From a56c100af7cd5d6036c1728b8427c562c8e634c1 Mon Sep 17 00:00:00 2001 From: Philipp Date: Sat, 19 Oct 2024 18:06:10 +0200 Subject: [PATCH] Added image capturing and text drawing. --- src/dm_camera.f90 | 235 +++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 211 insertions(+), 24 deletions(-) diff --git a/src/dm_camera.f90 b/src/dm_camera.f90 index a91aa6e..ecc2aa9 100644 --- a/src/dm_camera.f90 +++ b/src/dm_camera.f90 @@ -1,12 +1,14 @@ ! Author: Philipp Engel ! Licence: ISC module dm_camera - !! Module for handling IP cameras and webcams using FFmpeg. + !! Module for taking still images from RTSP video streams and USB webcams, + !! using FFmpeg. !! - !! On Linux, install the packages `ffmpeg` and `v4l-utils`: + !! On Linux, install the packages `ffmpeg`, `graphicsmagick`, and + !! `v4l-utils`: !! !! ``` - !! $ sudo apt-get install ffmpeg v4l-utils + !! $ sudo apt-get install ffmpeg graphicsmagick v4l-utils !! ``` !! !! List connected USB cameras: @@ -19,37 +21,222 @@ module dm_camera !! /dev/media0 !! ``` !! - !! Capture a still image from the camera attached to `/dev/video0`, add a - !! timestamp to the bottom right corner, and save it to `/tmp/image.jpg`: + !! GraphicsMagick is required to add text to captured camera frames. For a + !! list of all supported font names, run: !! !! ``` - !! $ ffmpeg -f video4linux2 -i /dev/video0 -vframes 1 -video_size 640x480 \ - !! -vf "drawtext=fontfile=DejaVuMono.ttf:fontsize=12:fontcolor=white:box=1:boxcolor=black:text='%{localtime}':x=(w-text_w):y=(h-text_h)" \ - !! -hide_banner -loglevel error -nostats -y \ - !! /tmp/image.jpg + !! $ gm convert -list font + !! Path: /usr/local/lib/GraphicsMagick/config/type-windows.mgk + !! + !! Name Family Style Stretch Weight + !! -------------------------------------------------------------------------------- + !! Arial Arial normal normal 400 + !! Arial-Black Arial normal normal 900 + !! Arial-Bold Arial normal normal 700 + !! Arial-Bold-Italic Arial italic normal 700 + !! Arial-Italic Arial italic normal 400 + !! ... + !! ``` + !! + !! The default font used is `Lucida-Console` in 12 points size. + !! + !! The following example captures an image from an attached USB webcam at + !! `/dev/video0` and adds a timestamp in ISO 8601 to it: + !! + !! ```fortran + !! character(len=*), parameter :: IMAGE_PATH = '/tmp/image.jpg' + !! + !! integer :: rc + !! type(camera_type) :: camera + !! + !! camera = camera_type(input='/dev/video0', device=CAMERA_DEVICE_V4L) + !! + !! rc = dm_camera_capture(camera, IMAGE_PATH) + !! if (dm_is_error(rc)) call dm_error_out(rc) + !! + !! rc = dm_camera_image_add_text(IMAGE_PATH, text=dm_time_now()) + !! if (dm_is_error(rc)) call dm_error_out(rc) !! ``` - use :: dm_file, only: FILE_PATH_LEN - use :: dm_mime, only: MIME_LEN, MIME_GIF, MIME_PNG, MIME_JPEG + use :: dm_error + use :: dm_file + use :: dm_string + use :: dm_time implicit none (type, external) private ! FFmpeg devices/formats. integer, parameter, public :: CAMERA_DEVICE_NONE = 0 !! No device selected. - integer, parameter, public :: CAMERA_DEVICE_V4L = 1 !! Video4Linux2. - integer, parameter, public :: CAMERA_DEVICE_RTSP = 2 !! RTSP stream. + integer, parameter, public :: CAMERA_DEVICE_RTSP = 1 !! RTSP stream. + integer, parameter, public :: CAMERA_DEVICE_V4L = 2 !! USB webcam via Video4Linux2. + integer, parameter, public :: CAMERA_DEVICE_LAST = 2 !! Never use this. + + integer, parameter, public :: CAMERA_COLOR_LEN = 32 !! Max. length of GM colour name. + integer, parameter, public :: CAMERA_COMMAND_LEN = FILE_PATH_LEN !! Max. length of command string. + integer, parameter, public :: CAMERA_FONT_LEN = 64 !! Max. length of GraphicsMagick font name. + integer, parameter, public :: CAMERA_GRAVITY_LEN = 32 !! Max. length of GM gravity. - integer, parameter, public :: CAMERA_FONT_LEN = 128 !! Max. length of font name or path. + character(len=*), parameter :: CAMERA_FFMPEG = 'ffmpeg' !! FFmpeg binary name. + character(len=*), parameter :: CAMERA_GM = 'gm' !! GraphicsMagick binary name. type, public :: camera_type - !! Camera context type. - integer :: device = CAMERA_DEVICE_NONE !! Input device. - character(len=FILE_PATH_LEN) :: input = ' ' !! Input path. - character(len=FILE_PATH_LEN) :: output = ' ' !! Output path. - character(len=MIME_LEN) :: mime = ' ' !! Output format (MIME type). - character(len=CAMERA_FONT_LEN) :: font = ' ' !! Overlay font name. - integer :: font_size = 12 !! Overlay font size - integer :: width = 0 !! Image width in pixels. - integer :: height = 0 !! Image size in pixels. - logical :: overlay = .false. !! Overlay flag. + !! Camera settings type. + character(len=FILE_PATH_LEN) :: input = ' ' !! Input device path (`/dev/video0` or `rtsp://10.0.0.1`). + integer :: device = CAMERA_DEVICE_NONE !! Input device. + integer :: width = 0 !! Camera stream width in pixels (optional). + integer :: height = 0 !! Camera stream height in pixels (optional). end type camera_type + + type, public :: camera_text_box_type + !! Text box settings for drawing text onto camera frame image. + character(len=CAMERA_GRAVITY_LEN) :: gravity = 'SouthWest' !! Text position. + character(len=CAMERA_COLOR_LEN) :: background = 'black' !! Box colour. + character(len=CAMERA_COLOR_LEN) :: foreground = 'white' !! Text colour. + character(len=CAMERA_FONT_LEN) :: font = 'Lucida-Console' !! GraphicsMagick font name. + integer :: font_size = 12 !! Font size in points. + end type camera_text_box_type + + public :: dm_camera_capture + public :: dm_camera_device_is_valid + public :: dm_camera_image_add_text + public :: dm_camera_prepare_command_ffmpeg + public :: dm_camera_prepare_command_gm +contains + ! ************************************************************************** + ! PUBLIC FUNCTIONS. + ! ************************************************************************** + integer function dm_camera_capture(camera, output) result(rc) + !! Captures a single frame from a V4L device or RTSP stream with + !! FFmpeg, and optionally adds a timestamp with GraphicsMagick. If the + !! input is an RTSP stream, the URL must start with `rtsp://`. + !! + !! The function returns the following error codes: + !! + !! * `E_EMPTY` if camera input or output is empty. + !! * `E_INVALID` if camera device or RTSP stream URL is invalid. + !! * `E_IO` if FFmpeg command execution failed. + !! + type(camera_type), intent(in) :: camera !! Camera type. + character(len=*), intent(in) :: output !! Output file. + + character(len=CAMERA_COMMAND_LEN) :: command + integer :: exit_stat + + rc = E_EMPTY + if (len_trim(camera%input) == 0 .or. len_trim(output) == 0) return + + rc = E_INVALID + if (.not. dm_camera_device_is_valid(camera%device)) return + if (camera%device == CAMERA_DEVICE_RTSP .and. .not. dm_string_starts_with(camera%input, 'rtsp://')) return + + rc = E_IO + call dm_camera_prepare_command_ffmpeg(command, camera, output) + call execute_command_line(trim(command), exitstat=exit_stat) + + if (exit_stat /= 0) return + if (.not. dm_file_exists(output)) return + + rc = E_NONE + end function dm_camera_capture + + logical function dm_camera_device_is_valid(device) result(is) + !! Returns `.true.` if device enumerator is valid. The device + !! `CAMERA_DEVICE_NONE` is invalid. + integer, intent(in) :: device !! Camera device enumerator. + + is = (device > CAMERA_DEVICE_NONE .and. device <= CAMERA_DEVICE_LAST) + end function dm_camera_device_is_valid + + integer function dm_camera_image_add_text(path, text, box) result(rc) + !! Draws text onto camera image file, using GraphicsMagick. By default, + !! the text box is drawn to the bottom-left corner of the image. + !! + !! The function returns the following error codes: + !! + !! * `E_EMPTY` if text or image path are empty. + !! * `E_IO` if GraphicsMagick command execution failed. + !! * `E_NOT_FOUND` if image at given path does no exist. + !! + character(len=*), intent(in) :: path !! Image file path. + character(len=*), intent(in) :: text !! Text to add. + type(camera_text_box_type), intent(in), optional :: box !! Camera box type. + + character(len=CAMERA_COMMAND_LEN) :: command + integer :: exit_stat + + rc = E_EMPTY + if (len_trim(path) == 0 .or. len_trim(text) == 0) return + + rc = E_NOT_FOUND + if (.not. dm_file_exists(path)) return + + rc = E_IO + call dm_camera_prepare_command_gm(command, path, text, box) + call execute_command_line(trim(command), exitstat=exit_stat) + if (exit_stat /= 0) return + + rc = E_NONE + end function dm_camera_image_add_text + + ! ************************************************************************** + ! PUBLIC SUBROUTINES. + ! ************************************************************************** + subroutine dm_camera_prepare_command_ffmpeg(command, camera, output) + !! Creates FFmpeg command to capture a single camera frame through V4L + !! or RTSP. The function returns `E_INVALID` on error. + character(len=CAMERA_COMMAND_LEN), intent(out) :: command !! Prepared command string. + type(camera_type), intent(in) :: camera !! Camera type. + character(len=*), intent(in) :: output !! Output file. + + character(len=32) :: video_size + + ! Disable logging and set output file. + command = ' -hide_banner -loglevel fatal -nostats -y ' // output + + ! Format argument `-f` must be before input argument `-i`. + select case (camera%device) + case (CAMERA_DEVICE_RTSP) + ! Capture RTSP stream for 0.5 seconds to get key frame, + ! overwrite output file. + command = ' -f image2 -i ' // trim(camera%input) // ' -update 1 -t 0.5' // command + + case (CAMERA_DEVICE_V4L) + ! Capture single frame from V4L device. + if (camera%width > 0 .and. camera%height > 0) then + write (video_size, '(" -video_size ", i0, "x", i0)') camera%width, camera%height + command = trim(video_size) // command + end if + + command = ' -f v4l2 -i ' // trim(camera%input) // ' -frames:v 1' // command + end select + + ! Concatenate command string. + command = CAMERA_FFMPEG // command + end subroutine dm_camera_prepare_command_ffmpeg + + subroutine dm_camera_prepare_command_gm(command, path, text, box) + !! Prepares GraphicsMagick command to add text to image. + character(len=CAMERA_COMMAND_LEN), intent(out) :: command !! Prepared command string. + character(len=*), intent(in) :: path !! Image file path. + character(len=*), intent(in) :: text !! Text to add. + type(camera_text_box_type), intent(in), optional :: box !! Camera box type. + + character(len=32) :: point_size + type(camera_text_box_type) :: box_ + + if (present(box)) box_ = box + + write (command, '(" -gravity ", a, " -box ", a, " -fill ", a, " -draw ''text 0,0 """, a, """''", 2(1x, a))') & + trim(box_%gravity), trim(box_%background), trim(box_%foreground), trim(text), trim(path), path + + if (box_%font_size > 0) then + write (point_size, '(" -pointsize ", i0)') box_%font_size + command = trim(point_size) // command + end if + + if (len_trim(box_%font) > 0) then + command = ' -font ' // trim(box_%font) // command + end if + + command = CAMERA_GM // ' convert' // command + end subroutine dm_camera_prepare_command_gm end module dm_camera