How to add transparent watermark.png over RTMP h264 stream using ffmpeg?

Question

I have a raspberry Pi with a new camera module connected to (in this case) Bambuser. You can see the stream here , this is from a windmill in the Netherlands (the camera position will be better in a few weeks).

I have a stream working successfully, but now I want to add an image (alpha-transparent png) on ​​top of the input stream, which is transmitted over the channel to ffmpeg for streaming to Bambuser.

Currently, I am using the following command (user details destroyed) to successfully transfer the stream from the raspberry camera module (this is great, HD and all, hardware rendering) to Bambuser, following an excellent tutorial from Slickstreamer:

raspivid -t 999999999 -w 960 -h 540 -fps 25 -b 500000 -o - | ffmpeg -i - -vcodec copy -an -metadata title="STREAM NAME" -f flv rtmp://USER_X.fme.bambuser.com/b-fme/USER_STREAM_KEY_X 

I followed the docs about ffmpeg and it seems to me that I should use the -vf command to apply the "movies:" filter, for example:

 raspivid -t 999999999 -w 960 -h 540 -fps 25 -b 500000 -o - | ffmpeg -i - -vf "movie='/home/USER/watermark.png' [logo]; [in][logo] overlay=main_w-overlay_w-10:10 [out]" -vcodec copy -an -metadata title="STREAM NAME" -f flv rtmp://USER_X.fme.bambuser.com/b-fme/USER_STREAM_KEY_X 

and various other -vf commands, such as '-vf vflip' or '-vf mandelbrot'. But this doesn't seem to work, as the stream simply shows a direct input from Raspberry's camera.

This is the result when the following -vf command is run:

 raspivid -t 999999999 -w 960 -h 540 -fps 25 -b 500000 -o - | ffmpeg -i - -vcodec copy -vf 'movie=0:png:/home/USER/watermark.png [watermark];[in] [watermark]overlay=0:0:1[out]' -an -metadata title="STREAM NAME" -f flv rtmp://USER_X.fme.bambuser.com/b-fme/USER_STREAM_KEY_X 

  ffmpeg version N-54036-g6c4516d Copyright (c) 2000-2013 the FFmpeg developers
   built on Jun 15 2013 XX: XX with gcc 4.6 (Debian 4.6.3-14 + rpi1)
   configuration: 
   libavutil 52.35.101 / 52.35.101
   libavcodec 55.16.100 / 55.16.100
   libavformat 55.8.102 / 55.8.102
   libavdevice 55.2.100 / 55.2.100
   libavfilter 3. 77.101 / 3. 77.101
   libswscale 2. 3.100 / 2. 3.100
   libswresample 0. 17.102 / 0. 17.102
 [h264 @ 0x1917cc0] max_analyze_duration 5,000,000 reached at 5,000,000 microseconds
 Input # 0, h264, from 'pipe:':
   Duration: N / A, bitrate: N / A
     Stream # 0: 0: Video: h264 (High), yuv420p, 960x540, 25 fps, 25 tbr, 1200k tbn, 50 tbc
 Output # 0, flv, to 'rtmp: //USER_X.fme.bambuser.com/b-fme/USER_STREAM_KEY_X':
   Metadata:
     title: STREAM NAME
     encoder: Lavf55.8.102
     Stream # 0: 0: Video: h264 ([7] [0] [0] [0] / 0x0007), yuv420p, 960x540, q = 2-31, 25 fps, 1k tbn, 1200k tbc
 Stream mapping:
   Stream # 0: 0 -> # 0: 0 (copy)
 frame = 2344 fps = 27 q = -1.0 size = 4827kB time = 00: 01: 33.72 bitrate = 421.9kbits / s 

As mentioned above, the other -vf filters also don't seem to be applied in the output stream on Bambuser, I think I'm basically doing something wrong.

• Should I display Raspivid-stream and display the image "watermark.png" on top of this? Would this be a solution? Does anyone come across this?

Thanks so much for your thoughts in advance.

Answer 1

You must transcode if you want to use filters, so ffmpeg will ignore -vf if you are also trying to copy streams using -vcodec copy / -codec:v copy / -c:v copy . From the stream, copy the documentation:

Since there is no decoding or encoding, the stream copy mode is very fast and there is no quality loss. However, in some cases this may not work due to many factors. Applying filters is obviously also not possible, since filters work with uncompressed data.

Other things:
-vf used for simple filters (one input, one output) and -filter_complex used for complex filtering graphs (one or more inputs, one or more outputs). Using -filter_complex means you can skip the movie filter for multimedia sources, which means a shorter and cleaner command.

Example:

 ffmpeg -i video.mp4 -i image.png -codec:v libx264 -preset ultrafast -filter_complex overlay output 

This will use the Raspberry processor for encoding, which, I think, will not lead to satisfactory performance.