diff options
| -rw-r--r-- | drivers/media/video/ivtv/ivtv-ioctl.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/media/video/ivtv/ivtv-ioctl.c b/drivers/media/video/ivtv/ivtv-ioctl.c index 8696527ab134..208fb54842f2 100644 --- a/drivers/media/video/ivtv/ivtv-ioctl.c +++ b/drivers/media/video/ivtv/ivtv-ioctl.c @@ -509,7 +509,6 @@ static int ivtv_try_fmt_sliced_vbi_cap(struct file *file, void *fh, struct v4l2_ static int ivtv_try_fmt_vid_out(struct file *file, void *fh, struct v4l2_format *fmt) { struct ivtv_open_id *id = fh; - struct ivtv *itv = id->itv; s32 w = fmt->fmt.pix.width; s32 h = fmt->fmt.pix.height; int field = fmt->fmt.pix.field; @@ -517,7 +516,22 @@ static int ivtv_try_fmt_vid_out(struct file *file, void *fh, struct v4l2_format w = min(w, 720); w = max(w, 2); - h = min(h, itv->is_out_50hz ? 576 : 480); + /* Why can the height be 576 even when the output is NTSC? + + Internally the buffers of the PVR350 are always set to 720x576. The + decoded video frame will always be placed in the top left corner of + this buffer. For any video which is not 720x576, the buffer will + then be cropped to remove the unused right and lower areas, with + the remaining image being scaled by the hardware to fit the display + area. The video can be scaled both up and down, so a 720x480 video + can be displayed full-screen on PAL and a 720x576 video can be + displayed without cropping on NTSC. + + Note that the scaling only occurs on the video stream, the osd + resolution is locked to the broadcast standard and not scaled. + + Thanks to Ian Armstrong for this explanation. */ + h = min(h, 576); h = max(h, 2); if (id->type == IVTV_DEC_STREAM_TYPE_YUV) fmt->fmt.pix.field = field; |