Intra-coded video frame caching for video telephony sessions

1. A method of processing video frame data of a video telephony (VT) call, the method comprising:

receiving, at a device, the video frame data of the VT call over a communications channel;

determining, by the device, that the received video frame data comprises i-frame data;

determining, by the device, that a video decoder of the device is in a pre-initialized state, the pre-initialized state representing a condition in which the video decoder cannot render the received video frame data for display;

based on the received video frame data comprising the i-frame data and the video decoder being in the pre-initialized state, storing, by the device, the i-frame data to a buffer of the device.

2. The method of claim 1 , the method further comprising:

detecting that the video decoder has transitioned from the pre-initialized state to an initialized state, the initialized state representing a condition in which the video decoder can render the received video frame data for display; and

based on the detected transition, retrieving the stored i-frame data from the buffer of the device;

decoding, by the video decoder, while in the initialized state, the retrieved i-frame data to form decoded i-frame data; and

rendering, by the video decoder, while in the initialized state, the decoded i-frame data for display.

3. The method of claim 2 , further comprising:

determining that a remote device that generated the received video frame data supports an audio video profile with feedback (AVPF) mode;

determining that a predetermined time has elapsed since the retrieved i-frame data was rendered for display; and

based on the predetermined time having elapsed since the retrieved i-frame data was rendered for display and the remote device supporting the AVPF mode:

generating an i-frame request, and

sending the generated i-frame request to the remote device.

4. The method of claim 2 , further comprising:

using, by the video decoder, while in the initialized state, the retrieved i-frame data to decode and render prediction frame data associated with the VT call.

5. The method of claim 1 , wherein a storage capacity of the buffer is equal to or greater than a maximum i-frame size that the device is configured to support.

6. The method of claim 1 , wherein the stored i-frame data is first i-frame data associated with a first i-frame, the method further comprising:

receiving, at the device, additional video frame data comprising second i-frame data associated with a second i-frame;

determining that the second i-frame was generated at a time more recent than a generation time of the first i-frame; and

based on the second i-frame having been generated at a time more recent than the generation time of the first i-frame,

overwriting, in the buffer, the first i-frame data with the second i-frame data.

7. The method of claim 1 , further comprising:

determining that a predetermined time has elapsed since the i-frame data was stored to the buffer; and

based on the predetermined time having elapsed since the i-frame data was stored to the buffer, determining that the stored i-frame data is no longer usable by the video decoder to render the video frame data of the VT call.

8. The method of claim 1 , further comprising:

in response to receiving the video frame data of the VT call, initiating a decoder initialization process with respect to the video decoder of the device, wherein the decoder initialization process is configured to transition the video decoder from the pre-initialized state to an initialized state, the initialized state representing a condition in which the video decoder can render the received video frame data for display.

9. The method of claim 1 , wherein determining that the received video frame data comprises the i-frame data comprises:

decapsulating a packet that includes the video frame data to obtain a video payload of the packet;

inspecting a first byte of the video payload; and

determining that the received video frame data comprises i-frame data based on the inspected first byte.

10. The method of claim 9 , wherein determining that the received video frame data comprises the i-frame data comprises:

determining, based on the inspected first byte indicating a decimal value of one hundred twenty eight (128), that the received video frame data comprises the i-frame data.

11. A device comprising:

a communication interface configured to receive, over a communications channel, video frame data of a video telephony (VT) call;

a memory;

a video decoder in communication with the memory; and

one or more processors in communication with the memory and the video decoder, the one or more processors being configured to:

determine that the video frame data received by the communication interface comprises i-frame data;

determine that the video decoder is in a pre-initialized state, the pre-initialized state representing a condition in which the video decoder cannot render the received video frame data for display; and

store, based on the video frame data received by the communication interface comprising the i-frame data and the video decoder being in the pre-initialized state, the i-frame data to the memory.

12. The device of claim 11 , wherein the memory implements a pre-initialization buffer, and wherein to store the i-frame data to the memory, the one or more processors are configured to store the i-frame data to the pre-initialization buffer.

13. The device of claim 12 , wherein the pre-initialization buffer includes storage capacity equal to or greater than a maximum i-frame size that the device is configured to support.

14. The device of claim 11 , wherein the device further comprises a display, and wherein the one or more processors are further configured to:

detect that the video decoder has transitioned from the pre-initialized state to an initialized state, the initialized state representing a condition in which the video decoder can render, for display, the video frame data received by the communication interface;

retrieve, based on the detected transition, the stored i-frame data from the memory;

and

cause the video decoder to:

decode the retrieved i-frame data to form decoded i-frame data, and

render the decoded i-frame data for output via the display.

15. The device of claim 14 , wherein the one or more processors are further configured to:

determine that a remote device that generated the received video frame data supports an audio video profile with feedback (AVPF) mode;

determine that a predetermined time has elapsed since the retrieved i-frame was rendered for output via the display device; and

based on the predetermined time having elapsed since the retrieved i-frame data was rendered for display and the remote device supporting the AVPF mode:

generate an i-frame request, and

send, via the communication interface, the generated i-frame request to the remote device.

16. The device of claim 14 , wherein the video decoder is configured to:

use, while in the initialized state, the retrieved i-frame data to decode and render prediction frame data associated with the VT call.

17. The device of claim 11 , wherein the stored i-frame data is first i-frame data associated with a first i-frame, wherein the communication interface is configured to receive, via the communications channel, additional video frame data comprising second i-frame data associated with a second i-frame, and wherein the one or more processors are further configured to:

determine that the second i-frame was generated at a time more recent than the generation time of the first i-frame; and

based on the second i-frame having been generated at a time more recent than a generation time of the first i-frame, overwrite, in the memory, the first i-frame data with the second i-frame data.

18. The device of claim 11 , wherein the one or more processors are further configured to:

determine that a predetermined time has elapsed since the i-frame data was stored to the memory; and

based on the predetermined time having elapsed since the i-frame data was stored to the memory, determine that the stored i-frame data is no longer usable by the video decoder to render the video frame data of the VT call.

19. The device of claim 11 , wherein the one or more processors are further configured to:

initiate, in response to the communication interface receiving the video frame data of the VT call, a decoder initialization process with respect to the video decoder of the device, wherein the decoder initialization process is configured to transition the video decoder from the pre-initialized state to an initialized state, the initialized state representing a condition in which the video decoder can render, for display, the video frame data received by the communication interface.

20. The device of claim 11 , wherein to determine that the video frame data received by the communication interface comprises the i-frame data, the one or more processors are further configured to:

decapsulate a packet that includes the video frame data to obtain a video payload of the packet;

inspect a first byte of the video payload; and

determine, based on the inspected first byte, that the video frame data received by the communication interface comprises the i-frame data.

21. The device of claim 20 , wherein to determine that the received video frame data comprises the i-frame data, the one or more processors are further configured to:

determine, based on the inspected first byte indicating a decimal value of one hundred twenty eight (128), that the received video frame data comprises the i-frame data.

22. An apparatus for processing video frame data of a video telephony (VT) call, the apparatus comprising:

means for receiving the video frame data of the VT call over a communications channel;

means for determining that the received video frame data comprises i-frame data;

means for determining that a video decoder of the apparatus is in a pre-initialized state, the pre-initialized state representing a condition in which the video decoder cannot render the received video frame data for display; and

means for storing, based on the received video frame data comprising the i-frame data and the video decoder being in the pre-initialized state, the i-frame data to a buffer of the apparatus.

23. The apparatus of claim 22 , further comprising:

means for detecting that the video decoder has transitioned from the pre-initialized state to an initialized state, the initialized state representing a condition in which the video decoder can render the received video frame data for display;

means for retrieving, based on the detected transition, the stored i-frame data from the buffer of the apparatus;

means for decoding, while the video decoder is in the initialized state, based on the detected transition, the retrieved i-frame data to form decoded i-frame data; and

means for rendering, while the video decoder is in the initialized state, based on the detected transition, the decoded i-frame data for display.

24. The apparatus of claim 23 , further comprising:

means for determining that a remote device that generated the received video frame data supports an audio video profile with feedback (AVPF) mode;

means for determining that a predetermined time has elapsed since the retrieved i-frame data was rendered for display;

means for generating, based on the predetermined time having elapsed since the retrieved i-frame data was rendered for display and the remote device supporting the AVPF mode, an i-frame request; and

means for sending the generated i-frame request to the remote device over the communications channel.

25. The apparatus of claim 23 , further comprising:

means for using the retrieved i-frame data to decode and render prediction video frame data associated with the VT call while the video decoder is in the initialized state.

26. The apparatus of claim 22 , wherein a storage capacity of the buffer is equal to or greater than a maximum i-frame size that the device is configured to support.

27. A non-transitory computer-readable storage medium encoded with instructions that, when executed, cause one or more processors of a device for processing video frame data of a video telephony (VT) call to:

receive the video frame data of the VT call over a communications channel;

determine that the received video frame data comprises i-frame data;

determine that a video decoder of the device is in a pre-initialized state, the pre-initialized state representing a condition in which the video decoder cannot render the received video frame data for display; and

based on the received video frame data comprising the i-frame data and the video decoder being in the pre-initialized state, store the i-frame data to a buffer of the device.

28. The non-transitory computer-readable storage medium of claim 27 , wherein the stored i-frame data is first i-frame data associated with a first i-frame, further encoded with instructions that, when executed, cause the one or more processors of the device to:

receive, via a communication interface, additional video frame data comprising second i-frame data associated with a second i-frame;

determine that the second i-frame was generated at a time more recent than a generation time of the first i-frame; and

based on the second i-frame having been generated at a time more recent than the generation time of the first i-frame, overwrite, in the buffer of the device, the first i-frame data with the second i-frame data.

29. The non-transitory computer-readable storage medium of claim 27 , further encoded with instructions that, when executed, cause the one or more processors of the device to:

determine that a predetermined time has elapsed since the i-frame data was stored to the memory; and

based on the predetermined time having elapsed since the i-frame data was stored to the buffer, determine that the stored i-frame data is no longer usable by the video decoder to render the video data of the VT call.

30. The non-transitory computer-readable storage medium of claim 27 , further encoded with instructions that, when executed, cause the one or more processors of the device to:

initiate, in response to receiving the video frame data, a decoder initialization process with respect to the video decoder of the device, wherein the decoder initialization process is configured to transition the video decoder from the pre-initialized state to an initialized state, the initialized state representing a condition in which the video decoder can render the received video frame data for display.