hi3520dv400 sample下的vdec 和 audio 不能同时运行

sample下的vdec 和 audio单独都是可以正确运行的；
两个同时运行，先运行 audio(能够播放出声音)再运行vdec 出现以下错误:

[Func]:MPI_AO_UpdateCircleBufferReadPtr [Line]:775 [Info]:Get AO(0) pub attr failed.
[Func]:MPI_AO_QueryCircleBufferReadData [Line]:709 [Info]:Get AO(0) pub attr failed.

[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
[Func]:HI_MPI_AO_SendFrame [Line]:1781 [Info]:can't get aodev0's attribute!
EVENT: HPD
HDMI start success.
wy x = 0,y = 0,W = 1920,H = 1080
get sink caps success!
SAMPLE_TEST: stop to receive stream and  instant to enable user pic now!
SAMPLE_TEST: Disable user pic and  start to receive stream now!
SAMPLE_TEST: stop to receive stream and  delay to enable user pic now!
SAMPLE_TEST: Disable user pic and  start to receive stream now!

声音没有了，视频开始显示。

请问为什么声音没了呢？这个错误如何解决