you пн, 19 мая 2025 г., 15:55 Terje J. Hanssen <terjejhans...@gmail.com>:
> My first backup generation of my PAL Analog S-video footages on tapes > was digitized to SD 576i50 DV25 with 8-bit 4:2:0 color depth and 25 Mb/s > video bit rate. > IMO playback from DV25 backup files visually lack some brightness and > colors compared with native playback from S-video tapes. > > Now I am testing another backup method with purpose of best practical > video quality using ffmpeg to encode lossless compressed FFV1.mkv files: > > Analog video camera/player --> S-video/HDMI converter --> HDMI/USB3 > capture card --> v4l2 --> ffmpeg/ FFV1.mkv > > 10-Bit 4:2:2 Video is recommended for Analog Tape Transfer due to color > shades and branding > https://www.archivalworks.com/blog/10-bit-video-transfer > > > Well, my ms2130 HDMI/USB3 video capture card while looking around for "something else" I noted this thread talks about patching firmware on ms2130 device to disable sharpening and get unclipped (full range) YUV values. Not that it should matter for cassette video source, but for VGA capture it apparently mattered: https://68kmla.org/bb/index.php?threads/decent-video-capture-for-30.49954/ If anyone want to test this route do not forgot to back up original firmware first! achieves YUYV2 or 8-bit > 4:2:2, which is not 10-bit but yet twice as much color info compared > with DV25 4:2:0. > > > Q1 > Therefore my question here if it yet may be > Benefits from Chroma "Upsampling" v4l2 8bit 422 to 10bit 422 FFV1 > backup? > > While some say this is fake upsampling like filling 8-bit data in a > 10-bit container, other say this may be beneficial with temporal noise > filtering > > https://www.eoshd.com/comments/topic/26710-8bit-%E2%86%92-10bit-video-with-temporal-noise-filtering-stunning-results/ > > Q2 > So let me hear if this may be applied with some ffmpeg denoising filters > like time base correcting, tape grain or snow? > > ms2130 seemingly doesn't support interlaced video (25fps), so I have > used 50fps for PAL. > > v4l2-ctl -V > Format Video Capture: > Width/Height : 1920/1080 > Pixel Format : 'YUYV' (YUYV 4:2:2) > Field : None > Bytes per Line : 3840 > Size Image : 4147200 > Colorspace : sRGB > Transfer Function : Rec. 709 > YCbCr/HSV Encoding: ITU-R 601 > Quantization : Default (maps to Limited Range) > Flags : > > > ffmpeg -hide_banner -f v4l2 -list_formats all -i /dev/video0 > [video4linux2,v4l2 @ 0x556f439fc7c0] Raw : yuyv422 : > YUYV 4:2:2 : 1920x1080 1600x1200 1360x768 1280x1024 1280x960 1280x720 > 1024x768 800x600 720x576 720x480 640x480 > [in#0 @ 0x556f439fc500] Error opening input: Immediate exit requested > Error opening input file /dev/video0. > > > As seen I have tested four cases with different input and output formats > in the table below. > > Q3 > I also wonder why the Video bitrate differs so much for the 10-bit > output files? > > Case Input format Video size Output format Bit depth/YUV > Video bitrate > ---- ------------ ---------- ------------- ------------- > ------------- > 1) - 720x576 - 8 bits 422p > 55.6 Mb/s > 2) - 720x576 yuv422p10 10 bits 422 > 68.0 Mb/s > 3) yuv422p10 720x576 yuv422p10 10 bits 422 > 32.0 Mb/s > 4) y210 720x576 y210 10 bits 422 > 35.8 Mb/s > > > Attach ffmpeg output for Case 2) below: > > ffmpeg -hide_banner -f v4l2 -video_size 720x576 -framerate 50 -i > /dev/video0 -c:v ffv1 -level 3 -vf format=pix_fmts='yuv422p10' -t 10 > output.mkv > > Input #0, video4linux2,v4l2, from '/dev/video0': > Duration: N/A, start: 239.890699, bitrate: 331776 kb/s > Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 720x576, > 331776 kb/s, 50 fps, 50 tbr, 1000k tbn > Stream mapping: > Stream #0:0 -> #0:0 (rawvideo (native) -> ffv1 (native)) > Press [q] to stop, [?] for help > [ffv1 @ 0x5571b7d55280] bits_per_raw_sample > 8, forcing range coder > > Output #0, matroska, to 'output.mkv': > Metadata: > encoder : Lavf61.7.100 > Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv422p10le(tv, > progressive), 720x576, q=2-31, 200 kb/s, 50 fps, 1k tbn > Metadata: > encoder : Lavc61.19.101 ffv1 > [out#0/matroska @ 0x5571b7d56d00] video:84659KiB audio:0KiB > subtitle:0KiB other streams:0KiB global headers:0KiB muxing overhead: > 0.007280% > frame= 500 fps= 50 q=-0.0 Lsize= 84665KiB time=00:00:10.00 > bitrate=69357.5kbits/s speed=0.998x > > > > > > > > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
