Title: Full Hardware Acceleration for USB Webcam 1080p@30fps to H.264 RTSP Stream on Raspberry Pi 4
Description:
I’m trying to achieve full GPU hardware acceleration for encoding video from a USB webcam (1920x1080@30fps) to H.264 RTSP stream using ffmpeg via MediaMTX Docker on a Raspberry Pi 4 Model B (4GB with PoE+ HAT and fan).
Current Setup:
Raspberry Pi 4B 4GB with PoE+ HAT
OS: Debian GNU/Linux 12 (bookworm) aarch64Kernel: 6.6.74-v8+ #1844 SMP PREEMPT Mon Jan 27 11:41:19 GMT 2025
Docker Compose:
MediaMTX Configuration (mediamtx.yml):
Problem:
MediaMTX, ffmpeg streaming, and hardware-accelerated encoding to H.264 using h264_v4l2m2m are working. However, CPU usage spikes due to pixel format conversion from MJPEG to yuv420p, which is required by the h264_v4l2m2m encoder. This pixel format conversion is handled by the CPU, causing a bottleneck.
What I’m Looking For:
I’m seeking a method to achieve full GPU hardware acceleration:
Either directly encode the MJPEG stream to H.264 using hardware acceleration.
Or hardware encode the MJPEG to yuv420p, and then to H.264 using GPU, bypassing CPU for pixel format conversion.
Additional Information:
The /dev/video11 device is the hardware encoder (bcm2835-codec) on the Raspberry Pi:
I had to add /dev/video11 in Docker to access the hardware encoder, and modified the MediaMTX configuration accordingly. Despite this, the pixel format conversion remains a CPU-bound process.
Any suggestions or tools that could help pipe the 1080p@30fps stream from /dev/video0 to the HW encoder and output in yuv420p format without CPU bottleneck would be greatly appreciated.
Thanks in advance!
Description:
I’m trying to achieve full GPU hardware acceleration for encoding video from a USB webcam (1920x1080@30fps) to H.264 RTSP stream using ffmpeg via MediaMTX Docker on a Raspberry Pi 4 Model B (4GB with PoE+ HAT and fan).
Current Setup:
Raspberry Pi 4B 4GB with PoE+ HAT
OS: Debian GNU/Linux 12 (bookworm) aarch64Kernel: 6.6.74-v8+ #1844 SMP PREEMPT Mon Jan 27 11:41:19 GMT 2025
Docker Compose:
Code:
services:mediamtx:image: bluenviron/mediamtx:latest-ffmpeg-rpirestart: alwaysenvironment:- MTX_RTSPTRANSPORTS=tcp- MTX_WEBRTCADDITIONALHOSTS=192.168.1.1XXports:- '8559:8559'devices:- "/dev/snd:/dev/snd"- "/dev/video11:/dev/video11"- "/dev/video0:/dev/video0"volumes:- /home/user/Documents/mediamtx/mediamtx_cam3.yml:/mediamtx.yml- /etc/localtime:/etc/localtime:roCode:
rtspAddress: :8559writeQueueSize: 8192protocols: [tcp]paths:swissten:runOnInit: >ffmpeg -hide_banner -hwaccel drm -thread_queue_size 64 -f v4l2 -input_format mjpeg -video_size 1920x1080 -framerate 30 -i /dev/video0 -f alsa -thread_queue_size 1024 -ac 2 -ar 48000 -i plughw:webcam -vsync 2 -b:v 4000k -maxrate 8000k -bufsize 7000k -acodec aac -b:a 226k -vf "format=yuv420p,vflip,hflip,drawtext=fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf:text='%{localtime:%d.%m.%Y - %H\:%M\:%S}':fontcolor=white:fontsize=20:borderw=2:bordercolor=black:x=w-tw-10:y=h-th-10" -c:v h264_v4l2m2m -preset ultrafast -tune zerolatency -f rtsp rtsp://localhost:8559/swissten -rtsp_transport tcprunOnInitRestart: yesMediaMTX, ffmpeg streaming, and hardware-accelerated encoding to H.264 using h264_v4l2m2m are working. However, CPU usage spikes due to pixel format conversion from MJPEG to yuv420p, which is required by the h264_v4l2m2m encoder. This pixel format conversion is handled by the CPU, causing a bottleneck.
What I’m Looking For:
I’m seeking a method to achieve full GPU hardware acceleration:
Either directly encode the MJPEG stream to H.264 using hardware acceleration.
Or hardware encode the MJPEG to yuv420p, and then to H.264 using GPU, bypassing CPU for pixel format conversion.
Additional Information:
The /dev/video11 device is the hardware encoder (bcm2835-codec) on the Raspberry Pi:
Code:
[h264_v4l2m2m @ 0x5594dd9d20] Using device /dev/video11[h264_v4l2m2m @ 0x5594dd9d20] driver 'bcm2835-codec' on card 'bcm2835-codec-encode' in mplane mode[h264_v4l2m2m @ 0x5594dd9d20] requesting formats: output=YU12 capture=H264Any suggestions or tools that could help pipe the 1080p@30fps stream from /dev/video0 to the HW encoder and output in yuv420p format without CPU bottleneck would be greatly appreciated.
Thanks in advance!
Statistics: Posted by Peterkal007 — Fri Feb 07, 2025 11:36 pm — Replies 0 — Views 25