Centricular

Thanks to the newly added atenc element, you can now use Apple's well-known AAC encoder directly in GStreamer!

gst-launch-1.0 -e audiotestsrc ! audio/x-raw,channels=2,rate=48000 ! atenc ! mp4mux ! filesink location=output.m4a

It supports all the usual rate control modes (CBR/LTA/VBR/CVBR), as well as settings relevant for each of them (target bitrate for CBR, perceived quality for VBR).

For now you can encode AAC-LC with up to 7.1 channels. Support for more AAC profiles and different output formats will be added in the future.

If you need decoding too, atdec is there to help and has supported AAC alongside a few other formats for a long time now.

GStreamer's VideoToolbox encoder recently gained support for encoding HEVC/H.265 videos containing an alpha channel.

A separate vtenc_h265a element has been added for this purpose. Assuming you're on macOS, you can use it like this:

gst-launch-1.0 -e videotestsrc ! alpha alpha=0.5 ! videoconvert ! vtenc_h265a ! mp4mux ! filesink location=alpha.mp4

Click here to see an example in action! It should work fine on macOS and iOS, in both Chrome and Safari. On other platforms it might not be displayed at all - compatibility is unfortunately still quite limited.

If your browser supports this format correctly, you will see a moving GStreamer logo on a constantly changing background - something like this. That background is entirely separate from the video and is generated using CSS.