Bug Report: Extra comma in filter command [-vf ", hflip"] causes encoding failure

[fyhtma]

Describe the bug
When using the "hflip" filter to horizontally flip a video, the current command includes an extra comma and space before the filter name, causing the encoding process to fail.

To Reproduce
Steps to reproduce the behavior:

1. Open WebM for Lazys v3.40.7 (or fresh install of v3.40.0 from WebMConverter-3.40.0.zip)
2. Attempt to encode a video with horizontal flip (or "Preview filters")
3. Observe the error message in the output

Expected behavior
The video should be successfully encoded with the horizontal flip applied.

Screenshots

Software version(please complete the following information):

• WebM for Lazys: v3.40.7
• Avisynth: 2.6

Additional information:
Claude AI informed that the current command includes -vf ", hflip", which results in an error:

WebM for Lazys v3.40.7: -vf ", hflip"

Arguments: -f nut -i pipe:0   -an -c:v libx264 -pix_fmt yuv420p -threads 8 -slices 8 -metadata title="2024-09-13 17.17.26 3456249318966763356_22797478" -lag-in-frames 16 -auto-alt-ref 1 -vf ", hflip" -qmin 17 -crf 19 -qmax 21 -qcomp 1 -b:v 0 -f mp4 -y "O:\4K Stogram\annelesemilton\story\2024-09-13 17.17.26 3456249318966763356_22797478-1.mp4"
--- CREATING AVISYNTH PROXY --- 
Input #0, nut, from 'pipe:0':
  Metadata:
--- FFMPEG HAS EXITED ---
    encoder         : Lavf56.40.101
  Duration: N/A, start: 0.000000, bitrate: N/A
  Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1080x1920, 30 tbr, 61440 tbn
[AVFilterGraph @ 00000159ce2666c0] No such filter: ''
[vost#0:0/libx264 @ 00000159ce265000] Error initializing a simple filtergraph
Error opening output file O:\4K Stogram\annelesemilton\story\2024-09-13 17.17.26 3456249318966763356_22797478-1.mp4.
Error opening output files: Filter not found

ffmpeg.exe exited with exit code -1279870712. That's usually bad.
If you have no idea what went wrong, open an issue on Github and copy paste the output of this window there, also upload test video.

The command should be -vf "hflip" without the extra comma and space. Removing the extra comma and space from the filter command resolves the issue.

WebM for Lazys v3.40.7: -vf "hflip" manually corrected in the tab Advanced -> section Arguments

Arguments: -f nut -i pipe:0   -an -c:v libx264 -pix_fmt yuv420p -threads 8 -slices 8 -metadata title="2024-09-13 17.17.26 3456249318966763356_22797478" -lag-in-frames 16 -auto-alt-ref 1 -vf "hflip" -qmin 17 -crf 19 -qmax 21 -qcomp 1 -b:v 0 -f mp4 -y "O:\4K Stogram\annelesemilton\story\2024-09-13 17.17.26 3456249318966763356_22797478-1.mp4"
--- CREATING AVISYNTH PROXY --- 
Input #0, nut, from 'pipe:0':
  Metadata:
    encoder         : Lavf56.40.101
  Duration: N/A, start: 0.000000, bitrate: N/A
  Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1080x1920, 30 tbr, 61440 tbn
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo (native) -> h264 (libx264))
[libx264 @ 000001e9d9ef5480] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 000001e9d9ef5480] profile High, level 4.0, 4:2:0, 8-bit
[libx264 @ 000001e9d9ef5480] 264 - core 164 r3172 c1c9931 - H.264/MPEG-4 AVC codec - Copyleft 2003-2023 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=8 lookahead_threads=1 sliced_threads=0 slices=8 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc=crf mbtree=0 crf=19.0 qcomp=1.00 qpmin=17 qpmax=21 qpstep=4 ip_ratio=1.40 pb_ratio=1.30 aq=1:1.00
Output #0, mp4, to 'O:\4K Stogram\annelesemilton\story\2024-09-13 17.17.26 3456249318966763356_22797478-1.mp4':
  Metadata:
    title           : 2024-09-13 17.17.26 3456249318966763356_22797478
    encoder         : Lavf60.16.100
  Stream #0:0: Video: h264 (avc1 / 0x31637661), yuv420p(progressive), 1080x1920, q=2-31, 30 fps, 15360 tbn
    Metadata:
      encoder         : Lavc60.31.102 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
frame=   88 fps= 20 q=19.0 size=    1280kB time=00:00:02.86 bitrate=3658.0kbits/s speed=0.656x    

[out#0/mp4 @ 000001e9d9ef40c0] video:1631kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.183116%
frame=  111 fps= 21 q=-1.0 Lsize=    1634kB time=00:00:03.60 bitrate=3717.9kbits/s speed=0.688x    
[libx264 @ 000001e9d9ef5480] frame I:1     Avg QP:17.54  size: 44947
[libx264 @ 000001e9d9ef5480] frame P:40    Avg QP:17.65  size: 23813
[libx264 @ 000001e9d9ef5480] frame B:70    Avg QP:18.68  size:  9598
--- FFMPEG HAS EXITED ---
[libx264 @ 000001e9d9ef5480] consecutive B-frames:  0.9% 45.0%  0.0% 54.1%
[libx264 @ 000001e9d9ef5480] mb I  I16..4: 36.9% 59.9%  3.3%
[libx264 @ 000001e9d9ef5480] mb P  I16..4:  9.6% 11.4%  0.5%  P16..4: 30.6% 14.6%  4.7%  0.0%  0.0%    skip:28.5%
[libx264 @ 000001e9d9ef5480] mb B  I16..4:  0.7%  0.7%  0.0%  B16..8: 21.2%  7.4%  1.3%  direct: 2.7%  skip:66.1%  L0:47.3% L1:40.9% BI:11.8%
[libx264 @ 000001e9d9ef5480] 8x8 transform intra:53.4% inter:83.8%
[libx264 @ 000001e9d9ef5480] coded y,uvDC,uvAC intra: 19.3% 32.5% 4.7% inter: 9.4% 9.5% 0.1%
[libx264 @ 000001e9d9ef5480] i16 v,h,dc,p: 48% 28%  9% 15%
[libx264 @ 000001e9d9ef5480] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 41% 15% 33%  2%  2%  2%  2%  2%  1%
[libx264 @ 000001e9d9ef5480] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 55% 15% 13%  2%  4%  5%  2%  3%  1%
[libx264 @ 000001e9d9ef5480] i8c dc,h,v,p: 66% 16% 15%  2%
[libx264 @ 000001e9d9ef5480] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 000001e9d9ef5480] ref P L0: 63.5%  5.9% 25.3%  5.2%
[libx264 @ 000001e9d9ef5480] ref B L0: 81.9% 16.0%  2.0%
[libx264 @ 000001e9d9ef5480] ref B L1: 98.2%  1.8%
[libx264 @ 000001e9d9ef5480] kb/s:3609.26

Video converted succesfully!

--- Final file size is 1,6 MB ---

And that file is correctly flipped.

[argorar]

Check latest update.