fix(downloads): GIF review round 1 — shape, HDR, caps, audio, copy

- A GIF squares its pixels before the size, so an anamorphic source keeps
  its shown shape (a 720x480 DVD at 16:9 was 480x320).
- An editor GIF of an HDR upload is tonemapped, as a clip GIF is.
- The length caps are judged in whole milliseconds: a range exactly at a
  cap is no longer refused for a float hair over it.
- A GIF is made of a video only: an audio file is refused with its reason
  and the editor offers no GIF for it.
- A GIF clip keeps no audio track: the track neither splits its cache key
  nor fails it.
- The editor's GIF notes keep their live region mounted; one size reads
  as one ("about 1 MB"), none is shown with nothing kept; the size choices
  show their unit; a shared picture that fails to load says so.
- Copy: the two-sentence GIF notes keep their last stop (a copy-rule test
  now holds it); the English warns of "only a still picture".

backend/tests/test_clip.py

@@ -740,6 +740,30 @@ def test_the_thirty_second_gif_cap_itself_is_allowed():
     assert clipmod.duration(clipmod.normalize("plex", "42", 0, 30, gif_side=480)) == 30
 
 
+@pytest.mark.parametrize(
+    ("start", "end", "kw"),
+    [
+        # Each a range exactly at a cap whose float difference lands a hair past it.
+        (30.529, 60.529, {"gif_side": 480}),
+        (424.005, 1024.005, {}),
+        (0.001, 1.001, {}),
+    ],
+)
+def test_a_range_exactly_at_a_cap_is_judged_in_milliseconds(start, end, kw):
+    assert end - start not in (1, 30, 600)  # the float difference is off the cap itself
+    assert round((end - start) * 1000) in (1000, 30000, 600000)
+    clipmod.normalize("youtube", "abcdefghijk", start, end, **kw)
+
+
+def test_a_gif_clip_keeps_no_audio_track_so_the_track_does_not_make_another_gif():
+    first = clipmod.normalize("plex", "42", 10, 20, audio_track=0, gif_side=480)
+    other = clipmod.normalize("plex", "42", 10, 20, audio_track=1, gif_side=480)
+    assert "audio_track" not in first
+    assert clipmod.sig(first) == clipmod.sig(other)
+    # A video clip keeps the track it was heard on.
+    assert clipmod.normalize("plex", "42", 10, 20, audio_track=1)["audio_track"] == 1
+
+
 def test_a_gif_clip_is_queued_as_a_file_and_too_long_says_its_own_cap(
     db, make_user, as_user, yt_video
 ):
@@ -810,6 +834,19 @@ def test_a_gif_clip_is_cut_through_the_gif_command_and_stored_as_an_image_file(
     assert cmd[cmd.index("-t") + 1] == "15.000"
 
 
+def test_a_gif_clip_is_never_refused_for_an_audio_track(
+    db, make_user, as_user, plex_episode, gif_worker
+):
+    # A GIF queued with a track (as one made before GIFs dropped it was): the file has one track,
+    # the spec names a fourth, and a GIF, which has no sound, is made all the same.
+    job = _clip(as_user(make_user()), source="plex", ref="777", gif_side=480, end_s=25).json()
+    row = db.get(DownloadJob, job["id"])
+    row.edit_spec = {**row.edit_spec, "audio_track": 3}
+    db.commit()
+    job, asset = gif_worker["run"](job)
+    assert (job.status, asset.status) == ("done", "ready")
+
+
 def test_a_gif_over_its_size_cap_is_not_kept_and_says_why(
     db, make_user, as_user, plex_episode, gif_worker, monkeypatch
 ):

backend/tests/test_edit_gif.py

@@ -3,12 +3,15 @@ to the GIF's limits at enqueue, and made by the worker with real ffmpeg."""
 
 import shutil
 import subprocess
+from pathlib import Path
 
 import pytest
 
 from app.config import settings
+from app.downloads import clip as clipmod
 from app.downloads import edit as editmod
 from app.downloads import pipeline, service
+from app.downloads import probe as probemod
 from app.downloads import gif as gifmod
 from app.downloads import upload as uploadmod
 from app.downloads.models import DownloadJob, MediaAsset
@@ -63,6 +66,84 @@ def test_a_gif_edit_it_cannot_make_is_refused_with_its_reason(
     assert e.value.reason == reason
 
 
+@needs_ffmpeg
+def test_a_gif_edit_of_exactly_thirty_seconds_is_allowed(db, make_user, tmp_path, monkeypatch):
+    monkeypatch.setattr(settings, "files_root", str(tmp_path / "root"))
+    u = make_user()
+    source = _source(db, u, tmp_path)
+    # Ends kept to the millisecond whose float difference lands a hair over 30 s.
+    assert 32.02 - 2.02 > gifmod.MAX_S
+    job = service.enqueue_edit(
+        db, u.id, source, {"trim": {"start_s": 2.02, "end_s": 32.02}, "gif": {"side": 480}}
+    )
+    assert job.edit_spec["gif"] == {"side": 480}
+
+
+@needs_ffmpeg
+def test_a_gif_is_made_of_a_video_never_of_audio(db, make_user, tmp_path, monkeypatch):
+    monkeypatch.setattr(settings, "files_root", str(tmp_path / "root"))
+    u = make_user()
+    src = tmp_path / "in.m4a"
+    subprocess.run(
+        [
+            "ffmpeg", "-y", "-loglevel", "error",
+            "-f", "lavfi", "-i", "sine=frequency=440:duration=10", "-c:a", "aac", str(src),
+        ],
+        check=True,
+    )  # fmt: skip
+    source = uploadmod.ingest_upload(
+        db, u.id, filename="in.m4a", src_path=src, size=src.stat().st_size
+    )
+    assert db.get(MediaAsset, source.asset_id).media_kind == "audio"
+    spec = {"trim": {"start_s": 1, "end_s": 5}}
+    with pytest.raises(service.EditError) as e:
+        service.enqueue_edit(db, u.id, source, {**spec, "gif": {"side": 480}})
+    assert e.value.reason == "gif_not_video"
+    # The same range as audio is an edit as it always was.
+    assert service.enqueue_edit(db, u.id, source, spec).edit_spec["trim"]["end_s"] == 5
+
+
+@needs_ffmpeg
+def test_an_hdr_source_is_tonemapped_before_its_gif_palette(db, make_user, tmp_path, monkeypatch):
+    monkeypatch.setattr(settings, "files_root", str(tmp_path / "root"))
+    u = make_user()
+    src = tmp_path / "hlg.mp4"
+    subprocess.run(
+        [
+            "ffmpeg", "-y", "-loglevel", "error",
+            "-f", "lavfi", "-i", "testsrc2=size=640x360:rate=10:duration=4",
+            "-vf", "setparams=color_trc=arib-std-b67:color_primaries=bt2020:colorspace=bt2020nc",
+            "-c:v", "libx264", "-pix_fmt", "yuv420p", str(src),
+        ],
+        check=True,
+    )  # fmt: skip
+    source = uploadmod.ingest_upload(
+        db, u.id, filename="hlg.mp4", src_path=src, size=src.stat().st_size
+    )
+    # The upload keeps its HLG tag, as an HDR phone video's does.
+    placed = Path(settings.files_root) / db.get(MediaAsset, source.asset_id).rel_path
+    assert clipmod.is_hdr(probemod.probe_json(placed) or {})
+    job = service.enqueue_edit(
+        db, u.id, source, {"trim": {"start_s": 1, "end_s": 3}, "gif": {"side": 320}}
+    )
+    asset = db.get(MediaAsset, job.asset_id)
+    job.status, asset.status = "running", "downloading"
+    db.commit()
+    seen: dict = {}
+    build = gifmod.build_cmd
+
+    def spy(*a, **k):
+        seen["pre"] = k["pre"]
+        return build(*a, **k)
+
+    monkeypatch.setattr(pipeline.gifmod, "build_cmd", spy)
+    pipeline._process_edit(job.id, asset.id)
+
+    assert "tonemap" in seen["pre"]
+    db.expire_all()
+    assert db.get(DownloadJob, job.id).status == "done"
+
+
 @needs_ffmpeg
 def test_a_gif_edit_is_made_by_the_worker_and_kept_as_an_image_file(
     db, make_user, tmp_path, monkeypatch

backend/tests/test_gif.py

@@ -66,11 +66,25 @@ def test_a_crop_or_a_tonemap_comes_before_the_scale_and_the_palette():
     assert graph.index("crop=100:100:0:0") < graph.index("scale=") < graph.index("palettegen")
 
 
-def _video(path: Path, size: str, seconds: int = 2) -> Path:
+def test_the_length_cap_counts_whole_milliseconds():
+    # Two ends kept to the millisecond whose float difference lands a hair over 30 s.
+    assert 60.529 - 30.529 > gifmod.MAX_S
+    assert not gifmod.too_long(30.529, 60.529)
+    assert not gifmod.too_long(0, 30)
+    assert gifmod.too_long(0, 30.001)
+
+
+def test_the_pixels_are_squared_after_the_crop_and_before_the_size():
+    graph = gifmod.filter_graph("crop=100:100:0:0", 480)
+    assert graph.index("crop=") < graph.index("setsar=1") < graph.index("flags=lanczos")
+
+
+def _video(path: Path, size: str, seconds: int = 2, sar: str = "1") -> Path:
     subprocess.run(
         [
             "ffmpeg", "-y", "-loglevel", "error",
             "-f", "lavfi", "-i", f"testsrc2=size={size}:rate=25:duration={seconds}",
+            "-vf", f"setsar={sar}",
             "-c:v", "libx264", "-pix_fmt", "yuv420p", str(path),
         ],
         check=True,
@@ -78,6 +92,24 @@ def _video(path: Path, size: str, seconds: int = 2) -> Path:
     return path
 
 
+@needs_ffmpeg
+@pytest.mark.parametrize(
+    ("size", "sar", "expected"),
+    [
+        # A DVD stored 720x480 and shown at 16:9: a GIF shows its stored pixels as they are, so
+        # they are squared first, or the picture comes out 480x320 (3:2), squeezed.
+        ("720x480", "32/27", (480, 270)),
+        # HDV: 1440x1080 shown at 16:9.
+        ("1440x1080", "4/3", (480, 270)),
+    ],
+)
+def test_a_source_with_wide_pixels_keeps_its_shown_shape(tmp_path, size, sar, expected):
+    src = _video(tmp_path / "in.mp4", size, sar=sar)
+    out = tmp_path / "out.gif"
+    subprocess.run(gifmod.build_cmd(src, out, 0.0, 1.0, pre="", side=480), check=True)
+    assert gifmod.size(out) == expected
+
+
 @needs_ffmpeg
 @pytest.mark.parametrize(
     ("size", "side", "expected"),