On Monday 07 October 2013 01:25 PM, Hans Verkuil wrote:
Hi Archit,
I've got a few comments below...
On 09/06/2013 12:12 PM, Archit Taneja wrote:
VPE is a block which consists of a single memory to memory path which can
perform chrominance up/down sampling, de-interlacing, scaling, and color space
conversion of raster or tiled YUV420 coplanar, YUV422 coplanar or YUV422
interleaved video formats.
We create a mem2mem driver based primarily on the mem2mem-testdev example.
The de-interlacer, scaler and color space converter are all bypassed for now
to keep the driver simple. Chroma up/down sampler blocks are implemented, so
conversion beteen different YUV formats is possible.
Each mem2mem context allocates a buffer for VPE MMR values which it will use
when it gets access to the VPE HW via the mem2mem queue, it also allocates
a VPDMA descriptor list to which configuration and data descriptors are added.
Based on the information received via v4l2 ioctls for the source and
destination queues, the driver configures the values for the MMRs, and stores
them in the buffer. There are also some VPDMA parameters like frame start and
line mode which needs to be configured, these are configured by direct register
writes via the VPDMA helper functions.
The driver's device_run() mem2mem op will add each descriptor based on how the
source and destination queues are set up for the given ctx, once the list is
prepared, it's submitted to VPDMA, these descriptors when parsed by VPDMA will
upload MMR registers, start DMA of video buffers on the various input and output
clients/ports.
When the list is parsed completely(and the DMAs on all the output ports done),
an interrupt is generated which we use to notify that the source and destination
buffers are done.
The rest of the driver is quite similar to other mem2mem drivers, we use the
multiplane v4l2 ioctls as the HW support coplanar formats.
Signed-off-by: Archit Taneja <arc...@ti.com>
---
drivers/media/platform/Kconfig | 16 +
drivers/media/platform/Makefile | 2 +
drivers/media/platform/ti-vpe/Makefile | 5 +
drivers/media/platform/ti-vpe/vpe.c | 1750 ++++++++++++++++++++++++++++++
drivers/media/platform/ti-vpe/vpe_regs.h | 496 +++++++++
include/uapi/linux/v4l2-controls.h | 4 +
6 files changed, 2273 insertions(+)
create mode 100644 drivers/media/platform/ti-vpe/Makefile
create mode 100644 drivers/media/platform/ti-vpe/vpe.c
create mode 100644 drivers/media/platform/ti-vpe/vpe_regs.h
<snip>
+
+static int vpe_g_fmt(struct file *file, void *priv, struct v4l2_format *f)
+{
+ struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
+ struct vpe_ctx *ctx = file2ctx(file);
+ struct vb2_queue *vq;
+ struct vpe_q_data *q_data;
+ int i;
+
+ vq = v4l2_m2m_get_vq(ctx->m2m_ctx, f->type);
+ if (!vq)
+ return -EINVAL;
+
+ q_data = get_q_data(ctx, f->type);
+
+ pix->width = q_data->width;
+ pix->height = q_data->height;
+ pix->pixelformat = q_data->fmt->fourcc;
+ pix->colorspace = q_data->colorspace;
+ pix->num_planes = q_data->fmt->coplanar ? 2 : 1;
+
+ for (i = 0; i < pix->num_planes; i++) {
+ pix->plane_fmt[i].bytesperline = q_data->bytesperline[i];
+ pix->plane_fmt[i].sizeimage = q_data->sizeimage[i];
+ }
+
+ return 0;
+}
+
+static int __vpe_try_fmt(struct vpe_ctx *ctx, struct v4l2_format *f,
+ struct vpe_fmt *fmt, int type)
+{
+ struct v4l2_pix_format_mplane *pix = &f->fmt.pix_mp;
+ struct v4l2_plane_pix_format *plane_fmt;
+ int i;
+
+ if (!fmt || !(fmt->types & type)) {
+ vpe_err(ctx->dev, "Fourcc format (0x%08x) invalid.\n",
+ pix->pixelformat);
+ return -EINVAL;
+ }
+
+ pix->field = V4L2_FIELD_NONE;
+
+ v4l_bound_align_image(&pix->width, MIN_W, MAX_W, W_ALIGN,
+ &pix->height, MIN_H, MAX_H, H_ALIGN,
+ S_ALIGN);
+
+ pix->num_planes = fmt->coplanar ? 2 : 1;
+ pix->pixelformat = fmt->fourcc;
+ pix->colorspace = fmt->fourcc == V4L2_PIX_FMT_RGB24 ?
You do this only for capture. Output sets the colorspace, so try_fmt should
leave the colorspace field untouched for the output direction.
+ V4L2_COLORSPACE_SRGB : V4L2_COLORSPACE_SMPTE170M;
The input to the VPE block can be various YUV formats, and the VPE can
generate both RGB and YUV formats.
So, I guess the output(V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) side has
choice only to set V4L2_COLORSPACE_SMPTE170M. And in the
capture(V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE) capture side we have both
SRG and SMPTE170M options.
One thing I am not clear about is whether the userspace application has
to set the colorspace in the v4l2 format for OUTPUT or CAPTURE or both?
From what I understood, the code should be as below.
For output:
if (!pix->colorspace)
pix->colorspace = V4L2_COLORSPACE_SMPTE170M;
And for capture:
pix->colorspace = fmt->fourcc == V4L2_PIX_FMT_RGB24 ?
V4L2_COLORSPACE_SRGB : V4L2_COLORSPACE_SMPTE170M;
Does this look correct?
Zero pix->priv as well:
pix->priv = 0;
pix here is of the type v4l2_pix_format_mplane, so there isn't a private
field here.
Thanks,
Archit
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