This option is similar to -filter_complex, the only difference is
that its argument is the name of the file from which a complex filtergraph description is to be read.
This option enables or disables accurate seeking in input files
with the -ss option. It is enabled by default, so seeking is accurate when transcoding. Use -noaccurate_seek to disable it, which may be useful e.g. when copying some streams and transcoding the others.
This option enables or disables seeking by timestamp in input files
with the -ss option. It is disabled by default. If enabled, the argument to the -ss option is considered an actual timestamp, and is not offset by the start time of the file. This matters only for files which do not start from timestamp 0, such as transport streams.
This option sets the maximum number of queued packets when reading
from the file or device. With low latency / high rate live streams,
Manual page ffmpeg(1) line 1558 (press h for help or q to quit)