[FFmpeg-user] Fast video to image conversion - QuickSync

[Li, Zhong]

> From: ffmpeg-user [mailto:ffmpeg-user-bounces at ffmpeg.org] On Behalf Of
> tikku
> Sent: Thursday, February 28, 2019 2:40 PM
> To: ffmpeg-user at ffmpeg.org
> Subject: [FFmpeg-user] Fast video to image conversion - QuickSync
> 
> I was trying out various flags to convert a video (eg. from rtsp stream) to an
> image.
> 
> The below command works, when dumping to null:
> 
> > ./ffmpeg -hwaccel qsv -c:v h264_qsv -init_hw_device qsv=foo
> > -filter_hw_device foo -rtsp_transport tcp -i
> > rtsp://user:pass@ipaddr:port/Streaming/Channels/101
> > -f null -
> 
> 
> This is the details about the output format for the above command:
> 
> Stream #0:0: Video: wrapped_avframe, qsv, 1920x1080 [SAR 189:190 DAR
> > 168:95], q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
> 
> 
> As seen, the pixel format is qsv. Formatting it to bgr24 etc are
> computationally expensive. Therefore, I would like to dump the frames in qsv
> format itself. Is this possible? If yes, what is the file extension? If no, what
> are the other alternatives to dump to image with very less cpu utilization?

The output format can be different as content. 
Mostly the decoded output is NV12 (for HEVC 10bit clips, it will be P010). 
You may want to see https://trac.ffmpeg.org/wiki/Hardware/QuickSync#FullExamples to see how to dump the output.