[FFmpeg-trac] #11409(ffmpeg:new): Using -af and -vf with non-exhistant filter succeeds if input lacks required stream type

[FFmpeg]

#11409: Using -af and -vf with non-exhistant filter succeeds if input lacks
required stream type
-------------------------------------+-------------------------------------
             Reporter:  Wes Castro   |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  ffmpeg       |                  Version:
                                     |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Summary of the bug:

 When invoking the FFmpeg binary with `-af` of `-vf` followed by a filter
 that doesn't exist (for example `not_a_filter`) it silently ignores the
 error and succeeds as if the option wasn't passed in if the input has no
 streams of the required type. For example, if an audio input is used and
 `-vf not_a_filter` is passed in, it succeeds. Similarly, if a video input
 is used and `-af not_a_filter` is passed in it will also succeed.

 Note that with `-filter_complex` it seems to always fail if a filter isn't
 found regardless of input type.

 How to reproduce:
 Audio input with `-vf`:
 {{{
 ./ffmpeg -f lavfi -i sine=frequency=1000:duration=1 -vf not_a_filter -f
 null -
 ffmpeg version N-118273-g251de1791e Copyright (c) 2000-2025 the FFmpeg
 developers
   built with gcc 11 (GCC)
   configuration: --enable-gpl
   libavutil      59. 54.101 / 59. 54.101
   libavcodec     61. 31.100 / 61. 31.100
   libavformat    61.  9.104 / 61.  9.104
   libavdevice    61.  4.100 / 61.  4.100
   libavfilter    10.  6.101 / 10.  6.101
   libswscale      8. 13.100 /  8. 13.100
   libswresample   5.  4.100 /  5.  4.100
   libpostproc    58.  4.100 / 58.  4.100
 [out @ 0x2fd9b80] The "sample_fmts" option is deprecated: set the
 supported sample formats
 [out @ 0x2fd9b80] The "all_channel_counts" option is deprecated: accept
 all channel counts
 Input #0, lavfi, from 'sine=frequency=1000:duration=1':
   Duration: N/A, start: 0.000000, bitrate: 705 kb/s
   Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (pcm_s16le (native) -> pcm_s16le (native))
 Press [q] to stop, [?] for help
 Output #0, null, to 'pipe:':
   Metadata:
     encoder         : Lavf61.9.104
   Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
     Metadata:
       encoder         : Lavc61.31.100 pcm_s16le
 [out#0/null @ 0x2fddfc0] video:0KiB audio:86KiB subtitle:0KiB other
 streams:0KiB global headers:0KiB muxing overhead: unknown
 size=N/A time=00:00:01.00 bitrate=N/A speed= 351x
 }}}

 Video input with `-af`:
 {{{
 ./ffmpeg -f lavfi -i testsrc -t 10 -af not_a_filter -f null -
 ffmpeg version N-118273-g251de1791e Copyright (c) 2000-2025 the FFmpeg
 developers
   built with gcc 11 (GCC)
   configuration: --enable-gpl
   libavutil      59. 54.101 / 59. 54.101
   libavcodec     61. 31.100 / 61. 31.100
   libavformat    61.  9.104 / 61.  9.104
   libavdevice    61.  4.100 / 61.  4.100
   libavfilter    10.  6.101 / 10.  6.101
   libswscale      8. 13.100 /  8. 13.100
   libswresample   5.  4.100 /  5.  4.100
   libpostproc    58.  4.100 / 58.  4.100
 Input #0, lavfi, from 'testsrc':
   Duration: N/A, start: 0.000000, bitrate: N/A
   Stream #0:0: Video: wrapped_avframe, rgb24, 320x240 [SAR 1:1 DAR 4:3],
 25 fps, 25 tbr, 25 tbn
 Stream mapping:
   Stream #0:0 -> #0:0 (wrapped_avframe (native) -> wrapped_avframe
 (native))
 Press [q] to stop, [?] for help
 Output #0, null, to 'pipe:':
   Metadata:
     encoder         : Lavf61.9.104
   Stream #0:0: Video: wrapped_avframe, rgb24(pc, gbr/unknown/unknown,
 progressive), 320x240 [SAR 1:1 DAR 4:3], q=2-31, 200 kb/s, 25 fps, 25 tbn
     Metadata:
       encoder         : Lavc61.31.100 wrapped_avframe
 [out#0/null @ 0x2fcd140] video:107KiB audio:0KiB subtitle:0KiB other
 streams:0KiB global headers:0KiB muxing overhead: unknown
 frame=  250 fps=0.0 q=-0.0 Lsize=N/A time=00:00:10.00 bitrate=N/A speed=
 315x
 }}}
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/11409>
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