I am refactoring a gstreamer element that takes two CSI cameras using the argus lib from nvidia - the refactor is from the old nvbuf_utils to NvUtils, https://developer.nvidia.com/sites/default/files/akamai/embedded/nvbuf_utils_to_nvutils_migration_guide.pdf .
The element itself consumes > 2 CSI cameras, syncs the frames and sends them to the src pad of the element. In the original element, the following pipelines respectively output 1 video with 1 frame and 1 video with two frames side-by-side.
Single Pipeline:
gst-launch-1.0 -v nvarguscameras sensors='0 1' silent=false sync-threshold=16700000 ! "video/x-raw(memory:NVMM),format=(string)NV12,width=(int)1920,height=(int)1080,framerate=(fraction)30/1" ! nvvideoconvert ! nvv4l2h264enc ! h264parse ! filesink location=single.mp4 -e
Double Pipeline:
gst-launch-1.0 -v nvarguscameras master-sensor=0 sensors='0 1' sync-threshold=16700000 silent=false ! nvvideoconvert ! "video/x-raw(memory:NVMM),format=(string)NV12,width=(int)1920,height=(int)1080,framerate=(fraction)30/1" ! nvmultistreamtiler width=3840 height=1080 rows= columns=2 ! nvvideoconvert ! 'video/x-raw(memory:NVMM), format=(string)I420' ! nvv4l2h264enc bitrate=800 ! h264parse ! qtmux ! filesink location="test.mp4" -e
In hte original implementation, the API used the NvBufferTransform to perform some modification on the frame. However, this time i just want to pass the frames through.
For reference the frameInfo is struct that holds the width,height and fd of the buffer from another thread.
Original implementation:
// copy buffer surface
GST_DEBUG_OBJECT (src, "consumer prepare buffer surfaces");
GstMapInfo outmap = GST_MAP_INFO_INIT;
gst_buffer_map (buffer, &outmap, GST_MAP_WRITE);
NvBufSurface* surf = (NvBufSurface*) outmap.data;
assert(surf->batchSize == src->sensors_num);
assert(frames_buffer->len <= src->sensors_num);
surf->numFilled = 0;
for (int i = 0; i < frames_buffer->len; i++) {
GST_DEBUG_OBJECT (src, "consumer fill buffer surface %d", i);
NvArgusFrameInfo *frameInfo = g_array_index(frames_buffer, NvArgusFrameInfo*, i);
gint retn = NvBufferTransform (frameInfo->fd, (gint)surf->surfaceList[i].bufferDesc, &src->transform_params);
if (retn != 0) {
GST_ERROR_OBJECT(src, "consumer NvBufferTransform Failed");
break;
}
surf->numFilled++;
// attach frame meta
NvDsFrameMeta *frame_meta = nvds_acquire_frame_meta_from_pool(batch_meta);
frame_meta->pad_index = i;
frame_meta->batch_id = i;
frame_meta->frame_num = frameInfo->frameNum;
frame_meta->buf_pts = frameInfo->frameTime;
frame_meta->ntp_timestamp = 0;
frame_meta->source_id = src->sensors[i];
frame_meta->num_surfaces_per_frame = 1;
frame_meta->source_frame_width = frameInfo->width;
frame_meta->source_frame_height = frameInfo->height;
nvds_add_frame_meta_to_batch(batch_meta, frame_meta);
}
gst_buffer_unmap (buffer, &outmap);
if (surf->numFilled != frames_buffer->len ||
batch_meta->num_frames_in_batch != frames_buffer->len) {
GST_ERROR_OBJECT(src, "consumer failed fill nvmm buffer");
break;
}
}
Updated Implementation:
// copy buffer surface
GST_DEBUG_OBJECT (src, "consumer prepare buffer surfaces");
GstMapInfo outmap = GST_MAP_INFO_INIT;
if (!gst_buffer_map (buffer, &outmap, GST_MAP_WRITE)){
g_print ("Error: Failed to map gst buffer\n");
break;
}
NvBufSurface* surf = (NvBufSurface*) outmap.data;
assert(surf->batchSize == src->sensors_num);
assert(frames_buffer->len <= src->sensors_num);
surf->numFilled = 0;
for (int i = 0; i < frames_buffer->len; i++) {
NvArgusFrameInfo *frameInfo = g_array_index(frames_buffer, NvArgusFrameInfo*, i);
surf->surfaceList[i].bufferDesc = frameInfo->fd;
surf->numFilled++;
NvDsFrameMeta *frame_meta = nvds_acquire_frame_meta_from_pool(batch_meta);
frame_meta->pad_index = i;
frame_meta->batch_id = i;
frame_meta->frame_num = frameInfo->frameNum;
frame_meta->buf_pts = frameInfo->frameTime;
frame_meta->ntp_timestamp = 0;
frame_meta->source_id = src->sensors[i];
frame_meta->num_surfaces_per_frame = 1;
frame_meta->source_frame_width = frameInfo->width;
frame_meta->source_frame_height = frameInfo->height;
nvds_add_frame_meta_to_batch(batch_meta, frame_meta);
}
gst_buffer_unmap (buffer, &outmap);
if (surf->numFilled != frames_buffer->len ||
batch_meta->num_frames_in_batch != frames_buffer->len) {
GST_ERROR_OBJECT(src, "consumer failed fill nvmm buffer");
break;
}
}
The single pipeline works fine, i can get the video of one frame, but when i try the second pipeline i just get a green video. Any suggestions here guys ?
I tried using the NvBufSurfTransform instead of just passing the fd to the NvBufSurface, but this yields the same results.
Both frames are available in my updated code as i can hard code in the for loop to choose which one is present in the single video pipeline.
