[FFmpeg-user] ffmpeg ignores video filter (-vf:v:0/1), possible bug?

[Jakub Vojáček]

Hello,

we are receiving multicast that has 2 audios and video. We'd like to create
a new multicast from this one and add one video in different bitrate and
resolution.

The command we're trying is

ffmpeg -i udp://@239.10.10.4:5004?fifo_size=100000000 \
-map i:0x7f9 -c:v:0 h264_nvenc -r:v:0 25 *-vf:v:0
"fps=25,scale_npp=640:360:format=same:interp_algo=lanczos"* -aspect:v:0
16:9 -g:v:0 80 -b:v:0 400K -minrate:v:0 400k -maxrate:v:0 400k \
-map i:0x7f9 -c:v:1 libx264 -r:v:1 25 *-vf:v:1 "fps=25,scale=1280:720"*
-aspect:v:1 16:9 -g:v:1 80 -b:v:1 4000K -minrate:v:1 4000k -maxrate:v:1
4000k \
-map i:0x7fc -c:a:0 aac -b:a:0 128k -ar 48k \
-map i:0x7fd -c:a:1 aac -b:a:1 64k -ar 48k \
-f mpegts udp://@239.0.0.123:1234?overrun_nonfatal_option=1

The ffmpeg starts but ignored the video filter options, both outputted
videos are in same resolution and bitrate, please see below:

Input #0, mpegts, from 'udp://@239.10.10.4:5004?fifo_size=100000000':
  Duration: N/A, start: 83042.271433, bitrate: N/A
  Program 10104
    Metadata:
      service_name    : CT 24
      service_provider: Ceska televize
    Stream #0:0[0x7f9]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k
tbn, 50 tbc
    Stream #0:1[0x7fa](cze): Subtitle: dvb_teletext ([6][0][0][0] /
0x0006), 492x250
    Stream #0:2[0x7fc](cze): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
stereo, s16p, 192 kb/s
    Stream #0:3[0x7fd](cze): Audio: mp2 ([3][0][0][0] / 0x0003), 48000 Hz,
mono, s16p, 64 kb/s (visual impaired)
    Stream #0:4[0x7ff]: Unknown: none ([5][0][0][0] / 0x0005)
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg2video (native) -> h264 (h264_nvenc))
  Stream #0:0 -> #0:1 (mpeg2video (native) -> h264 (libx264))
  Stream #0:2 -> #0:2 (mp2 (native) -> aac (native))
  Stream #0:3 -> #0:3 (mp2 (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x55f373354a40] VBV maxrate specified, but no bufsize, ignored
[libx264 @ 0x55f373354a40] using SAR=1/1
[libx264 @ 0x55f373354a40] using cpu capabilities: MMX2 SSE2Fast SSSE3
SSE4.2 AVX FMA3 AVX2 LZCNT BMI2
[libx264 @ 0x55f373354a40] profile High, level 3.1
Output #0, mpegts, to 'udp://@239.0.0.123:1235?overrun_nonfatal_option=1':
  Metadata:
    encoder         : Lavf58.9.100
    Stream #0:0:* Video: h264 (h264_nvenc) (Main), yuv420p, 1280x720 [SAR
1:1 DAR 16:9], q=-1--1, 400 kb/s, 25 fps, 90k tbn, 25 tbc*
    Metadata:
      encoder         : Lavc58.10.100 h264_nvenc
    Side data:
      cpb: bitrate max/min/avg: 400000/0/400000 buffer size: 800000
vbv_delay: -1
    Stream #0:1: *Video: h264 (libx264), yuv420p, 1280x720 [SAR 1:1 DAR
16:9], q=-1--1, 4000 kb/s, 25 fps, 90k tbn, 25 tbc*
    Metadata:
      encoder         : Lavc58.10.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 4000000/0/4000000 buffer size: 0 vbv_delay:
-1
    Stream #0:2(cze): Audio: aac (LC), 48000 Hz, stereo, fltp, 128 kb/s
    Metadata:
      encoder         : Lavc58.10.100 aac
    Stream #0:3(cze): Audio: aac (LC), 48000 Hz, mono, fltp, 64 kb/s
(visual impaired)
    Metadata:
      encoder         : Lavc58.10.100 aac

It seems like the *-vf:v:0 *and *-vf:v:1* are being ignored while all other
modifiers (-g:v:0, -b:v:1 -minrate:v:0, ... are working). Is it a bug in
ffmpeg or am I doing something wrong?

Thank you
Jakub