exiftool frames/frame_00123.png | grep -i comment No comment fields. Run zsteg on a few frames (install from Ruby gems or use stegsolve for a quick visual test):
dd if=fc2_1864525.mp4 of=payload.bin bs=1 skip=124567890 strings payload.bin | grep -i flag # => flagFC2_PPV_1864525_fake Flag: fc2-ppv-1864525
Using an online Morse decoder (or the morse Python library): exiftool frames/frame_00123
Use exiftool on a few frames to see if any hidden data was appended: fc2-ppv-1864525