From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A0319481DD; Sun, 1 Feb 2026 23:17:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769987830; cv=none; b=iX0ij2r+F8Bvi+9qwsnCvRgi+r5JGTWaZalavYCK7/LZ1/ybCF52TaoCZWPHRcS4BQn2Th9v1UlPeM6UIdAtyUxEfj4aLqRfqwgO2jT2XLvSi4BRtxPu+TTXfMyiDzqfat+1g9LLbvGsUmJ6zuPmdWJiCiG53J4PGV2T6HBwH/M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769987830; c=relaxed/simple; bh=RdOT8+Y+yiwtt66D2dg3A7FAu7IL2cpBnVTher2Wu1Q=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=k5UCmtGY/5gEdtS6MC1rk7DdEvetLqPDPNyKCvoa7p722ogxMpr1ctue9HsVIT/3uv202jDqOGKfLy/oXBD+RuWLNcgv28lAgv2KqAS0Srt6OkjOOqAB+ECLHDKr4zXs+ByuVdhkzAbx3qyO9+B3VoDVqO/Nqn6Q5CZgZTnZq9o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EUtyyCqC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EUtyyCqC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD847C4CEF7; Sun, 1 Feb 2026 23:17:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769987830; bh=RdOT8+Y+yiwtt66D2dg3A7FAu7IL2cpBnVTher2Wu1Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=EUtyyCqCXhdc9ubZtXMYY017HNTDCvJ/q12oadvWcwK2COYclzciPAIGKXssFk6uL KT1/XTR21vc35ckYgVOVMspNzSFyqDYZSnzcvekmIPzFtVPkZiI0B583+SXDLdQDg8 9xxlD2YUCoqYeIJfFkDlXVTluvH0E6OApjNPoD6o8uq884z0fntt+vsZjBLnpquTnd J+fgLaXfisGZVPTJyRhBHiMR6zCao7zrcJHgNNyNdwQrkH0AZSEJbAzmVJ3koOLxcK IBuJxPa9g5mAyOikH/IaWNyiBaOaChKJB3vQhzajl0U5j31/+ZyyzeSmJV8CXrgYQL O13ULAmjhg+Rw== Date: Mon, 2 Feb 2026 00:17:04 +0100 From: Mauro Carvalho Chehab To: Oleksandr Natalenko Cc: Laurent Pinchart , Jarkko Sakkinen , linux-media@vger.kernel.org, jani.nikula@linux.intel.com, anisse@astier.eu, Mauro Carvalho Chehab , Hans Verkuil , Sakari Ailus , Jacopo Mondi , Ricardo Ribalda , open list Subject: Re: [RFC PATCH] media: Virtual camera driver Message-ID: <20260202001704.2419778a@foz.lan> In-Reply-To: <5073898.31r3eYUQgx@natalenko.name> References: <20260201133342.335680-1-jarkko@kernel.org> <12828248.O9o76ZdvQC@natalenko.name> <20260201212133.1849a49e@foz.lan> <5073898.31r3eYUQgx@natalenko.name> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Sun, 01 Feb 2026 21:26:24 +0100 Oleksandr Natalenko wrote: > On ned=C4=9Ble 1. =C3=BAnora 2026 21:21:33, st=C5=99edoevropsk=C3=BD stan= dardn=C3=AD =C4=8Das Mauro Carvalho Chehab wrote: > > > My use-case for v4l2loopback is to stream a webcam from one machine t= o another (with the help of ffmpeg). Is this covered by something other tha= n v4l2loopback now? =20 > >=20 > > Using a kernel driver for something like that is a bad idea and may end > > causing dead lock problems. You may also have performance issues and > > high network traffic. The best solution for it is to use a proper > > userspace tool, like obs: > >=20 > > https://obsproject.com/kb/linux-installation =20 >=20 > Ignoring the fact I've never had any performance issues, and I don't care= much about how big the traffic is in my isolated VLAN dedicated to this sp= ecific task, the OBS solution still uses v4l2loopback under the hood. Could= you please tell me what do I miss in this regard? No. At the machine with the camera, obs can read from a V4L input, generate a mpeg TS stream, and listen to a UDP port (for instance).=20 At the remote machine, you can just pass the URL to ffmpeg. No need to use OOT kernel drivers.=20 Btw, there are other solutions that work the same way, like motioneye. Thanks, Mauro From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 542882D8DDD; Sun, 1 Feb 2026 23:17:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769987847; cv=none; b=k/x2j+9SM+BIzmQwKAyFLzjxxiFzvAoNuPbzXQCYwzlHmWosHTKUu8AAFhbYz+5Oshqhkky6ZmXJ3NOOxFWzLt920o2yGQuz2bgGz8cQ1/3QtT8HNTOsHIE41lAXl9ySLMboCaC/ycLY/Ga6UEW4xb+RwveL8jLQqpQJ7C20cKI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769987847; c=relaxed/simple; bh=wgw8AoOY0i0p+4ce6cgfsbCbwuuC+MkOqtN27UYaR3w=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CXgDL/gdSamNIWx1r8QPePKsNl4T71e5lhiRR16YPH99Sd8/IEAPZoqGCubScJAm8yo6kUrn+646QEq+ueG3Mz8nAyVjRDCSkFjwVfyHwQ499PiQBUdEzZAz2i+LB+GhZnZj+X8i1PQ7C4UyKkhRd3Oqr5im700OS+NJey4dgsw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=allW24Pc; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="allW24Pc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68B6FC4CEF7; Sun, 1 Feb 2026 23:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1769987847; bh=wgw8AoOY0i0p+4ce6cgfsbCbwuuC+MkOqtN27UYaR3w=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=allW24PcwwlIyoK+hZ1gFo7K4p6yeepCJm5CAMPsSAkRGOQJbKayNOk4LGqu1/3DZ tgrW2F5HwotTpt6uvs8pck9XrKhyNGuZUB9kmeNmjhx07SM4RXtuHFCO4R3pzMN+Yx R0JtcQ/n+L7skUUSMLv/477iccKkcOVXa56icAdupuQLahAdYuRbTiAWgYZf19K6DI 6M4eopu+eL6+ZHH9tNwRurXxOZoG8cyA4l5kZkd6q7k+l57qCzEeFZalNgiy3CQZsr iLt5Faq4AZ92cS8wsaQ9XzQ5FQHPNilEirXKb5EVHhHDg9O2yM6wnhX3Omad0F+JQJ DQw6F0MFR84Zg== Date: Mon, 2 Feb 2026 00:17:20 +0100 From: Mauro Carvalho Chehab To: Oleksandr Natalenko Cc: Laurent Pinchart , Jarkko Sakkinen , linux-media@vger.kernel.org, jani.nikula@linux.intel.com, anisse@astier.eu, Mauro Carvalho Chehab , Hans Verkuil , Sakari Ailus , Jacopo Mondi , Ricardo Ribalda , open list Subject: Re: [RFC PATCH] media: Virtual camera driver Message-ID: <20260202001704.2419778a@foz.lan> In-Reply-To: <5073898.31r3eYUQgx@natalenko.name> References: <20260201133342.335680-1-jarkko@kernel.org> <12828248.O9o76ZdvQC@natalenko.name> <20260201212133.1849a49e@foz.lan> <5073898.31r3eYUQgx@natalenko.name> X-Mailer: Claws Mail 4.3.1 (GTK 3.24.51; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Message-ID: <20260201231720.8R88fQZaE7CTceGsjQdOzJWm9c_sUPLDV81YAyPyzHo@z> On Sun, 01 Feb 2026 21:26:24 +0100 Oleksandr Natalenko wrote: > On ned=C4=9Ble 1. =C3=BAnora 2026 21:21:33, st=C5=99edoevropsk=C3=BD stan= dardn=C3=AD =C4=8Das Mauro Carvalho Chehab wrote: > > > My use-case for v4l2loopback is to stream a webcam from one machine t= o another (with the help of ffmpeg). Is this covered by something other tha= n v4l2loopback now? =20 > >=20 > > Using a kernel driver for something like that is a bad idea and may end > > causing dead lock problems. You may also have performance issues and > > high network traffic. The best solution for it is to use a proper > > userspace tool, like obs: > >=20 > > https://obsproject.com/kb/linux-installation =20 >=20 > Ignoring the fact I've never had any performance issues, and I don't care= much about how big the traffic is in my isolated VLAN dedicated to this sp= ecific task, the OBS solution still uses v4l2loopback under the hood. Could= you please tell me what do I miss in this regard? No. At the machine with the camera, obs can read from a V4L2 input, generate a mpeg TS stream, and listen to a UDP port (for instance).=20 At the remote machine, you can just pass the URL to ffmpeg. No need to use OOT kernel drivers.=20 Btw, there are other solutions that work the same way, like motioneye. Thanks, Mauro