/** Make a picture frame from a 2D (monoscopic) asset.
* @param reader Reader for the asset's MXF file.
* @param n Frame within the asset, not taking EntryPoint into account.
/** Make a picture frame from a 2D (monoscopic) asset.
* @param reader Reader for the asset's MXF file.
* @param n Frame within the asset, not taking EntryPoint into account.