Indicating picture usefulness for playback optimization
View Patent ↗In one embodiment the invention provides a method for outputting auxiliary information for use in playing back a video sequence, the method comprising obtaining a measure of usefulness of a particular picture for playing back the video sequence, wherein the measure of usefulness indicates a performance of playing back the video sequence if the particular picture is available in a decoded state at a time of playback versus the particular picture not being available in a decoded state at a time of playback; determining a position in a data stream that includes the video sequence; and storing the auxiliary information at the determined position in the data stream.
1. A method for outputting auxiliary information for use in playing back a video sequence, the method comprising:
obtaining a measure of usefulness of a particular picture for playing back the video sequence, wherein the measure of usefulness indicates a performance of playing back the video sequence if the particular picture is available in a decoded state at a time of playback versus the particular picture not being available in a decoded state at a time of playback;
determining a position in a data stream that includes the video sequence; and
storing the auxiliary information at the determined position in the data stream, the auxiliary information corresponding to the measure of usefulness for the particular picture, the auxiliary information further formed from a combination of one or more properties of the particular picture and one or more interdependency characteristics of the particular picture.
2. The method of claim 1 , wherein playback occurs from a storage device in a set-top box.
3. The method of claim 2 , wherein the measure of usefulness includes an indication of the usefulness of the particular picture during playback at a slower speed than normal.
4. The method of claim 2 , wherein the measure of usefulness includes an indication of the usefulness of the particular picture during playback at a higher speed than normal.
5. The method of claim 2 , wherein the measure of usefulness includes an indication of the usefulness of the particular picture during playback while skipping frames.
6. The method of claim 2 , wherein the measure of usefulness includes an indication of the usefulness of the particular picture during a pause operation.
7. The method of claim 1 , wherein the measure of usefulness includes an indication of an output-delay-property.
8. The method of claim 1 , wherein the measure of usefulness includes an indication of a complete-information-property.
9. The method of claim 1 , wherein the measure of usefulness includes an indication of an importance-level-property.
10. The method of claim 1 , wherein the measure of usefulness is only stored during a playback operation that uses a trick play.
11. An apparatus for outputting auxiliary information for use in playing back a video sequence, the apparatus comprising:
a processor;
one or more instructions executable by the processor for obtaining a measure of usefulness of a particular picture for playing back the video sequence, wherein the measure of usefulness indicates a performance of playing back the video sequence if the particular picture is available in a decoded state at a time of playback versus the particular picture not being available in a decoded state at a time of playback;
determining a position in a data stream that includes the video sequence; and
storing the auxiliary information at the determined position in the data stream, the auxiliary information corresponding to the measure of usefulness for the particular picture, the auxiliary information further formed from a combination of one or more properties of the particular picture and one or more interdependency characteristics of the particular picture.
12. The apparatus of claim 11 , wherein the apparatus is included as part of a set-top box.
13. The apparatus of claim 11 , wherein the apparatus is included as part of a video encoder.
14. The apparatus of claim 11 , wherein the apparatus is included as part of a video decoder.
15. The apparatus of claim 11 , wherein the apparatus is included as part of a network device.
16. The apparatus of claim 11 , wherein the apparatus is included as part of a display system.
17. A non-transitory memory encoded with one or more instructions executable by a processor for:
obtaining a measure of usefulness of a particular picture for playing back the video sequence, wherein the measure of usefulness indicates a performance of playing back the video sequence if the particular picture is available in a decoded state at a time of playback versus the particular picture not being available in a decoded state at a time of playback;
determining a position in a data stream that includes the video sequence; and
storing the auxiliary information at the determined position in the data stream, the auxiliary information corresponding to the measure of usefulness for the particular picture, the auxiliary information further formed from a combination of one or more properties of the particular picture and one or more interdependency characteristics of the particular picture.
18. A method for splicing from a first video sequence to a second video sequence, wherein each video sequence includes encoded pictures that are decoded into decoded pictures in a decode order, wherein decoded pictures are displayed in a presentation order at picture output times, the method comprising:
identifying an exit point for the first video sequence, wherein the exit point determines a last frame to display of the first video sequence;
determining a number of pictures of the first video sequence that are already decoded into a decode picture buffer;
reading a first data field in the first video sequence to obtain a first value, wherein the value indicates a number of consecutive pictures prior to the exit point; and
initiating decoding of the second video sequence so that a sufficient number of pictures in the second video sequence are decoded at a time of displaying the last picture from the decode picture buffer so that displaying of pictures in the second video sequence can begin at a next picture output time.
19. The method of claim 18 , further comprising:
reading a second data field in the first video sequence to obtain a second value, wherein the second value indicates a number of decoded pictures in the decoded picture buffer (DPB).
20. The method of claim 19 , wherein the second value indicates a number of decoded pictures in the DPB that have successive picture output times.
21. The method of claim 20 , wherein a first of the successive output times includes a picture output time immediately after the decompression time of a last consecutive picture prior to the exit point as indicated by the first value.
22. The method of claim 18 , wherein the actions are performed at a video splicing device located in a headend of a digital video broadcast system.
23. The method of claim 18 , further comprising:
assigning picture output times to the pictures in the picture decode buffer in accordance with an original order of the pictures in the picture decode buffer.
24. The method of claim 23 , further comprising:
ensuring that all of the pictures from the first video sequence to be decoded are decoded prior to the exit point.
25. The method of claim 24 , further comprising:
decoding a number of pictures from the second video sequence as indicated by the second value, wherein the decoding occurs prior to completion of a transition period.
26. The method of claim 25 , further comprising:
setting an earliest picture output time of a picture from the second video sequence to be just after an end of the transition period.
27. The method of claim 18 , wherein the first value is larger than the second value.
28. The method of claim 27 , wherein the first value is also greater than a predetermined threshold.
29. The method of claim 28 , wherein the predetermined threshold is equal to three picture output times.
30. The method of claim 19 , wherein the first and second data fields are provided in association with multiple pictures.
31. The method of claim 30 , wherein the first and second data fields are provided in association with each of the determined number of pictures of the first video sequence.
32. The method of claim 31 , wherein the first data field's value is N for the first picture and decreases by one successively in each successive instance of the first data field in a subsequent picture.
33. The method of claim 18 , further comprising:
causing display of a first picture of the second video sequence to be equal to a presentation time stamp of a first picture in the DPB.
34. The method of claim 33 , wherein the displayed first picture of the second video sequence includes an instantaneous decoding refresh picture.
35. The method of claim 34 , wherein the instantaneous decoding refresh picture includes an I-frame.
36. An apparatus for splicing from a first video sequence to a second video sequence, wherein each video sequence includes encoded pictures that are decoded into decoded pictures in a decode order, wherein decoded pictures are displayed in a presentation order at picture output times, the apparatus comprising:
a processor;
a non-transitory memory encoded with instructions for execution by the processor, including one or more instructions for:
identifying an exit point for the first video sequence, wherein the exit point determines a last frame to display of the first video sequence;
determining a number of pictures of the first video sequence that are already decoded into a decode picture buffer;
reading a first data field in the first video sequence to obtain a first value, wherein the value indicates a number of consecutive pictures prior to the exit point; and
initiating decoding of the second video sequence so that a sufficient number of pictures in the second video sequence are decoded at a time of displaying the last picture from the decode picture buffer so that displaying of pictures in the second video sequence can begin at a next picture output time.
37. The apparatus of claim 36 , wherein the memory further includes one or more instructions encoded therein for:
reading a second data field in the first video sequence to obtain a second value, wherein the second value indicates a number of decoded pictures in the decoded picture buffer (DPB).
38. A computer readable medium including one or more instructions encoded therein for splicing from a first video sequence to a second video sequence, wherein each video sequence includes encoded pictures that are decoded into decoded pictures in a decode order, wherein decoded pictures are displayed in a presentation order at picture output times, the memory comprising one or more instructions encoded therein for:
identifying an exit point for the first video sequence, wherein the exit point determines a last frame to display of the first video sequence;
determining a number of pictures of the first video sequence that are already decoded into a decode picture buffer;
reading a first data field in the first video sequence to obtain a first value, wherein the value indicates a number of consecutive pictures prior to the exit point; and
initiating decoding of the second video sequence so that a sufficient number of pictures in the second video sequence are decoded at a time of displaying the last picture from the decode picture buffer so that displaying of pictures in the second video sequence can begin at a next picture output time.
39. The non-transitory computer readable medium of claim 38 , further comprising one or more instructions encoded therein for:
reading a second data field in the first video sequence to obtain a second value, wherein the second value indicates a number of decoded pictures in the decoded picture buffer (DPB).