Methods and apparatus for monitoring compressed bitstreams
View Patent ↗Methods and an apparatus for monitoring compressed bitstreams are disclosed. The disclosed methods and apparatus receive an encoded signal including encoded video frames and determine if video represented by the encoded video frames is frozen or blacked out based on a comparison of sizes of the encoded frames.
1. A method of monitoring broadcast quality, comprising:
receiving an encoded signal including encoded frames at a processor, wherein the encoded signal further comprises encoded audio having frames including sub-band allocation values;
determining, at a processor, if video represented by the encoded frames includes one or more of a video freeze and a video blackout; and
determining, at a processor, if audio represented by the encoded signal is substantially silent based on the sub-band allocation values.
2. The method of claim 1 , wherein determining if video represented by the encoded frames includes one or more of a video freeze and a video blackout comprises comparing a first frame type and a second frame type.
3. The method of claim 1 , wherein the encoded signal comprises a motion picture experts group (MPEG) encoded signal.
4. The method of claim 3 , wherein determining if video represented by the encoded frames includes one or more of a video freeze and a video blackout comprises comparing an I-frame size and an average P-frame size.
5. The method of claim 4 , wherein determining if video represented by the encoded frames includes one or more of a video freeze and a video blackout comprises comparing an I-frame size and an average B-frame size.
6. The method of claim 1 , wherein determining if audio represented by the encoded signal is substantially silent comprises correlating sub-band allocation values of at least two audio frames.
7. The method of claim 6 , wherein determining if audio represented by the encoded signal is substantially silent further comprises comparing a maximum sub-band allocation to a threshold.
8. A computer accessible medium storing a plurality of computer accessible instructions that, when executed, cause a computer to:
receive an encoded signal including encoded video frames wherein the encoded signal further comprises encoded audio having frames including sub-band allocation values;
determine if video represented by the encoded video frames includes one or more of a video freeze and a video blackout; and
determine if audio represented by the encoded signal is substantially silent based on the sub-band allocation vales.
9. The computer accessible medium of claim 8 , wherein the encoded signal comprises a motion picture experts group (MPEG) encoded signal.
10. The computer accessible medium of claim 9 , wherein the determination whether video represented by the encoded video frames includes one or more of a video freeze and a video blackout comprises a comparison of an I-frame size and an average P-frame size.
11. The computer accessible medium of claim 10 , wherein the determination whether video represented by the encoded video frames includes one or more of a video freeze and a video blackout comprises a comparison of an I-frame size and an average B-frame size.
12. The computer accessible medium of claim 8 , wherein determining if audio represented by the encoded signal is substantially silent comprises correlating sub-band allocation values of at least two audio frames.
13. The computer accessible medium of claim 12 , wherein determining if audio represented by the encoded signal is substantially silent further comprises comparing a maximum sub-band allocation to a threshold.
14. A transmission station, comprising:
program source means for providing content including audio and video;
encoder means, coupled to the program source means, for generating an encoded signal including encoded video frames of the content;
uplink frequency converter means coupled to the encoder means for converting the encoded signal into a signal for transmission; and
a processor coupled to the encoder means, for receiving the encoded signal including encoded video frames and for determining if video represented by the encoded video frames includes one or more of a video freeze and a video blackout based on a comparison of sizes of the encoded frames.
15. The transmission station of claim 14 , wherein the comparison of sizes of the encoded frames comprises a comparison of a first frame type and a second frame type.
16. The transmission station of claim 14 , wherein the encoded signal comprises a motion picture experts group (MPEG) encoded signal.
17. The transmission station of claim 16 , wherein the comparison of sizes of the encoded frames comprises a comparison of an I-frame size and an average P-frame size.
18. The transmission station of claim 14 , wherein the encoded signal further comprises encoded audio having frames including sub-band allocation values and wherein the quality monitor means is further configured to cause the machine to determine if audio represented by the encoded signal is substantially silent based on the sub-band allocation values.
19. The transmission station of claim 18 , wherein determining if audio represented by the encoded signal is substantially silent comprises correlating sub-band allocation values of at least two audio frames.
20. The transmission station of claim 19 , wherein determining if audio represented by the encoded signal is substantially silent further comprises comparing a maximum sub-band allocation to a threshold.