Hi to all

I am writing a plugin that supports ISampleProvider2 interface in order to make media composer accept my video in JPeg2000 4:2:2 format (unfortunately up to now accept Jpeg2000 RGB format only). I am facing the problem to detect when the device should supply Video Sample for playing and when for rendering in order to optimize decompression.  In the SampleProvider2 interface there is a flag kPlaybackRender that should be set when the host is playing for rendering.That is, as I figured out, when the host calls SetupWithFlags it should specify that the play is for rendering setting kPlaybackRender.  In practice when I export a sequence the call is made with a zero value (on media composer 6.5) and the plugin can't detect the rendering.  Morever I should develop the same plugin  for MediaComposer 5 that doesn't support ISampleProvider2 but only ISampleProvider interface. In this last case how can I detect the playing for rendering ?

best regards

Hi Francesco,

Welcome to the forum.

The kPlaybackRender flag isn't being set during an AMA export, but should be.  That will be fixed in a future patch of 6.5 and 7.0 (when exact version numbers are known, we'll post another reply).

However, note that those sample-provider flags (kPlaybackRealtime, kPlaybackSingleFrame, kPlaybackRender) are intended to identify the type of playback so you can optimize your I/O and decoding pipeline, but must not impact the quality of the decoded image.  There are other mechanisms for managing AMA playback quality:

For timeline playback in Media Composer the quality of image requested from AMA plug-in depends on the setting in Video Quality Menu - the green/yellow icon at the bottom of the timeline. When playing with the best image quality (Video Quality icon is all green) or when performing render, mixdown or transcode, the 'R3D Source Quality (Debayer)' menu in Media Creation settings is used to set the image quality in the plug-in. Note that we are planning to remove the “R3D” from the settings UI as soon as possible; it should say just ‘Source Quality (Debayer)'.

AMA::IUncompressedImageProvider has 2 methods for adjusting image quality: SetWorkingImageScale() and SetWorkingImageQuality(). An IUncompressedImageProvider implementation has to implement at least one of these methods.  The Media Composer player uses these methods to pass the quality settings described above to your AMA plug-in.   Those have been available since Media Composer 5.

- Don