From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:20198 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794Ab2JGNDe (ORCPT ); Sun, 7 Oct 2012 09:03:34 -0400 Message-ID: <50717DFF.8000004@redhat.com> Date: Sun, 07 Oct 2012 15:05:03 +0200 From: Hans de Goede MIME-Version: 1.0 To: =?UTF-8?B?RnJhbmsgU2Now6RmZXI=?= CC: linux-media@vger.kernel.org Subject: Re: [PATCH] libv4lconvert: clarify the behavior and resulting restrictions of v4lconvert_convert() References: <1349282919-15332-1-git-send-email-fschaefer.oss@googlemail.com> In-Reply-To: <1349282919-15332-1-git-send-email-fschaefer.oss@googlemail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Frank, Thanks for all your work on this. I'm afraid that atm I'm very busy with work, so I don't have time to review your patches. I hope to find some time for this next weekend... Regards, Hans On 10/03/2012 06:48 PM, Frank Schäfer wrote: > Signed-off-by: Frank Schäfer > --- > lib/include/libv4lconvert.h | 20 ++++++++++++++++++-- > 1 Datei geändert, 18 Zeilen hinzugefügt(+), 2 Zeilen entfernt(-) > > diff --git a/lib/include/libv4lconvert.h b/lib/include/libv4lconvert.h > index 167b57d..509655e 100644 > --- a/lib/include/libv4lconvert.h > +++ b/lib/include/libv4lconvert.h > @@ -89,8 +89,24 @@ LIBV4L_PUBLIC int v4lconvert_needs_conversion(struct v4lconvert_data *data, > const struct v4l2_format *src_fmt, /* in */ > const struct v4l2_format *dest_fmt); /* in */ > > -/* return value of -1 on error, otherwise the amount of bytes written to > - dest */ > +/* This function does the following conversions: > + - format conversion > + - cropping > + if enabled: > + - processing (auto whitebalance, auto gain, gamma correction) > + - horizontal/vertical flipping > + - 90 degree (clockwise) rotation > + > + NOTE: the last 3 steps are enabled/disabled depending on > + - the internal device list > + - the state of the (software emulated) image controls > + > + Therefore this function should > + - not be used when getting the frames from libv4l > + - be called only once per frame > + Otherwise this may result in unintended double conversions ! > + > + Returns the amount of bytes written to dest an -1 on error */ > LIBV4L_PUBLIC int v4lconvert_convert(struct v4lconvert_data *data, > const struct v4l2_format *src_fmt, /* in */ > const struct v4l2_format *dest_fmt, /* in */ >