Am Di., 17. März 2020 um 16:04 Uhr schrieb penguin flying <[email protected]>: > > using this cmd > ffmpeg -i in.mp4 -copyts -f image2 -vframes 5 -y %03d.jpg > will decode one frame and then encode it to one jpg at the same time, > AND the picture will be encoded in default quality. > > BUT when I want to improve the quality of the image after adding the param > "qscale", > ffmpeg -i in.mp4 -copyts -f image2 -vframes 5 -qscale:v 2 -y %03d.jpg > > I found that three or more frames must be send to the encoder before the > first jpg comes out. > > How to send one frame and then one picture out when using "qscale"
The output option -threads 1 should ensure this... > PS: the source file in.mp4 has B frames ... but this may not be possible for streams with B frames. Carl Eugen _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
