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[FFmpeg-devel,7/7] doc: add doc about dolby_e decoder and wav support

Message ID 20230309175125.19691-2-nicolas.gaullier@cji.paris
State New
Headers show
Series avformat/wavdec: s337m support | expand

Commit Message

Nicolas Gaullier March 9, 2023, 5:51 p.m. UTC
 doc/decoders.texi | 20 ++++++++++++++++++++
 doc/demuxers.texi | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
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diff --git a/doc/decoders.texi b/doc/decoders.texi
index 5ba85cf9b1..750fb4bd7a 100644
--- a/doc/decoders.texi
+++ b/doc/decoders.texi
@@ -223,6 +223,26 @@  Loud sounds are fully compressed.  Soft sounds are enhanced.
 @end table
+@section dolby_e
+Dolby E audio decoder.
+This is a raw decoder without any further processing, which means the output
+sample rate is different from the 48KHz input sample rate.
+A dolby E stream is always carried in a s337m muxer, as a raw file
+or muxed in any format that is able to transport an AES3
+or an equivalent uncompressed audio stream (stereo, 48KHz, 16/20/24 bits).
+Currently, only wav and raw file formats are supported. Other formats require
+two passes of processing: a first one to extract the s337m stream,
+and another to decode it.
+In case of AES3, or if the format itself supports it, the non-PCM mode may
+be signaled, but in a more general manner, a stream has to be probed to be
+handled as dolby E rather than pcm.
+By default, stream probing is enabled which forbids pass-through as no s337m
+muxer is implemented yet. In order to pass-through a dolby E stream,
+@code{--non_pcm_mode copy} must be specified (see input muxer options).
 @section flac
 FLAC audio decoder.
diff --git a/doc/demuxers.texi b/doc/demuxers.texi
index 3c81024f03..c86bd91461 100644
--- a/doc/demuxers.texi
+++ b/doc/demuxers.texi
@@ -928,4 +928,37 @@  which in turn, acts as a ceiling for the size of scripts that can be read.
 Default is 1 MiB.
 @end table
+@section wav, w64
+WAV/RF64/BW64/Wave64 demuxer.
+This demuxer supports spdif and s337m probing, as well as direct codec
+probing in some cases (dts).
+Concerning dolby E, see @ref{dolby_e,,the dolby E section in the ffmpeg-codecs manual,ffmpeg-codecs}.
+@subsection Options
+This demuxer supports the following options:
+@table @option
+@item ignore_length @var{bool}
+Ignore the length field of the 'data' chunk: read everything as data up to eof. Default is disabled.
+This option is not supported in the Wave64 demuxer.
+@item max_size
+Max size of a single packet. Default is 4096.
+@item non_pcm_mode
+This option is active only if s337m data is probed.
+Specify how this data shall be handled. Default is to demux.
+@table @samp
+@item copy
+Pass-through as pcm: s337m will not be reported
+@item demux
+Demux and report the encoded stream for later decoding
+@end table
+@end table
 @c man end DEMUXERS