this IS season 4. other uploaders ar miss-naming these episodes.  check BBC Iplayer for confirmation


https://www.imdb.com/title/tt3815412



Format : MPEG-4 
Format profile : Base Media 
Codec ID : isom (isom/iso2/avc1/mp41) 
Overall bit rate mode : Variable 
Overall bit rate : 1 658 kb/s 



Video 
ID : 1 
Format : AVC 
Format/Info : Advanced Video Codec 
Format profile : [email protected] 
Format settings : CABAC / 4 Ref Frames 
Format settings, CABAC : Yes 
Format settings, Reference frames : 4 frames 
Format settings, GOP : M=8, N=96 
Codec ID : avc1 
Codec ID/Info : Advanced Video Coding 
Duration : 57 min 38 s 
Bit rate : 1 559 kb/s 
Width : 960 pixels 
Height : 540 pixels 
Display aspect ratio : 16:9 
Frame rate mode : Constant 
Frame rate : 25.000 FPS 
Color space : YUV 
Chroma subsampling : 4:2:0 
Bit depth : 8 bits 
Scan type : Progressive 
Bits/(Pixel*Frame) : 0.120 
Stream size : 643 MiB (94%) 
Color range : Limited 
Color primaries : BT.709 
Transfer characteristics : BT.709 
Matrix coefficients : BT.709 
Codec configuration box : avcC 

Audio 
ID : 2 
Format : AAC LC SBR 
Format/Info : Advanced Audio Codec Low Complexity with Spectral Band Replication 
Commercial name : HE-AAC 
Format settings : Implicit 
Codec ID : mp4a-40-2 
Duration : 57 min 38 s 
Bit rate mode : Variable 
Bit rate : 96.0 kb/s 
Maximum bit rate : 97.9 kb/s 
Channel(s) : 2 channels 
Channel layout : L R 
Sampling rate : 48.0 kHz 
Frame rate : 23.438 FPS (2048 SPF) 
Compression mode : Lossy 
Stream size : 39.6 MiB (6%) 
Language : English 
Default : Yes 
Alternate group : 1