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author | Antoine Soulier via ffmpeg-devel <ffmpeg-devel@ffmpeg.org> | 2024-04-01 21:32:04 +0000 |
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committer | Stefano Sabatini <stefasab@gmail.com> | 2024-04-04 17:47:31 +0200 |
commit | 240fd04db231efa4abad3abbd808140b4112324a (patch) | |
tree | 3eece6e3346badfd9a5e20f9e444d233d42d9af4 /doc/encoders.texi | |
parent | e3335e9e9ebfff4acea97fd715b2824ec1957b96 (diff) | |
download | ffmpeg-240fd04db231efa4abad3abbd808140b4112324a.tar.gz |
avcodec/liblc3: add encoding/decoding support of LC3 audio codec
The LC3 audio codec is the default codec of Bluetooth LE audio.
This is a wrapper over the liblc3 library (https://github.com/google/liblc3).
Signed-off-by: Antoine Soulier <asoulier@google.com>
Diffstat (limited to 'doc/encoders.texi')
-rw-r--r-- | doc/encoders.texi | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/doc/encoders.texi b/doc/encoders.texi index 7c223ed74c..66847191e1 100644 --- a/doc/encoders.texi +++ b/doc/encoders.texi @@ -814,6 +814,63 @@ ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a @end example @end itemize +@anchor{liblc3-enc} +@section liblc3 + +liblc3 LC3 (Low Complexity Communication Codec) encoder wrapper. + +Requires the presence of the liblc3 headers and library during configuration. +You need to explicitly configure the build with @code{--enable-liblc3}. + +This encoder has support for the Bluetooth SIG LC3 codec for the LE Audio +protocol, and the following features of LC3plus: +@itemize +@item +Frame duration of 2.5 and 5ms. +@item +High-Resolution mode, 48 KHz, and 96 kHz sampling rates. +@end itemize + +For more information see the liblc3 project at +@url{https://github.com/google/liblc3}. + +@subsection Options + +The following options are mapped on the shared FFmpeg codec options. + +@table @option +@item b @var{bitrate} +Set the bit rate in bits/s. This will determine the fixed size of the encoded +frames, for a selected frame duration. + +@item ar @var{frequency} +Set the audio sampling rate (in Hz). + +@item channels +Set the number of audio channels. + +@item frame_duration +Set the audio frame duration in milliseconds. Default value is 10ms. +Allowed frame durations are 2.5ms, 5ms, 7.5ms and 10ms. +LC3 (Bluetooth LE Audio), allows 7.5ms and 10ms; and LC3plus 2.5ms, 5ms +and 10ms. + +The 10ms frame duration is available in LC3 and LC3 plus standard. +In this mode, the produced bitstream can be referenced either as LC3 or LC3plus. + +@item high_resolution @var{boolean} +Enable the high-resolution mode if set to 1. The high-resolution mode is +available with all LC3plus frame durations and for a sampling rate of 48 KHz, +and 96 KHz. + +The encoder automatically turns off this mode at lower sampling rates and +activates it at 96 KHz. + +This mode should be preferred at high bitrates. In this mode, the audio +bandwidth is always up to the Nyquist frequency, compared to LC3 at 48 KHz, +which limits the bandwidth to 20 KHz. +@end table + @anchor{libmp3lame} @section libmp3lame |