def mp4_to_gif(input_fn, output_fn, framerate):
# Generate the palette
palette_name = 'palette.png'
if get_os_name() == 'win':
command = get_ffmpeg_path(
) + f" -loglevel panic -i {input_fn} -vf 'palettegen' -y {palette_name}"
else:
command = get_ffmpeg_path(
) + f" -loglevel panic -i {input_fn} -vf 'fps={framerate}," \
f"scale=320:640:flags=lanczos,palettegen' -y {palette_name}"
# print command
os.system(command)
# Generate the GIF
command = get_ffmpeg_path(
) + f" -loglevel panic -i {input_fn} -i {palette_name} -lavfi paletteuse -y {output_fn}"
# print command
os.system(command)
os.remove(palette_name)
def vector_to_fast_image(img: template(), out: ndarray_type.ndarray()):
# FIXME: Why is ``for i, j in img:`` slower than:
for i, j in ndrange(*img.shape):
r, g, b = 0, 0, 0
color = img[i, img.shape[1] - 1 - j]
if static(img.dtype in [f16, f32, f64]):
r, g, b = min(255, max(0, int(color * 255)))
else:
static_assert(img.dtype == u8)
r, g, b = color
idx = j * img.shape[0] + i
# We use i32 for |out| since OpenGL and Metal doesn't support u8 types
if static(get_os_name() != 'osx'):
out[idx] = (r << 16) + (g << 8) + b
else:
# What's -16777216?
#
# On Mac, we need to set the alpha channel to 0xff. Since Mac's GUI
# is big-endian, the color is stored in ABGR order, and we need to
# add 0xff000000, which is -16777216 in I32's legit range. (Albeit
# the clarity, adding 0xff000000 doesn't work.)
alpha = -16777216
out[idx] = (b << 16) + (g << 8) + r + alpha