Changes between Version 2 and Version 3 of Encode/AV1

Timestamp:

Jun 3, 2018, 12:24:27 PM (8 years ago)

Author:

Gyan

Comment:

a few rewrites and clean-up

Encode/AV1

@@ -3 +3 @@
 [[PageOutline(2, Contents)]]
 
-`libaom-av1` is the AOMedia video encoder for AV1, an open, royalty-free media file format. `libaom-av1` can save about 30% bitrate compared to VP9 and H.265 / HEVC while retaining the same visual quality.
+`libaom-av1` is the AOMedia video encoder for AV1, an open source & royalty-free video codec. `libaom-av1` can save about 30% bitrate compared to VP9 and H.265 / HEVC while retaining the same visual quality.
 
-To install FFmpeg with support for `llibaom-av1`, look at the [https://ffmpeg.org/trac/ffmpeg/wiki/CompilationGuide Compilation Guides] and compile FFmpeg with the {{{--enable-libaom}}} option.
+To install FFmpeg with support for `libaom-av1`, look at the [https://ffmpeg.org/trac/ffmpeg/wiki/CompilationGuide Compilation Guides] and compile FFmpeg with the {{{--enable-libaom}}} option.
 
-The default audio encoder for AV1 is `libopus`.
 
-libaom offers different rate control modes, which determine the quality and file size:
+libaom offers the following rate-control modes, which determine the quality and file size obtained:
 
 - 1-pass average bitrate
@@ -27 +26 @@
 
 {{{
-ffmpeg -i input.mp4 -c:v libaom-av1 -b:v 2M -c:a opus -strict -2 av1_test.mkv
+ffmpeg -i input.mp4 -c:v libaom-av1 -b:v 2M -strict -2 av1_test.mkv
 }}}
 
-Only use this option if you do not care about acheiving the best possible quality.
+Use this option if file size and encoding time are more important.
 
 === Constant Quality ===#constantq
 
-In addition to the "default" VBR mode, there's a constant quality (CQ) mode (like CRF in the x264 encoder) that will ensure that every frame gets the number of bits it deserves to achieve a certain (perceptual) quality level, rather than forcing the stream to have an average bit rate. This results in better overall quality. If you do not care about the file size, this should be your method of choice.
+In addition to the "default" VBR mode, there's a constant quality (CQ) mode (like CRF in x264 and x265) which will ensure that every frame gets the number of bits it deserves to achieve a certain (perceptual) quality level, rather than encoding each frame to meet a bit rate target. This results in better overall quality. If there isn't a fixed target file size, this should be your method of choice.
 
 {{{
-ffmpeg -i input.mp4 -c:v libaom-av1 -crf 30 -c:a opus -strict -2 av1_test.mkv
+ffmpeg -i input.mp4 -c:v libaom-av1 -crf 30 -strict -2 av1_test.mkv
 }}}
 
-The CRF value can be from 0–63. Lower values mean better quality. 
+The CRF value can be from 0–63. Lower values mean better quality and greater file size. 
 
 === Controlling Speed / Quality ===
 
-`-cpu-used` sets how efficient the compression will be. The default is 1. Lower values mean slower encoding with better quality, and vice-versa.
+`-cpu-used` sets how efficient the compression will be. Default is 1. Lower values mean slower encoding with better quality, and vice-versa.