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Viewing changes to src/QtImageReader.cpp

  • Committer: Jonathan Thomas
  • Date: 2016-09-14 09:11:12 UTC
  • Revision ID: jonathan@openshot.org-20160914091112-mcxg747f4zniwscx
Added SetMaxSize for image optimizations in QImageReader and FFmpegReader, which lets the timeline pass down the max size to all clips and readers, so they can optionally optimize the size of images (especially useful for optimizing preview performance). Removed convoluted image scaling code in FFmpegReader, and replaced with simpler version. Also, fixed a few regressions from the new Caching code, primarily a crash when reaching the end of the last clip on the timeline.

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src/QtImageReader.cpp
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        if (!is_open)
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                throw ReaderClosed("The Image is closed.  Call Open() before calling this method.", path);
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        // Create or get frame object
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        tr1::shared_ptr<Frame> image_frame(new Frame(requested_frame, info.width, info.height, "#000000", Frame::GetSamplesPerFrame(requested_frame, info.fps, info.sample_rate, info.channels), info.channels));
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        // Add Image data to frame
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        image_frame->AddImage(image);
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        // return frame object
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        return image_frame;
 
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        // Determine if we need to scale the image (for performance reasons)
 
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        // The timeline passes its size to the clips, which pass their size to the readers, and eventually here
 
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        // A max_width/max_height = 0 means do not scale (probably because we are scaling the image larger than 100%)
 
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        if (max_width != 0 && max_height != 0 && max_width < info.width && max_height < info.height)
 
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        {
 
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                // Scale image smaller (or use a previous scaled image)
 
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                if (!cached_image) {
 
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                        // Create a scoped lock, allowing only a single thread to run the following code at one time
 
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                        const GenericScopedLock<CriticalSection> lock(getFrameCriticalSection);
 
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                        // We need to resize the original image to a smaller image (for performance reasons)
 
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                        // Only do this once, to prevent tons of unneeded scaling operations
 
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                        cached_image = tr1::shared_ptr<QImage>(new QImage(image->scaled(max_width, max_height, Qt::KeepAspectRatio, Qt::SmoothTransformation)));
 
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                        cached_image = tr1::shared_ptr<QImage>(new QImage(cached_image->convertToFormat(QImage::Format_RGBA8888)));
 
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                }
 
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                // Create or get frame object
 
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                tr1::shared_ptr<Frame> image_frame(new Frame(requested_frame, cached_image->width(), cached_image->height(), "#000000", Frame::GetSamplesPerFrame(requested_frame, info.fps, info.sample_rate, info.channels), info.channels));
 
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                // Add Image data to frame
 
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                image_frame->AddImage(cached_image);
 
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                // return frame object
 
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                return image_frame;
 
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        } else {
 
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                // Use original image (higher quality but slower)
 
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                // Create or get frame object
 
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                tr1::shared_ptr<Frame> image_frame(new Frame(requested_frame, info.width, info.height, "#000000", Frame::GetSamplesPerFrame(requested_frame, info.fps, info.sample_rate, info.channels), info.channels));
 
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                // Add Image data to frame
 
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                image_frame->AddImage(image);
 
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                // return frame object
 
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                return image_frame;
 
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        }
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}
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// Generate JSON string of this object