Changes between Version 65 and Version 66 of Encode/AAC

Timestamp:

Apr 21, 2023, 5:14:21 PM (3 years ago)

Author:

Mingye Wang

Comment:

aac_at: be more clear

Encode/AAC

@@ -119 +119 @@
 ----
 
-= Native FFmpeg AAC Encoder =
+= Native FFmpeg AAC Encoder (`aac`) =#native
 
 The native FFmpeg AAC encoder. This is currently the second highest-quality AAC encoder available in FFmpeg and does not require an external library like the other AAC encoders described here. This is the default AAC encoder.
@@ -143 +143 @@
 
 ----
-= audiotoolbox Encoder =
-When a build is configured with --enable-audiotoolbox, Apple's audioToolbox.framework (normally available only on macOS) will provide a series of codecs suffixed `_at`. Apple's encoder [[https://wiki.hydrogenaud.io/index.php?title=Apple_AAC|is even better than FDK-AAC according to HydrogenAudio]] and has HE-AAC support, so that the exact same list of `-profile:a` flags from FDK work. You may have come across this implementation on other platforms as "QAAC" or "audioToolboxWrapper", but licensing issues for these modifications is too much for FFmpeg to deal with.
+= audiotoolbox Encoder (`aac_at`) =#aac_at
+When a build is configured with --enable-audiotoolbox, Apple's audioToolbox.framework (normally available only on macOS) will provide a series of codecs suffixed `_at`. Apple's encoder [[https://wiki.hydrogenaud.io/index.php?title=Apple_AAC|is even better than FDK-AAC according to HydrogenAudio]]. You may have come across this implementation on other platforms as "QAAC" or "audioToolboxWrapper", but licensing issues for these modifications is too much for FFmpeg to deal with.
+
+Bitrate control is done by global flags. `-global_quality:a` can range from 0~14 for VBR and `-b:a` by default gives CBR. `-aac_at_mode` can be used to instead cause `-b:a` to provide AVR and CVBR. All profiles for `libfdk_aac`'s `-profile:a` option, including both versions of HE-AAC, are available.
+
 {{{#!comment
-see audiotoolboxenc.c, ffat_get_format_id()
+see audiotoolboxenc.c, ffat_get_format_id() for pfofiles
 }}}