why ffmpeg new version take fps different fps using the same commandline?

[marcorocchini]

Hi please help the poor cat

I try to encode the same source with 2 different version of ffmpeg

ffmpeg12ago2026.exe -v quiet -stats -y -i %4 -i %audiosource% -vf scale=interl=1:in_range=%inRange%:out_range=%outRange%,interlace=lowpass=1:scan=tff -x264-params interlaced=1 -c:v libx264 -profile:v main %lvl_String% -g 33 -bf 2 -crf 20 -flags +ildct+ilme -vf setfield=tff -pix_fmt yuv420p %AudioSettings2CHffmpegAug2026% -aspect 16:9 "%~n1_Mp4_reg1unico_420_2canaliAudio%panState%.mp4"

ffmpeg64bit2019.exe   -v quiet -stats -y -i %4 -i %audiosource% -vf scale=interl=1:in_range=%inRange%:out_range=%outRange%,interlace=lowpass=1:scan=tff -c:v libx264 -profile:v main %lvl_String% -g 33 -bf 2 -crf 20 -flags +ildct+ilme -top 1 -pix_fmt yuv420p %AudioSettings2CH% -aspect 16:9 "%~n1_Mp4_reg1unico_420_2canaliAudio%panState%ffmpeg2019.mp4"

but using ffmpeg12ago2026.exe I get in mediainfo 50FPS MBAFF encoding, meanwhile using ffmpeg64bit2019.exe is correctly 25 fps interlaced MBAFF

My input source is 50P, my target is to get 25i. Using ffmpeg64bit2019.exe seems correct 25 interlaced FPS and MBAFF, but with ffmpeg12ago2026.exe, the mediainfo signalling 50FPS MBAFF so it don't seems to me correct (?)

WHy?
[Attachment 93857 - Click to enlarge]

[Sharc]

It's not due to ffmpeg version. Your commandlines are different.

[marcorocchini]

https://www.swisstransfer.com/dl/01a0c92a-0f6f-73d1-93a1-4c8ed11553e8

please download my input source: is a 50P mxf

and the 2 output: outFFMPEGbuild12ago2026.mp4 + outFFMPEGbuild2019.mp4

FFMPEG12ago2026.exe -y -i v:\A034C240_260922XD_CANON.MXF -vf interlace -c:v libx264 -profile:v main -level:v 4.2 -g 33 -bf 2 -crf 22 -flags +ildct+ilme -vf setfield=tff -pix_fmt yuv420p -aspect 16:9 -an outFFMPEGbuild12ago2026.mp4

ffmpeg64bit2019.exe -y -i v:\A034C240_260922XD_CANON.MXF -vf interlace -c:v libx264 -profile:v main -level:v 4.2 -g 33 -bf 2 -crf 22 -flags +ildct+ilme -top 1 -pix_fmt yuv420p -aspect 16:9 -an outFFMPEGbuild2019.mp4

please explain to the cat thanks

I think my target is to get a "right" 25i final mp4 output. If "right" is mediainfo says "25 FPS" seems that the old version of ffmpeg (the ffmpeg64bit2019.exe) that can include the "-top 1" in commandline take this:

Generale
Complete name                            : V:\outFFMPEGbuild2019.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 9,54MiB
Duration                                 : 9s 600 ms
Overall bit rate                         : 8.333 kb/s
Writing application                      : Lavf58.20.100

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.2
Format settings, CABAC                   : Si
Format settings, ReFrames                : 4 frame
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 9s 600 ms
Bit rate                                 : 8.330 kb/s
Width                                    : 1.920 pixel
Height                                   : 1.080 pixel
Display aspect ratio                     : 16:9
Frame rate mode                          : Costante
Frame rate                               : 25,000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bit
Scan type                                : MBAFF
Scan order                               : Top field first
Bits/(Pixel*Frame)                       : 0.161
Stream size                              : 9,53MiB (100%)
Writing library                          : x264 core 157 r2935 545de2f
Encoding settings                        : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=24 / lookahead_threads=4 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=tff / bluray_compat=0 / constrained_intra=0 / bframes=2 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=0 / keyint=33 / keyint_min=3 / scenecut=40 / intra_refresh=0 / rc_lookahead=33 / rc=crf / mbtree=1 / crf=22.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

but using the new version of ffmpeg, if I include the "-top 1" --> ffmpeg return an error during encoding. So I have replace the "-top 1" with "-vf setfield=tff" but exactly I don't know if it is correct or not, however using "-vf setfield=tff" or not --> mediainfo says:

Generale
Complete name                            : V:\outFFMPEGbuild12ago2026.mp4
Format                                   : MPEG-4
Format profile                           : Base Media
Codec ID                                 : isom (isom/iso2/avc1/mp41)
File size                                : 11,8MiB
Duration                                 : 9s 600 ms
Overall bit rate                         : 10,3 Mb/s
Writing application                      : Lavf63.1.101

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4.2
Format settings, CABAC                   : Si
Format settings, ReFrames                : 4 frame
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 9s 600 ms
Bit rate                                 : 10,3 Mb/s
Width                                    : 1.920 pixel
Height                                   : 1.080 pixel
Display aspect ratio                     : 16:9
Frame rate mode                          : Costante
Frame rate                               : 50,000 FPS
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bit
Scan type                                : MBAFF
Scan order                               : Top field first
Bits/(Pixel*Frame)                       : 0.100
Stream size                              : 11,8MiB (100%)
Writing library                          : x264 core 165 r3223 0480cb0
Encoding settings                        : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=24 / lookahead_threads=4 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=tff / bluray_compat=0 / constrained_intra=0 / bframes=2 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=0 / keyint=33 / keyint_min=3 / scenecut=40 / intra_refresh=0 / rc_lookahead=33 / rc=crf / mbtree=1 / crf=22.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Color range                              : Limited
Color primaries                          : BT.709
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.709

so is it right or not that mediainfo says 50FPS ? I think not, why it? I need a 25i output mp4, not a 50

but the ffmpeg does not allow the use of "-top 1", so how can solve it?


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if I use ffmpeg buld 4 may 2026 and I exclude the "-vf setfield=tff" and include the "-top 1"

v:\automazioneclip\FFMPEG04MAY2026\ffmpeg.exe -y -i v:\A034C240_260922XD_CANON.MXF -vf interlace -c:v libx264 -profile:v main -level:v 4.2 -g 33 -bf 2 -crf 22 -flags +ildct+ilme -top 1 -pix_fmt yuv420p -aspect 16:9 -an outFFMPEGbuild4may2026.mp4

mediainfo says a correct 25 fps output mp4.

But using the ffmpeg build 12 ago 2026 whe you try to use the "-top 1" option the encoding complete fails: meanwhile I was expecting standard encoding 25i

[ProWo]

if I use ffmpeg buld 4 may 2026 and I exclude the "-vf setfield=tff" and include the "-top 1"
mediainfo says a correct 25 fps output mp4.

But using the ffmpeg build 12 ago 2026 whe you try to use the "-top 1" option the encoding complete fails: meanwhile I was expecting standard encoding 25i

With latest ffmpeg:

Codec AVOption top (top field first) is not a encoding option

Using

-vf interlace,setfield=tff

instead gives:

Frame rate mode : Constant
Frame rate : 25.000 FPS
Scan type : MBAFF
Scan type, store method : Interleaved fields
Scan order : Top Field First