different frame counts in the source and in the destination file

[Selur]

Since you didn't post the whole mediainfo output: You didn't mix up Video&Audio frames, right?

Video
Count : 390
Count of stream of this kind : 1
Kind of stream : Video
Kind of stream : Video
Stream identifier : 0
StreamOrder : 0
ID : 1
ID : 1
Unique ID : 532451975017205657
Format : AV1
Format : AV1
Format/Info : AOMedia Video 1
Format/Url : http://aomedia.org/
Commercial name : AV1
Format profile : Main@L3.0
Codec ID : V_AV1
Codec ID/Url : http://aomedia.org/
Duration : 14848.000000
Duration : 14 s 848 ms
Duration : 14 s 848 ms
Duration : 14 s 848 ms
Duration : 00:00:14.848
Duration : 00:00:14;25
Duration : 00:00:14.848 (00:00:14;25)
Bit rate : 2910438
Bit rate : 2 910 kb/s
Width : 640
Width : 640 pixels
Height : 480
Height : 480 pixels
Sampled_Width : 640
Sampled_Height : 480
Pixel aspect ratio : 1.000
Display aspect ratio : 1.333
Display aspect ratio : 4:3
Frame rate mode : CFR
Frame rate mode : Constant
Frame rate : 29.970
Frame rate : 29.970 FPS
Frame count : 445
Color space : YUV
Chroma subsampling : 4:2:0
Chroma subsampling : 4:2:0
Bit depth : 10
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.316
Delay : 0
Delay : 00:00:00.000
Delay : 00:00:00;00
Delay : 00:00:00.000 (00:00:00;00)
Delay, origin : Container
Delay, origin : Container
Stream size : 5401773
Stream size : 5.15 MiB (65%)
Stream size : 5 MiB
Stream size : 5.2 MiB
Stream size : 5.15 MiB
Stream size : 5.152 MiB
Stream size : 5.15 MiB (65%)
Proportion of this stream : 0.65377
Default : Yes
Default : Yes
Forced : Yes
Forced : Yes
colour_description_present : Yes
colour_description_present_Source : Container / Stream
colour_range_Source : Container
colour_range_Original : Limited
colour_range_Original_Source : Stream
colour_primaries_Source : Stream
transfer_characteristics_Source : Stream
Matrix coefficients : BT.470 System B/G
matrix_coefficients_Source : Container / Stream

Audio
Count : 285
Count of stream of this kind : 1
Kind of stream : Audio
Kind of stream : Audio
Stream identifier : 0
StreamOrder : 1
ID : 2
ID : 2
Unique ID : 12750930280863998902
Format : PCM
Format : PCM
Commercial name : PCM
Format settings : Little / Signed
Format settings, Endianness : Little
Format settings, Sign : Signed
Codec ID : A_PCM/INT/LIT
Duration : 14848.000000
Duration : 14 s 848 ms
Duration : 14 s 848 ms
Duration : 14 s 848 ms
Duration : 00:00:14.848
Duration : 00:00:14.848
Bit rate mode : CBR
Bit rate mode : Constant
Bit rate : 1536000
Bit rate : 1 536 kb/s
Channel(s) : 2
Channel(s) : 2 channels
Samples per frame : 1916
Sampling rate : 48000
Sampling rate : 48.0 kHz
Samples count : 712704
Frame rate : 25.054
Frame rate : 25.054 FPS (1916 SPF)
Frame count : 372
Bit depth : 16
Bit depth : 16 bits
Delay : 0
Delay : 00:00:00.000
Delay : 00:00:00.000
Delay, origin : Container
Delay, origin : Container
Delay relative to video : 0
Delay relative to video : 00:00:00.000
Delay relative to video : 00:00:00.000
Stream size : 2850848
Stream size : 2.72 MiB (35%)
Stream size : 3 MiB
Stream size : 2.7 MiB
Stream size : 2.72 MiB
Stream size : 2.719 MiB
Stream size : 2.72 MiB (35%)
Proportion of this stream : 0.34503
Default : Yes
Default : Yes
Forced : No
Forced : No

Audio frames: 372 (will change when audio is converted)
Video frames: 445

Cu Selur