[gst-devel] PNG encoding produces empty file with ffenc_png

[Stefan Kost]

Franz TRIERWEILER wrote:
> Hello,
>
> I am trying on a Freescale ARM-based board to encode JPEG or PNG
> picture from a webcam source through gst-launch this way:
>
> gst-launch-0.10 --verbose v4l2src num-buffers=1 ! ffenc_png ! 
> filesink location=toto.png
>
> (I was advised by Freescal support to set num-buffers to 1 because
> gst-launch never gets out).
Just also use pngenc on the freescaleboard. If you can't for whatever
reasons, you will need to dig into bthe differences and figure whats the
bug on the ffenc_png element.

Stefan

>
> The result is as follows and produces an empty file:
>
> Setting pipeline to PAUSED ...
> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps =
> video/x-raw-yuv, 1
> Pipeline is live and does not need PREROLL ...
> Setting pipeline to PLAYING ...
> New clock: GstSystemClock
> /GstPipeline:pipeline0/ffenc_png:ffenc_png0.GstPad:src: caps =
> image/png, width1
> /GstPipeline:pipeline0/ffenc_png:ffenc_png0.GstPad:sink: caps =
> video/x-raw-yuv1
> Got EOS from element "pipeline0".
> Execution ended after 7175133452 ns.
> Setting pipeline to PAUSED ...
> Setting pipeline to READY ...
> /GstPipeline:pipeline0/ffenc_png:ffenc_png0.GstPad:src: caps = NULL
> /GstPipeline:pipeline0/ffenc_png:ffenc_png0.GstPad:sink: caps = NULL
> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps = NULL
> Setting pipeline to NULL ...
> Freeing pipeline ...
> root at freescale ~$ ls
>
> When I try the same command on an Ubuntu system with the same webcam
> (*replacing ffenc_png with pngenc - I do not know why pngenc has been
> replaced with ffenc_png on the Freescale Linux distro*) then I get a
> right PNG file:
>
> gst-launch-0.10 --verbose v4l2src num-buffers=1 ! pngenc !  filesink
> location=toto.png
>
> This produces:
> Définition du pipeline à PAUSED...
> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps =
> video/x-raw-rgb, bpp=(int)24, depth=(int)24, red_mask=(int)16711680,
> green_mask=(int)65280, blue_mask=(int)255, endianness=(int)4321,
> width=(int)640, height=(int)480, framerate=(fraction)30/1
> Le pipeline est actif et n'a pas besoin de phase PREROLL...
> Passage du pipeline à la phase PLAYING...
> New clock: GstSystemClock
> /GstPipeline:pipeline0/GstPngEnc:pngenc0.GstPad:src: caps = image/png,
> width=(int)640, height=(int)480, framerate=(fraction)30/1
> /GstPipeline:pipeline0/GstPngEnc:pngenc0.GstPad:sink: caps =
> video/x-raw-rgb, bpp=(int)24, depth=(int)24, red_mask=(int)16711680,
> green_mask=(int)65280, blue_mask=(int)255, endianness=(int)4321,
> width=(int)640, height=(int)480, framerate=(fraction)30/1
> /GstPipeline:pipeline0/GstFileSink:filesink0.GstPad:sink: caps =
> image/png, width=(int)640, height=(int)480, framerate=(fraction)30/1
> EOS reçu de l'élément « pipeline0 ».
> Execution ended after 791913102 ns.
> Définition du pipeline à PAUSED...
> Définition du pipeline à READY (prêt)...
> /GstPipeline:pipeline0/GstFileSink:filesink0.GstPad:sink: caps = NULL
> /GstPipeline:pipeline0/GstPngEnc:pngenc0.GstPad:src: caps = NULL
> /GstPipeline:pipeline0/GstPngEnc:pngenc0.GstPad:sink: caps = NULL
> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps = NULL
> Définition du pipeline à NULL...
> Libération du pipeline (FREE)...
>
> On Ubuntu, the first pipe gives more information about the v4l2src,
> not on the Freescale.
>
> What I know is that the webcam is providing video data since I can
> fill a file when I simply do:
>
> gst-launch-0.10 --verbose v4l2src num-buffers=1 ! filesink loc
> ation=toto.raw
>
> I am ready to provide more information if required for debugging this.
> My first goal is:
> 1- Do I use the correct syntax with ffenc_png?
> 2- What do the debug messages mean?
>
> I have other issues with the jpeg encoding but first I prefer focusing
> on PNG encoding.
>
> Best Regards,
> Franz
>
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