Xiph.org is renowned for high-quality, unencumbered test media. While they focus on Theora and VP8, they host clean YUV sources. You can encode these into H.263 yourself using FFmpeg to guarantee quality.
Sometimes you find a decent sample with one flaw—like too much noise or incorrect timing. You can fix it without re-encoding (which would degrade quality). Use in FFmpeg: h 263 video sample download better
Whether you are testing a new mobile application for older hardware or researching the evolution of video compression, here is why you need reliable H.263 samples and how to find them. What is H.263 and Why Does it Still Exist? Xiph.org is renowned for high-quality