[Libav-user] Overlay filter (add Watermark to video)

Alberto Martín Fernandez amartin at grupoblidoo.com
Wed Oct 1 17:48:21 CEST 2014


I am using ffmpeg 1.0.9 & SDL 1.2 and i am trying to add a watermark.
I started to implement my media player basing on the ffplay example, adding
funtionalities, buttons...

I have to implement an overlay filter, so i do:

FILTER 1:(Video base) INPUT
   avfilter_graph_create_filter(&filt_src, avfilter_get_by_name("buffer"),
"in", buffersrc_args,NULL,graph);

FILTER 2: (overlay filter, watermark(png)) INPUT

"overlay",  argsStrOvrlay, NULL, graph);

FILTER 3: (buffersink filter) OUTPUT
"out", NULL, buffersink_params, graph);

Then i call :
[in_1]; buffer=video_size=512x128:pix_fmt=2:time_base=1/1:pixel_aspect=0
[in_2]; [in_1] [in_2] overlay=0:0 [out]; [out] buffersink", inputs,
&outputs, NULL);

Then i call avfilter_graph_config(graph, NULL);
and it returnrs -22 error (AVERROR_INVALIDDATA)

I have some questions:

Which are the correct parameters to set in a overlay filter (argsStrOvrlay)?
I set sprintf_s(argsStrOvrlay, sizeof(argsStrOvrlay),
pCodecCtxImage->width, pCodecCtxImage->height, pCodecCtxImage->pix_fmt);

I am not sure if i need to link the filters using avfilter_link.

Has anyone an example of adding a watermark image to a video using overlay
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://ffmpeg.org/pipermail/libav-user/attachments/20141001/533946e1/attachment.html>

More information about the Libav-user mailing list