Selective decoding of enhanced video stream
An MPEG decoding system selectively decodes MPEG enhanced streams, based on a select identification of an enhancement region of a series of image frames. MPEG blocks within the enhancement region are decoded with the enhancement-layer, while blocks outside the enhancement region are decoded at the base-layer. Additionally, the user is provided the option of displaying the series of images in a window that is selectively sized to contain only the enhancement region, or the enhancement region surrounded by a base-layer region, or a custom sized window that may include all or some of the enhancement and base-layer regions.
1. A decoder comprising: base-layer components that are configured to decode a base-layer input stream, and to produce therefrom a base-layer output stream, enhancement-layer components that are configured to decode an enhancement-layer input stream, and to produce therefrom information that supplements the base-layer output stream to provide an enhanced output stream, and a controller, operably coupled to the enhancement-layer components, that is configured to control the decoding of the enhancement-layer input stream, based on a user-defined subset of the base-layer output stream;
wherein the base-layer input stream corresponds to an encoding of a series of image frames, and the defined subset of the base-layer output stream includes a defined region within the image frames that is smaller in size than the image frames.
2. The decoder of claim 1 , wherein the enhancement-layer input stream corresponds to at least one of: a spatial enhancement, a temporal enhancement, a data enhancement, and a signal-to-noise enhancement.
3. The decoder of claim 2 , wherein the temporal enhancement includes MPEG B-frames.
4. The decoder of claim 1 , further including a second controller that is configured to extract at least a portion of the enhanced output stream and the base-layer output stream for rendering to a display device.
5. The decoder of claim 1 , wherein the base-layer components include: a base-layer variable-length decoder that is configured to provide a series of DCT encodings from the base-layer input stream, an inverse discrete-cosine-transform, operably coupled to the base-layer variable-length decoder, that is configured to provide direct-coded pixel values and error-term values corresponding the series of DCT encodings, a motion compensation device that is configured to receive motion vectors corresponding to prior pixel values and to produce therefrom translated pixel values, and a summer that is configured to combine the translated pixel values and the error-term values to produce motion compensated pixel values, and wherein the base-layer output stream includes the direct-coded pixel values and the motion compensated pixel values.
6. The decoder of claim 5 , wherein the enhancement-layer components include: an enhancement-layer variable-length decoder that is configured to provide a series of enhancement DCT encodings from the enhancement-layer input stream, an enhancement inverse discrete-cosine-transform, operably coupled to the enhancement-layer variable-length decoder, that is configured to provide enhancement values corresponding the series of enhancement DCT encodings, and a second summer that is configured to combine the enhancement values to the base-layer output stream to produce the enhanced output stream.
7. The decoder of claim 5 , wherein the enhancement-layer input stream corresponds to an enhancement frame, and includes motion vectors relative to the base-layer input stream, and the enhancement-layer components include an interleaver that is configured to insert the enhancement frame into the base-layer output stream to produce the enhanced output stream.
8. The decoder of claim 1 , further including a user interface, operably coupled to the controller, that is configured to facilitate identifying the defined subset.
9. A image processing system comprising: a camera system that is configured to provide a base-level input stream and a corresponding enhancement-level stream, a base-level decoder that is configured to provide a base-level output stream corresponding to the base-level input stream, an enhancement-level decoder that is configured to provide an enhancement stream corresponding to the enhancement-level stream, a combiner that is configured to combine the enhancement stream to the base-level output stream to produce an enhanced output stream, and a controller that is configured to control the enhancement-level decoder to selectively decode the enhancement-level stream to provide the enhancement stream, based on a defined region of a field of view of the camera system.
10. The image processing system of claim 9 , wherein the defined region of the field of view is based on at least one of: a user selection, a location parameter, a pattern recognition, and a color recognition.
11. A method of providing an enhanced output stream, comprising: receiving a base-layer input stream, receiving an enhancement-layer input stream, decoding the base-layer input stream to provide a base-layer output stream, selectively decoding the enhancement-layer input stream, based on a user-defined subset of the base-layer output stream, to provide an enhancement output stream, and combining the base-layer output stream and the enhancement output stream to provide the enhanced output streams;
wherein the base-layer input stream corresponds to an encoding of a series of image frames, and the defined subset of the base-layer output stream includes a defined region within the image frames that is smaller in size than the image frames.
12. The method of claim 11 , wherein the enhancement-layer input stream corresponds to at least one of: a spatial enhancement, a temporal enhancement, a data enhancement, and a signal-to-noise enhancement.
13. The method of claim 12 , wherein the temporal enhancement includes MPEG B-frames.
14. The method of claim 11 , further including extracting at least a portion of the enhanced output stream and the base-layer output stream for rendering to a display device.
15. The method of claim 11 , wherein decoding the base-layer input stream includes: decoding variable-length bit streams in the base-layer input stream to provide a series of DCT encodings, decoding, via an inverse discrete-cosine-transform, the series of DCT encodings to provide direct-coded pixel values and error-term values, receiving motion vectors corresponding to prior pixel values, producing translated pixel values from the prior pixel values, and combining the translated pixel values and the error-term values to produce motion compensated pixel values, and wherein the base-layer output stream includes the direct-coded pixel values and the motion compensated pixel values.
16. The method of claim 15 , wherein decoding the enhancement-layer input stream includes: decoding variable-length bit streams in the enhancement-layer input stream to provide a series of enhancement DCT encodings, decoding, via an enhancement inverse discrete-cosine-transform-, the series of enhancement DCT encodings to produce enhancement values, and combining the enhancement values to the base-layer output stream to produce the enhanced output stream.
17. The method of claim 15 , wherein the enhancement-layer input stream corresponds to an enhancement frame, and includes motion vectors relative to the base-layer input stream, and interleaving the enhancement frame into the base-layer output stream to produce the enhanced output stream.
18. The method of claim 10 , further including providing a user interface to facilitate identifying the defined subset.