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--- docs:vidcap [2022/05/17 12:11] – created root
+++ docs:vidcap [2022/05/19 06:16] (current) – [Composite] root
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 ====== Video capture on Linux ======
+The following guide is specifically targeted to capture analog video signals.
+Checklist:
+  * Capturing Video+Audio FIXME
+  * Capturing Subtitle with VBI TODO
+  * Authoring subtitles TODO
+  * Authoring chapters TODO
+  * Lossless content encoding TODO
+  * Lossy content encoding FIXME
+===== Video path types =====
+==== Composite ====
+TODO
+[[https://superuser.com/questions/1677633/simultaneous-capture-and-monitor-with-ffmpeg]]
+==== Y/C - S-Video ====
+FIXME
+Luma and Chroma are transported on distinct wire pairs.
+Recommended over Composite if your A/V equipment has no better signal to offer, especially if Digital->Analog conversion is performed onboard (e.g. LaserDisc player with digital framebuffer, D-VHS w/o Components, etc).
+It's also recommended
+  * If your capture card has a poor comb filter (your mileage may vary, make an A/B test with your specific setup). Typical artefacts of a poor comb filter is a blurry luma, and a smudged chroma, especially if you have an OSD.
+  * If your video path from source to acquisition goes through processing equipment, so that losses induced by comb filters is minimized.
+==== RGBHV ====
+Best solution if you don't have access to Components video, when it comes to signal accuracy.
+Capture hardware is scarce and expensive.
+  * [[http://www.micomsoft.co.jp/xcapture-1.htm|Micomsoft XCapture-1]]
+  * [[https://junkerhq.net/xrgb/index.php/XRGB-mini_FRAMEMEISTER|XRGB Framemeister]]
+==== Component - YPbPr ====
+TODO
+The only way to get analog progressive scan content. The other peculiarity is you can transport HDTV content with it (up to 1080i/p).
+Capture cards I've found:
+  * Osprey 260e with a suitable cable. Apparently supported by Linux, according to a quick search.
+Alternatively, you can use a components to HDMI converter, then a digital acquisition card to process those signals.
+==== MUSE - Hi-Vision ====
+Best way to deal with it is getting through a MUSE decoder, then capturing the components.
 ===== Capture cards =====
+==== August VGB100 ====
-  * Easy Cap DC60 [[https://fr.aliexpress.com/item/32485611956.html|Aliexpress product page]]
+^ Input ^ Works? ^
+| Composite | Yes, OOB, (input=0) |
+| S-Video | Yes, black and white only on Linux (input=1) |
+| Audio | Yes, OOB |
+Remarks:
+  * ''VIDIOC_S_PARM'' ioctl natively supported.
+  * I suspect there is a signal integrity issue with this device, since I've had frequent video glitches that are unrelated to the video source (cross-tested with an Easycap DC60).
+==== Easy Cap DC60 ====
+Sourcing: [[https://fr.aliexpress.com/item/32485611956.html|Aliexpress product page]]
 If you have issues with this card (dmesg yelling that it's a model with the generic USB PVID), you need either to reload the kernel module with ''modprobe em28xx card=64'', or adding ''options em28xx card64'' to ''/etc/modprobe.d/easycap-em28xx.conf'', but this will screw with other capture cards using the eMPIA em28xx controllers.
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 <code>ffmpeg -f v4l2 -i /dev/video2 -f alsa -i hw:1,0 -vcodec ayuv -acodec copy -map 0:0 -map 1:0 -f avi pipe:1 | ffplay -</code>
+===== Capturing video signal =====
+Unless you have a decent machine, it is recommended to first save an uncompressed capture that you will process in a second time, then compress (either losslessly for mastering/archival, or lossily for final consumption).
+===== Authoring chapters =====
+This can be performed using a ''ffmetadata'' file. Add the following options to insert an external metadata file:
+<code>-i example.ini -map_metadata 1</code>
+File example:
+<code ini example.ini>;FFMETADATA1
+title=bike\\shed
+;this is a comment
+artist=FFmpeg troll team
+[CHAPTER]
+TIMEBASE=1/1000
+START=0
+#chapter ends at 0:01:00
+END=60000
+title=chapter \#1
+[STREAM]
+title=multi\
+line
+</code>
+Doc for more info: [[https://ffmpeg.org/ffmpeg-formats.html#Metadata-1]]
+===== Lossy content encoding =====
+  * Transparent, x264
+<code>ffmpeg -i master.avi -c:v libx264 -preset slow -crf 18 -c:a opus -b:a 192 output.mkv</code>
+  * Transparent, x265
+<code>ffmpeg -i master.avi -c:v libx265 -preset slow -crf 24 -c:a opus -b:a 192 output.mkv</code>
+Additionally, you should tune the encoder by inserting -tune <option> depending on the kind of content you're encoding:
+^ Option ^ Target ^
+| film | use for high quality movie content; lowers deblocking |
+| animation | good for anime and cartoons; uses higher deblocking and more reference frames |
+| grain | preserves the grain structure in old, grainy film material |
+| stillimage | good for slideshow-like content |
+If you wish to have a smaller file, you can tune the CRF up to 28 for x264, and FIXME for x265.