#!/usr/bin/env -S retext --preview

Magewell PRO capture to Transport Stream

This application reads audio and video from a Magewell PRO capture card and muxes them into a Transport Stream.

If bitstream audio is detected it will be muxed directly into the resulting Transport Stream. LPCM audio will be encoded as AC3 and then muxed.

Both AC3 and EAC3 are supported if the source device outputs them as a bitstream.

More than two channels of LPCM are not currently supported. Adding such support should be easy but I do not have a source device to test with.

The Magewell driver provides V4L2 and ALSA interfaces to the card. This application by-passes those interfaces and talks directly to it via the Magewell API. A big advantage to this is you don't have to figure out which /dev/videoX or ALSA "device" is needed to make it work. The other advantage is that a raw bitstream can be captured. Unfortunately, the Magewell API depends on ALSA so we have to link it even though it is not used.

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Caveats

The Magewell PRO capture cards capture raw audio and video. The video (at least) needs compressed and it is up to the Linux PC to do that. The only practical way of accomplishing this is with GPU assist. Intel QSV & VAAPI and nVidia nvenc are supported.

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Versions

• release/v1

    - Supports hevc_nvenc and h264_nvenc for video codec.
    - Does not handle audio or video changes at all, which can usually be worked around by using the '-n' (no audio) option.
  

• release/v2

    - Adds support for hevc_qsv and h264_qsv for video codec.
    - Does a decent job at handling audio and video changes midstream.
  

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Magewell driver

The Magewell driver can be found here: https://www.magewell.com/downloads/pro-capture#/driver/linux-x86

Install the driver:

mkdir -p ~/src/Magewell
cd ~/src/Magewell
gtar -xzvf ~/Downloads/ProCaptureForLinux_4390.tar.gz
cd ProCaptureForLinux_4236/
sudo ./install.sh

With newer kernels, it may be necessary to add "ibt=off" to the kernel parameters:

sudo grubby --update-kernel=All --args="ibt=off"
sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Testing the Magewell driver

Find ALSA audio input:

arecord -L

Pick an audio input

export AUDIO=sysdefault:CARD=HDMI_3

After you figure out which video device is appropriate, select it:

export VIDEO=/dev/video3

The following command should work to capture audio and video even with AC3 as long as you have loaded an appropriate EDID onto the Magewell card:

ffmpeg -ac 2 -f alsa -i $AUDIO -c:a copy -f wav - | ffmpeg -f wav -i pipe:0 -f v4l2 -i $VIDEO -c:v libx264 -map 0:a -map 1:v cap.ts

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Installing this application

Building

The Magewell SDK can be found here: https://www.magewell.com/sdk

Download the Linux version. Then unpacket it

mkdir -p ~/src/Magewell/
cd ~/src/Magewell/
gtar -xzvf ~/Download/Magewell_Capture_SDK_Linux_3.3.1.1313.tar.gz

In the Magewell SDK directory, grab the source for this application:

cd ~/src/Magewell/Magewell_Capture_SDK_Linux_3.3.1.131
git clone https://github.com/jpoet/Magewell2TS.git

If you place the Magewell2TS source somewhere else, you will need to edit Magewell2TS/helpers/FindMagewell.cmake and teach it how to find the Magewell SDK.

Dependencies

Fedora:

sudo dnf install -y make gcc gcc-c++ libstdc++-devel libv4l-devel patch kernel-devel alsa-lib-devel v4l-utils-devel-tools systemd-devel

Ubuntu:

sudo apt-get install build-essential libv4l-dev cmake libudev-dev nvidia-cuda-toolkit

Intel

For Intel QSV you will also need oneVPL libs. For example:

sudo dnf install oneVPL-devel intel-media-driver

See https://www.intel.com/content/www/us/en/developer/articles/guide/onevpl-installation-guide.html for more information.

Nvidia

For nVidia you will want to have the closed source driver installed as well as cuda libs. For example:

sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm https://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm`
sudo dnf install akmod-nvidia xorg-x11-drv-nvidia-cuda xorg-x11-drv-nvidia-cuda-libs vdpauinfo

FFmpeg

FFmpeg is also required. If you want eac3 to work, then a minimum of version 6.1 shoudl be used.

sudo dnf install ffmpeg-devel

or

apt-get install ffmpeg-dev

Building the application

cd ~/src/Magewell/Magewell_Capture_SDK_Linux_3.3.1.131/Magewell2TS

Use CMake to compile and install:

mkdir build
cd build
cmake ..
make
sudo make install

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Running

The application provides help via --help or -h:

magewellpro2ts -h
magewellpro2ts --list
magewellpro2ts -i 1 -m -n | mpv -

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MythTV

The easiest way to use this with MythTV is to create an "External Recorder" configuration file. Something like (/home/mythtv/etc/magewell-2.conf):

[VARIABLES]
INPUT=1
DEVICE=roku1
TUNER=/usr/local/bin/roku-control.py --device %DEVICE%

#DEVICE=onn1
#TUNER=/usr/local/bin/adb-control.py --device %DEVICE%

CODEC=hevc_qsv -q 25
#CODEC=h264_nvenc -q 20


[RECORDER]
# The recorder command to execute.  %URL% is optional, and
# will be replaced with the channel's "URL" as defined in the
# [TUNER/channels] (channel conf) configuration file
command="/usr/local/bin/magewellpro2ts -i %INPUT% -s 100 -m -c %CODEC%"

# cleanup="/home/mythtv/mythtvguide/adb-1-finished.sh"
cleanup="%TUNER% --reset"

# Used in logging events, %ARG% are replaced from the channel info
desc="%DEVICE%-%INPUT%"

[TUNER]
# An optional CONF file which provides channel details.  If it does not
# exist, then channel changes are not supported.
#channels=/home/mythtv/etc/adb-channels.conf

# If [TUNER/command] is provided, it will be executed to "tune" the
# channel. A %URL% parameter will be substituted with the "URL" as
# defined in the [TUNER/channels] configuration file

command="%TUNER% --waitafter 1 --sourceid %SOURCEID% --channum %CHANNUM% --recordid %RECORDID%"
# newepisodecommand="%TUNER% --touch %CHANNUM% &"
#ondatastart="%TUNER% --device %DEVICE% --wait 2 --keys down"

timeout=30000

Then configure a MythTV External Recorder capture card with an appropriate command such as:

/usr/local/bin/mythexternrecorder --conf /home/myth/etc/magewell-1.conf

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EDID

If you want to allow AC3 and/or EAC3 then a different EDID needs written to the Magewell card. This data does not survive a reboot, though, so you may want to setup systemd to load the EDID. This can be done in the same service file used to start mythbackend, for example:

Create a service file (/etc/systemd/system/mythbackend.service):

[Unit]
Description=MythTV backend service
Wants=dev-hvr2250_1.device dev-hvr2250_2.device
After=full-internet.target mysqld.service dev-hvr2250_1.device dev-hvr2250_2.device 
OnFailure=notify-email@%i.service

[Service]
Type=simple
Environment=MYTHCONFDIR=/home/mythtv/.mythtv
Environment=HOME=/home/mythtv
LimitCORE=infinity
User=mythtv
PermissionsStartOnly=true
ExecStartPre=/usr/local/bin/magewellpro2ts --wait-for 4 -i 1 -s 100 -w /home/mythtv/etc/EDID/ProCaptureHDMI-EAC3.bin
ExecStartPre=/usr/local/bin/magewellpro2ts --wait-for 4 -i 2 -s 100 -w /home/mythtv/etc/EDID/ProCaptureHDMI-EAC3.bin
ExecStartPre=/usr/local/bin/magewellpro2ts --wait-for 4 -i 3 -s 100 -w /home/mythtv/etc/EDID/ProCaptureHDMI-EAC3.bin
ExecStartPre=/usr/local/bin/magewellpro2ts --wait-for 4 -i 4 -s 100 -w /home/mythtv/etc/EDID/ProCaptureHDMI-EAC3.bin

ExecStart=/usr/local/bin/mythbackend -q --syslog none --logpath /var/log/mythtv -v channel,record
RestartSec=5
Restart=on-failure


[Install]
WantedBy=multi-user.target

That will load the eac3 EDID and set the volume level to 100.

Multi GPU systems

If you have both Intel and nVidia GPUs enabled in the same system, it can result in confusion:

$ vainfo
Trying display: wayland
libva info: VA-API version 1.16.0
libva info: User environment variable requested driver 'nvidia'
libva info: Trying to open /usr/lib64/dri/nvidia_drv_video.so
libva info: va_openDriver() returns -1
vaInitialize failed with error code -1 (unknown libva error),exit

To get it to show for the intel, you must use an env variable of either i965 or iHD:

$ LIBVA_DRIVER_NAME=iHD vainfo
Trying display: wayland
libva info: VA-API version 1.16.0
libva info: User environment variable requested driver 'iHD'
libva info: Trying to open /usr/lib64/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_16
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.16 (libva 2.16.0)
vainfo: Driver version: Intel iHD driver for Intel(R) Gen Graphics - 22.5.4 ()
vainfo: Supported profile and entrypoints
      VAProfileNone                   : VAEntrypointVideoProc
      VAProfileNone                   : VAEntrypointStats
... etc.

Intel Arc

The Intel Arc GPUs may need a new version of the linux firmware

git clone git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git