How do I extract thumbnail from video?
Grabs a single frame as a JPEG or PNG, seeking to the timestamp first so it is fast on long files.
Extract a thumbnail from a video
Grabs a single frame as a JPEG or PNG, seeking to the timestamp first so it is fast on long files.
ffmpeg -ss 2 -i https://cdn.rendobar.com/assets/examples/sample.mp4 -frames:v 1 -q:v 2 out.jpg- Encode
- 127 ms
- Output
- 49.8 KB
- Cost
- $0.0014
- Result
- 1280x720
job_1563ceb5d68f4ca5
The part everyone gets wrong
-frames:v 1 stops after one frame. Without it, and without -vframes, FFmpeg happily writes a numbered sequence of every frame in the file. -q:v runs 2 (best) to 31 (worst) for JPEG, which is the opposite direction to CRF.
What the common version does
Seeking after the input decodes every frame up to the timestamp, which is wasted work when you want one picture.
ffmpeg -i https://cdn.rendobar.com/assets/examples/sample.mp4 -ss 2 -frames:v 1 -q:v 2 out.jpgIt succeeds, and that is the problem
It did not error. It produced 49.8 KB against the correct command's 49.8 KB, a 1.0x smaller file. A pipeline would accept this silently.
job_42f0f069da954a05
Frequently asked questions
What goes wrong most often?
-frames:v 1 stops after one frame. Without it, and without -vframes, FFmpeg happily writes a numbered sequence of every frame in the file. -q:v runs 2 (best) to 31 (worst) for JPEG, which is the opposite direction to CRF.
What happens if I get it wrong?
We ran the naive version too. It did not error. It produced 49.8 KB against the correct command's 49.8 KB, a 1.0x smaller file. A pipeline would accept this silently.
Do I need FFmpeg installed?
Not with Rendobar. The command on this page ran through the API against a URL, with no local FFmpeg and no server. The job id below it is the job that produced these numbers.
More recipes, all measured
Extract audio from video with FFmpeg Pulls the audio track out of a video, copying it without re-encoding when the format allows. Export every frame as an image Writes each frame to a numbered image file, or samples at a fixed rate to keep the count manageable. Make a contact sheet from a video Samples frames across the video and lays them out in a grid as a single image. Convert MP4 to GIF with FFmpeg Turns a video into an animated GIF using a generated palette, which is the difference between a usable GIF and a muddy one.
Run this without installing FFmpeg
This exact command ran through the API against a URL.