Just one more question about this. The v4l2 encoder, which is the last element in my processing chain, is an H.264 encoder that has to know about previous frames to encode. For these kind of devices it is very useful to know whether a frame has been lost to introduce a skip frame and improve the encoding process. But, with the current approach we don't have any way to communicate this to the device. One option would be that the user specified a sequence number when issuing VIDIOC_QBUF at the output queue so that the device could detect any discontinuity and introduce a skip frame. But this would break your rule that sequence number introduced at the output queue has to be ignored by the driver. -- Javier Martin Vista Silicon S.L. CDTUC - FASE C - Oficina S-345 Avda de los Castros s/n 39005- Santander. Cantabria. Spain +34 942 25 32 60 www.vista-silicon.com -- 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