On Wed, Dec 9, 2020 at 8:26 AM Nicolas Dufresne <nicolas@xxxxxxxxxxxx> wrote: > > Le lundi 30 novembre 2020 à 11:10 -0800, Fritz Koenig a écrit : > > When can bitrate, etc., be changed by VIDIOC_TRY_EXT_CTRLS? Any time > > during encode? Only before VIDIOC_STREAMON? > > > > My understanding is that VIDIOC_STREAMON should start actually > > processing frames, everything before then is configuration. If > > something needs to be adjusted then VIDIOC_STREAMOFF should be called, > > changes made, and then VIDIOC_STREAMON again. Is this correct? > > Bitrate is paticular is expected to be changeable at runtime (in STREAMON > state). But a firmware may not support it, hence a driver is allowed to return > EBUSY (iirc). > > Changing the bitrate without producing a new keyframe (whath cycling > STREAMOFF/ON would cause) is a highly common use case while encoding for live > streaming. > Thanks. That makes sense. > This of course should be documented. > > > > > I didn't see anything in the documentation about this. > > > > Thanks. > > > > -Fritz > >
