Colour-space switches before input

E:\Test>ffmpeg -loglevel debug -colorspace bt709 -color_trc bt709 -color_primaries bt709 -color_range tv -i Meridian.mp4 -frames:v 1 -f null -
ffmpeg version 2024-11-25-git-04ce01df0b-full_build-www.gyan.dev Copyright (c) 2000-2024 the FFmpeg developers
  built with gcc 14.2.0 (Rev1, Built by MSYS2 project)
  configuration: --enable-gpl --enable-version3 --enable-static --disable-w32threads --disable-autodetect --enable-fontconfig --enable-iconv --enable-gnutls --enable-libxml2 --enable-gmp --enable-bzlib --enable-lzma --enable-libsnappy --enable-zlib --enable-librist --enable-libsrt --enable-libssh --enable-libzmq --enable-avisynth --enable-libbluray --enable-libcaca --enable-sdl2 --enable-libaribb24 --enable-libaribcaption --enable-libdav1d --enable-libdavs2 --enable-libopenjpeg --enable-libquirc --enable-libuavs3d --enable-libxevd --enable-libzvbi --enable-libqrencode --enable-librav1e --enable-libsvtav1 --enable-libvvenc --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs2 --enable-libxeve --enable-libxvid --enable-libaom --enable-libjxl --enable-libvpx --enable-mediafoundation --enable-libass --enable-frei0r --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-liblensfun --enable-libvidstab --enable-libvmaf --enable-libzimg --enable-amf --enable-cuda-llvm --enable-cuvid --enable-dxva2 --enable-d3d11va --enable-d3d12va --enable-ffnvcodec --enable-libvpl --enable-nvdec --enable-nvenc --enable-vaapi --enable-libshaderc --enable-vulkan --enable-libplacebo --enable-opencl --enable-libcdio --enable-libgme --enable-libmodplug --enable-libopenmpt --enable-libopencore-amrwb --enable-libmp3lame --enable-libshine --enable-libtheora --enable-libtwolame --enable-libvo-amrwbenc --enable-libcodec2 --enable-libilbc --enable-libgsm --enable-liblc3 --enable-libopencore-amrnb --enable-libopus --enable-libspeex --enable-libvorbis --enable-ladspa --enable-libbs2b --enable-libflite --enable-libmysofa --enable-librubberband --enable-libsoxr --enable-chromaprint
  libavutil      59. 47.101 / 59. 47.101
  libavcodec     61. 25.103 / 61. 25.103
  libavformat    61.  9.100 / 61.  9.100
  libavdevice    61.  4.100 / 61.  4.100
  libavfilter    10.  6.101 / 10.  6.101
  libswscale      8. 12.100 /  8. 12.100
  libswresample   5.  4.100 /  5.  4.100
  libpostproc    58.  4.100 / 58.  4.100
Splitting the commandline.
Reading option '-loglevel' ... matched as option 'loglevel' (set logging level) with argument 'debug'.
Reading option '-colorspace' ... matched as AVOption 'colorspace' with argument 'bt709'.
Reading option '-color_trc' ... matched as AVOption 'color_trc' with argument 'bt709'.
Reading option '-color_primaries' ... matched as AVOption 'color_primaries' with argument 'bt709'.
Reading option '-color_range' ... matched as AVOption 'color_range' with argument 'tv'.
Reading option '-i' ... matched as input url with argument 'Meridian.mp4'.
Reading option '-frames:v' ... matched as option 'frames' (set the number of frames to output) with argument '1'.
Reading option '-f' ... matched as option 'f' (force container format (auto-detected otherwise)) with argument 'null'.
Reading option '-' ... matched as output url.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option loglevel (set logging level) with argument debug.
Successfully parsed a group of options.
Parsing a group of options: input url Meridian.mp4.
Successfully parsed a group of options.
Opening an input file: Meridian.mp4.
[AVFormatContext @ 0000023d4cd773c0] Opening 'Meridian.mp4' for reading
[file @ 0000023d4cd779c0] Setting default whitelist 'file,crypto,data'
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] Format mov,mp4,m4a,3gp,3g2,mj2 probed with size=2048 and score=100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] ISO: File Type Major Brand: isom
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] Unknown dref type 0x206c7275 size 12
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] Processing st: 0, edit list 0 - media time: 2002, duration: 43136100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] Offset DTS by 2002 to make first pts zero.
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] Setting codecpar->delay to 2 for stream st: 0
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] Before avformat_find_stream_info() pos: 850587087 bytes read:339287 seeks:1 nb_streams:1
[h264 @ 0000023d4cd8a240] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 @ 0000023d4cd8a240] Decoding VUI
[h264 @ 0000023d4cd8a240] nal_unit_type: 8(PPS), nal_ref_idc: 3
[h264 @ 0000023d4cd8a240] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 @ 0000023d4cd8a240] Decoding VUI
[h264 @ 0000023d4cd8a240] nal_unit_type: 8(PPS), nal_ref_idc: 3
[h264 @ 0000023d4cd8a240] nal_unit_type: 6(SEI), nal_ref_idc: 0
[h264 @ 0000023d4cd8a240] nal_unit_type: 5(IDR), nal_ref_idc: 3
[h264 @ 0000023d4cd8a240] Format yuv420p chosen by get_format().
[h264 @ 0000023d4cd8a240] Reinit context to 3840x2160, pix_fmt: yuv420p
[h264 @ 0000023d4cd8a240] no picture
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] All info found
[mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd773c0] After avformat_find_stream_info() pos: 2261 bytes read:372055 seeks:2 frames:1
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Meridian.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf56.25.101
  Duration: 00:11:58.93, start: 0.000000, bitrate: 9464 kb/s
  Stream #0:0[0x1](und), 1, 1/60000: Video: h264 (High), 1 reference frame (avc1 / 0x31637661), yuv420p(tv, bt709, progressive, left), 3840x2160 [SAR 1:1 DAR 16:9], 0/1, 9461 kb/s, 59.94 fps, 59.94 tbr, 60k tbn (default)
    Metadata:
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
Successfully opened the file.
Parsing a group of options: output url -.
Applying option frames:v (set the number of frames to output) with argument 1.
Applying option f (force container format (auto-detected otherwise)) with argument null.
Successfully parsed a group of options.
Opening an output file: -.
[out#0/null @ 0000023d4cd77840] No explicit maps, mapping streams automatically...
[vost#0:0/wrapped_avframe @ 0000023d4cd81000] Created video stream from input stream 0:0
detected 4 logical cores
[h264 @ 0000023d4d431c00] nal_unit_type: 7(SPS), nal_ref_idc: 3
[h264 @ 0000023d4d431c00] Decoding VUI
[h264 @ 0000023d4d431c00] nal_unit_type: 8(PPS), nal_ref_idc: 3
Successfully opened the file.
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> wrapped_avframe (native))
[vost#0:0/wrapped_avframe @ 0000023d4cd81000] Starting thread...
[vf#0:0 @ 0000023d4cd7c600] Starting thread...
[vist#0:0/h264 @ 0000023d4d5b6040] [dec:h264 @ 0000023d4cd7c780] Starting thread...
[in#0/mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd77000] Starting thread...
Press [q] to stop, [?] for help
[h264 @ 0000023d4d431c00] nal_unit_type: 6(SEI), nal_ref_idc: 0
[h264 @ 0000023d4d431c00] nal_unit_type: 5(IDR), nal_ref_idc: 3
[h264 @ 0000023d4d431c00] Format yuv420p chosen by get_format().
[h264 @ 0000023d4d431c00] Reinit context to 3840x2160, pix_fmt: yuv420p
[h264 @ 0000023d4d431c00] no picture
[h264 @ 0000023d4d249700] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 2
[h264 @ 0000023d4d249700] no picture
[h264 @ 0000023d4d302480] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 2
[h264 @ 0000023d4d302b40] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 0
[h264 @ 0000023d4d5aa3c0] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 0
[h264 @ 0000023d4d431c00] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 2
[h264 @ 0000023d4d249700] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 2
[graph -1 input from stream 0:0 @ 0000023d4cd80700] w:3840 h:2160 pixfmt:yuv420p tb:1/60000 fr:60000/1001 sar:1/1 csp:bt709 range:tv
[AVFilterGraph @ 0000023d4d5b33c0] query_formats: 3 queried, 6 merged, 0 already done, 0 delayed
Output #0, null, to 'pipe:':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf61.9.100
[h264 @ 0000023d4d302480] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 0
  Stream #0:0(und), 0, 1001/60000: Video: wrapped_avframe, 1 reference frame, yuv420p(tv, bt709, progressive, left), 3840x2160 [SAR 1:1 DAR 16:9], 0/1, q=2-31, 200 kb/s, 59.94 fps, 59.94 tbn (default)
    Metadata:
      encoder         : Lavc61.25.103 wrapped_avframe
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
[out#0/null @ 0000023d4cd77840] Starting thread...
[h264 @ 0000023d4d302b40] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 0
[out#0/null @ 0000023d4cd77840] sq: send 0 ts 0.0166833
[out#0/null @ 0000023d4cd77840] sq: 0 frames_max 1 reached
[out#0/null @ 0000023d4cd77840] sq: finish 0; head ts 0.0166833
[h264 @ 0000023d4d5aa3c0] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 2
[out#0/null @ 0000023d4cd77840] sq: finish queue
[out#0/null @ 0000023d4cd77840] sq: receive 0 ts 0.0166833 queue head 0 ts 0.0166833
[vf#0:0 @ 0000023d4cd7c600] All consumers returned EOF
[vost#0:0/wrapped_avframe @ 0000023d4cd81000] [enc:wrapped_avframe @ 0000023d4d430dc0] Encoder thread received EOF
[vost#0:0/wrapped_avframe @ 0000023d4cd81000] Terminating thread with return code 0 (success)
[out#0/null @ 0000023d4cd77840] All streams finished
[h264 @ 0000023d4d431c00] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 2
[out#0/null @ 0000023d4cd77840] Terminating thread with return code 0 (success)
[h264 @ 0000023d4d249700] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 0
[in#0/mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd77000] Terminating thread with return code 0 (success)
[h264 @ 0000023d4d302480] nal_unit_type: 1(Coded slice of a non-IDR picture), nal_ref_idc: 0
[out#0/null @ 0000023d4cd77840] sq: 0 EOF
[out#0/null @ 0000023d4cd77840] sq: finish queue
[vist#0:0/h264 @ 0000023d4d5b6040] [dec:h264 @ 0000023d4cd7c780] Decoder returned EOF, finishing
[vf#0:0 @ 0000023d4cd7c600] Terminating thread with return code 0 (success)
[vist#0:0/h264 @ 0000023d4d5b6040] [dec:h264 @ 0000023d4cd7c780] Terminating thread with return code 0 (success)
[out#0/null @ 0000023d4cd77840] Output file #0 (pipe:):
[out#0/null @ 0000023d4cd77840]   Output stream #0:0 (video): 1 frames encoded; 1 packets muxed (440 bytes);
[out#0/null @ 0000023d4cd77840]   Total: 1 packets (440 bytes) muxed
[out#0/null @ 0000023d4cd77840] video:0KiB audio:0KiB subtitle:0KiB other streams:0KiB global headers:0KiB muxing overhead: unknown
frame=    1 fps=0.0 q=-0.0 Lsize=N/A time=00:00:00.01 bitrate=N/A speed=0.17x
[in#0/mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd77000] Input file #0 (Meridian.mp4):
[in#0/mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd77000]   Input stream #0:0 (video): 22 packets read (7207 bytes); 7 frames decoded; 0 decode errors;
[in#0/mov,mp4,m4a,3gp,3g2,mj2 @ 0000023d4cd77000]   Total: 22 packets (7207 bytes) demuxed
[AVIOContext @ 0000023d4cd81840] Statistics: 372055 bytes read, 2 seeks