[Cin] ffv1hd422p.mkv - groundwork for a preservation purpose

[Terje J. Hanssen]

This example capture a raw video stream (optional tape playback) from 
the camera sensor over HDMI out and transcode audio to PCM into 
ffv1hd422p.mkv for preservation purpose.
-input_format yuyv422 -video_size hd1080 possibly may be commented out, 
as the encoder default uses the maximum capability it get from the 
capture card ms2130 and driver v4l2

The video part is used from this source
https://avpres.net/FFmpeg/im_FFV1.html

At this high bitrate 320Mbps+ here, a combination with segmented 
recording is recommended and neccesary to control the file sizes 
(segments) and eventually corrupted parts better.

ffmpeg -hide_banner -f v4l2 -framerate 50 -i /dev/video0 -f alsa -ac 2 
-i hw:CARD=UHD,DEV=0 -c:v ffv1 -level 3 -threads 8 -coder 1 -context 1 
-g 1 -slices 24 -slicecrc 1 -c:a pcm_s16le -t 10 -f matroska 
ffv1hd422p_preserv.mkv

Input #0, video4linux2,v4l2, from '/dev/video0':
   Duration: N/A, start: 89.753684, bitrate: 1658880 kb/s
   Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1920x1080, 
1658880 kb/s, 50 fps, 50 tbr, 1000k tbn
[aist#1:0/pcm_s16le @ 0x560bdabb0480] Guessed Channel Layout: stereo
Input #1, alsa, from 'hw:CARD=UHD,DEV=0':
   Duration: N/A, start: 1749208074.680286, bitrate: 1536 kb/s
   Stream #1:0: Audio: pcm_s16le, 48000 Hz, stereo, s16, 1536 kb/s
Stream mapping:
   Stream #0:0 -> #0:0 (rawvideo (native) -> ffv1 (native))
   Stream #1:0 -> #0:1 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help

Output #0, matroska, to 'ffv1hd422p_preserv.mkv':
   Metadata:
     encoder         : Lavf61.7.100
   Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv422p(tv, 
progressive), 1920x1080, q=2-31, 200 kb/s, 50 fps, 1k tbn
       Metadata:
         encoder         : Lavc61.19.101 ffv1
   Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, 
stereo, s16, 1536 kb/s
       Metadata:
         encoder         : Lavc61.19.101 pcm_s16le
[out#0/matroska @ 0x560bdabb0600] video:388733KiB audio:1875KiB 
subtitle:0KiB other streams:0KiB global headers:0KiB muxing overhead: 
0.014887%

frame=  500 fps= 50 q=-0.0 Lsize=  390666KiB time=00:00:10.00 
bitrate=320033.5kbits/s speed=0.999x