Green screen in the beginning of video call

[nanang]

In YUV format, if the buffer is all zero, it will be displayed as green (as compared to RGBA format, where it will be black). Unfortunately currently buffer is initialized with zero. As most video codecs uses I420 format, perhaps it is better to have special initialization for I420 so the screen will be black.

The allocation and initialization of frame buffer is done in pjmedia/src/pjmedia/vid_port.c, in function pjmedia_vid_port_create().

[nanang]

In 5862:

Close #2103: Initiate video port frame buffer with black for I420 & YV12 formats.

[ming]

In 5866:

Re #2103: Move the black screen initialization of the renderer to pjmedia_vid_port_start() instead

[ming]

In 5867:

Re #2103: Darwin's capture device is passive, thus the video port's clock will fetch the frames much earlier than when the device is ready, getting zero frames and resulting in green screen on the remote side.

[ming]

In 5868:

Re #2103:
A couple of improvements:

• Now initialize both video port's renderer AND capture buffer
• Support RGB format as well.

Known limitation: YUV currently only supports I420 and YV12