RTSP cams is not working in 4.6.2

[MrDimly]

Hello
I use Motion 4.3.2
Have some cam with rtsp urls
After update to 4.6.0 i have error from 1 rtsp cam (other rtsp is working correctrly)
HTTP-cgi is working but resolution is low

[3:av0:CamBW] [INF] [NET] [Aug 05 13:19:25] netcam_init_swdecoder: norm: Initializing decoder
[3:av0:CamBW] [INF] [ENC] [Aug 05 13:19:25] ffmpeg_avcodec_log: Invalid NAL unit 0, skipping.
[3:av0:CamBW] [INF] [ENC] [Aug 05 13:19:25] ffmpeg_avcodec_log: VPS 0 does not exist
[3:av0:CamBW] [ERR] [NET] [Aug 05 13:19:25] netcam_rtsp_decoder_error: norm: avcodec_open2: Invalid data found when processing input
[3:ml3:CamBW] [ERR] [NET] [Aug 05 13:19:25] netcam_rtsp_open_context: norm: Unable to open codec context: Operation not permitted
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:25] netcam_rtsp_cleanup: norm: Shutting down network camera.
[3:ml3:CamBW] [NTC] [NET] [Aug 05 13:19:25] netcam_rtsp_cleanup: Normal resolution: Shut down complete.
[3:ml3:CamBW] [ERR] [VID] [Aug 05 13:19:25] vid_start: Netcam RTSP failed to open
[3:ml3:CamBW] [WRN] [ALL] [Aug 05 13:19:25] motion_init: Could not fetch initial image from camera
[3:ml3:CamBW] [WRN] [ALL] [Aug 05 13:19:25] motion_init: Motion continues using width and height from config file(s)
[3:ml3:CamBW] [NTC] [ALL] [Aug 05 13:19:25] image_ring_resize: Resizing pre_capture buffer to 1 items
[3:ml3:CamBW] [NTC] [ALL] [Aug 05 13:19:25] image_ring_resize: Resizing pre_capture buffer to 8 items
[3:ml3:CamBW] [WRN] [ALL] [Aug 05 13:19:30] mlp_retry: Retrying until successful connection with camera
[3:ml3:CamBW] [NTC] [VID] [Aug 05 13:19:30] vid_start: Opening Netcam RTSP
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_rtsp_set_parms: Setting up norm stream.
[3:ml3:CamBW] [DBG] [ALL] [Aug 05 13:19:30] util_parms_add: Parsed: >decoder< >NULL<
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_rtsp_set_path: Setting up rtsp via netcam
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_rtsp_set_options: norm: Setting rtsp/rtmp
[3:ml3:CamBW] [DBG] [ALL] [Aug 05 13:19:30] util_parms_add: Parsed: >rtsp_transport< >tcp<
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_rtsp_set_options: norm: option: rtsp_transport = tcp
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_rtsp_open_context: norm: Opened camera(CamBW)
[3:ml3:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: Invalid NAL unit 0, skipping.
[3:ml3:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: VPS 0 does not exist
[3:ml3:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: Invalid NAL unit 0, skipping.
[3:ml3:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: VPS 0 does not exist
[3:ml3:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: PTL information too short
[3:av0:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_init_swdecoder: norm: Initializing decoder
[3:av0:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: Invalid NAL unit 0, skipping.
[3:av0:CamBW] [INF] [ENC] [Aug 05 13:19:30] ffmpeg_avcodec_log: VPS 0 does not exist
[3:av0:CamBW] [ERR] [NET] [Aug 05 13:19:30] netcam_rtsp_decoder_error: norm: avcodec_open2: Invalid data found when processing input
[3:ml3:CamBW] [ERR] [NET] [Aug 05 13:19:30] netcam_rtsp_open_context: norm: Unable to open codec context: Operation not permitted
[3:ml3:CamBW] [INF] [NET] [Aug 05 13:19:30] netcam_rtsp_cleanup: norm: Shutting down network camera.
[3:ml3:CamBW] [NTC] [NET] [Aug 05 13:19:30] netcam_rtsp_cleanup: Normal resolution: Shut down complete.
[3:ml3:CamBW] [ERR] [VID] [Aug 05 13:19:30] vid_start: Netcam RTSP failed to open

[Mr-Dave]

Are you comfortable editing code, recompiling, testing and willing to spend time to investigate this?

[MrDimly]

I am a Delphi and Java developer, and I have never compiled C++ on Linux (and I don't write C++). But I have experience debugging other people's code in different strange languages ​​I think the error is only with my camera, and only I must to dig into it. Although it is a standard StarCam, like others that work.

As an variant...
Can you write in 5 words the compilation instructions (and prerequisites) and an interesting moment in the code for this error?
I think it func netcam_rtsp_decoder_error in netcam_rtsp.c, and need added log "what happened" and compare with other cams.

Maybe I can do it, I have long dreamed of becoming a contributor to an interesting project, if i will have enough time

[Mr-Dave]

Well, lets try 5 paragraphs (instead of words).

1. Get and compile the code without any changes. (This assumes you are on a debian based distro)

 sudo apt-get install autoconf automake autopoint build-essential pkgconf libtool libzip-dev libjpeg-dev git libavformat-dev libavcodec-dev libavutil-dev libswscale-dev libavdevice-dev libwebp-dev gettext libmicrohttpd-dev 
 cd ~
 git clone https://github.com/Motion-Project/motion.git
 cd motion
 git checkout 4.6
 autoreconf -fiv
 ./configure
 make

2. Close / stop existing motion application and test the new one.

   sudo systemctl stop motion
   ~/motion/src/motion -c /etc/motion/motion.conf
   

3. Assuming that 2 above still reported a problem with the camera, test a change.
   Open the netcam_rstp.c file in ~/motion/src using a text editor and find this line
   change it from
   rtsp_data->codec_context->err_recognition = AV_EF_EXPLODE;
   to
   rtsp_data->codec_context->err_recognition = AV_EF_IGNORE_ERR;

Save the file.
Go back to the terminal screen, recompile and test again.

  make
  ~/motion/src/motion -c /etc/motion/motion.conf

4. If it still fails, go back to the same section and try to comment out the TWO lines in that section by using a //
   Change

  rtsp_data->codec_context->error_concealment = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
  rtsp_data->codec_context->err_recognition = AV_EF_EXPLODE;

to

  //rtsp_data->codec_context->error_concealment = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
  //rtsp_data->codec_context->err_recognition = AV_EF_EXPLODE;

Save file.
Recompile, test again.

  make
 ~/motion/src/motion -c /etc/motion/motion.conf

5. Finally, re-start the official distribution of Motion and report back results.

   sudo systemctl start motion
   

[MrDimly]

Thanks for such detailed instructions, I thought I'd have to find the problem myself

I did steps 1,2 on a clean virtual machine, everything is ok
I connected 2 StarCam cameras, one works RTSP, the second one has topic error

After start the errors again on second cam - it's ok
Changed to
rtsp_data->codec_context->err_recognition = AV_EF_IGNORE_ERR;

The camera is repaired

[2:av0:CamBW] [INF] [NET] [Aug 17 11:12:36] netcam_init_swdecoder: norm: Initializing decoder
[2:av0:CamBW] [INF] [ENC] [Aug 17 11:12:36] ffmpeg_avcodec_log: VPS 0 does not exist
[2:av0:CamBW] [INF] [NET] [Aug 17 11:12:36] netcam_rtsp_open_codec: norm: Decoder opened
[2:ml2:CamBW] [DBG] [NET] [Aug 17 11:12:36] netcam_check_buffsize: expanding buffer from [0/0] to [0/3112960] bytes.
[2:ml2:CamBW] [INF] [ENC] Above message repeats 1 times

Than I skipped steps 4,5 as not matters

As I understand it, AV_EF_IGNORE_ERR does not solve the problem, but skips the error?
Problem in the camera firmware or will you include AV_EF_IGNORE_ERR in the new build?

[Mr-Dave]

Yes, the new setting just ignores the reported errors in the codec from the camera firmware. I'll push some revisions shortly to change the setting in the Motion code.

Thanks for testing/confirming the change works.