According to macau, audio over hdmi works well in android. Lunatic_charade confirmed this info.
Me (stuw) and zombah made a patch for hdmi audio (https://dl.dropboxusercontent.com/u/40761340/www/ac100/patches/paz00-spdif.patch, started from juliank's message and Seaboard: Add SPDIF/HDMI support patch, our patch based on board-ventana.c и tegra_wm8903.c). zombah tried the patch on android 4.1 with audio only (tinyplay -D 0 -d 1, IIRC) and didn't get working audio (maybe because there is some issues with android).
Linux (l4t-r16-r2-ac100) http://gitorious.org/~marvin24/ac100/marvin24s-kernel/commit/621832ee7e5cfbd8e7ff3dd494f64fc8d32ddcdb http://gitorious.org/~marvin24/ac100/marvin24s-kernel/commit/f3c6f0ff087a08c73437161dfe129fe466235c41
tegradc tegradc.1: hdmi: can't set audio to 32000 at 82000000 pix_clock
< srwarren> stuw, HDMI audio should be able to work at pretty much any pixel clock frequency. The L4T kernel probably only supports it in a pre-define set of cases, i.e. specific modes such as 1080p, 720p, etc. If you take a look in the ChromeOS kernel, perhaps their 3.2 branch, you should find code to make the calculation more general.
Android 4.x (android-spdif) http://gitorious.org/~zombah/ac100/zombahs-marvin24s-kernel/commit/40e3246325ebf6d1a99ca91f83434e59e3c78077 http://gitorious.org/~zombah/ac100/zombahs-marvin24s-kernel/commit/f2a7ec34a5befefef4a01f4b5b277871584c7f97 https://github.com/zombah/android_device_toshiba_paz00-common/commit/0ccd89d81839dc7faac4d9863b172793f0ea293c
stuw> звук по hdmi есть? вах ) <zombah> есть да только что ролик h264 посмотрел норм звучит