From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752781AbbALPik (ORCPT ); Mon, 12 Jan 2015 10:38:40 -0500 Received: from lb3-smtp-cloud6.xs4all.net ([194.109.24.31]:57702 "EHLO lb3-smtp-cloud6.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751699AbbALPij (ORCPT ); Mon, 12 Jan 2015 10:38:39 -0500 Message-ID: <54B3EA71.9020005@xs4all.nl> Date: Mon, 12 Jan 2015 16:38:25 +0100 From: Hans Verkuil User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.3.0 MIME-Version: 1.0 To: Philipp Zabel CC: Kamil Debski , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, =?UTF-8?B?RnLDqWTDqXJpYyBTdXJlYXU=?= , Jean-Michel Hautbois , Nicolas Dufresne Subject: Re: [RFC PATCH] [media] coda: Use S_PARM to set nominal framerate for h.264 encoder References: <1419264000-11761-1-git-send-email-p.zabel@pengutronix.de> <54B3E24B.5030403@xs4all.nl> <1421076959.3081.63.camel@pengutronix.de> In-Reply-To: <1421076959.3081.63.camel@pengutronix.de> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/12/2015 04:35 PM, Philipp Zabel wrote: > Hi Hans, > > thank you for the comments! > > Am Montag, den 12.01.2015, 16:03 +0100 schrieb Hans Verkuil: >> On 12/22/2014 05:00 PM, Philipp Zabel wrote: >>> 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 >>> --- >>> 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); >>> + >> >> If a->type != V4L2_BUF_TYPE_VIDEO_OUTPUT, then return -EINVAL. > > If the decoder can retrieve the framerate from the stream, wouldn't it > make sense to allow G_PARM for a->type == V4L2_BUF_TYPE_VIDEO_CAPTURE ? Certainly. But that wasn't in the patch :-) Regards, Hans > >> Ditto for s_parm. > > Will do. > >>> + a->parm.output.timeperframe.denominator = 1; >>> + a->parm.output.timeperframe.numerator = ctx->params.framerate; >>> + >>> + 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; >> >> Hmm, what happens if the denominator is 1 and the numerator is 2? >> You probably want to clamp ctx->params.framerate to the range of allowed framerates. >> And at least ensure a framerate > 0. >> >> Also check with v4l2_compliance! You'd have caught at least the missing a->type check. > > Oh dear, I need to improve my v4l-utils update habits. I'll fix this > patch and resend it. > > regards > Philipp >