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MPEG-4 encoder settings 295
Note: In the standard case, the "Aspect ratio" remains set the way it is. You should only
change the settings if the resulting video is exported distorted or stretched or if you need to
correct the video because it is in the wrong aspect ratio.
GOP structure
Max GOP length
Determines the maximum
GOP (view page 303) length. High values mean improved
compression. Lower values create stronger security protection and enable improved
access to individual frames for processing the video.
Max b-frames count
The maximum number of b-frames (view page 305). Several cases of application, e.g. video
conferences require "no b-frames" in order to achieve the shortest possible reaction times
during transfer.
to
ew page 304) after a scene change.
Input info
Information about the incoming video stream is displayed here during live recordings.
Statistics
Information about the encoder activity is displayed here during live recordings.
AMR
AMR involves a parametric codec with different data rates between 4.75 and 12.2 kbit/s.
The 12.2-kbit/s settings throughly corresponds with the GSM-EFR codec in terms of
algorithm and audio quality.
This audio format is used by mobile telephones for transferring the conversation and is
s). Low bit rates provide compensation for
mobile phones in case of transfer errors, i.e. bad reception. Depending on the signal
strength, the compression increases or decreases to enable the best possible quality for a
conversation. The AMR sound, on the other hand, encodes a fixed sample rate of 8,000 Hz
compared to AAC sound.
The advanced AMR audio menu includes the following settings options:
The bit rate can be set between 4.75 and 12.2kbit/s. The higher the bit rate, the greater the
file size and the higher level of audio quality. The standard settings provide a bit rate of 7.4
kbit/s. The highest bit rate for this format is more suited for transferring conversations.
Scene change detection
If this option is activated the scenes will be detected during encoding, thus allowing you
insert an
I frame (vi
optimized for encoding conversation (voice