23 November 2022
F Smith
[FYI request #21087 email]
Dear Fraser
Official Information Act Request
We refer to your email of 9 November requesting details on the capabilities of TVNZ+.
The information below is from our Technical Specifications and Service Description in
which TVNZ supplies to distributors. The other important piece of information is that
TVNZ+ currently has a bit rate cap in place of 2,600 kbp/s which means typical y
1080P is never available to end consumers. This was put in place in 2020 as a cost
saving measure and also in preparation if TVNZ was asked to lower its internet
footprint during Covid.
Encoding Profiles – VOD
TVNZ+ content utilises Brightcove’s Context Aware Encoding (CAE) which
dynamical y alters output renditions numbers, resolutions and bit rates within specified
minimum and maximum ranges. The below table shows the resolutions that are used
within the transcode profile. The profile creates a minimum of three renditions and a
maximum of eight renditions and varies for piece of content.
Video
Audio
Resolution Frame Codec Profile
Bitrate
Channels Codec Bitrate Sampling
Rate
(kbp/s)
(kbit/s)
512 x 288
25fps
MPEG- Baseline Low
Stereo
AAC
64
48 kHZ
4 AVC
400
640 x 360 25fps
MPEG- Main
Variable Stereo
AAC
128
48 kHZ
4 AVC
960 x 540 25fps
MPEG- Main
Variable Stereo
AAC
128
48 kHZ
4 AVC
1024 x
25fps
MPEG- Main
Variable Stereo
AAC
128
48 kHZ
576
4 AVC
1280 x
25fps
MPEG- Main
Variable Stereo
AAC
128
48 kHZ
720
4 AVC
1920 x
25fps
MPEG- High
Max
Stereo
AAC
128
48 kHZ
1080
4 AVC
4,800
NOTE:
Al resolutions are in 16:9 aspect ratio. Source files received in 4:3 are pil ar-
boxed to the 16:9 format.
High Definition (720P and 1080P) resolutions are only used where rights
permit
Encoding Profiles – Simulcast (HLS)
Video
Audio
Resolution Frame Codec Profile
Bitrate Channels Codec Bitrate Sampling
Rate
(kbp/s)
480 x 270 25 fps MPEG- Baseline 400
Stereo
AAC
64
48 kHZ
4 AVC
640 x 360 25 fps MPEG- Baseline 700
Stereo
AAC
128
48 kHZ
4 AVC
960 x 540 25 fps MPEG- Main
1,100
Stereo
AAC
128
48 kHZ
4 AVC
1024 x
25 fps MPEG- Main
1,500
Stereo
AAC
128
48 kHZ
576
4 AVC
1280 x
25 fps MPEG- Main
2,400
Stereo
AAC
128
48 kHZ
720
4 AVC
And how does a viewer find out what resolution. Bitrate. Audio formats for the
content they are viewing?
Currently TVNZ+ does not provide a method for showcasing which quality is currently
being used for both video and audio. We hope to have a quality selector function in
the future for TVNZ+.
Yours sincerely
OIA Team
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