Live streaming with the Panasonic GH4

Live streaming

Although a handful of vision mixers, including the ATEM Production Studio 4K used for our test video, can handle 50p signals, most encoder cards cannot, as yet, support these higher framerates.

It is possible to stream 25p from the GH4, but only if the camera is first set to AVCHD recording. The output is then PSF (a 25p stream in a 50i wrapper) which needs a pull down to record as progressive.

Atomos, the external recorder company, has put together a useful video on how to do this.

In earlier tests, though, we found that converting in software from the 1080i50 (or PSF) stream live produced results that fell somewhat short of expectations. A better option is to downconvert the GH4 output, especially if have access to the YAGH and want to take advantage of the more robust nature of SDI.

As the video here shows, we set the Panasonic up for HD recording, at 1080p50, 200mbps, in .mov format. Then we went from the 3G SDI output on the YAGH, to a converter which turned the 1080p50 stream into a 1080p25 PSF stream (25p over a 50i signal) which matched the output from our Sony cameras. Other cameras would allow an all-progressive signal path.

[youtube]https://www.youtube.com/watch?v=BPz5oE3GcVw[/youtube]

It is also possible to record 4K, as QFHD, in camera on the GH4 and output a downconverted 1080p signal; we will try this in a future test.

Hopefully Panasonic can address the framerate issue in a future firmware release. But for now, live streaming from the GH4 is possible and, with the YAGH, gives a high quality signal over professional connections.