3.13.0

Same n8.1.3 FFmpeg, dav1d, zimg, libzvbi 0.2.46 and filter set as 3.12.1. One local patch changes behaviour: the DTS:X height patch no longer subtracts anything from the bed.

What changes

• x_heights outputs the DTS:X bed as coded (AetherEngine, DTS:X through its bed regression): with the option on, the dca decoder still decodes the height channel set of DTS:X's standard presentation and outputs 7.1.4, but the 7.1 bed now comes out exactly as coded, with the four heights still folded into it at -3 dB, next to the heights. Through 3.12.1 the decoder removed that fold from the bed at output resolution. Separating the heights from the bed is now the player's job; AetherEngine builds its layout from that bed with its BedRegression. This is a behaviour change for anyone who sets x_heights: a player that relied on the cleaned bed now plays the heights twice (once folded into the bed, once on their own speakers) until it separates them itself.
• Checked against the 3.12.1 decode on a DTS:X window (62 s, 3,014,656 frames): the four heights and the four unfolded bed channels are bit-identical, and every folded channel (L, R, Lsr, Rsr) equals the 3.12.1 channel plus the fold within the 0.5 LSB the old subtraction rounded. Without the option the decoder's output is unchanged.

Build

Full rebuild of all slices; only libavcodec changes in content. BUILD-INFO.txt records the inputs and hashes. swift test: 45 tests in 16 suites pass.