Improve CrystalHD decoding for BCM 70012

[czhang1974@…]

This patch fixes the green overlay problem reported in the following thread on the bcm70012.

​http://www.gossamer-threads.com/lists/mythtv/dev/453116

The default output format from CrystalHD on the bcm70012 is NV12, not YV12. It can be changed to use YV12 by setting some flags if we use the DtsProcOutput? instead of DtsProcOutputNoCopy?, but further reading of the library source code shows that it was converted to YV12 in software anyways. The hardware output is always in NV12, so there is no gain in using YV12.

I also had to make sure that the buffer is always released after decoding. I am still not sure why the code checked for mpa_pic.data[3] before calling the release_buffer, which effectively blocked the call since that would always be NULL for the crystalhd decoder. It most likely is breaking something else that I don't know about, but I will leave that to someone more familiar with the other private decoders.

This now works reasonably well for 720P on my AppleTV. 1080i is still having serious stuttering problem that I can't find the root cause of yet.

[czhang1974@…]

crystalhd bcm70012 patch

[markk]

Finally managed to test this in master. Unfortunately, while some streams play others are pretty broken. From memory, the BCM70012 needs an alignment fix for streams that are not 'normal' widths of 720 or 1920. Additionally, some streams that are straightforward 1080p still look slightly broken.

I'll see what I can do.

(N.B. not regression tested with the BCM70015 either)