support the loop option in html video output (#3697)

* support the loop option in html video output

* add to changelog

* try adding html animation to docs

* Update animation.md

* revert doc animation changes

* fix warning test

---------

Co-authored-by: Anshul Singhvi <asinghvi17@simons-rock.edu>

CHANGELOG.md

@@ -52,6 +52,7 @@
 - Provided an interface to convert markers in CairoMakie separately (`cairo_scatter_marker`) so external packages can overload it. [#3811](https://github.com/MakieOrg/Makie.jl/pull/3811)
 - Updated to DelaunayTriangulation v1.0 [#3787](https://github.com/MakieOrg/Makie.jl/pull/3787).
 - Added methods `hidedecorations!`, `hiderdecorations!`, `hidethetadecorations!` and  `hidespines!` for `PolarAxis` axes [#3823](https://github.com/MakieOrg/Makie.jl/pull/3823).
+- Added `loop` option support for HTML outputs when recording videos with `record` [#3697](https://github.com/MakieOrg/Makie.jl/pull/3697).
 
 ## [0.20.9] - 2024-03-29
 

src/ffmpeg-util.jl

@@ -24,14 +24,14 @@
 you have issues playing a video, try `profile = "high"` or `profile = "main"`.
 - `pixel_format = "yuv420p"`: A ffmpeg compatible pixel format (`-pix_fmt`). Currently only
 applies to `mp4`. Defaults to `yuv444p` for `profile = "high444"`.
-- `loop = 0`: Number of times the video is repeated, for a `gif`. Defaults to `0`, which
-means infinite looping. A value of `-1` turns off looping, and a value of `n > 0` and above
-means `n` repetitions (i.e. the video is played `n+1` times).
+- `loop = 0`: Number of times the video is repeated, for a `gif` or `html` output. Defaults to `0`, which
+means infinite looping. A value of `-1` turns off looping, and a value of `n > 0`
+means `n` repetitions (i.e. the video is played `n+1` times) when supported by backend.
 
     !!! warning
     `profile` and `pixel_format` are only used when `format` is `"mp4"`; a warning will be issued if `format`
     is not `"mp4"` and those two arguments are not `nothing`. Similarly, `compression` is only
-    valid when `format` is `"mp4"` or `"webm"`, and `loop` is only valid when `format` is `"gif"`.
+    valid when `format` is `"mp4"` or `"webm"`.
 """
 struct VideoStreamOptions
     format::String
@@ -63,15 +63,12 @@ struct VideoStreamOptions
             (compression === nothing) && (compression = 20)
         end
 
-        if format == "gif"
-            (loop === nothing) && (loop = 0)
-        end
+        (loop === nothing) && (loop = 0)
 
         # items are name, value, allowed_formats
         allowed_kwargs = [("compression", compression, ("mp4", "webm")),
                           ("profile", profile, ("mp4",)),
-                          ("pixel_format", pixel_format, ("mp4",)),
-                          ("loop", loop, ("gif",))]
+                          ("pixel_format", pixel_format, ("mp4",))]
 
         for (name, value, allowed_formats) in allowed_kwargs
             if !(format in allowed_formats) && value !== nothing

src/recording.jl

@@ -181,9 +181,11 @@ end
 function Base.show(io::IO, ::MIME"text/html", vs::VideoStream)
     mktempdir() do dir
         path = save(joinpath(dir, "video.mp4"), vs)
+        # <video> only supports infinite looping, so we loop forever even when a finite number is requested
+        loopoption = vs.options.loop ≥ 0 ? "loop" : ""
         print(
             io,
-            """<video autoplay controls><source src="data:video/x-m4v;base64,""",
+            """<video autoplay controls $loopoption><source src="data:video/x-m4v;base64,""",
             base64encode(open(read, path)),
             """" type="video/mp4"></video>"""
         )

test/record.jl

@@ -58,7 +58,6 @@ mktempdir() do tempdir
                     warn_fmts=["mkv", "webm", "gif"],
                     no_warn_fmts=["mp4"],
                 ),
-                (:loop, 0, ["mkv", "webm", "mp4"], ["gif"]),
             ]
 
             for (kwarg, value, warn_fmts, no_warn_fmts) in warn_tests