Missing multiple end frames when decoding some movies (e.g. some DNxHD-encoded video in MOV containers)

GStreamer version: 1.16.2.

Operating system: Windows 8.1 x64 (desktop), macOS 10.14.6.

Reproduce:

0. Download the attachment (created with Adobe Media Encoder): AVID_DNxHD_75_SQ_8-bit_TC 1. Run the following command (substitute the real file system path):

gst-launch-1.0 uridecodebin uri="file:///path/to/footage/AVID_DNxHD_75_SQ_8-bit_TC.mov" ! videoconvert ! video/x-raw, format=RGB ! pngenc ! multifilesink location=gst_dec_%02d.png

Expected: 30 PNG files (timecodes 01:00:00:00 to 01:00:00:29).

Actual: 23 PNG files (timecodes 01:00:00:00 to 01:00:00:22) in Windows, 27 PNG files in macOS.

Note: FFmpeg of version git-2020-05-19-74dfc88 decodes the movie as expected: ffmpeg -i "AVID_DNxHD_75_SQ_8-bit_TC.mov" ffmpeg_dec_%02d.png