[Libav-user] How to convert "-q:v 1" to API form

[Arthur Muller]

Carl,

I don't have the data in front of my anymore, but the difference was from 1.5Mb to about 4Mb.

But I suspect my quality problem is not related to this issue; it's probably coming from my convertion rgb->yuv. When using the command line version of ffmpeg this conversion is done inside ffmpeg, whereas in my code I do the conversion myself and then put the result in OutputStream->frame which then gets written. I just started from one of the examples that used yuv data and massaged the code.

I guess I'm going to have to use sws_scale to let ffmpeg do this transformation.

The funny thing is that if I dump my converted yuv images to a file, or use ffmpeg to generate a .yuv file rather than an mp4, the resulting files are exactly the same size; but my image is properly displayed with a yuv player but the ffmpeg file is not.

I could post all of my data here - the png files, my yuv file, and the yuv file generated by the ffmpeg command line. But I'm reluctant to fill all subscriber's mailboxes with this data. If you want I can send you the data on a separate email out of consideration to other subscribers.

Thanks again.

-Arthur