Playground command parsing error

[tehfra]

Commandline:

ffmpeg.exe -nostdin -analyzeduration 100M -probesize 100M -i "input_video.mkv" -vf "scale=-1:-1:flags=lanczos,pad=1920:1080:-1:-1,subtitles='subtitles.srt':stream_index=0:force_style='Fontname=Gotham Rounded Medium,Fontsize=17,Alignment=2,PrimaryColour=&Hffffff&,MarginV=25'" -sn -map 0:a:0 -map 0:v:0 -c:a aac -b:a 192k -ac 2 -c:v libx264 -crf 18 -preset slow -tune film -aq-strength 1.8 -mbtree 0 -pix_fmt yuv420p -y -hide_banner -loglevel error -stats -map_metadata -1 -map_chapters -1 "output_video.mp4"

Error:

Error parsing FFmpeg command: Unexpected token '#', "# Error: " is not valid JSON

[lucemia]

NOTE: need to support more complex filter syntax

https://ffmpeg.org/ffmpeg-filters.html#Filtergraph-syntax-1

A filterchain consists of a sequence of connected filters, each one connected to the previous one in the sequence. A filterchain is represented by a list of ","-separated filter descriptions.

A filtergraph consists of a sequence of filterchains. A sequence of filterchains is represented by a list of ";"-separated filterchain descriptions.

A filter is represented by a string of the form: [in_link_1]...[in_link_N]filter_name@id=arguments[out_link_1]...[out_link_M]

If an output pad is not labelled, it is linked by default to the first unlabelled input pad of the next filter in the filterchain. For example in the filterchain

[lucemia]

@tehfra

Thanks for the report. The issue comes from two FFmpeg filtergraph rules that aren’t fully supported yet:

1. Unlabeled pad linking:
   If an output pad is not labelled, it is implicitly linked to the first unlabelled input pad of the next filter.
2. Filterchain definition:
   A filterchain consists of a sequence of connected filters, each one connected to the previous one. It’s represented by a list of comma-separated filter descriptions.

Our parser currently doesn’t handle these implicit connections correctly. We’ll work on adding proper support for these filterchain behaviors soon. Thanks again for your detailed example!