Video rendering: FFMpeg AV1 codec encoding support

Previously, the Blender video renderer did not have support for
encoding video to AV1 (not to be confused with the container AVI).
The proposed solution is to leverage the existing FFMpeg renderer
to encode to AV1.

Note that avcodec_find_encoder(AV_CODEC_ID_AV1) usually returns
"libaom-av1" which is the "reference implementation" for AV1 encoding
(the default for FFMpeg, and is slow). "libsvtav1" is faster and
preferred so there is extra handling when fetching the AV1 codec for
encoding such that "libsvtav1" is used when possible.

This commit should only affect the options available for video
rendering, which includes the additional AV1 codec to choose from, and
setting "-crf".

Also note that the current release of FFMpeg for ArchLinux does not
support "-crf" for "libsvtav1", but the equivalent option "-qp" is
supported and used as a fallback when "libsvtav1" is used (as
mentioned here: https://trac.ffmpeg.org/wiki/Encode/AV1#SVT-AV1 ).
(Actually, both "-crf" and "-qp" is specified with the same value in
the code. When a release of FFMpeg obtains support for "-crf" for
"libsvtav1" is released, the code shouldn't be needed to change.)

The usage of the AV1 codec should be very similar to the usage of the
H264 codec, but is limited to the "mp4" and "mkv" containers.

This patch pertains to the "VFX & Video" module, as its main purpose
is to supplement the Video Sequencer tool with the additional AV1
codec for encoded video output.

Differential Revision: https://developer.blender.org/D14920

Reviewed By: sergey , ISS, zeddb

1 files changed, 14 insertions, 2 deletions

diff --git a/release/scripts/startup/bl_ui/properties_output.py b/release/scripts/startup/bl_ui/properties_output.py
index ca0e698500e..61384f25afb 100644
--- a/release/scripts/startup/bl_ui/properties_output.py
+++ b/release/scripts/startup/bl_ui/properties_output.py
@@ -380,7 +380,14 @@ class RENDER_PT_encoding_video(RenderOutputButtonsPanel, Panel):
         layout = self.layout
         ffmpeg = context.scene.render.ffmpeg
 
-        needs_codec = ffmpeg.format in {'AVI', 'QUICKTIME', 'MKV', 'OGG', 'MPEG4', 'WEBM'}
+        needs_codec = ffmpeg.format in {
+            'AVI',
+            'QUICKTIME',
+            'MKV',
+            'OGG',
+            'MPEG4',
+            'WEBM'
+        }
         if needs_codec:
             layout.prop(ffmpeg, "codec")
 
@@ -391,7 +398,12 @@ class RENDER_PT_encoding_video(RenderOutputButtonsPanel, Panel):
             layout.prop(ffmpeg, "use_lossless_output")
 
         # Output quality
-        use_crf = needs_codec and ffmpeg.codec in {'H264', 'MPEG4', 'WEBM'}
+        use_crf = needs_codec and ffmpeg.codec in {
+            'H264',
+            'MPEG4',
+            'WEBM',
+            'AV1'
+        }
         if use_crf:
             layout.prop(ffmpeg, "constant_rate_factor")