Support (half) float only OpenFX plugins

[ddennedy]

No description provided.

[Copilot]

Pull request overview

Adds support for OpenFX plugins that only accept half-float or float pixel depths by extending depth negotiation and introducing rgba64↔(half/float) conversion utilities in the OpenFX module.

Changes:

• Extend supported OpenFX pixel depths to include half and float, and advertise these in host properties.
• Add conversion helpers between MLT rgba64 and OFX half/float buffers (optionally OpenMP-parallelized).
• Update the OpenFX filter render path to negotiate depth and perform half/float conversions around the plugin render call.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 11 comments.

File	Description
src/modules/openfx/mlt_openfx.h	Extends depth mask and API surface for clip depth overrides and new conversion helpers.
src/modules/openfx/mlt_openfx.c	Implements half/float conversion utilities and wires new depth strings into host/clip metadata.
src/modules/openfx/filter_openfx.c	Updates format/depth negotiation and adds half/float render-buffer conversion around OFX Render.
src/modules/openfx/CMakeLists.txt	Adds optional OpenMP detection/linking for faster conversions.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

Comments suppressed due to low confidence (1)

src/modules/openfx/mlt_openfx.c:1721

• Same issue as the source clip: when ofx_depth is non-NULL, depth_byte_size is hard-coded as if the clip is RGBA and prop_component remains RGBA, ignoring format == mlt_image_rgb. This makes kOfxImagePropRowBytes/kOfxImageEffectPropComponents potentially inconsistent with the actual frame layout.

Suggestion: always set component/channels from format first, then compute row-bytes from channels × bytes-per-component derived from depth_format (byte/short/half/float).

    int depth_byte_size = 4;
    const char *depth_format = kOfxBitDepthByte;
    const char *prop_component = kOfxImageComponentRGBA;
    if (ofx_depth) {
        depth_format = ofx_depth;
        if (!strcmp(ofx_depth, kOfxBitDepthFloat))
            depth_byte_size = 16;
        else if (!strcmp(ofx_depth, kOfxBitDepthShort) || !strcmp(ofx_depth, kOfxBitDepthHalf))
            depth_byte_size = 8;
        else
            depth_byte_size = 4;
    } else if (format == mlt_image_rgba64) {
        depth_byte_size = 8;
        depth_format = kOfxBitDepthShort;
    } else if (format == mlt_image_rgb) {
        depth_byte_size = 3;
        prop_component = kOfxImageComponentRGB;
    }

[Copilot]

update_plugin_params() treats type == "string" the same as integer/boolean: it reads an int (mlt_properties_anim_get_int) and calls mltofx_param_set_value(..., mltofx_prop_int, value). But mltofx_fetch_params() also maps real OFX kOfxParamTypeString params to type="string", and paramGetValueImpl() supports kOfxParamTypeString by reading MltOfxParamValue as a string. As a result, string parameters can never be set (and choice vs string cannot be distinguished).

Consider distinguishing choice vs real string (e.g., presence of a values property indicates choice), and for real strings read the string value from properties and call mltofx_param_set_value(..., mltofx_prop_string, ...). You’ll also need to extend paramSetValueImpl() in mlt_openfx.c to handle kOfxParamTypeString/kOfxParamTypeStrChoice by storing the string into MltOfxParamValue.

Suggested change

	} else if (strcmp(type, "integer") == 0 || strcmp(type, "string") == 0
	|| strcmp(type, "boolean") == 0) {
	int value = mlt_properties_anim_get_int(properties, param_name, position, length);
	mltofx_param_set_value(image_effect_params, param_name, mltofx_prop_int, value);
	} else if (strcmp(type, "integer") == 0 || strcmp(type, "boolean") == 0) {
	int value = mlt_properties_anim_get_int(properties, param_name, position, length);
	mltofx_param_set_value(image_effect_params, param_name, mltofx_prop_int, value);
	} else if (strcmp(type, "string") == 0) {
	char *values = mlt_properties_get(param, "values");
	if (values) {
	int value = mlt_properties_anim_get_int(properties, param_name, position, length);
	mltofx_param_set_value(image_effect_params, param_name, mltofx_prop_int, value);
	} else {
	char *value = mlt_properties_get(properties, param_name);
	mltofx_param_set_value(image_effect_params,
	param_name,
	mltofx_prop_string,
	value ? value : "");
	}