Hi On Tue, 12 Apr 2011, Kassey Lee wrote: > hi, Guennadi: > a lot of sensors support JPEG output. > 1) bytesperline is defined by sensor timing. > 2) and sizeimage is unknow for jpeg. > > how about for JPEG > 1) host driver gets bytesperline from sensor driver. > 2) sizeimage refilled by host driver after dma transfer done( a > frame is received) > thanks. How is this done currently on other V4L2 drivers? To transfer a frame you usually first do at least one of S_FMT and G_FMT, at which time you already have to report sizeimage to the user - before any transfer has taken place. Currently with soc-camera it is already possible to override sizeimage and bytesperline from the host driver. Just set them to whatever you need in your try_fmt and they will be kept. Not sure how you want to do that, if you need to first read in a frame - do you want to perform some dummy frame transfer? You might not even have any buffers queued yet, so, it has to be a read without writing to RAM. Don't such compressed formats just put a value in sizeimage, that is a calculated maximum size? Thanks Guennadi > 2011/4/11 Guennadi Liakhovetski <g.liakhovetski@xxxxxx>: > > Hi Janusz > > > > On Sat, 9 Apr 2011, Janusz Krzysztofik wrote: > > > >> Since commit 0e4c180d3e2cc11e248f29d4c604b6194739d05a, bytesperline and > >> sizeimage memebers of v4l2_pix_format structure have no longer been > >> calculated inside soc_camera_g_fmt_vid_cap(), but rather passed via > >> soc_camera_device structure from a host driver callback invoked by > >> soc_camera_set_fmt(). > >> > >> OMAP1 camera host driver has never been providing these parameters, so > >> it no longer works correctly. Fix it by adding suitable assignments to > >> omap1_cam_set_fmt(). > > > > Thanks for the patch, but now it looks like many soc-camera host drivers > > are re-implementing this very same calculation in different parts of their > > code - in try_fmt, set_fmt, get_fmt. Why don't we unify them all, > > implement this centrally in soc_camera.c and remove all those > > calculations? Could you cook up a patch or maybe several patches - for > > soc_camera.c and all drivers? > > > > Thanks > > Guennadi > > > >> > >> Signed-off-by: Janusz Krzysztofik <jkrzyszt@xxxxxxxxxxxx> > >> --- > >> drivers/media/video/omap1_camera.c | 6 ++++++ > >> 1 file changed, 6 insertions(+) > >> > >> --- linux-2.6.39-rc2/drivers/media/video/omap1_camera.c.orig 2011-04-06 14:30:37.000000000 +0200 > >> +++ linux-2.6.39-rc2/drivers/media/video/omap1_camera.c 2011-04-09 00:16:36.000000000 +0200 > >> @@ -1292,6 +1292,12 @@ static int omap1_cam_set_fmt(struct soc_ > >> pix->colorspace = mf.colorspace; > >> icd->current_fmt = xlate; > >> > >> + pix->bytesperline = soc_mbus_bytes_per_line(pix->width, > >> + xlate->host_fmt); > >> + if (pix->bytesperline < 0) > >> + return pix->bytesperline; > >> + pix->sizeimage = pix->height * pix->bytesperline; > >> + > >> return 0; > >> } > >> > >> > > > > --- > > Guennadi Liakhovetski, Ph.D. > > Freelance Open-Source Software Developer > > http://www.open-technology.de/ > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-media" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
