Hi All,<div><br></div><div>I followed Tim's advice on using gst-launch to display a PNG file, and Luciana's fix for getting my PNG to "mix" with a video stream (thanks again to you both), but doing that, I discovered that the PNG file, which has a transparent alpha component, is showing opaque, so the video never shows thru. (I know it's there though, 'cause if I draw the video on top of the PNG instead of underneath it, it shows fine.</div>
<div><br>The command I'm using is:</div><div><br></div><div>gst-launch-0.10 filesrc location=overlay.png ! pngdec ! ffmpegcolorspace ! videoscale ! imagefreeze ! videomixer name=mix ! autovideosink videotestsrc ! video/x-raw-yuv, width=320, height=240 ! mix.</div>
<div><br></div><div>Looking at the documentation, the only possible solution I could find is an element called "alphacolor", but nowhere placed in the pipeline does it work, so I'm stumped again.</div><div><br>
</div><div>So, that's my main question: how to I get a PNG file WITH transparent sections to properly render?</div><div><br></div><div>And, if I could ask a few more questions, I'd appreciate it (my boss says I'm taking too long at this :)...</div>
<div><br></div><div>2. we have ALSA audio, and I see there's an element called "alsasink", though I couldn't find much documentation on it. Is there a way with alsasink to specify the output channel? (our card has 8, so 4 stereo pairs).</div>
<div><br></div><div>3. Is there a way to have the other PNG images fade in and fade out of the window to/from black?</div><div><br></div><div>4. Is there a way to loop between two particular frames on a video?</div><div>
<br></div><div>5. Is videobox the best way to position my video behind the overlay PNG? I got it to work kind of, but there were artifacts, like everything to the left and above the video is black.</div><div><br></div><div>
6. I thought someone must have written a translator that takes a gst-launch command line and converts it to the equivalent C code, but couldn't find one. Did I just not look in the right place?</div><div><br></div><div>
Sorry for the pile of questions, but as I say, the heat is on, and these are all problems I'd better solve soon, or I'm back to using straight X11 and OpenGL, and I guess libxine to pull apart my video into frames.</div>
<div><br></div><div>Thanks, thanks, thanks!<br><br>Bill.</div>