Changes between Version 26 and Version 27 of Encode/AV1

Timestamp:

Aug 9, 2021, 9:44:15 AM (5 years ago)

Author:

veikk0

Comment:

section on keyframe placement, link to FFmpeg's online docs

Encode/AV1

@@ -14 +14 @@
 - 1-pass average bitrate
 
-For a list of options, run `ffmpeg -h encoder=libaom-av1`.
+For a list of options, run `ffmpeg -h encoder=libaom-av1` or check FFmpeg's [https://ffmpeg.org/ffmpeg-codecs.html#libaom_002dav1 online documentation].
 
 {{{
@@ -86 +86 @@
 `-cpu-used` sets how efficient the compression will be. Default is 1. Lower values mean slower encoding with better quality, and vice-versa.
 
-`-row-mt 1` enables row-based multi-threading which maximizes CPU usage. To enable fast decoding performance, also add tiles (i.e. `-tiles 4x1` or `-tiles 2x2` for 4 tiles). Enabling `row-mt` is only faster when the CPU has more threads than the number of encoded tiles. 
+`-row-mt 1` enables row-based multi-threading which maximizes CPU usage. To enable fast decoding performance, also add tiles (i.e. `-tiles 4x1` or `-tiles 2x2` for 4 tiles). Enabling `row-mt` is only faster when the CPU has more threads than the number of encoded tiles.
+
+== Keyframe placement ==
+
+By default, libaom's maximum keyframe interval is 9999 frames. This can lead to slow seeking, especially with content that has few or infrequent scene changes.
+
+The `-g` option can be used to set the maximum keyframe interval. Anything up to 10 seconds is considered reasonable for most content, so for 30 frames per second content one would use `-g 300`, for 60 fps content `-g 600`, etc.
+
+To set a fixed keyframe interval, set both `-g` and `-keyint_min` to the same value. Note that currently `-keyint_min` is ignored unless it's the same as `-g`, so the minimum keyframe interval can't be set on its own.
+
+For intra-only output, use `-g 0`.
 
 == HDR ==