video/image_writer: add avif screenshot support

Notes:
- converts the (image) write() api to filenames, because using avio
with FILE* is a pain.
- adds more debug logs for screenshots.

build: rename av1 dependency to avif_muxer
wscript: unify lavf dependency with meson

1 files changed, 28 insertions, 0 deletions

diff --git a/DOCS/man/options.rst b/DOCS/man/options.rst
index 9a418ac730..a93e4f48ce 100644
--- a/DOCS/man/options.rst
+++ b/DOCS/man/options.rst
@@ -4317,6 +4317,7 @@ Screenshot
     :jpeg:      JPEG (alias for jpg)
     :webp:      WebP
     :jxl:       JPEG XL
+    :avif:      AVIF
 
 ``--screenshot-tag-colorspace=<yes|no>``
     Tag screenshots with the appropriate colorspace.
@@ -4472,6 +4473,33 @@ Screenshot
     Set the JPEG XL compression effort. Higher effort (usually) means better
     compression, but takes more CPU time. The default is 4.
 
+``--screenshot-avif-encoder=<encoder>``
+    Specify the AV1 encoder to be used by libavcodec for encoding avif
+    screenshots.
+
+    Default: ``libaom-av1``
+
+``--screenshot-avif-pixfmt=<format>``
+    Specify the pixel format to the libavcodec encoder.
+
+    Default: ``yuv420p``
+
+``--screenshot-avif-opts=key1=value1,key2=value2,...``
+    Specifies libavcodec options for selected encoder. For more information,
+    consult the FFmpeg documentation.
+
+    Default: ``usage=allintra,crf=32,cpu-used=8,tune=ssim``
+
+    Note: the default is only guaranteed to work with the libaom-av1 encoder.
+    Above options may not be valid and or optimal for other encoders.
+
+    This is a key/value list option. See `List Options`_ for details.
+
+    .. admonition:: Example
+
+        "``--screenshot-avif-opts=crf=32,aq-mode=complexity``"
+            sets the crf to 32 and quantization (aq-mode) to complexity based.
+
 ``--screenshot-sw=<yes|no>``
     Whether to use software rendering for screenshots (default: no).