Last week we demonstrated how simple 4fps thumbnail contact sheets offer an incredibly powerful way of previewing unenriched television news, while yesterday we showcased this on a selection of broadcasts from Russian channels 1TV, NTV and RUSSIA1 exploring how they are covering the invasion of Ukraine.
How might this same approach allow us to better understand how the early months of the COVID-19 pandemic were covered around the world, looking at local television news programming from a selection of countries?
The following contact sheets were generated for each broadcast:
- 160 Pixel 1/4FPS. The broadcast is sampled at a fixed framerate of exactly one frame every 4 seconds. Each frame is 160 pixels wide, making it compact enough to easily survey an entire broadcast in seconds, though fine detail is lost and text becomes illegible.
- 500 Pixel 1/4FPS. The broadcast is sampled at a fixed framerate of exactly one frame every 4 seconds. Each frame is 500 pixels wide, making it difficult to rapidly survey the broadcast, but making text legible. Segments of interest from the 160 pixel contact sheet can be referenced here to see fine detail like text.
- 160 Pixel Avg Frame. FFMPEG's built-in thumbnail generation filter batches the video into sequences of 100 frames and for each batch computes the color histogram of each frame, averages them together to derive the average histogram of that sequence, then selects the frame that is closest to the average and thus most "representative" of that sequence of frames. This enhances the temporal representativeness of the fixed frame rate previews by largely filtering out isolated interstitial frames or motion bursts, ensuring that for each sequence of 100 frames, the thumbnail selected best represents the average imagery of that sequence.
Below you will find each broadcast and the three contact sheets described above.
ALMAGHRIBIA (Morocco): May 22, 2020 11:00-11:31AM UTC
Canal Algerie – TV2 (Algeria): May 22, 2020 6:30-7:00AM CET
JRTV (Jordan): May 22, 2020 8:30-9:00PM EEST
RTP Internacional – RTPi (Portugal): May 22, 2020 3:00-4:01AM WEST
Sharjah TV (UAE): May 22, 2020 9:00-9:30PM UTC+04
Sudan TV (Sudan): May 22, 2020 9:00-9:30PM CAT
Tele Congo (Republic Of Congo): May 22, 2020 4:00-4:31PM WAT