From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from EUR05-AM6-obe.outbound.protection.outlook.com (mail-am6eur05on2083.outbound.protection.outlook.com [40.107.22.83]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 299223FB31; Fri, 10 Jan 2025 02:25:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.22.83 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736475920; cv=fail; b=bhdutUBY1Jahu27USpl50Mz45JIIbkZwOTMO5vK1Q17k7sFitLl+gi2oF7WewhhwcQq+HMiqC6iBoFRAvVzcLw9YM9ubp6a9iTOxa5eBYU9UpMcaoEJLI3eCdf7+gKGqvV9LbXDq5Rkjq45oVzQdOBjmti0Xf9acoV7uQKxqO4E= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736475920; c=relaxed/simple; bh=c9JBVzt3EfM8Jct6t5V+d3rfUXWS/pCH7epy6nbIv6U=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=hodEQ4XpZptIP84U1XSoZ3hRn4UZOYpgQPRVSG7E5Q7XkC1jOu5c5YqukEYAVcrIuDXktLxjCbsU0sB8kbRlFF2dCD2XG7qbh04An3Ds3LZTwfojpOXMddmTaF9BqT1IZFTZqR57iArVGw2uOgDUsNKjgkbn8Obu4Rg3cwhV7RY= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=oss.nxp.com; spf=pass smtp.mailfrom=oss.nxp.com; dkim=pass (2048-bit key) header.d=NXP1.onmicrosoft.com header.i=@NXP1.onmicrosoft.com header.b=b7c9dRfh; arc=fail smtp.client-ip=40.107.22.83 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=oss.nxp.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.nxp.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=NXP1.onmicrosoft.com header.i=@NXP1.onmicrosoft.com header.b="b7c9dRfh" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=rTHuW5c5GM2s58k/q0sUA7JDgvdK+GFjKP2scR4OQTbh23g/aljuCPxnHoouB/F0ZHN0imumn/O9rDxdj1D9W79cjILIlEXzZ5KZFhsoY4Cr6JzlE0hwTIROeu8brBhM3W70RsJchGJJko/DZqQqKPToYkxhN82bxPKKNhE/RCV/uLJog5i6qTBqTZnLhyMjk/YgYuBXODyNramqnIXEaNMbEinicjcDeJtMbORbRVe42WixRq7CQRmDYdp8UwDLpGE/Mys4pcpwYc2FUR3krNeD0GQEgARZYqJHEozbEC8zozvatYZveyJe7M1Vi/V/KCsKTAok4Q8y5b6Vlk4+eg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=1IwgAwzjR6D4MYF8zB1C5w9zUGdzGRCQqw+TGjqlxLM=; b=asUyLjtJMTcCUMc5VVypGWfS5D8OJtfvFjc7NsX76wVgeVV9+BHrlpJKYDilAf/5TvurDHA/QSprSyDvqoFMcpgWtFZZguOCHK/NvYBaSsmRKXpc/fjiSDepq7rDYMmNFphHc22ktoqEhDsxvOn3lOhoVypIJEXxzt+aG1C/j2zx1eCQqkPNaYy58j4SC5J7Of4dD3nZS5qPQMRrrGZ2oTY2WrmS+VJPzCzAL7vPLSsvue6JW/+crht3rTUACk+rcceRAPZic9dE+HVRj6g/czdr2LbpPDVBovWHFZoXVu81jEAUlMC6qM+++Jd9aagDFTYUWa246VW5lbFHwY7tQA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oss.nxp.com; dmarc=pass action=none header.from=oss.nxp.com; dkim=pass header.d=oss.nxp.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=NXP1.onmicrosoft.com; s=selector1-NXP1-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=1IwgAwzjR6D4MYF8zB1C5w9zUGdzGRCQqw+TGjqlxLM=; b=b7c9dRfhjYt5XKp7RJvhlz7nSSZAycuzklFpgUjLv7rxJ8udZ1UoTImauO0qAsZxXHoD06vOeIkx5hzM2FWtJ63XGgv4nJRb4Nv+cOC82uDzZ5crH6e4LJr8kQMRKh92V4u7V0xG7WU97/eKHlWCBYm5oheYVzG8FbIbx+s9zr8Zp5QLMrM2AdxSx8cm22BgkTYxMuYlt7zohbv2pesr7TcL4EKJ7A2jNYNU7cewfLYAZecwOApF5NpzLxhcxDhJU2oYZ57gTbmHGwXLyvg5uKyn/jbuviZ4lSQR/4d3u7yxyn8bMtFYTjzrDbltyeDGayVxGDHJ7m1Je4R2gVO+8w== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=oss.nxp.com; Received: from PAXPR04MB8254.eurprd04.prod.outlook.com (2603:10a6:102:1cd::24) by AM7PR04MB6872.eurprd04.prod.outlook.com (2603:10a6:20b:106::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8335.13; Fri, 10 Jan 2025 02:25:14 +0000 Received: from PAXPR04MB8254.eurprd04.prod.outlook.com ([fe80::2755:55ac:5d6f:4f87]) by PAXPR04MB8254.eurprd04.prod.outlook.com ([fe80::2755:55ac:5d6f:4f87%6]) with mapi id 15.20.8335.012; Fri, 10 Jan 2025 02:25:13 +0000 Message-ID: <008e32de-d0ac-4835-9024-c59fddc320de@oss.nxp.com> Date: Fri, 10 Jan 2025 10:25:03 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] media: docs: dev-decoder: Trigger dynamic source change for colorspace To: Nicolas Dufresne , mchehab@kernel.org, hverkuil-cisco@xs4all.nl Cc: shawnguo@kernel.org, robh+dt@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, xiahong.bao@nxp.com, eagle.zhou@nxp.com, tao.jiang_2@nxp.com, imx@lists.linux.dev, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20250107053622.1287461-1-ming.qian@oss.nxp.com> <1c1bb1b3-7e58-4a49-83bb-2c560cd66858@oss.nxp.com> From: "Ming Qian(OSS)" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SG2PR04CA0151.apcprd04.prod.outlook.com (2603:1096:4::13) To PAXPR04MB8254.eurprd04.prod.outlook.com (2603:10a6:102:1cd::24) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PAXPR04MB8254:EE_|AM7PR04MB6872:EE_ X-MS-Office365-Filtering-Correlation-Id: 6aca39bd-c8b7-45e9-21e0-08dd311e0362 X-MS-Exchange-SharedMailbox-RoutingAgent-Processed: True X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016; X-Microsoft-Antispam-Message-Info: =?utf-8?B?VkN2Mkd2RW1UZ0hCN2U4b1FiTE5ZZjFrb2hCRWlBSHUzajdVTmU0TkRBRXZv?= =?utf-8?B?clphUi91ZG54K1BsRW1IT1F1VEtKZjBKZGNMUjNoS1NkU09FRUh1aE02ZTFl?= =?utf-8?B?ckFtNDI2aEZNTHFmeHVZQmlEU1dvcXV4dUh1VWVxS1JFeE1Ua2dTY3pUMllj?= =?utf-8?B?bTZHS0xJMEtXUnV5bHh2a056d1djV3dlTDU0VWVOVVJuWUxtclZWRjBjei81?= =?utf-8?B?ZjUyOVZxL2NKeEo4ODhiVnJKTmNONDl4UFN2U2VqdDg0VWMyTE5uZjZhNEQw?= =?utf-8?B?UVp4MVMveElSNDZmMjhJYlU0dUJXRkRWNzZ4cHh3RWlLSHNVSmpFYmpLS0xx?= =?utf-8?B?aFZQWThYSzhtNExpMXQxMEhla1dodzAvcmNPb3JRVVlqMEZ5Mjhud3VJQVNw?= =?utf-8?B?SmQ5anlMUDBDV3ZFMkkwdjhKZmhIdlltLzRDdytwY3RYZ1R5bnhLOWJ5SmhB?= =?utf-8?B?QWMzTnZOcW1wb2tpdjNxbGpIZktpTUF3MURwR2JBaDFTK09uUVZUWnBtbWNS?= =?utf-8?B?VmkxVHI2VjJuaU9rRHlOclRueXh2RXE0QWlHRHpqMkdOdExsTVNiRzNMdFR0?= =?utf-8?B?SGhxd2VNcjEwSEViQ1ZpQzVDYzNJY2RKaERlUE1QZzFpUHJPYSsxTlM4OVJv?= =?utf-8?B?VkNXTTVITHp5eFB3MkpHVThZbzVCWmpGWmg3S3hLMm9FN2JIcjl1Y3l1UnBu?= =?utf-8?B?dWRPelFHZzk3UGJvZnBEMTVtZEZRNUozNXlwaG1xWnhlK0ZsYkdRSXBsUWMr?= =?utf-8?B?NVU5bG4zb0RPSm5qUU00dVhNOUFReGNBL0VtdVNsWUEydGpoNEpIUmVrODU4?= =?utf-8?B?ZEkrZElkYWtaQk9BTGhqWnFhOVBUOTNBZkNCNUpDT3BIeFRUZ20zTnpDUnpa?= =?utf-8?B?cjhrZlFSSG1wNHVNYnljeURDNFo1czVveHYwRndBYUNERW1oZVJnODFSRXNx?= =?utf-8?B?L0F1djJaZjBHSHVDbHl1OHpsc0QwN2JjYmRKVHpXZUxoVjBuaHcrR2VmV0E0?= =?utf-8?B?eEc4czkwdFN1N3Q3L01RUVViL00wRCs3WWRVekZDeTY2eVRPTEQxT3NBVXNj?= =?utf-8?B?MjhvRXNZWm54SGRxWTFueUx4UER5azZreWZBYm1aNHlkYTIzMkpjNU1RVHUr?= =?utf-8?B?L2hkbU1lRWZYejJ0NjBEdDNsWVpkY2R4V2JnRW9McitpMnR6UVFLd2llYlpQ?= =?utf-8?B?M1ZNSUExVnNNRzRCTjZZVE4rTTFEWmZsOWkyUENQSXRPb3Z2UERpaDBaMVU0?= =?utf-8?B?UXZmdkxtVXdnbEgrN0ZxbjQvMUR1K0srR2Y1R1lnbEoyR0p6em9jaHViZmJQ?= =?utf-8?B?U2lCajBiWVVWL2xBRjFiMnM5OGtUNDkyNG5jN1RGQkJ3Vms4NTVIcGlyQkh4?= =?utf-8?B?YnlVRHFGeHZ6KzBna2tzTW1RaVUya1U5ODJ3bXNyeDlUMkVYWkRQeGRQQ3Nu?= =?utf-8?B?NlhCMVpPbDRSZzkvaXFTYzVWei9nQ0FCTFREK004YTlFUHZYUGVZZVJlc3BP?= =?utf-8?B?cHlOM0RYMVduT1V3cnMvNEFkT3ZrUit5VVZhSFgrZEZGWFFUekIxTDVvMnpo?= =?utf-8?B?S0cySW9pQWdCUlJ1Z1hCdzc1VGtXSHJuclk1aEpldDVJbFpLUWl5NFZkUUdq?= =?utf-8?B?enZ0YmhaWk44Uy9TbFg4WG1ZU1BPV2tZVVo2ZklSemNLVy9maXlwWUJkc3NG?= =?utf-8?B?dTExbU10eGx5SEtyam5IcnJBY2hlOXJjaTZzOWYyaWU0OWF0YVJYNnY0OWkv?= =?utf-8?B?UlNkT0c5dzdwSC80R3N3NndRL05VMTI2NlgvL3I3SHFkN2hmZEM2aFhIVTVY?= =?utf-8?B?NjJ3NVRXNGxMbzNFTGVJTC84aHFnbkp2SURHRFVGdzJDMmI0WGE2TTFKZm1Z?= =?utf-8?Q?l5ovsVmtw4iI+?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PAXPR04MB8254.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?UFcvSGE0THFnYnVwVjA5NXB4WnNwKzVzdjZCaGl4MnFaTDBuZ0F5a2RuaUYr?= =?utf-8?B?M0VseldNK3FDZU4rTUgvcVlqdThCMStaUVlHQjFpTFRYZDM3NU0wMHcvTmd0?= =?utf-8?B?MTk0NTh3U3JYOXVRYWgwNGF1MGR3Y1drS3cyU3BUd21USUh2cCtJRXhCWWlM?= =?utf-8?B?VDJhSk9oMkw0U0FnYmhCYi9ZZDFUUXNFdklhZjdRQmZ5YVU4RFViMURZRE03?= =?utf-8?B?L1gwaGg1YUdiL01EcWFsYXpzR3dwL3Noc25BbFRkWkpRaWh1ZFhDdDZZK1Zw?= =?utf-8?B?MmdVaXJqa3krUUsxREVFS0pjRG5rS0ZralNKUldTYXJKVTRucUg3SGduUWRU?= =?utf-8?B?b1o4a3FYLzNvU01sNDZvcVhncEJJVmRBaENxV09FOWpQZ3lGdW9zNEhWRHdm?= =?utf-8?B?VnJYVytSamlnWlVwSFkwekpuTmxaRjV3cnB5VDI0VXhFYTFsckxGcDJxYkdB?= =?utf-8?B?elFVT3FRc1d0OW94ZndoRUwzLyt2K3Z5dkNjSStFbUI4T2s4UzJGUFNDUXIr?= =?utf-8?B?MVJua3JHSXdTVCtnZ1JiSk1DbTBucG9KNXh6M2VSL0wwN2R4SVRsSnBVMDJP?= =?utf-8?B?ckR5aU0xTkl2RkJiWUxFQVBWVlZpR0EwVG5CcHNYR1kxMVNZOHRBcmxVRkxq?= =?utf-8?B?anEranFEMFRGVUVRLzJxbnh2YjJEMzRETjRFbU5VL213YTFvaVJUaEpyaVRG?= =?utf-8?B?OXRibE5FRUFJNGV5My9QM29peVJTcnFKa2xZcmgrQWJsckdvTjlNQkUxN1Zl?= =?utf-8?B?UHptVHZXNzVlSzkybEIyS0REZmtiL08vUnVmbG5STmpLQTN2QlZXaGFoMHV3?= =?utf-8?B?Zkk5bkFaWUYvLzNSb2dzT3NCYWNXUHN0UUJyV2RlR3h2YmV6clFKTGxObUd0?= =?utf-8?B?c1FOS0ZraGVHZ1dYMzc2UUM5Y0UrWXV5YTEwQ2R0UUFZRG54TGY1Zng3U0F4?= =?utf-8?B?d2g4U1lCTnVyY0o1K2Y0aGt3bkwzdUppbXJWaDFzbGlKK0FFdkcvMFJGd2RN?= =?utf-8?B?T1BnMVFxcDhQRTRhdVBjaHZPNk1nL0NrQnpzZnRqWTVhNUxueDBiMkh1V0Zh?= =?utf-8?B?YVZIblh6UDJlcjhUVXZDdm5wQzhuYlBKU2NjVS9pTUN0aXp3Q0x5SjdPQmVX?= =?utf-8?B?WHNtZkRDY1JFaFI4c21KYnI0NlViLy9uQ0VDdW1RYlVqSFlUcDBycmdGb1c4?= =?utf-8?B?Y0hMMk1YcWpXMVRhUTRRU3BwRFMwSFZuV2NoRTJSVEgwcGtVU3dNOVNyNmZj?= =?utf-8?B?UXpZQTJXWlRzT09rTW1kZnd4TUJCZDdmOWkyOFUrVW5XaGQ1NVhKdm9TQzEx?= =?utf-8?B?UXl5VitVWVkreWtMTnBlS1h3VlJpeSs5Z2I4d2t1Vm96NlloNUpBNEtJYkZT?= =?utf-8?B?TDQvKzVENGpkTytPVTJoZzFKQ3ZycFlqTDFIbEhETjBCMlVLOUhwZHZGQkZJ?= =?utf-8?B?cjdXcjZkaVlBSjE0ZDc3cFFUcUJQTC9wU2ZrZVJjTDBLNDJWdEtCL1dmR1V4?= =?utf-8?B?UGdHOHl3LzNHT1BmRVNHTmNjYjZTbTliczdJMHVwcnQ0ck41eXhpaWM3blZH?= =?utf-8?B?dU1sT1Zwa013T0RVV25HakNsNzNEbEplN3BleU9BVFlJV2lRZnJjTFBRc3I5?= =?utf-8?B?SXhRdEVGTldyU1lkVHVZU2hoZ2djZ0hPRm5nTGhqdGdPTHZ2VTBUUFBzVFVu?= =?utf-8?B?TzNWVXNidWh4MHU4KysyUzMzSWMvN0FoajZLeFMxSnYxSHpSR3Z3UkVJaW1T?= =?utf-8?B?eFB0dVlNbENVdWVxLzlWQ2FtVTNLZ2tPYU1YTnZqUmk3Y1diTCs4Tys1OEpC?= =?utf-8?B?UTcwRksyV2g3Mm95QVRXREdqRVBBMDlRYitLUFB2bjBvbEpEeXRxWmJwdE95?= =?utf-8?B?aG9MclJYOGdqYVB1UWl2dnczNFcrRWdzNllzZnZ4VmNlU0pQWUZSYW5nV2V5?= =?utf-8?B?QVBkak9qUS8zSFJKZ29yMlNIL0JoQ2xjTnJxelZKaGhOM0FyWCtZYUx0bHpR?= =?utf-8?B?K0NVQWIvaTVhUXhkSWdEVEdoZUkvQTFKVFZVUlRDUi9LYkJoTXJqMTZvVlpw?= =?utf-8?B?WlZ0d3M1TGNkaC9HUlc4dFZXVWdDbHZqamdkVnVYcTQyUGhXTUZJNlYwRlZ5?= =?utf-8?Q?84IZymAtAFGR+ZyGT8Nh8l8Iv?= X-OriginatorOrg: oss.nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6aca39bd-c8b7-45e9-21e0-08dd311e0362 X-MS-Exchange-CrossTenant-AuthSource: PAXPR04MB8254.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Jan 2025 02:25:13.8087 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: EoXjcSGxpBi6TIMQJh9dOyUyoa97+swpXZZOsKw6MTsO8LfluP9F23de9XMlDwXS5kq97qbLPJPqyMsaxqM7Hw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: AM7PR04MB6872 Hi Nicolas, On 2025/1/10 0:03, Nicolas Dufresne wrote: > Le jeudi 09 janvier 2025 à 10:25 +0800, Ming Qian(OSS) a écrit : >> Hi Nicolas, >> >> On 2025/1/9 3:34, Nicolas Dufresne wrote: >>> Hi, >>> >>> Le mardi 07 janvier 2025 à 14:36 +0900, Ming Qian a écrit : >>>> If colorspace changes, the client needs to renegotiate the pipeline, >>>> otherwise the decoded frame may not be displayed correctly. >>>> >>>> If it can trigger an source change event, then client can switch to the >>>> correct stream setting. And each frame can be displayed properly. >>>> >>>> So add colorspace as a trigger parameter for dynamic resolution change. >>>> >>>> Signed-off-by: Ming Qian >>>> --- >>>> Documentation/userspace-api/media/v4l/dev-decoder.rst | 4 +++- >>>> 1 file changed, 3 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/Documentation/userspace-api/media/v4l/dev-decoder.rst b/Documentation/userspace-api/media/v4l/dev-decoder.rst >>>> index ef8e8cf31f90..49566569ad26 100644 >>>> --- a/Documentation/userspace-api/media/v4l/dev-decoder.rst >>>> +++ b/Documentation/userspace-api/media/v4l/dev-decoder.rst >>>> @@ -932,7 +932,9 @@ reflected by corresponding queries): >>>> >>>> * the minimum number of buffers needed for decoding, >>>> >>>> -* bit-depth of the bitstream has been changed. >>>> +* bit-depth of the bitstream has been changed, >>>> + >>>> +* colorspace of the bitstream has been changed. >>> >>> Did you really mean colorspace in the way this term is used in V4L2 ? What we >>> want this event to be used for is when the capture storage size or amount >>> changes, perhaps you mean when the capture pixelformat changes ? This will >>> indeed happen if you change the bit-depth, subsampling (not mentioned here >>> either) or change the way colors are repsented (RGB, YCbCr, etc.). >>> >> >> I am referring to the following attributes in v4l2_pix_fmt: >> __u32 colorspace; /* enum v4l2_colorspace */ >> __u32 ycbcr_enc; /* enum v4l2_ycbcr_encoding */ >> __u32 quantization; /* enum v4l2_quantization */ >> __u32 xfer_func; /* enum v4l2_xfer_func */ >> >> For decoder, they are parsed from the sequence header. >> Our issue is that when only these properties change in the middle of >> some bitstream, but not the resolution or dpb amount, the decoder needs >> to nofity the user. As these properties are in v4l2_pix fmt, user need >> to get/set them via VIDIOC_G_FMT/VIDIOC_S_FMT. >> So in my opinion, it's reasonable to nitify user a source change event, >> then user can call v4l_g_fmt() and renegotiate the pipeline. >> >> Apart from this, all I can think of is that user call v4l_g_fmt() before >> dequeueing each frame. But I don't think this is a good idea. > > I agree an event is better then this ... > >> >> As these properties are parts of the v4l2_format, I think it's >> reasonable to handle their changes via the dynamic source change flow. >> >> We're currently facing some real cases on android. >> >> Or do you have any good suggestions? Then I can give a try. > > But I think this is too much to put this under the changes > > #define V4L2_EVENT_SRC_CH_RESOLUTION (1 << 0) > > We include under "resolution" everything that affects the allocation. So perhaps > for this one we can introduce > > #define V4L2_EVENT_SRC_CH_COLORSPACE (2 << 0) > > Of course, userspace implementation will be needed. Anyone one else have an > opinion here ? > > Nicolas > I agree with you. Defining a new colorspace changes does make things more clearer. And it can avoid buffer reallocations. Then it will not affect the existing flow. Maybe I can prepare a v2 patch after doing some basic verification. Thanks, Ming >> >> Thanks, >> Ming >> >>>> >>>> Whenever that happens, the decoder must proceed as follows: >>>> >>> >