Lock mutex error

[GregCornis]

I'm trying to connect a Canon camera to a M350 via the PSDK. However, I'm struggling with the live view, with the following message

Encoding frame 5
Encoded with frameSize=34929
[21.517][utils]-[Error]-[DjiFlowController_SendData:330) mutex lock error
[21.517][channel]-[Error]-[DjiHighSpeedDataChannel_SendVideoStreamData:609) Send video stream error: 0x000000E3.
[21.517][user]-[Error]-[startMockLiveView:756) send video stream error: 0x000000E3.

I have the same error when I call DjiPayloadCamera_GetVideoStreamState

[47.718][channel]-[Error]-[DjiHighSpeedDataChannel_GetVideoStreamState:547) Lock mutex error.
[47.718][user]-[Info]-[startMockLiveView:715) Video state: busy 0 - 0 0 0

Here is basically the code that I'm running

// Task to send Live View data
void *startMockLiveView(void *ctx) {
  while (1) {
    // Get H264 NAL from somewhere else
    DjiPayloadCamera_SendVideoStream((const uint8_t *) nal->p_payload, size);
    usleep(100000);
  }
}


registerAbstractionHandlers();        // Register Osal & Nal & UART etc handlers 
DjiCore_Init(&userInfo);              // Correct info, the rest of the PSDK works,
DjiPayloadCamera_Init();
DjiPayloadCamera_RegCommonHandler(&mockHandler);
DjiCore_ApplicationStart();
T_DjiOsalHandler *handler = DjiPlatform_GetOsalHandler();
T_DjiTaskHandle *task;
handler->TaskCreate("liveview", startMockLiveView, 2048, NULL, task);

I'm seeing a similar issue in the PSDK demo :

[12.065][core]-[Info]-[DjiIdentityVerify_UpdatePolicy:482) Update dji sdk policy file successfully
[13.204][infor]-[Info]-[DjiAircraftInfo_GetAdapterSerialNumber:806) Get serial number of Skyport V2 or X-Port is 39CDKCS0010013
[13.205][core]-[Info]-[DjiCore_Init:174) Identify AircraftType = Matrice 350 RTK, MountPosition = Payload Port NO1, SdkAdapterType = Skyport V2
[13.387][time_sync]-[Info]-[DjiTimeSync_PushAppTimeHandle:111) Current time: 2024.10.25 17:45:55.
[22.391][cam]-[Error]-[DjiPayloadCamera_RegMediaDownloadPlaybackHandler:987) lock mutex error: 0x000000E3.
[22.391][user]-[Error]-[DjiTest_CameraEmuMediaStartService:199) psdk camera media function init error.
[22.391][user]-[Error]-[main:249) camera emu media init error

Do you know what is going wrong ? Thanks

[GregCornis]

Edit : I've added

const T_DjiDataChannelBandwidthProportionOfHighspeedChannel bandwidthProportionOfHighspeedChannel =
        {10, 60, 30};
DjiHighSpeedDataChannel_SetBandwidthProportion(bandwidthProportionOfHighspeedChannel);

Now I don't have the warning anymore, and can successfully call DjiPayloadCamera_GetVideoStreamState. However no image is shown on DJI Pilot

[GregCornis]

I've also tried to set the format to H264_CUSTOM but that fails, though I'm doing it before ApplicationStart()

[25.272][cam]-[Error]-[DjiPayloadCamera_SetVideoStreamType:799) remove negotiated device sync error: 0x000000E1.
[25.272][user]-[Error]-[main:1179) Set stream type error

I'm sending video as NAL decoded with libx264 (annex B enabled), so it should be spec-compliant.

[dji-dev]

Agent comment from Leon in Zendesk ticket #120335:

Hello, which version of PSDK are you using? If it is 3.9.1, it only supports setting DJI-H264 channel, but not Custom-H264. We suggest that you replace the H264 video file pushed in the sample to your own directory, use your code to push the sample file, and see if there is a black screen and whether it can be pushed successfully. This way, you can check whether there is a problem with your own code implementation.

°°°

[GregCornis]

Ok I didn't know that (I don't think it's written in the docs). So what is DJI-H264 ? It looks like it's NAL H264 concatenated with audio ({0x00, 0x00, 0x00, 0x01, 0x09, 0x10}) .
Also, are there specific H264 parameters to use ? Here is what I'm using

    // x264 param
    x264_param_default_preset(&param, "ultrafast", NULL)
    param.i_bitdepth = 8;
    param.i_csp = X264_CSP_I422;
    param.b_vfr_input = 0;
    param.b_repeat_headers = 1;
    param.b_annexb = 1;
    param.i_bframe = 0;
    param.b_cabac = 0;
    param.b_deblocking_filter = 0;
    param.i_bframe_adaptive = 0;
    param.analyse.b_transform_8x8 = 0;
    param.analyse.i_me_method = X264_ME_DIA;
    param.analyse.i_trellis = 0;
    param.rc.b_mb_tree = 0;
    param.i_sync_lookahead = 0;
    param.rc.i_lookahead = 0;

[dji-dev]

Agent comment from Leon in Zendesk ticket #120335:

Hello, sorry, this is our oversight. We did not inform developers of this issue in advance or publicly. We are currently fixing it and will soon be able to use two channels of streaming separately. We have given the standards for video streaming in the document, which are for DJI format and Custom format respectively. You can check here:
https://developer.dji.com/doc/payload-sdk-tutorial/en/model-instruction/payload-develop-criterion.html#video-stream-transmission-standard
In the code, you only need to pay attention to the setting of the function:
DjiPayloadCamera_SetVideoStreamType(DJI_CAMERA_VIDEO_STREAM_TYPE_H264_DJI_FORMAT);
s_cameraVideoStreamType = DJI_CAMERA_VIDEO_STREAM_TYPE_H264_DJI_FORMAT;

°°°