Specify embedded Hebrew xml:lang; update expectations (#7).

[skynavga]

Closes #7.

[palemieux]

How are the following two issues related?

• addition of xml:lang
• update to expectations

[skynavga]

@palemieux

• ttml1-prstn-break - fix rendering logic in ttpe; former expectation bad; see also rendering of ttml1-prstn-break is incorrect skynav/ttt#299
• ttml1-prstn-direction - partially fix rendering logic in ttpe; former expectation bad; see also rendering of ttml1-prstn-direction is incorrect skynav/ttt#297
• ttml1-prstn-font-family - shouldn't have been updated at this time, will remove from PR; but see also rendering of ttml1-prstn-font-family incorrect skynav/ttt#296, which fix will update this expectation
• ttml1-prstn-font-size-anamorphic-cell - svg rendering artifact difference only
• ttml1-prstn-font-size-anamorphic-em - svg rendering artifact difference only
• ttml1-prstn-font-size-inherited-em - fix rendering logic in ttpe; former expectation bad; see also rendering of ttml1-prstn-font-size-inherited-em is incorrect skynav/ttt#300

svg rendering artifact difference only refers to changes in ttpe that generate different svg outputs while still retaining the same visual result; these are housekeeping updates that keep the expectations synchronized with ttpe

[skynavga]

Removed erroneously updated expectation noted above in #8 (comment).

[skynavga]

@palemieux any further comment or change requested?

[palemieux]

@skynavga Can you provide a PNG of the expected results, to remove the SVG rendered from the chain?

[skynavga]

@palemieux re: #8 (comment), in theory yes, but in practice no; I would be happy to explain my reasons in a ttwg call;

[skynavga]

@palemieux to elaborate a bit:

• there are at present 190 *.expected.zip files in the w3c/ttml1-tests and w3c/ttml1-tests repositories, all of which would have to be converted, or 190 additional *.png.expected.zip files added, a substantial project that would require sponsorship;
• the current expectation files were provided by Skynav to the group when these two repositories were populated for exemplar purposes only and for use as evidence of some (non-normative) rendering for implementation reports;
• the current README.md files of both this repository w3c/ttml1-tests and w3c/ttml1-tests include the following text:

For tests having primarily visual presentation semantics, each presentation test is associated with a like named ZIP archive with the suffix .expected.zip, which contains the output of a particular reference implementation (TTPE). Each such reference archive contains a manifest file and one or more image frames represented in some image format. In the present form of the reference archives, the image format is image/svg+xml. These image frames should not be construed as normative, but merely serve as a possible reference image for performing (human visual) comparisons of expected output.

• the use of PNG files as an alternative to SVG effectively makes some SVG renderer implementation a dependency, at least with respect to using TTPE;
• at present the SVG renderer used by TTPE is Apache Batik, which is quite dated and almost entirely unmaintained, meaning that I don't trust it as a normative renderer; using an alternative SVG renderer would require revision of TTPE, a substantial project that would require sponsorship, and the result would still be to have such alternative renderer as a dependency;
• the original (and current) requirement for use of the expectation files w.r.t. TTPE is to enable regression testing that is independent of SVG rendering, i.e., independent of actual pixel output; therefore, changing to PNG renderings would abrogate this requirement;
• finally, if you are asking me to provide an extra-exemplary rendering of a particular SVG output from TTPE, for discussion purposes only (i..e., not to go into the repository), then I could arrange for that; I would simple use Chrome to render the SVG and then take a screen shot of the results on my MacOS laptop; then again, you (or anyone) can already do this without my help;

Comments addressed.