doc/ffmpeg: add vstats format documentation

Address issue:
http://trac.ffmpeg.org/ticket/7520
This commit is contained in:
Stefano Sabatini 2023-01-24 23:56:54 +01:00
parent fd97a16157
commit 261fb55e39

View File

@ -1025,20 +1025,19 @@ factor if negative.
@item -psnr
Calculate PSNR of compressed frames. This option is deprecated, pass the
PSNR flag to the encoder instead, using @code{-flags +psnr}.
@item -vstats
Dump video coding statistics to @file{vstats_HHMMSS.log}.
Dump video coding statistics to @file{vstats_HHMMSS.log}. See the
@ref{vstats_file_format,,vstats file format} section for the format description.
@item -vstats_file @var{file}
Dump video coding statistics to @var{file}.
Dump video coding statistics to @var{file}. See the
@ref{vstats_file_format,,vstats file format} section for the format description.
@item -vstats_version @var{file}
Specifies which version of the vstats format to use. Default is 2.
Specify which version of the vstats format to use. Default is @code{2}. See the
@ref{vstats_file_format,,vstats file format} section for the format description.
version = 1 :
@code{frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s}
version > 1:
@code{out= %2d st= %2d frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s}
@item -top[:@var{stream_specifier}] @var{n} (@emph{output,per-stream})
top=1/bottom=0/auto=-1 field first
@item -vtag @var{fourcc/tag} (@emph{output})
@ -2087,6 +2086,7 @@ encoder/muxer, it does not change the stream to conform to this value. Setting
values that do not match the stream properties may result in encoding failures
or invalid output files.
@anchor{stats_enc_options}
@item -stats_enc_pre[:@var{stream_specifier}] @var{path} (@emph{output,per-stream})
@item -stats_enc_post[:@var{stream_specifier}] @var{path} (@emph{output,per-stream})
@item -stats_mux_pre[:@var{stream_specifier}] @var{path} (@emph{output,per-stream})
@ -2254,6 +2254,63 @@ search for the file @file{libvpx-1080p.avpreset}.
If no such file is found, then ffmpeg will search for a file named
@var{arg}.avpreset in the same directories.
@anchor{vstats_file_format}
@section vstats file format
The @code{-vstats} and @code{-vstats_file} options enable generation of a file
containing statistics about the generated video outputs.
The @code{-vstats_version} option controls the format version of the generated
file.
With version @code{1} the format is:
@example
frame= @var{FRAME} q= @var{FRAME_QUALITY} PSNR= @var{PSNR} f_size= @var{FRAME_SIZE} s_size= @var{STREAM_SIZE}kB time= @var{TIMESTAMP} br= @var{BITRATE}kbits/s avg_br= @var{AVERAGE_BITRATE}kbits/s
@end example
With version @code{2} the format is:
@example
out= @var{OUT_FILE_INDEX} st= @var{OUT_FILE_STREAM_INDEX} frame= @var{FRAME_NUMBER} q= @var{FRAME_QUALITY}f PSNR= @var{PSNR} f_size= @var{FRAME_SIZE} s_size= @var{STREAM_SIZE}kB time= @var{TIMESTAMP} br= @var{BITRATE}kbits/s avg_br= @var{AVERAGE_BITRATE}kbits/s
@end example
The value corresponding to each key is described below:
@table @option
@item avg_br
average bitrate expressed in Kbits/s
@item br
bitrate expressed in Kbits/s
@item frame
number of encoded frame
@item out
out file index
@item PSNR
Peak Signal to Noise Ratio
@item q
quality of the frame
@item f_size
encoded packet size expressed as number of bytes
@item s_size
stream size expressed in KiB
@item st
out file stream index
@item time
time of the packet
@item type
picture type
@end table
See also the @ref{stats_enc_options,,-stats_enc options} for an alternative way
to show encoding statistics.
@c man end OPTIONS
@chapter Examples