Refactor Input / Output options

[lucemia]

current parse-c approach missed some options, should come from -help

[lucemia]

In FFmpeg, there are different option categories, general options looks like

• no type in docs
• support -no(option) syntax
• options can be per-stream, per-file, global, and -help doesn't tell

Global options (affect whole program instead of just one file):
-loglevel loglevel  set logging level
-v loglevel         set logging level
-report             generate a report
-max_alloc bytes    set maximum size of a single allocated block
-y                  overwrite output files
-n                  never overwrite output files
-ignore_unknown     Ignore unknown stream types
-filter_threads     number of non-complex filter threads
-filter_complex_threads  number of threads for -filter_complex
-stats              print progress report during encoding

-hwaccel[:stream_specifier] hwaccel (input,per-stream)
Use hardware acceleration to decode the matching stream(s). The allowed values of hwaccel are:

none
Do not use any hardware acceleration (the default).

auto
Automatically select the hardware acceleration method.

vdpau
Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.

dxva2
Use DXVA2 (DirectX Video Acceleration) hardware acceleration.

d3d11va
Use D3D11VA (DirectX Video Acceleration) hardware acceleration.

vaapi
Use VAAPI (Video Acceleration API) hardware acceleration.

qsv
Use the Intel QuickSync Video acceleration for video transcoding.

Unlike most other values, this option does not enable accelerated decoding (that is used automatically whenever a qsv decoder is selected), but accelerated transcoding, without copying the frames into the system memory.

For it to work, both the decoder and the encoder must support QSV acceleration and no filters must be used.

videotoolbox
Use Video Toolbox hardware acceleration.

This option has no effect if the selected hwaccel is not available or not supported by the chosen decoder.

Note that most acceleration methods are intended for playback and will not be faster than software decoding on modern CPUs. Additionally, ffmpeg will usually need to copy the decoded frames from the GPU memory into the system memory, resulting in further performance loss. This option is thus mainly useful for testing.

AVOptions looks like

AVCodecContext AVOptions:
  -b                 <int64>      E..VA...... set bitrate (in bits/s) (from 0 to I64_MAX) (default 200000)
  -ab                <int64>      E...A...... set bitrate (in bits/s) (from 0 to INT_MAX) (default 128000)
  -bt                <int>        E..VA...... Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate tolerance specifies how far ratecontrol is willing to deviate from the target average bitrate value. This is not related to minimum/maximum bitrate. Lowering tolerance too much has an adverse effect on quality. (from 0 to INT_MAX) (default 4000000)
  -flags             <flags>      ED.VAS..... (default 0)
     unaligned                    .D.V....... allow decoders to produce unaligned output

• has type
• per stream
• don't support -no(option) syntax

Filter Options looks like

edgedetect AVOptions:
   high              <double>     ..FV....... set high threshold (from 0 to 1) (default 0.196078)
   low               <double>     ..FV....... set low threshold (from 0 to 1) (default 0.0784314)
   mode              <int>        ..FV....... set mode (from 0 to 2) (default wires)
     wires           0            ..FV....... white/gray wires on black
     colormix        1            ..FV....... mix colors
     canny           2            ..FV....... detect edges on planes
   planes            <flags>      ..FV....... set planes to filter (default y+u+v+r+g+b)
     y                            ..FV....... filter luma plane