Enforcing synchronization by embedding audio within video frame data
View Patent ↗Synchronization of audio and video data can be enforced by embedding audio within video frame data. In a network environment in which audio and video data are generated on a source computing device and then transferred over the network to a destination computing device for output, the source computing device can be configured to encode the video data into an encoded video stream. As part of this encoding, the source computing device can also embed audio in the encoded video stream in a manner that associates the audio with corresponding video frames. The encoded video stream with the embedded audio can then be transferred over the network. The destination computing device can be configured to parse the encoded video stream to remove the audio and route it to an audio buffer and then route the encoded video stream to a GPU.
1. A method for enforcing synchronization by embedding audio within video frame data, the method comprising:
receiving, on a source computing device, a sequence of audio segments;
for each received audio segment, embedding the audio segment in a network abstraction layer (NAL) unit of an access unit that defines a corresponding video frame; and
transmitting the access units having the NAL units with the embedded audio segments over a network to a destination computing device.
2. The method of claim 1 , wherein each audio segment represents a number of audio samples.
3. The method of claim 1 , wherein the audio samples represented in each audio segment correspond in time with the corresponding video frame.
4. The method of claim 1 , wherein the NAL unit comprises a Supplemental Enhancement Information (SEI) NAL unit.
5. The method of claim 4 , wherein the SEI NAL unit has a payload of type 5.
6. The method of claim 1 , wherein embedding the audio segment in the NAL unit comprises storing the audio segment in an existing NAL unit.
7. The method of claim 1 , wherein embedding the audio segment in the NAL unit comprises adding the NAL unit to the access unit.
8. The method of claim 1 , wherein the access units conform to the H.264 or the H.265 standard.
9. The method of claim 1 , further comprising:
receiving, at the destination computing device, the access units having the NAL units with the embedded audio segments;
processing the access units to extract the audio segments from the NAL units;
providing the audio segments to an audio buffer; and
providing the access units to a graphics processing unit (GPU).
10. The method of claim 9 , wherein processing the access units to extract the audio segments from the NAL units comprises examining the NAL units to detect SEI NAL units having a payload of type 5 and extracting the payload from the detected SEI NAL units.
11. The method of claim 9 , wherein the NAL units with the embedded audio segments are removed from the access units prior to providing the access units to the GPU.
12. The method of claim 9 , wherein the access units provided to the GPU still have the NAL units with the embedded audio segments.
13. A method for enforcing synchronization by embedding audio within video frame data, the method comprising:
receiving, at a destination computing device, a sequence of access units, each access unit defining a corresponding video frame;
processing each access unit by examining network abstraction layer (NAL) units of the access unit;
upon detecting a Supplemental Enhancement Information (SEI) NAL unit in an access unit, extracting a payload of the SEI NAL unit and storing the payload in an audio buffer; and
providing each access unit to a GPU graphics processing unit (GPU).
14. The method of claim 13 , wherein detecting an SEI NAL unit in an access unit comprises detecting an SEI NAL unit having a payload type identifying a payload as user data.
15. The method of claim 14 , wherein the payload type identifying a payload as user data comprises a payload of type 5.
16. The method of claim 13 , further comprising:
removing the SEI NAL unit from the access unit.
17. The method of claim 13 , wherein the access units provided to the GPU still include the SEI NAL unit.
18. The method of claim 13 , wherein the payload of the SEI NAL unit in each access unit comprises an audio segment corresponding to a video frame defined by the access unit.
19. One or more computer storage media storing computer-executable instructions which when executed implement an encoder that is configured to perform the following:
receive audio and video data; and
generate an encoded video stream by:
creating an access unit for each frame defined in the video data; and
for each respective access unit, storing a segment of the audio in a Supplemental Enhancement Information (SEI) network abstraction layer (NAL) unit of the respective access unit.
20. The computer storage media of claim 19 , wherein storing a segment of the audio in an SEI NAL unit of the access unit comprises configuring a payload type of the SEI NAL unit to have a value identifying the payload as user data.