get time position of all keyframes in mp4/mkv/webm
npm install retrieve-keyframes#### `var retrieve = require("retrieve-keyframes").get
#### retrieve(url, container, cb)
url - URL (http) to video file
container - "matroska" (mkv or webm) or "mp4"
cb - callback(err, frames)
##### frames is an array of objects: { index: Number, timestamp: Number }; the index is the numeric index of the frame, applicable when we use mp4; the timestamp is the pts value of the frame
`bash`
./cli.js http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_30fps_normal.mp4
`bash`
./cli.js http://jell.yfish.us/media/jellyfish-3-mbps-hd-h264.mkv
`bash`
./cli.js http://ia902508.us.archive.org/17/items/CartoonClassics/Krazy_Kat_-_Keeping_Up_With_Krazy.mp4
NOTE: You can also use the cli with WebM files.
A script is included - keyframes.sh - to compare results to ffprobe. All the results match so far, with the exception that ffmpeg likes to pick either dts or pts and consider that value as both pts and dts`.