Re: [RFC PATCH] [media] coda: Use S_PARM to set nominal framerate for h.264 encoder

From: Frédéric Sureau
Date: Thu Jan 15 2015 - 11:59:55 EST


Hi Philipp,

Le 22/12/2014 17:00, Philipp Zabel a écrit :
The encoder needs to know the nominal framerate for the constant bitrate
control mechanism to work. Currently the only way to set the framerate is
by using VIDIOC_S_PARM on the output queue.

Signed-off-by: Philipp Zabel<p.zabel@xxxxxxxxxxxxxx>
---
drivers/media/platform/coda/coda-common.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)

diff --git a/drivers/media/platform/coda/coda-common.c b/drivers/media/platform/coda/coda-common.c
index 39330a7..63eb510 100644
--- a/drivers/media/platform/coda/coda-common.c
+++ b/drivers/media/platform/coda/coda-common.c
@@ -803,6 +803,32 @@ static int coda_decoder_cmd(struct file *file, void *fh,
return 0;
}
+static int coda_g_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
+{
+ struct coda_ctx *ctx = fh_to_ctx(fh);
+
+ a->parm.output.timeperframe.denominator = 1;
+ a->parm.output.timeperframe.numerator = ctx->params.framerate;
+
Maybe a->parm.output.capability should be set to V4L2_CAP_TIMEPERFRAME here.
I think it is required by GStreamer V4L2 plugin.
+ return 0;
+}
+
+static int coda_s_parm(struct file *file, void *fh, struct v4l2_streamparm *a)
+{
+ struct coda_ctx *ctx = fh_to_ctx(fh);
+
+ if (a->type == V4L2_BUF_TYPE_VIDEO_OUTPUT &&
+ a->parm.output.timeperframe.numerator != 0) {
+ ctx->params.framerate = a->parm.output.timeperframe.denominator
+ / a->parm.output.timeperframe.numerator;
+ }
+
+ a->parm.output.timeperframe.denominator = 1;
+ a->parm.output.timeperframe.numerator = ctx->params.framerate;
+
+ return 0;
+}
+
static int coda_subscribe_event(struct v4l2_fh *fh,
const struct v4l2_event_subscription *sub)
{
@@ -843,6 +869,9 @@ static const struct v4l2_ioctl_ops coda_ioctl_ops = {
.vidioc_try_decoder_cmd = coda_try_decoder_cmd,
.vidioc_decoder_cmd = coda_decoder_cmd,
+ .vidioc_g_parm = coda_g_parm,
+ .vidioc_s_parm = coda_s_parm,
+
.vidioc_subscribe_event = coda_subscribe_event,
.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
};
Thanks for the patch!
Fred
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