oak-editor/app/codec/oiio/oiiodecoder.cpp

/***

  Olive - Non-Linear Video Editor
  Copyright (C) 2022 Olive Team
  Modifications Copyright (C) 2025 mikesolar

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.

***/

#include "oiiodecoder.h"

#include <QDebug>
#include <QDir>
#include <QFileInfo>

#include "common/oiioutils.h"
#include "render/renderer.h"

namespace olive
{

QStringList OIIODecoder::supported_formats;

OIIODecoder::OIIODecoder()
	: image_(nullptr)
{
}

QString OIIODecoder::id() const
{
	return QStringLiteral("oiio");
}

FootageDescription OIIODecoder::probe(const QString &filename,
									  CancelAtom *cancelled) const
{
	Q_UNUSED(cancelled)

	FootageDescription desc(id());

	// Filter out any file extensions that aren't expected to work - sometimes OIIO will crash trying
	// to open a file that it can't if it's given one
	if (!file_type_is_supported(filename)) {
		return desc;
	}

	std::string std_filename = filename.toStdString();

	auto in = OIIO::ImageInput::open(std_filename);

	if (!in) {
		return desc;
	}

	// Filter out OIIO detecting an "FFmpeg movie", we have a native FFmpeg decoder that can handle
	// it better
	if (!strcmp(in->format_name(), "FFmpeg movie")) {
		return desc;
	}

	bool stream_enabled = true;

	int i;
	for (i = 0; in->seek_subimage(i, 0); i++) {
		OIIO::ImageSpec spec = in->spec();

		VideoParams video_params = get_video_params_from_image_spec(spec);

		video_params.set_stream_index(i);

		if (i > 1) {
			// This is a multilayer image and this image might have an offset
			OIIO::ImageSpec root_spec = in->spec(0);

			float norm_x = spec.x + float(spec.width) * 0.5f -
						   float(root_spec.width) * 0.5f;
			float norm_y = spec.y + float(spec.height) * 0.5f -
						   float(root_spec.height) * 0.5f;

			video_params.set_x(norm_x);
			video_params.set_y(norm_y);
		}

		// By default, only enable the first subimage (presumably the combined image). Later we will
		// ask the user if they want to enable the layers instead.
		video_params.set_enabled(stream_enabled);
		stream_enabled = false;

		// OIIO automatically premultiplies alpha
		// FIXME: We usually disassociate the alpha for the color management later, for 8-bit images this
		//        likely reduces the fidelity?
		video_params.set_premultiplied_alpha(true);

		desc.add_video_stream(video_params);
	}

	desc.set_stream_count(i);

	// If we're here, we have a successful image open
	in->close();

	return desc;
}

bool OIIODecoder::open_internal()
{
	// If we can open the filename provided, assume everything is working
	return open_image_handler(stream().filename(), stream().stream());
}

TexturePtr OIIODecoder::retrieve_video_internal(const RetrieveVideoParams &p)
{
	FramePtr frame = retrieve_video_frame_internal(p);
	if (!frame) {
		return nullptr;
	}

	return p.renderer->create_texture(frame->video_params(), frame->data(),
									 frame->linesize_pixels());
}

FramePtr OIIODecoder::retrieve_video_frame_internal(const RetrieveVideoParams &p)
{
	VideoParams vp = get_video_params_from_image_spec(image_->spec());
	vp.set_divider(p.divider);

	if (!buffer_.is_allocated() || last_params_.divider != p.divider) {
		last_params_ = p;

		buffer_.destroy();
		buffer_.set_video_params(vp);
		buffer_.allocate();

		if (p.divider == 1) {
			// Just upload straight to the buffer
			image_->read_image(0, 0, 0, -1, oiio_pix_fmt_, buffer_.data());
		} else {
			OIIO::ImageBuf buf(image_->spec());
			image_->read_image(0, 0, 0, -1, image_->spec().format,
							   buf.localpixels(), buf.pixel_stride(),
							   buf.scanline_stride(), buf.z_stride());

			// Roughly downsample image for divider (for some reason OIIO::ImageBufAlgo::resample failed here)
			int px_sz = vp.get_bytes_per_pixel();
			for (int dst_y = 0; dst_y < buffer_.height(); dst_y++) {
				int src_y = dst_y * buf.spec().height / buffer_.height();

				for (int dst_x = 0; dst_x < buffer_.width(); dst_x++) {
					int src_x = dst_x * buf.spec().width / buffer_.width();
					memcpy(buffer_.data() + buffer_.linesize_bytes() * dst_y +
							   px_sz * dst_x,
						   static_cast<uint8_t *>(buf.localpixels()) +
							   buf.scanline_stride() * src_y + px_sz * src_x,
						   px_sz);
				}
			}
		}
	}

	// Force F32 output for all still images
	if (vp.format() != PixelFormat::f32) {
		FramePtr f32_frame = buffer_.convert(PixelFormat::f32);
		if (f32_frame) {
			f32_frame->set_timestamp(p.time);
			return f32_frame;
		}
	}

	FramePtr frame = Frame::create();
	frame->set_video_params(buffer_.video_params());
	frame->set_timestamp(p.time);
	if (!frame->allocate()) {
		return nullptr;
	}
	memcpy(frame->data(), buffer_.const_data(),
		   size_t(buffer_.allocated_size()));
	return frame;
}

void OIIODecoder::close_internal()
{
	close_image_handle();
}

bool OIIODecoder::file_type_is_supported(const QString &fn)
{
	// We prioritize OIIO over FFmpeg to pick up still images more effectively, but some OIIO decoders (notably OpenJPEG)
	// will segfault entirely if given unexpected data (an MPEG-4 for instance). To workaround this issue, we use OIIO's
	// "extension_list" attribute and match it with the extension of the file.

	// Check if we've created the supported formats list, create it if not
	if (supported_formats.isEmpty()) {
		QStringList extension_list =
			QString::fromStdString(OIIO::get_string_attribute("extension_list"))
				.split(';');

		// The format of "extension_list" is "format:ext", we want to separate it into a simple list of extensions
		foreach (const QString &ext, extension_list) {
			QStringList format_and_ext = ext.split(':');

			supported_formats.append(format_and_ext.at(1).split(','));
		}
	}

	if (!supported_formats.contains(QFileInfo(fn).suffix(),
									 Qt::CaseInsensitive)) {
		return false;
	}

	return true;
}

bool OIIODecoder::open_image_handler(const QString &fn, int subimage)
{
	image_ = OIIO::ImageInput::open(fn.toStdString());

	if (!image_) {
		return false;
	}

	if (!image_->seek_subimage(subimage, 0)) {
		return false;
	}

	// Check if we can work with this pixel format
	const OIIO::ImageSpec &spec = image_->spec();

	// We use RGBA frames because that tends to be the native format of GPUs
	pix_fmt_ = OIIOUtils::get_format_from_oiio_basetype(
		static_cast<OIIO::TypeDesc::BASETYPE>(spec.format.basetype));

	if (pix_fmt_ == PixelFormat::invalid) {
		qWarning()
			<< "Failed to convert OIIO::ImageDesc to native pixel format";
		return false;
	}

	oiio_pix_fmt_ = OIIOUtils::get_oiio_base_type_from_format(pix_fmt_);

	if (oiio_pix_fmt_ == OIIO::TypeDesc::UNKNOWN) {
		qCritical()
			<< "Failed to determine appropriate OIIO basetype from native format";
		return false;
	}

	return true;
}

void OIIODecoder::close_image_handle()
{
	if (image_) {
		image_->close();
		image_ = nullptr;
	}

	buffer_.destroy();
}

VideoParams
OIIODecoder::get_video_params_from_image_spec(const OIIO::ImageSpec &spec)
{
	VideoParams video_params;

	video_params.set_width(spec.width);
	video_params.set_height(spec.height);
	video_params.set_format(OIIOUtils::get_format_from_oiio_basetype(
		static_cast<OIIO::TypeDesc::BASETYPE>(spec.format.basetype)));
	video_params.set_channel_count(spec.nchannels);
	video_params.set_pixel_aspect_ratio(
		OIIOUtils::get_pixel_aspect_ratio_from_oiio(spec));
	video_params.set_video_type(VideoParams::k_video_type_still);

	return video_params;
}

}