streamer default h265

bendraper

It looks like if you are to use voxl-streamer to encode a RAW8 pipe, it will default to encoding it in h264. Is there a way to change this to 265? I tried recompiling the service and editing the pipeline.c file to use the 265 encoder where applicable (and changed other mentions of 264 to 265) but the stream fails when I try to start it. Is there a simpler way to achieve what I'm trying to do that I'm missing?

Alex Kushleyev

@bendraper , unfortunately we have not tried using voxl-streamer for encoding h265. voxl-camera-server does support h265 encoding and by the way we recently fixed the CBR functionality : https://docs.modalai.com/voxl-camera-server/#constant-quantization-vs-constant-bitrate-mode

Do you need to encode an image that you modify outside of the camera server?

If you are willing to share the changes you made while trying to get it to work, i can test it and see if I can spot anything that's easy to fix (you could provide a patch or link to a fork). If we can get it to work, it could be a nice extension of voxl-streamer.

Alex

bendraper

@Alex-Kushleyev Thanks for getting back. Here's our fork of voxl-streamer and the specific commit

As you can see, not much going on here. I just noticed how the 265 omx encoder object would be created but just unused when encoding a raw stream (using hires_small_grey in my tests which is RAW8).

When I try to connect to the stream, streamer gives the following

voxl2-mini:~$ voxl-streamer -i hires_small_grey -s -b 2000000 -p 554
Waiting for pipe hires_small_grey to appear
Found Pipe
detected following stats from pipe:
w: 1024 h: 768 fps: 30 format: RAW8
Stream available at rtsp://127.0.0.1:554/live
A new client rtsp://169.254.4.2:40732(null) has connected, total clients: 1
Camera server Connected
gbm_create_device(156): Info: backend name is: msm_drm
rtsp client disconnected, total clients: 0
no more rtsp clients, closing source pipe intentionally

and using ffmpeg to connect gives the following

ffplay version 4.4.2-0ubuntu0.22.04.1 Copyright (c) 2003-2021 the FFmpeg developers
  built with gcc 11 (Ubuntu 11.2.0-19ubuntu1)
  configuration: --prefix=/usr --extra-version=0ubuntu0.22.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 70.100 / 56. 70.100
  libavcodec     58.134.100 / 58.134.100
  libavformat    58. 76.100 / 58. 76.100
  libavdevice    58. 13.100 / 58. 13.100
  libavfilter     7.110.100 /  7.110.100
  libswscale      5.  9.100 /  5.  9.100
  libswresample   3.  9.100 /  3.  9.100
  libpostproc    55.  9.100 / 55.  9.100
[rtsp @ 0x74e358000cc0] method DESCRIBE failed: 503 Service Unavailable
rtsp://169.254.4.1:554/live: Server returned 5XX Server Error reply

bendraper

@Alex-Kushleyev it's probably just my gstreamer ignorance and it not being as simple to set up an h265 stream as swapping our h264 with h265

Alex Kushleyev

@bendraper , you got 90% there!

I just tested your version and was able to reproduce the issue, but the following change fixes it:

from

"profile", G_TYPE_STRING, "baseline",

to

"profile", G_TYPE_STRING, "main",

There is no baseline profile in h265. Please try it - i was able to stream h265 with modified voxl-streamer and play using ffplay.

full diff below. We will test more and probably mainline this soon.

Alex

diff --git a/src/pipeline.c b/src/pipeline.c
index 53f47b7..5f88315 100644
--- a/src/pipeline.c
+++ b/src/pipeline.c
@@ -398,9 +398,9 @@ GstElement *create_custom_element(GstRTSPMediaFactory *factory, const GstRTSPUrl
     // g_object_set(context->h264_parser, "alignment", "nal", NULL);
 
     // Configure the OMX encoder
-    g_object_set(context->omx_encoder, "control-rate", 1, 
+    g_object_set(context->omx_h265_encoder, "control-rate", 1, 
                                        "interval-intraframes", 30, NULL);
-    g_object_set(context->omx_encoder, "target-bitrate",
+    g_object_set(context->omx_h265_encoder, "target-bitrate",
                  context->output_stream_bitrate, NULL);
 
     // Configure the RTP input queue
@@ -443,10 +443,10 @@ GstElement *create_custom_element(GstRTSPMediaFactory *factory, const GstRTSPUrl
         gst_caps_unref(filtercaps);
 
         // Configure the caps filter to reflect the output of the OMX encoder
-        filtercaps = gst_caps_new_simple("video/x-h264",
+        filtercaps = gst_caps_new_simple("video/x-h265",
                                         "width", G_TYPE_INT, context->output_stream_width,
                                         "height", G_TYPE_INT, context->output_stream_height,
-                                        "profile", G_TYPE_STRING, "baseline",
+                                        "profile", G_TYPE_STRING, "main",
                                         NULL);
     }
     if ( ! filtercaps) {
@@ -482,10 +482,10 @@ GstElement *create_custom_element(GstRTSPMediaFactory *factory, const GstRTSPUrl
                         context->video_rotate,
                         context->video_rotate_filter,
                         context->encoder_queue,
-                        context->omx_encoder,
+                        context->omx_h265_encoder,
                         context->rtp_filter,
                         context->rtp_queue,
-                        context->rtp_payload,
+                        context->rtp_h265_payload,
                         NULL);
     }
 
@@ -536,10 +536,10 @@ GstElement *create_custom_element(GstRTSPMediaFactory *factory, const GstRTSPUrl
         last_element = context->video_rotate_filter;
         if ( ! gst_element_link_many(last_element,
                                      context->encoder_queue,
-                                     context->omx_encoder,
+                                     context->omx_h265_encoder,
                                      context->rtp_filter,
                                      context->rtp_queue,
-                                     context->rtp_payload,
+                                     context->rtp_h265_payload,
                                      NULL)) {
             M_ERROR("Couldn't finish pipeline linking part 4\n");
             return NULL;

bendraper

@Alex-Kushleyev Incredible, it works! Thanks Alex

Alex Kushleyev

@bendraper , great! Thank you for doing most of the work

I will add an option to specify output encoder type (for the unencoded input case) so h264/5 can be selected via command line argument.

Alex

bendraper

@Alex-Kushleyev Awesome. On a different note, do you know why ffmpeg has no issue with the aspect ratio of the stream but in QGroundControl, the stream seems to be vertically squished? I would guess ffmpeg correctly makes some assumptions about the aspect ratio that voxl-streamer doesn't outwardly declare and maybe QGC doesn't make these assumptions?

Alex Kushleyev

@bendraper , i believe that when the encoder starts producing frames, the first frame is a header frame that has the stream description. This condition is also triggered if client disconnects (encoding stops) and then reconnects, causing the stream to start again. I am not sure what the whole pipeline looks like for getting video to QGC, but if the header is not sent over or is not parsed, this can lead to incorrect stream dimension? However i would assume that is the header is lost, the video would be completely garbled, not just aspect ratio, which probably means that QGC is in fact decoding correctly but simply rendering the image using a fixed aspect ratio…

Alex Kushleyev

I just pushed two updates to a branch of voxl-streamer:

https://gitlab.com/voxl-public/voxl-sdk/services/voxl-streamer/-/commits/enable-h265-encode
add option to use h265 encoder for non-encoded input frames (use either command line option -e h265 or --encoder h265 or in voxl-streamer.conf file "encoder": "h264"
switch the h264 profile from baseline to main which allows using CABAC coding, which has better compression properties than default CAVLC at some expense of HW encoder usage (negligible) and potential additional cpu usage on decoding side. However, this will definitely be better for low bandwidth streaming. h265 uses CABAC coding as the only option.

It seems like it's working well, but not much testing has been done so far..

Alex