Using lavfi-complex, various properties relating to frame count '0' or 'not available'

mpv Information

mpv 0.39.0 Copyright © 2000-2024 mpv/MPlayer/mplayer2 projects
 built on Sep 28 2024 01:30:48
libplacebo version: v7.349.0 (v7.349.0-13-ga018ab0-dirty)
FFmpeg version: N-117212-g01c47dd23
FFmpeg library versions:
   libavcodec      61.20.100
   libavdevice     61.4.100
   libavfilter     10.5.100
   libavformat     61.8.100
   libavutil       59.40.100
   libswresample   5.4.100
   libswscale      8.4.100

Other Information

- Windows version: 11
- GPU model, driver and version: Nvidia Geforce RTX 2060
- Source of mpv: official
- Latest known working version: ?
- Issue started after the following happened: n/a

Reproduction Steps

mpv "test.mp4" "--lavfi-complex=[vid1]scale=100:100[vo];[aid1]aresample=async=1[ao]" --script=mpv-frame-report.lua

mpv-frame-report.lua:

local msg = require("mp.msg")
mp.enable_messages("info")
mp.add_periodic_timer(1, function ()
    msg.info("estimated-frame-count: "..tostring(mp.get_property_native("estimated-frame-count")))
    msg.info("estimated-frame-number: "..tostring(mp.get_property_native("estimated-frame-number")))
end)

I think these properties depend on container_fps, but when using lavfi-complex container_fps = 0

Expected Behavior

Outputs correct values.

Actual Behavior

[mpv_frame_report] estimated-frame-count: 0
[mpv_frame_report] estimated-frame-number: 0
[mpv_frame_report] estimated-frame-count: 0
[mpv_frame_report] estimated-frame-number: 0
[mpv_frame_report] estimated-frame-count: 0
[mpv_frame_report] estimated-frame-number: 0
...

Log File

out.txt

Sample Files

https://0x0.st/83eT.mp4

I carefully read all instruction and confirm that I did the following:

• I tested with the latest mpv version to validate that the issue is not already fixed.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start by running the reported mpv command with lavfi-complex and mpv-frame-report.lua, then trace how estimated-frame-count and estimated-frame-number are computed when container_fps is 0. Compare the property behavior with and without lavfi-complex and use the supplied log and sample file to confirm the cause. Done means the properties report correct values instead of 0 or unavailable.