On Tue, 5 Aug 2003, Billy Biggs wrote:
>> >> Then some cameras supported by qc-usb can deliver MJPEG compressed frames
>> >> and I have used
>> >> #define VIDEO_PALETTE_MJPEG (('q'<<8) | 2) /* Grab video in compressed MJPEG format */
>> No. Looks like it's in 4:2:2 packed format (YUY2, I guess). I didn't write
> mpeg2dec only has 4:2:0 conversion code, no 4:2:2 code, since MPEG2
You're right. Looks like it's 4:2:0 planar, not 4:2:2 packed. This is the
relevant conversion function (where yuv2rgb_func converts two scanlines):
/* Convert YUV image to RGB */
static void qc_mjpeg_yuv2rgb(struct qc_mjpeg_data *md, void *dst, u8 *py,
u8 *pu, u8 *pv,
int width, int height, int rgb_stride, int y_stride, int uv_stride)
{
height >>= 1;
do {
md->yuv2rgb_func(md, py, py + y_stride, pu, pv, dst, ((u8 *)dst) + rgb_stride, width);
py += 2 * y_stride;
pu += uv_stride;
pv += uv_stride;
dst = ((u8 *)dst) + 2 * rgb_stride;
} while (--height);
}
> It sounds like you might be using the wrong conversion function.
No, the function is right, I was just reading it wrong.
