@spec configure_channel(t(), 0..2, keyword()) :: :ok | {:error, term()}

Configure a camera channel before start_stream/2.

Must be called after init/2. Attempting to change the format after the stream has started returns {:error, _}.

Options

• :format - pixel format atom. Supported: :rgb888, :yuv422, :gray, :jpeg, :h264, :h265, :nv12, :nv21. Note: :rgb565 and :rgb888_planar are not supported as native camera channel formats.
• :width and :height - frame dimensions (must both be provided together).
• :fps - target frame rate.

H.264 / H.265 encoder options

The following options are only applied when format: is :h264 or :h265. If none are provided the encoder template defaults are used.

• :bitrate - target bitrate in kbps (default: 1000 for H264, 3000 for H265)
• :max_bitrate - peak bitrate in kbps; set equal to :bitrate for pure CBR (defaults to the value of :bitrate)
• :gop - keyframe interval in frames (default: 50)

• :rc_mode - rate control mode: :cbr | :vbr | :avbr | :fixqp (default: :cbr)

• :min_qp - P-frame QP floor (default: 20)
• :max_qp - P-frame QP ceiling; too low causes malformed P-frames on high-motion scenes in CBR mode (default: 35)
• :min_iqp - I-frame QP floor (default: 20)
• :max_iqp - I-frame QP ceiling (default: 35)

• :profile - codec profile: :baseline | :main | :high (default: :baseline)

JPEG quality

Quality control (set_ctrl(cam, :quality, value)) applies to the channel that is currently selected. Select the channel with configure_channel/3 (which leaves it as current) or set_ctrl(cam, :channel, n) before setting quality.

Examples

# Two RGB888 channels at different resolutions
:ok = Camera.configure_channel(cam, 0, format: :rgb888, width: 1920, height: 1080)
:ok = Camera.configure_channel(cam, 1, format: :rgb888, width: 640, height: 480)

# JPEG on channel 2
:ok = Camera.configure_channel(cam, 2, format: :jpeg, width: 1280, height: 720)

# Set JPEG quality for channel 2 (channel 2 is still selected after configure_channel above)
{:ok, :ok} = Camera.set_ctrl(cam, :quality, 75)

# H.264 with tuned encoder params
:ok = Camera.configure_channel(cam, 2,
  format: :h264, width: 640, height: 360, fps: 15,
  bitrate: 3000, gop: 15, max_qp: 45
)

@spec count(SSCMEx.Device.t()) :: {:ok, non_neg_integer()} | {:error, term()}

Get the number of cameras available on the device.

Examples

{:ok, count} = SSCMEx.Camera.count(device)

@spec deinit(t()) :: {:ok, :deinitialized} | {:error, term()}

Deinitialize the camera.

Examples

{:ok, :deinitialized} = SSCMEx.Camera.deinit(camera)

@spec get(SSCMEx.Device.t(), non_neg_integer()) :: {:ok, t()} | {:error, term()}

Get a camera from the device by index.

Parameters

• device - Device obtained from SSCMEx.Device.get_instance/0
• index - Camera index (0-based)

Examples

{:ok, camera} = SSCMEx.Camera.get(device, 0)

@spec get_ctrl(t(), ctrl_type()) :: {:ok, term()} | {:error, term()}

Get a camera control value.

Control Types and return values

Standard Controls

• :window -> {width, height}
• :channel -> channel index integer
• :format -> pixel format atom
• :fps -> fps integer
• :quality -> quality integer (1-99, value 50 is reserved)

ISP Controls

• :ae_mode -> :auto or :manual
• :max_iso -> maximum ISO integer (100-12800)
• :exposure_us -> current exposure time in microseconds
• :gain -> current analog gain (10-bit: 1024=1x)
• :exposure_range -> {min_us, max_us} tuple
• :max_exposure_us -> max auto-exposure shutter cap in microseconds
• :tnr_enable -> true or false
• :tnr_strength -> TNR strength integer (0-255)
• :brightness -> brightness integer (0-255)
• :contrast -> contrast integer (0-255)
• :saturation -> saturation integer (0-255)
• :sharpness -> sharpness integer (0-255)
• :nr_strength -> raw/Bayer NR strength integer (0-255)
• :ynr_strength -> luma NR strength integer (0-255)
• :cnr_strength -> chroma NR strength integer (0-255)

For channel-specific controls (:window, :format, :fps), this reads the currently selected channel. Use set_ctrl(camera, :channel, idx) first.

Examples

{:ok, quality} = SSCMEx.Camera.get_ctrl(camera, :quality)
{:ok, :auto} = SSCMEx.Camera.get_ctrl(camera, :ae_mode)
{:ok, {min_us, max_us}} = SSCMEx.Camera.get_ctrl(camera, :exposure_range)
{:ok, 800} = SSCMEx.Camera.get_ctrl(camera, :max_iso)

@spec get_id(t()) :: {:ok, non_neg_integer()} | {:error, term()}

Get the camera ID.

Examples

{:ok, id} = SSCMEx.Camera.get_id(camera)

@spec get_preset_idx(t()) :: {:ok, non_neg_integer()} | {:error, term()}

Get the current preset index.

Examples

{:ok, idx} = SSCMEx.Camera.get_preset_idx(camera)

@spec get_presets(t()) :: {:ok, [preset()]} | {:error, term()}

Get available presets for the camera.

Each preset describes a resolution/framerate combination.

Examples

{:ok, presets} = SSCMEx.Camera.get_presets(camera)
# => [%{description: "1920x1080 @ 30fps"}, ...]

@spec init(t(), non_neg_integer()) :: {:ok, :initialized} | {:error, term()}

Initialize the camera with a preset.

Presets define resolution and framerate combinations.

Parameters

• camera - Camera resource
• preset_idx - Index of preset (see get_presets/1)

Examples

{:ok, :initialized} = SSCMEx.Camera.init(camera, 0)

@spec is_initialized(t()) :: {:ok, boolean()} | {:error, term()}

Check if the camera is initialized.

Examples

{:ok, true} = SSCMEx.Camera.is_initialized(camera)

@spec is_streaming(t()) :: {:ok, boolean()} | {:error, term()}

Check if the camera is currently streaming.

Examples

{:ok, true} = SSCMEx.Camera.is_streaming(camera)

@spec isp_available() :: {:ok, boolean()} | {:error, term()}

Check if the ISP (Image Signal Processor) is available.

Probes the ISP by attempting to read exposure attributes on pipe 0.

Examples

{:ok, true} = SSCMEx.Camera.isp_available()

@spec request_keyframe(t(), 0..2) :: :ok | {:error, term()}

Request an immediate IDR keyframe on a running H.264/H.265 channel.

When a new viewer connects to a live stream mid-GOP it must wait up to gop / fps seconds for the next natural IDR before it can decode anything. Calling this injects an IDR immediately, giving sub-100ms first-frame time regardless of GOP size.

The stream must be running. Returns {:error, :request_keyframe_failed} if the VENC channel is not active or the codec is not H.264/H.265.

Examples

:ok = SSCMEx.Camera.request_keyframe(camera, 2)

@spec retrieve_frame(t(), 0..2) :: {:ok, frame()} | {:error, term()}

Retrieve a frame from the camera.

Pixel Formats

• :rgb888 - RGB888 format (raw pixels)
• :yuv422 - YUV422 format
• :jpeg - JPEG encoded
• :h264 - H.264 encoded video frame
• :h265 - H.265 encoded video frame

Channel selection

Use configure_channel/3 before start_stream/2 to assign a format and resolution to each channel. Retrieve frames by channel index:

{:ok, frame} = SSCMEx.Camera.retrieve_frame(camera, 0)

Returns

Returns %SSCMEx.Image{}.

The image includes:

• width, height, format, data
• metadata fields when available from the camera pipeline (size, timestamp, key)

Examples

{:ok, image} = SSCMEx.Camera.retrieve_frame(camera, 0)
# image.data contains pixels in the format configured for channel 0

@spec set_ctrl(t(), ctrl_type(), term()) :: {:ok, :ok} | {:error, term()}

Set a camera control value.

Standard Controls

• :window - Set resolution {width, height}
• :channel - Set channel index
• :format - Set pixel format
• :fps - Set frames per second
• :quality - Set JPEG encoding quality (1-99, value 50 is reserved)

ISP Controls (requires isp_available?/0 to return true)

AE (Auto-Exposure) Controls

• :ae_mode - Set AE mode (:auto or :manual)
• :max_iso - Set maximum ISO for auto-exposure (100-12800)
• :exposure_us - Set manual exposure time in microseconds (1-1000000)
• :gain - Set manual analog gain, 10-bit precision (1024=1x, 2048=2x, range 1024-65536)
• :exposure_range - Set auto-exposure time limits {min_us, max_us} (1-1000000)
• :max_exposure_us - Cap auto-exposure max shutter time in microseconds (1-1000000)

TNR (Temporal Noise Reduction) Controls

• :tnr_enable - Enable/disable 3D noise reduction (true or false)
• :tnr_strength - Set TNR intensity (0-255, manual mode)

Image Tuning Controls

• :brightness - Set image brightness via YContrast CenterLuma (0-255)
• :contrast - Set image contrast via YContrast ContrastHigh (0-255)
• :saturation - Set color saturation (0-255)
• :sharpness - Set edge sharpness via Sharpen GlobalGain (0-255)

Noise Reduction Controls

• :nr_strength - Raw/Bayer spatial NR strength (0-255); higher = less grain
• :ynr_strength - Luma NR strength post-demosaic (0-255); reduces luma noise
• :cnr_strength - Chroma NR strength (0-255); reduces color noise/fringing

Examples

# Set resolution
{:ok, :ok} = SSCMEx.Camera.set_ctrl(camera, :window, {1280, 720})

# Set FPS
{:ok, :ok} = SSCMEx.Camera.set_ctrl(camera, :fps, 15)

# Set JPEG quality (1-99, higher = less compression)
{:ok, :ok} = SSCMEx.Camera.set_ctrl(camera, :quality, 75)

# Limit max ISO to reduce noise in low light
{:ok, :ok} = SSCMEx.Camera.set_ctrl(camera, :max_iso, 800)

# Enable 3D noise reduction
{:ok, :ok} = SSCMEx.Camera.set_ctrl(camera, :tnr_enable, true)

# Increase brightness slightly
{:ok, :ok} = SSCMEx.Camera.set_ctrl(camera, :brightness, 140)

@spec start_stream(t(), stream_mode()) :: {:ok, :streaming} | {:error, term()}

Start the camera stream.

Stream Modes

• :refresh_on_return - Frame buffer is refreshed when frame is returned
• :refresh_on_retrieve - Frame buffer is refreshed when frame is retrieved

Examples

{:ok, :streaming} = SSCMEx.Camera.start_stream(camera, :refresh_on_return)

@spec stop_stream(t()) :: {:ok, :stopped} | {:error, term()}

Stop the camera stream.

Examples

{:ok, :stopped} = SSCMEx.Camera.stop_stream(camera)