a longer delay and video that would take longer to
recover from a lost or corrupted frame.
Audio Encoding: Opus
,
MPEG1
,
or
AAC
. Default is
AAC
. This setting specifies what format to
use for audio encoding. MPEG1 is perhaps the most widely interoperable. AAC is best for
music and maintaining the highest fidelity. For speech and verbal content, we recommend
Opus, which is used by Google in Android phones. (See Figure 9, below.)