Pulseaudio not working well with HDMI (jessie 5.05, orangepi h3)

Hello, I am runnign armbian 5.05 jessie server on an OrangePi One.

I wish to test network audio streams so I installed pulseaudio to do some tests.

As long as ALSA works fine with HDMI output, I thought that pulseaudio would work the same, but I was wrong.

The basic pulseaudio installation (apt-get install pulseaudio) turned to be a non effective way to obtain pulseaudio support.

Actually this is strange because if I set the default pulseaudio sink to analog audio, it works fine (I get no sound but just because the Opi One has no analog connector).

When I set the default sink to hdmi audio, I get indiscernible short discharges instead of music and pulseaudio continously laments buffer underruns. This is the log of pulseaudio while trying to produce some output:

I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Starting playback.
I: [pulseaudio] sink-input.c: Created input 1 "libao[ogg123] playback stream" on alsa_output.platform-sndhdmi.analog-stereo with sample spec s16le 2ch 44100Hz and channel map front-left,front-right
I: [pulseaudio] sink-input.c:     media.name = "libao[ogg123] playback stream"
I: [pulseaudio] sink-input.c:     application.name = "libao[ogg123]"
I: [pulseaudio] sink-input.c:     native-protocol.peer = "UNIX socket client"
I: [pulseaudio] sink-input.c:     native-protocol.version = "29"
I: [pulseaudio] sink-input.c:     application.process.id = "5921"
I: [pulseaudio] sink-input.c:     application.process.user = "paolo"
I: [pulseaudio] sink-input.c:     application.process.host = "orangepione"
I: [pulseaudio] sink-input.c:     application.process.binary = "ogg123"
I: [pulseaudio] sink-input.c:     application.language = "C"
I: [pulseaudio] sink-input.c:     application.process.machine_id = "89107ace91b54204bd18fe15ddd2684c"
I: [pulseaudio] sink-input.c:     application.process.session_id = "3"
I: [pulseaudio] sink-input.c:     module-stream-restore.id = "sink-input-by-application-name:libao[ogg123]"
I: [pulseaudio] protocol-native.c: Requested tlength=250.00 ms, minreq=20.00 ms
I: [pulseaudio] protocol-native.c: Final latency 250.01 ms = 105.01 ms + 2*20.00 ms + 105.00 ms
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Underrun!
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Increasing wakeup watermark to 30.00 ms

I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Underrun!
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Increasing wakeup watermark to 40.00 ms
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Underrun!
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Increasing wakeup watermark to 50.00 ms
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Underrun!
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Increasing wakeup watermark to 60.00 ms
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Underrun!
I: [alsa-sink-SUNXI-HDMIAUDIO sndhdmi-0] alsa-sink.c: Increasing wakeup watermark to 70.00 ms
I: [pulseaudio] sink-input.c: Freeing input 1 "libao[ogg123] playback stream"

Still, if I uninstall pulseaudio completely, ALSA works perfectly with both analog or HDMI sound