Exported video 2 frames missing

[jacob-resch]

Something weird is probably happening with the encoder because the exported video is missing 2 frames.

From media info this is the codec information of the original

General
Complete name : 20250307_0124_Loop Video_loop_01jnpzt0dkfkpre012tnzskr5v.mp4
Format : MPEG-4
Format profile : Base Media
File size : 5.66 MiB
Duration : 9 s 600 ms
Overall bit rate : 4 949 kb/s
Frame rate : 30.000 FPS
Writing application : Lavf60.16.100
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High
Format level : 3.2
Format settings, CABAC : Yes
Format settings, Reference frames : 4 frames
Codec ID : avc1
Duration : 9 s 600 ms
Bit rate : 4 933 kb/s
Width : 480 pixels
Height : 854 pixels
Display aspect ratio : 0.562
Frame rate mode : Constant
Frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.401
Stream size : 5.64 MiB (100%)
Writing library : x264 core 164 r3108 31e19f9
Encoding settings : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=6 / 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=27 / lookahead_threads=4 / sliced_threads=0 / 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=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=crf / mbtree=1 / crf=12.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=10000 / vbv_bufsize=20000 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Codec configuration box : avcC

And this is the new realsrgan exported version

General
Complete name : 20250307_0124_Loop Video_loop_01jnpzt0dkfkpre012tnzskr5v.realesrgan.mp4
Format : MPEG-4
Format profile : Base Media
File size : 33.6 MiB
Duration : 9 s 534 ms
Overall bit rate : 29.5 Mb/s
Frame rate : 30.000 FPS
Writing application : Lavf61.7.100
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High
Format level : 5.1
Format settings, CABAC : Yes
Format settings, Reference frames : 5 frames
Codec ID : avc1
Duration : 9 s 534 ms
Bit rate : 29.5 Mb/s
Width : 1 920 pixels
Height : 3 416 pixels
Display aspect ratio : 0.562
Frame rate mode : Constant
Frame rate : 30.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.150
Stream size : 33.6 MiB (100%)
Writing library : x264 core 164 r3192 c24e06c
Encoding settings : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=18 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Codec configuration box : avcC

Notice that the duration of the realsrgan is slightly shorter.

What is the reason for this ?

[jacob-resch]

When adjusting the input video to exactly 10s at 30fps the output is correct. So maybe there is like a rounding error or something that messes it up if it's an uneven number maybe

[k4yt3x]

This is a duplicate of #1318