Have tested motion with my SAA7130 based card, a 16 channel 4 chip card.
Everything worked OK when using 4 inputs, trying to setup RoundRobin.
To get it to work I had to set the roundrobin_skip to 12, if setting lower the picture wasn't in "sync". The picture started half way down and then wrapped.

Looking at the source for the driver and reading the chip doc I found that changing some registers can make this work better. I changed the driver as below and now i'm able to set the roundrobin_skip to 2 instead. This was a great improvment.

The problem with this is that I have changed the V4L2_STD_PAL format, and is not able to configure if I want to use this "fast switch" mode or "normal". Is there a way to define a new one e.g. V4L2_PAL_FASTSWITCH and have motion to use that instead of "PAL"?

Best regards
Dag Erlandsson

static struct saa7134_tvnorm tvnorms[] = {
                .name          = "PAL", /* autodetect */
                .id            = V4L2_STD_PAL,

// DE           .sync_control  = 0x18, // Track video signal with some inertia, surviving noisy signal and missing sync pulses
                .sync_control  = 0x09, // Immediate mode e.g. catch after source switch, Fieldrate 50Hz/625lines
                .luma_control  = 0x40,
// DE           .chroma_ctrl1  = 0x81, // Normal time constant for Chroma gain adjustment
                .chroma_ctrl1  = 0x85, // Fast color detection for special app. e.g. observation cameras
                .chroma_gain   = 0x2a,
                .chroma_ctrl2  = 0x06,
// DE           .vgate_misc    = 0x1c, // 3 field for color standard detection
                .vgate_misc    = 0x0c, // 1 Field color detection