Cache latest frame to support multiple concurrent consumers - #54
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oliviamiller wants to merge 2 commits into
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Cache latest frame to support multiple concurrent consumers#54oliviamiller wants to merge 2 commits into
oliviamiller wants to merge 2 commits into
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…rames Previously every get_images call pulled a sample directly from the appsink, which dequeues it: with N consumers each frame went to exactly one caller and everyone else blocked until the next frame arrived (up to 1/frame_rate seconds). Now the appsink new-sample callback stores each frame in a shared latest-frame cache and consumers read the cache, so any number of clients get the most recent frame immediately. Follows the pattern used by viam-camera-realsense: frames are stamped with their actual capture time (now reported as captured_at), and get_images throws if the cached frame is older than 3 frame intervals so a stalled pipeline surfaces as an error instead of serving a stale image. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
oliviamiller
changed the title
oliviamiller
marked this pull request as ready for review
August 24, 2026 15:16
Naveed Jooma (njooma)
approved these changes
Aug 24, 2026
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Don't have hardware, but code looks reasonable |
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Right now
get_imagespulls straight from the appsink, and pulling a sampleconsumes it. So with more than one consumer, whoever asks first takes the
frame and everyone else sits waiting for the next one — at 1 fps that's seconds of
waiting per client.
This changes it so the appsink callback keeps the newest frame in a cache and
get_imagesjust reads from that. Any number of clients can grab the latestframe without stealing it from each other. Same approach as realsense and orbbec modules.