[{"id":26238,"web_url":"https://patchwork.libcamera.org/comment/26238/","msgid":"<167388575603.42371.7911015366897654333@Monstersaurus>","date":"2023-01-16T16:15:56","subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Naushir Patuck via libcamera-devel (2022-12-09 09:00:39)\n> Add a new hints flags field in the StreamConfiguration structure to allow the\n> application to specify certain intended behavior when driving libcamera.\n> Pipeline handlers are expected to look at these hint flags and may optimise\n> internal operations based on them.\n> \n> Currently, only one flag is listed, MandatoryRequestBuffer, which the\n> application sets to guarantee that a buffer will be provided in the Request for\n> each configured stream.\n> \n> Signed-off-by: Naushir Patuck \n> ---\n> include/libcamera/stream.h | 8 ++++++++\n> src/libcamera/stream.cpp | 24 ++++++++++++++++++++++++\n> 2 files changed, 32 insertions(+)\n> \n> diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h\n> index 29235ddf0d8a..1c5273004297 100644\n> --- a/include/libcamera/stream.h\n> +++ b/include/libcamera/stream.h\n> @@ -13,6 +13,8 @@\n> #include \n> #include \n> \n> +#include \n> +\n> #include \n> #include \n> #include \n> @@ -51,6 +53,12 @@ struct StreamConfiguration {\n> \n> std::optional colorSpace;\n> \n> + enum class Hint {\n> + None = 0,\n> + MandatoryRequestBuffer = (1 << 0),\n\nMight be bikeshedding, but reading later in the series I understand this\nto mean that this is a 'Mandatory Stream'.\n\nThat makes me think \"MandatoryStream\" is what we're hinting at ? But\neven that might not convey it fully, so I'm not opposed to\nMandatoryRequestBuffer.\n\nI get the idea here, but I don't currently know how we might expose to\napplications if the hints are 'possible'/'usable'/'valid'?\n\nOr maybe it doesn't matter for hints. Applications could just set them\nto say \"I'm going to do this...\" ? And it doesn't matter if the pipeline\nsupports it or not...\n\n\n> + };\n> + Flags hints;\n> +\n> Stream *stream() const { return stream_; }\n> void setStream(Stream *stream) { stream_ = stream; }\n> const StreamFormats &formats() const { return formats_; }\n> diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp\n> index 67f308157fbf..504c6d86cd04 100644\n> --- a/src/libcamera/stream.cpp\n> +++ b/src/libcamera/stream.cpp\n> @@ -349,6 +349,30 @@ StreamConfiguration::StreamConfiguration(const StreamFormats &formats)\n> * color spaces can be supported and in what combinations.\n> */\n> \n> +/**\n> + * \\enum StreamConfiguration::Hint\n> + * \\brief List of available hint flags provided by the application for a stream\n> + *\n> + * \\var StreamConfiguration::Hint::None\n> + * No hints for this stream.\n> + * \\var StreamConfiguration::Hint::MandatoryRequestBuffer\n> + * Informs the pipeline handler that the application guarantee to provide a\n\ns/guarantee/guarantees/\nor ..\nwill guarantee\n\n> + * buffer for the configured stream in the Request. This may allow the pipeline\n\n/in the Request/in every Request/\n\n> + * handler to allocate fewer (or no) buffers for internal use.\n> + */\n> +\n> +/**\n> + * \\var StreamConfiguration::hints\n> + * \\brief Application provided StreamConfiguration::Hint flags for specific\n> + * stream behavior\n> + *\n> + * Provides hints from the application to the pipeline handlers on how it\n> + * intends on handling a given configured stream. These hints may alter the\n> + * behavior of the pipeline handlers, for example, by allocating fewer buffers\n> + * for internal use if an application guarantees to always provide a buffer in\n> + * the Request for a stream.\n> + */\n> +\n> /**\n> * \\fn StreamConfiguration::stream()\n> * \\brief Retrieve the stream associated with the configuration\n> -- \n> 2.25.1\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 82CEFBD87C\n\tfor ;\n\tMon, 16 Jan 2023 16:16:01 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id ECAA6625E4;\n\tMon, 16 Jan 2023 17:16:00 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 63E4D61F01\n\tfor ;\n\tMon, 16 Jan 2023 17:15:59 +0100 (CET)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id E2D76802;\n\tMon, 16 Jan 2023 17:15:58 +0100 (CET)"],"DKIM-Signature":["v=1; 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dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"uEt6e+l9\"; dkim-atps=neutral","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<20221209090050.19441-2-naush@raspberrypi.com>","References":"<20221209090050.19441-1-naush@raspberrypi.com>\n\t<20221209090050.19441-2-naush@raspberrypi.com>","To":"Naushir Patuck ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 16 Jan 2023 16:15:56 +0000","Message-ID":"<167388575603.42371.7911015366897654333@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Kieran Bingham via libcamera-devel\n\t","Reply-To":"Kieran Bingham ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":26242,"web_url":"https://patchwork.libcamera.org/comment/26242/","msgid":"<167389089871.42371.14126090746612754535@Monstersaurus>","date":"2023-01-16T17:41:38","subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Kieran Bingham (2023-01-16 16:15:56)\n> Quoting Naushir Patuck via libcamera-devel (2022-12-09 09:00:39)\n> > Add a new hints flags field in the StreamConfiguration structure to allow the\n> > application to specify certain intended behavior when driving libcamera.\n> > Pipeline handlers are expected to look at these hint flags and may optimise\n> > internal operations based on them.\n> > \n> > Currently, only one flag is listed, MandatoryRequestBuffer, which the\n> > application sets to guarantee that a buffer will be provided in the Request for\n> > each configured stream.\n> > \n> > Signed-off-by: Naushir Patuck \n> > ---\n> > include/libcamera/stream.h | 8 ++++++++\n> > src/libcamera/stream.cpp | 24 ++++++++++++++++++++++++\n> > 2 files changed, 32 insertions(+)\n> > \n> > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h\n> > index 29235ddf0d8a..1c5273004297 100644\n> > --- a/include/libcamera/stream.h\n> > +++ b/include/libcamera/stream.h\n> > @@ -13,6 +13,8 @@\n> > #include \n> > #include \n> > \n> > +#include \n> > +\n> > #include \n> > #include \n> > #include \n> > @@ -51,6 +53,12 @@ struct StreamConfiguration {\n> > \n> > std::optional colorSpace;\n> > \n> > + enum class Hint {\n> > + None = 0,\n> > + MandatoryRequestBuffer = (1 << 0),\n> \n> Might be bikeshedding, but reading later in the series I understand this\n> to mean that this is a 'Mandatory Stream'.\n> \n> That makes me think \"MandatoryStream\" is what we're hinting at ? But\n> even that might not convey it fully, so I'm not opposed to\n> MandatoryRequestBuffer.\n> \n> I get the idea here, but I don't currently know how we might expose to\n> applications if the hints are 'possible'/'usable'/'valid'?\n> \n> Or maybe it doesn't matter for hints. Applications could just set them\n> to say \"I'm going to do this...\" ? And it doesn't matter if the pipeline\n> supports it or not...\n\nAnd to throw in a spanner / go for discussions:\n\nTrying to think about this, I would expect that the 'default' case of\nmost applications handling a stream would be such that on that single\nstream - it's expected that the stream is a mandatory stream.\n\nThat means I'm tempted to suggest this is inverted...\n\nMake the stream hint 'optional' ... and only if the stream is marked as\noptional can the buffers not be added to a request?\n\nThat way - applications for single streams get the correct behaviour 'by\ndefault' ... while more complex systems with multiple streams define\nwhich stream is likely to be only provided optionally...\n\nThoughts anyone?\n\n--\nKieran\n\n\n> \n> \n> > + };\n> > + Flags hints;\n> > +\n> > Stream *stream() const { return stream_; }\n> > void setStream(Stream *stream) { stream_ = stream; }\n> > const StreamFormats &formats() const { return formats_; }\n> > diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp\n> > index 67f308157fbf..504c6d86cd04 100644\n> > --- a/src/libcamera/stream.cpp\n> > +++ b/src/libcamera/stream.cpp\n> > @@ -349,6 +349,30 @@ StreamConfiguration::StreamConfiguration(const StreamFormats &formats)\n> > * color spaces can be supported and in what combinations.\n> > */\n> > \n> > +/**\n> > + * \\enum StreamConfiguration::Hint\n> > + * \\brief List of available hint flags provided by the application for a stream\n> > + *\n> > + * \\var StreamConfiguration::Hint::None\n> > + * No hints for this stream.\n> > + * \\var StreamConfiguration::Hint::MandatoryRequestBuffer\n> > + * Informs the pipeline handler that the application guarantee to provide a\n> \n> s/guarantee/guarantees/\n> or ..\n> will guarantee\n> \n> > + * buffer for the configured stream in the Request. This may allow the pipeline\n> \n> /in the Request/in every Request/\n> \n> > + * handler to allocate fewer (or no) buffers for internal use.\n> > + */\n> > +\n> > +/**\n> > + * \\var StreamConfiguration::hints\n> > + * \\brief Application provided StreamConfiguration::Hint flags for specific\n> > + * stream behavior\n> > + *\n> > + * Provides hints from the application to the pipeline handlers on how it\n> > + * intends on handling a given configured stream. These hints may alter the\n> > + * behavior of the pipeline handlers, for example, by allocating fewer buffers\n> > + * for internal use if an application guarantees to always provide a buffer in\n> > + * the Request for a stream.\n> > + */\n> > +\n> > /**\n> > * \\fn StreamConfiguration::stream()\n> > * \\brief Retrieve the stream associated with the configuration\n> > -- \n> > 2.25.1\n> >","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id B9267C3240\n\tfor ;\n\tMon, 16 Jan 2023 17:41:43 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 29557625E4;\n\tMon, 16 Jan 2023 18:41:43 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id D475B61F01\n\tfor ;\n\tMon, 16 Jan 2023 18:41:41 +0100 (CET)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 61CC6802;\n\tMon, 16 Jan 2023 18:41:41 +0100 (CET)"],"DKIM-Signature":["v=1; 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dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"KAFJ1km5\"; dkim-atps=neutral","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<167388575603.42371.7911015366897654333@Monstersaurus>","References":"<20221209090050.19441-1-naush@raspberrypi.com>\n\t<20221209090050.19441-2-naush@raspberrypi.com>\n\t<167388575603.42371.7911015366897654333@Monstersaurus>","To":"Naushir Patuck ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 16 Jan 2023 17:41:38 +0000","Message-ID":"<167389089871.42371.14126090746612754535@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Kieran Bingham via libcamera-devel\n\t","Reply-To":"Kieran Bingham ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":26243,"web_url":"https://patchwork.libcamera.org/comment/26243/","msgid":"<167389101492.42371.8814323026565581440@Monstersaurus>","date":"2023-01-16T17:43:34","subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Kieran Bingham (2023-01-16 17:41:38)\n> Quoting Kieran Bingham (2023-01-16 16:15:56)\n> > Quoting Naushir Patuck via libcamera-devel (2022-12-09 09:00:39)\n> > > Add a new hints flags field in the StreamConfiguration structure to allow the\n> > > application to specify certain intended behavior when driving libcamera.\n> > > Pipeline handlers are expected to look at these hint flags and may optimise\n> > > internal operations based on them.\n> > > \n> > > Currently, only one flag is listed, MandatoryRequestBuffer, which the\n> > > application sets to guarantee that a buffer will be provided in the Request for\n> > > each configured stream.\n> > > \n> > > Signed-off-by: Naushir Patuck \n> > > ---\n> > > include/libcamera/stream.h | 8 ++++++++\n> > > src/libcamera/stream.cpp | 24 ++++++++++++++++++++++++\n> > > 2 files changed, 32 insertions(+)\n> > > \n> > > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h\n> > > index 29235ddf0d8a..1c5273004297 100644\n> > > --- a/include/libcamera/stream.h\n> > > +++ b/include/libcamera/stream.h\n> > > @@ -13,6 +13,8 @@\n> > > #include \n> > > #include \n> > > \n> > > +#include \n> > > +\n> > > #include \n> > > #include \n> > > #include \n> > > @@ -51,6 +53,12 @@ struct StreamConfiguration {\n> > > \n> > > std::optional colorSpace;\n> > > \n> > > + enum class Hint {\n> > > + None = 0,\n> > > + MandatoryRequestBuffer = (1 << 0),\n> > \n> > Might be bikeshedding, but reading later in the series I understand this\n> > to mean that this is a 'Mandatory Stream'.\n> > \n> > That makes me think \"MandatoryStream\" is what we're hinting at ? But\n> > even that might not convey it fully, so I'm not opposed to\n> > MandatoryRequestBuffer.\n> > \n> > I get the idea here, but I don't currently know how we might expose to\n> > applications if the hints are 'possible'/'usable'/'valid'?\n> > \n> > Or maybe it doesn't matter for hints. Applications could just set them\n> > to say \"I'm going to do this...\" ? And it doesn't matter if the pipeline\n> > supports it or not...\n> \n> And to throw in a spanner / go for discussions:\n> \n> Trying to think about this, I would expect that the 'default' case of\n> most applications handling a stream would be such that on that single\n> stream - it's expected that the stream is a mandatory stream.\n> \n> That means I'm tempted to suggest this is inverted...\n> \n> Make the stream hint 'optional' ... and only if the stream is marked as\n> optional can the buffers not be added to a request?\n> \n> That way - applications for single streams get the correct behaviour 'by\n> default' ... while more complex systems with multiple streams define\n> which stream is likely to be only provided optionally...\n\nThis way around, we can also add a check when the request is queued. If\nany stream is not marked as optional - and doesn't have a buffer, -\nfail the request ?\n\n--\nKieran\n\n\n> \n> Thoughts anyone?\n> \n> --\n> Kieran\n> \n> \n> > \n> > \n> > > + };\n> > > + Flags hints;\n> > > +\n> > > Stream *stream() const { return stream_; }\n> > > void setStream(Stream *stream) { stream_ = stream; }\n> > > const StreamFormats &formats() const { return formats_; }\n> > > diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp\n> > > index 67f308157fbf..504c6d86cd04 100644\n> > > --- a/src/libcamera/stream.cpp\n> > > +++ b/src/libcamera/stream.cpp\n> > > @@ -349,6 +349,30 @@ StreamConfiguration::StreamConfiguration(const StreamFormats &formats)\n> > > * color spaces can be supported and in what combinations.\n> > > */\n> > > \n> > > +/**\n> > > + * \\enum StreamConfiguration::Hint\n> > > + * \\brief List of available hint flags provided by the application for a stream\n> > > + *\n> > > + * \\var StreamConfiguration::Hint::None\n> > > + * No hints for this stream.\n> > > + * \\var StreamConfiguration::Hint::MandatoryRequestBuffer\n> > > + * Informs the pipeline handler that the application guarantee to provide a\n> > \n> > s/guarantee/guarantees/\n> > or ..\n> > will guarantee\n> > \n> > > + * buffer for the configured stream in the Request. This may allow the pipeline\n> > \n> > /in the Request/in every Request/\n> > \n> > > + * handler to allocate fewer (or no) buffers for internal use.\n> > > + */\n> > > +\n> > > +/**\n> > > + * \\var StreamConfiguration::hints\n> > > + * \\brief Application provided StreamConfiguration::Hint flags for specific\n> > > + * stream behavior\n> > > + *\n> > > + * Provides hints from the application to the pipeline handlers on how it\n> > > + * intends on handling a given configured stream. These hints may alter the\n> > > + * behavior of the pipeline handlers, for example, by allocating fewer buffers\n> > > + * for internal use if an application guarantees to always provide a buffer in\n> > > + * the Request for a stream.\n> > > + */\n> > > +\n> > > /**\n> > > * \\fn StreamConfiguration::stream()\n> > > * \\brief Retrieve the stream associated with the configuration\n> > > -- \n> > > 2.25.1\n> > >","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 77DFAC3240\n\tfor ;\n\tMon, 16 Jan 2023 17:43:40 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id D5E36625D8;\n\tMon, 16 Jan 2023 18:43:39 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 921D861F01\n\tfor ;\n\tMon, 16 Jan 2023 18:43:37 +0100 (CET)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 25AA6802;\n\tMon, 16 Jan 2023 18:43:37 +0100 (CET)"],"DKIM-Signature":["v=1; 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dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"FTB713a3\"; dkim-atps=neutral","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"<167389089871.42371.14126090746612754535@Monstersaurus>","References":"<20221209090050.19441-1-naush@raspberrypi.com>\n\t<20221209090050.19441-2-naush@raspberrypi.com>\n\t<167388575603.42371.7911015366897654333@Monstersaurus>\n\t<167389089871.42371.14126090746612754535@Monstersaurus>","To":"Naushir Patuck ,\n\tlibcamera-devel@lists.libcamera.org","Date":"Mon, 16 Jan 2023 17:43:34 +0000","Message-ID":"<167389101492.42371.8814323026565581440@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Kieran Bingham via libcamera-devel\n\t","Reply-To":"Kieran Bingham ","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":26247,"web_url":"https://patchwork.libcamera.org/comment/26247/","msgid":"","date":"2023-01-17T09:02:53","subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","submitter":{"id":34,"url":"https://patchwork.libcamera.org/api/people/34/","name":"Naushir Patuck","email":"naush@raspberrypi.com"},"content":"Hi Kieran,\n\nThanks for your feedback!\n\nOn Mon, 16 Jan 2023 at 17:43, Kieran Bingham <\nkieran.bingham@ideasonboard.com> wrote:\n\n> Quoting Kieran Bingham (2023-01-16 17:41:38)\n> > Quoting Kieran Bingham (2023-01-16 16:15:56)\n> > > Quoting Naushir Patuck via libcamera-devel (2022-12-09 09:00:39)\n> > > > Add a new hints flags field in the StreamConfiguration structure to\n> allow the\n> > > > application to specify certain intended behavior when driving\n> libcamera.\n> > > > Pipeline handlers are expected to look at these hint flags and may\n> optimise\n> > > > internal operations based on them.\n> > > >\n> > > > Currently, only one flag is listed, MandatoryRequestBuffer, which the\n> > > > application sets to guarantee that a buffer will be provided in the\n> Request for\n> > > > each configured stream.\n> > > >\n> > > > Signed-off-by: Naushir Patuck \n> > > > ---\n> > > > include/libcamera/stream.h | 8 ++++++++\n> > > > src/libcamera/stream.cpp | 24 ++++++++++++++++++++++++\n> > > > 2 files changed, 32 insertions(+)\n> > > >\n> > > > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h\n> > > > index 29235ddf0d8a..1c5273004297 100644\n> > > > --- a/include/libcamera/stream.h\n> > > > +++ b/include/libcamera/stream.h\n> > > > @@ -13,6 +13,8 @@\n> > > > #include \n> > > > #include \n> > > >\n> > > > +#include \n> > > > +\n> > > > #include \n> > > > #include \n> > > > #include \n> > > > @@ -51,6 +53,12 @@ struct StreamConfiguration {\n> > > >\n> > > > std::optional colorSpace;\n> > > >\n> > > > + enum class Hint {\n> > > > + None = 0,\n> > > > + MandatoryRequestBuffer = (1 << 0),\n> > >\n> > > Might be bikeshedding, but reading later in the series I understand\n> this\n> > > to mean that this is a 'Mandatory Stream'.\n> > >\n> > > That makes me think \"MandatoryStream\" is what we're hinting at ? But\n> > > even that might not convey it fully, so I'm not opposed to\n> > > MandatoryRequestBuffer.\n> > >\n> > > I get the idea here, but I don't currently know how we might expose to\n> > > applications if the hints are 'possible'/'usable'/'valid'?\n> > >\n> > > Or maybe it doesn't matter for hints. Applications could just set them\n> > > to say \"I'm going to do this...\" ? And it doesn't matter if the\n> pipeline\n> > > supports it or not...\n> >\n> > And to throw in a spanner / go for discussions:\n> >\n> > Trying to think about this, I would expect that the 'default' case of\n> > most applications handling a stream would be such that on that single\n> > stream - it's expected that the stream is a mandatory stream.\n> >\n> > That means I'm tempted to suggest this is inverted...\n> >\n> > Make the stream hint 'optional' ... and only if the stream is marked as\n> > optional can the buffers not be added to a request?\n> >\n> > That way - applications for single streams get the correct behaviour 'by\n> > default' ... while more complex systems with multiple streams define\n> > which stream is likely to be only provided optionally...\n>\n\nSo your suggestion would be to have the hint be inverted so perhaps called\noptionalStream, and buffers must always be passed in through the requests\nfor\nstreams where optionalStream == false? That seems reasonable to me.\n\n\n>\n> This way around, we can also add a check when the request is queued. If\n> any stream is not marked as optional - and doesn't have a buffer, -\n> fail the request ?\n>\n\nWe do exactly this a few commits in - but for the current sense of the hint.\nIt should be trivial to flip the sense of this test.\n\nI'll wait a bit for any more feedback on the rest of the patches and post a\nv6\nwith this change soon.\n\nRegards,\nNaush\n\n\n>\n> --\n> Kieran\n>\n>\n> >\n> > Thoughts anyone?\n> >\n> > --\n> > Kieran\n> >\n> >\n> > >\n> > >\n> > > > + };\n> > > > + Flags hints;\n> > > > +\n> > > > Stream *stream() const { return stream_; }\n> > > > void setStream(Stream *stream) { stream_ = stream; }\n> > > > const StreamFormats &formats() const { return formats_; }\n> > > > diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp\n> > > > index 67f308157fbf..504c6d86cd04 100644\n> > > > --- a/src/libcamera/stream.cpp\n> > > > +++ b/src/libcamera/stream.cpp\n> > > > @@ -349,6 +349,30 @@ StreamConfiguration::StreamConfiguration(const\n> StreamFormats &formats)\n> > > > * color spaces can be supported and in what combinations.\n> > > > */\n> > > >\n> > > > +/**\n> > > > + * \\enum StreamConfiguration::Hint\n> > > > + * \\brief List of available hint flags provided by the application\n> for a stream\n> > > > + *\n> > > > + * \\var StreamConfiguration::Hint::None\n> > > > + * No hints for this stream.\n> > > > + * \\var StreamConfiguration::Hint::MandatoryRequestBuffer\n> > > > + * Informs the pipeline handler that the application guarantee to\n> provide a\n> > >\n> > > s/guarantee/guarantees/\n> > > or ..\n> > > will guarantee\n> > >\n> > > > + * buffer for the configured stream in the Request. This may allow\n> the pipeline\n> > >\n> > > /in the Request/in every Request/\n> > >\n> > > > + * handler to allocate fewer (or no) buffers for internal use.\n> > > > + */\n> > > > +\n> > > > +/**\n> > > > + * \\var StreamConfiguration::hints\n> > > > + * \\brief Application provided StreamConfiguration::Hint flags for\n> specific\n> > > > + * stream behavior\n> > > > + *\n> > > > + * Provides hints from the application to the pipeline handlers on\n> how it\n> > > > + * intends on handling a given configured stream. These hints may\n> alter the\n> > > > + * behavior of the pipeline handlers, for example, by allocating\n> fewer buffers\n> > > > + * for internal use if an application guarantees to always provide\n> a buffer in\n> > > > + * the Request for a stream.\n> > > > + */\n> > > > +\n> > > > /**\n> > > > * \\fn StreamConfiguration::stream()\n> > > > * \\brief Retrieve the stream associated with the configuration\n> > > > --\n> > > > 2.25.1\n> > > >\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id 9F55EBD87C\n\tfor ;\n\tTue, 17 Jan 2023 09:03:11 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id DED6C625E4;\n\tTue, 17 Jan 2023 10:03:10 +0100 (CET)","from mail-yb1-xb35.google.com (mail-yb1-xb35.google.com\n\t[IPv6:2607:f8b0:4864:20::b35])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id C7A1661EFE\n\tfor ;\n\tTue, 17 Jan 2023 10:03:09 +0100 (CET)","by mail-yb1-xb35.google.com with SMTP id c124so33135222ybb.13\n\tfor ;\n\tTue, 17 Jan 2023 01:03:09 -0800 (PST)"],"DKIM-Signature":["v=1; 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boundary=\"000000000000f128a205f271f79f\"","Subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Naushir Patuck via libcamera-devel\n\t","Reply-To":"Naushir Patuck ","Cc":"libcamera-devel@lists.libcamera.org","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":26248,"web_url":"https://patchwork.libcamera.org/comment/26248/","msgid":"<167394750126.42371.15160310746013863236@Monstersaurus>","date":"2023-01-17T09:25:01","subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Quoting Naushir Patuck (2023-01-17 09:02:53)\n> Hi Kieran,\n> \n> Thanks for your feedback!\n> \n> On Mon, 16 Jan 2023 at 17:43, Kieran Bingham <\n> kieran.bingham@ideasonboard.com> wrote:\n> \n> > Quoting Kieran Bingham (2023-01-16 17:41:38)\n> > > Quoting Kieran Bingham (2023-01-16 16:15:56)\n> > > > Quoting Naushir Patuck via libcamera-devel (2022-12-09 09:00:39)\n> > > > > Add a new hints flags field in the StreamConfiguration structure to\n> > allow the\n> > > > > application to specify certain intended behavior when driving\n> > libcamera.\n> > > > > Pipeline handlers are expected to look at these hint flags and may\n> > optimise\n> > > > > internal operations based on them.\n> > > > >\n> > > > > Currently, only one flag is listed, MandatoryRequestBuffer, which the\n> > > > > application sets to guarantee that a buffer will be provided in the\n> > Request for\n> > > > > each configured stream.\n> > > > >\n> > > > > Signed-off-by: Naushir Patuck \n> > > > > ---\n> > > > > include/libcamera/stream.h | 8 ++++++++\n> > > > > src/libcamera/stream.cpp | 24 ++++++++++++++++++++++++\n> > > > > 2 files changed, 32 insertions(+)\n> > > > >\n> > > > > diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h\n> > > > > index 29235ddf0d8a..1c5273004297 100644\n> > > > > --- a/include/libcamera/stream.h\n> > > > > +++ b/include/libcamera/stream.h\n> > > > > @@ -13,6 +13,8 @@\n> > > > > #include \n> > > > > #include \n> > > > >\n> > > > > +#include \n> > > > > +\n> > > > > #include \n> > > > > #include \n> > > > > #include \n> > > > > @@ -51,6 +53,12 @@ struct StreamConfiguration {\n> > > > >\n> > > > > std::optional colorSpace;\n> > > > >\n> > > > > + enum class Hint {\n> > > > > + None = 0,\n> > > > > + MandatoryRequestBuffer = (1 << 0),\n> > > >\n> > > > Might be bikeshedding, but reading later in the series I understand\n> > this\n> > > > to mean that this is a 'Mandatory Stream'.\n> > > >\n> > > > That makes me think \"MandatoryStream\" is what we're hinting at ? But\n> > > > even that might not convey it fully, so I'm not opposed to\n> > > > MandatoryRequestBuffer.\n> > > >\n> > > > I get the idea here, but I don't currently know how we might expose to\n> > > > applications if the hints are 'possible'/'usable'/'valid'?\n> > > >\n> > > > Or maybe it doesn't matter for hints. Applications could just set them\n> > > > to say \"I'm going to do this...\" ? And it doesn't matter if the\n> > pipeline\n> > > > supports it or not...\n> > >\n> > > And to throw in a spanner / go for discussions:\n> > >\n> > > Trying to think about this, I would expect that the 'default' case of\n> > > most applications handling a stream would be such that on that single\n> > > stream - it's expected that the stream is a mandatory stream.\n> > >\n> > > That means I'm tempted to suggest this is inverted...\n> > >\n> > > Make the stream hint 'optional' ... and only if the stream is marked as\n> > > optional can the buffers not be added to a request?\n> > >\n> > > That way - applications for single streams get the correct behaviour 'by\n> > > default' ... while more complex systems with multiple streams define\n> > > which stream is likely to be only provided optionally...\n> >\n> \n> So your suggestion would be to have the hint be inverted so perhaps called\n> optionalStream, and buffers must always be passed in through the requests\n> for\n> streams where optionalStream == false? That seems reasonable to me.\n> \n> \n> >\n> > This way around, we can also add a check when the request is queued. If\n> > any stream is not marked as optional - and doesn't have a buffer, -\n> > fail the request ?\n> >\n> \n> We do exactly this a few commits in - but for the current sense of the hint.\n> It should be trivial to flip the sense of this test.\n\nThat's true, of course the test can be done in both orientations ;-)\n\n> I'll wait a bit for any more feedback on the rest of the patches and post a\n> v6\n> with this change soon.\n\nI'll highlight this to the others to see if anyone can object or\n'prefer' one way or the other sooner rather than later.\n\n--\nKieran\n\n\n> Regards,\n> Naush\n> \n> \n> >\n> > --\n> > Kieran\n> >\n> >\n> > >\n> > > Thoughts anyone?\n> > >\n> > > --\n> > > Kieran\n> > >\n> > >\n> > > >\n> > > >\n> > > > > + };\n> > > > > + Flags hints;\n> > > > > +\n> > > > > Stream *stream() const { return stream_; }\n> > > > > void setStream(Stream *stream) { stream_ = stream; }\n> > > > > const StreamFormats &formats() const { return formats_; }\n> > > > > diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp\n> > > > > index 67f308157fbf..504c6d86cd04 100644\n> > > > > --- a/src/libcamera/stream.cpp\n> > > > > +++ b/src/libcamera/stream.cpp\n> > > > > @@ -349,6 +349,30 @@ StreamConfiguration::StreamConfiguration(const\n> > StreamFormats &formats)\n> > > > > * color spaces can be supported and in what combinations.\n> > > > > */\n> > > > >\n> > > > > +/**\n> > > > > + * \\enum StreamConfiguration::Hint\n> > > > > + * \\brief List of available hint flags provided by the application\n> > for a stream\n> > > > > + *\n> > > > > + * \\var StreamConfiguration::Hint::None\n> > > > > + * No hints for this stream.\n> > > > > + * \\var StreamConfiguration::Hint::MandatoryRequestBuffer\n> > > > > + * Informs the pipeline handler that the application guarantee to\n> > provide a\n> > > >\n> > > > s/guarantee/guarantees/\n> > > > or ..\n> > > > will guarantee\n> > > >\n> > > > > + * buffer for the configured stream in the Request. This may allow\n> > the pipeline\n> > > >\n> > > > /in the Request/in every Request/\n> > > >\n> > > > > + * handler to allocate fewer (or no) buffers for internal use.\n> > > > > + */\n> > > > > +\n> > > > > +/**\n> > > > > + * \\var StreamConfiguration::hints\n> > > > > + * \\brief Application provided StreamConfiguration::Hint flags for\n> > specific\n> > > > > + * stream behavior\n> > > > > + *\n> > > > > + * Provides hints from the application to the pipeline handlers on\n> > how it\n> > > > > + * intends on handling a given configured stream. These hints may\n> > alter the\n> > > > > + * behavior of the pipeline handlers, for example, by allocating\n> > fewer buffers\n> > > > > + * for internal use if an application guarantees to always provide\n> > a buffer in\n> > > > > + * the Request for a stream.\n> > > > > + */\n> > > > > +\n> > > > > /**\n> > > > > * \\fn StreamConfiguration::stream()\n> > > > > * \\brief Retrieve the stream associated with the configuration\n> > > > > --\n> > > > > 2.25.1\n> > > > >\n> >","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id AD006C3240\n\tfor ;\n\tTue, 17 Jan 2023 09:25:06 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 1AB5E625D8;\n\tTue, 17 Jan 2023 10:25:06 +0100 (CET)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 4B36561EFE\n\tfor ;\n\tTue, 17 Jan 2023 10:25:04 +0100 (CET)","from pendragon.ideasonboard.com\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id BED4310C;\n\tTue, 17 Jan 2023 10:25:03 +0100 (CET)"],"DKIM-Signature":["v=1; a=rsa-sha256; c=relaxed/simple; d=libcamera.org;\n\ts=mail; t=1673947506;\n\tbh=MtUOBuv4sOXIgNsQVFZ/v4BCPu8Kku2aN06XDnMxRZs=;\n\th=In-Reply-To:References:To:Date:Subject:List-Id:List-Unsubscribe:\n\tList-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:\n\tFrom;\n\tb=Rpi5qgszvQ4Dq+9DUoIK+/2S1ckrSUci0MOJgJlTJos9TAyjTy9/lWGRDKgoWv3yj\n\t9IzOJ1qLjSYalTt6PWaiYAuazBFsjoz/UYDeiFZY40Isyf64cAzut6qKc+AyZGQXu5\n\tjmlTTSxrr912K5xkERnqMjA5PXT0rCYihnywKxhUMwltwF714BS541nXGnapdy/4WH\n\tTEFIDwIOFYQTD4ZempobkncRYi9Iq7e0X6h2XE8DEjQ021Vx9rQOyHWnK6LzY7rbHI\n\tP4vC8N3hbkOpq5ag4WGzUXlpD36FIqwq+YJAQV2JffiWwKOVTB28Mj97HrB3mCPqsu\n\tuw+41jjzjUe/Q==","v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1673947503;\n\tbh=MtUOBuv4sOXIgNsQVFZ/v4BCPu8Kku2aN06XDnMxRZs=;\n\th=In-Reply-To:References:Subject:From:Cc:To:Date:From;\n\tb=aDAaEOUMo0BRfdXujdKJuADX67P6kwtUzyaYOco44xWWWv6GEyc7KAFeY9ne46wP9\n\t9ZIb51MEEIIql4Oj+dZiHaNhAJt+J5BnaCzUJOSyNqk8CSCYFgJIuvtjf93Y39ncEU\n\t962YNUbtir632AnO1XH84d1MRzgxaVOQzRNGz4KI="],"Authentication-Results":"lancelot.ideasonboard.com; dkim=pass (1024-bit key; \n\tunprotected) header.d=ideasonboard.com\n\theader.i=@ideasonboard.com\n\theader.b=\"aDAaEOUM\"; dkim-atps=neutral","Content-Type":"text/plain; charset=\"utf-8\"","MIME-Version":"1.0","Content-Transfer-Encoding":"quoted-printable","In-Reply-To":"","References":"<20221209090050.19441-1-naush@raspberrypi.com>\n\t<20221209090050.19441-2-naush@raspberrypi.com>\n\t<167388575603.42371.7911015366897654333@Monstersaurus>\n\t<167389089871.42371.14126090746612754535@Monstersaurus>\n\t<167389101492.42371.8814323026565581440@Monstersaurus>\n\t","To":"Naushir Patuck ","Date":"Tue, 17 Jan 2023 09:25:01 +0000","Message-ID":"<167394750126.42371.15160310746013863236@Monstersaurus>","User-Agent":"alot/0.10","Subject":"Re: [libcamera-devel] [PATCH v4 01/12] libcamera: stream: Add\n\tstream hints to StreamConfiguration","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","From":"Kieran Bingham via libcamera-devel\n\t","Reply-To":"Kieran Bingham ","Cc":"libcamera-devel@lists.libcamera.org","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]