Duster: Libvpx

They traced it to LibVPX’s vpx_codec_enc_config_t structure. The encoder was reusing a configuration object but not resetting the rc_min_quantizer and rc_max_quantizer internal states. A developer wrote a simple Duster routine:

Duster is the windshield wiper. It acknowledges a hard truth: Even elegant codecs leave behind messes. And sometimes, the most important tool in the stack isn’t the encoder—it’s the silent janitor that follows it, making sure the next job starts with a clean slate. duster libvpx

A real-world example: In 2022, a European OTT (Over-The-Top) streaming service noticed that after 72 hours of uptime, their transcoding nodes were using 4x the normal memory. Worse, the first frame of every new live stream showed ghosting artifacts—faint remnants of the previous channel’s logo. It acknowledges a hard truth: Even elegant codecs

void duster_libvpx_scrub(vpx_codec_ctx_t *ctx) { vpx_codec_err_t res; // Force full reset of rate control model res = vpx_codec_control(ctx, VP8E_RESET_ON_KEYFRAME, 1); // Clear frame buffer pool res = vpx_codec_control(ctx, VP9E_SET_FRAME_PARALLEL_DECODING, 0); // Reinitialize entropy pointers to NULL memset(ctx->priv, 0, sizeof(ctx->priv)); } Within 24 hours, memory usage normalized, ghosting vanished, and node uptime extended from 3 days to 90+ days. Worse, the first frame of every new live

Hidden in temporary buffers, partially decoded frames, motion vector tables, and probability models are gigabytes of "zombie data." If left alone, these remnants will slow down the next encoding job, cause memory bloat, and eventually crash the worker node.