Please provide a log file of such a recording session that ended at 19:00
Here's how...
Ran a few tests of shorter times (5:00, 7:30, 10:00) and they worked fine. Tried a real one again with the output timer set to 27:30. Now that I know how to look at the logs I see that it says it stopped recording due to output timer timeout, but the video I got out of it was only 18:23.
Looking at it I'm suspicious of the line "Number of lagged frames due to rendering lag/stalls: 29067 (59.4%)", even though what I've got is ~67% and what I'm missing is ~33%, but of course I still don't really know what I'm looking at.
17:39:17.555: ==== Recording Start ===============================================
17:39:17.555: [ffmpeg muxer: 'simple_file_output'] Writing file 'W:/Video/Captures/2022-04-16 17-39-17.mp4'...
17:39:17.613: [qsv encoder: 'simple_h264_recording'] settings:
17:39:17.613: rate_control: ICQ
17:39:17.614: ICQ Quality: 21
17:39:17.614: fps_num: 30
17:39:17.614: fps_den: 1
17:39:17.614: width: 1280
17:39:17.614: height: 720
17:39:17.614: [qsv encoder: 'simple_h264_recording'] debug info:
17:39:18.096: m_nSurfNum: 12
17:39:18.105: m_nTaskPool: 4
18:06:27.552: Stopping recording due to OutputTimer timeout
18:06:27.561: Stopping recording due to OutputTimer timeout
18:06:27.572: Stopping recording due to OutputTimer timeout
18:06:27.585: Stopping recording due to OutputTimer timeout
18:06:27.595: Stopping recording due to OutputTimer timeout
18:06:27.603: Stopping recording due to OutputTimer timeout
18:06:27.612: Stopping recording due to OutputTimer timeout
18:06:27.621: Stopping recording due to OutputTimer timeout
18:06:27.623: [ffmpeg muxer: 'simple_file_output'] Output of file 'W:/Video/Captures/2022-04-16 17-39-17.mp4' stopped
18:06:27.623: Output 'simple_file_output': stopping
18:06:27.623: Output 'simple_file_output': Total frames output: 33094
18:06:27.623: Output 'simple_file_output': Total drawn frames: 19834 (48901 attempted)
18:06:27.623: Output 'simple_file_output': Number of lagged frames due to rendering lag/stalls: 29067 (59.4%)
18:06:27.639: Stopping recording due to OutputTimer timeout
18:06:27.648: Stopping recording due to OutputTimer timeout
18:06:27.660: ==== Recording Stop ================================================
18:06:28.109: Video stopped, number of skipped frames due to encoding lag: 33114/33358 (99.3%)