On 03/19/2014 12:18 AM, m silverstri wrote: > I am using v4l2 m2m framework to develop a resize driver. I have an > image , pass it to the driver and it generated a resize output image. > > My v4l2 sequence is > 1. qbuf OUTPUT, CAPTURE > 2. stream on OUTPUT, CAPTURE > 3. dqbuf OUTPUT, CAPTURE > 4. stream off OUTPUT, CAPTURE > > this works if i have a full frame of image before i start streaming. > > But what I only have partial buffers when I start streaming, how can I > qbuf more buffer after I 'stream on' OUTPUT, You can't. Each buffer passed to the driver must contain a full image. So your application needs some logic to keep filling a buffer until it is complete and only then do you issue the QBUF. Regards, Hans > > I try this, but this fail > 1. qbuf OUTPUT, CAPTURE (I qbuf only partial OUTPUT) > 2. stream on OUTPUT, CAPTURE > > // do this in a loop: > 3. dqbuf OUTPUT (I want to queue more OUTPUT as they become available) > 4. qbuf OUTPUT > > // now I am done, I want to dqbuf my output > 5. dqbuf CAPTURE > 6. stream off OUTPUT, CAPTURE > > I try to do dqbuf/qbuf OUTPUT in step #3, #4 above, but it just stuck > in dqbuf OUTPUT. > > How can I queue more of my input data after I stream on? > > Thank you. > -- > 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 > -- 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
