On Mon, Nov 12, 2012 at 8:24 AM, Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx> wrote: > Actually what I had in mind was a packed binary representation of > infoframes as specified by HDMI 1.3a (I don't have access to 1.4, but I > would think it doesn't differ in this respect) in section 5.3 and 5.3.5 > more specifically. According to the specification, the ECC bytes only > come into play at a later stage, when data is actually transmitted on > the TMDS link (Section 5.2.3). Tegra, nouveau and radeon also seem to be > doing the checksumming in hardware, so I guess we don't need to compute > the ECC bytes in software at all (for now). > > Once we have this for the AVI infoframes I guess the same concept can be > used for audio infoframes and for vendor-specific infoframes (for HDMI > 1.4 3D). Iirc there's more than one checksum: The ECC field at byte 3 and the checksum field at byte 4. All intel hw computes the ECC itself, but some want us to store the infoframe with an empty ECC byte as placeholder, whereas others (sdvo encoders) insert that byte themselves, i.e. the infoframe is actually one byte shorter. In any case, that kind of mangling can be done in the driver with easy. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
