Add background image to TextSample and TTML output

Issue #832

Change-Id: I50f23223fa4362559087ada9b40488c089594450
This commit is contained in:
Jacob Trimble 2020-11-20 13:03:16 -08:00
parent 1ca89edec2
commit fe44b5e13c
5 changed files with 71 additions and 9 deletions

View File

@ -17,7 +17,7 @@ namespace media {
bool TextFragment::is_empty() const {
return std::all_of(sub_fragments.begin(), sub_fragments.end(),
std::mem_fn(&TextFragment::is_empty)) &&
body.empty();
body.empty() && image.empty();
}
TextSample::TextSample(const std::string& id,

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@ -80,7 +80,7 @@ struct TextFragmentStyle {
};
/// Represents a recursive structure of styled blocks of text. Only one of
/// sub_fragments, body, or newline will be set.
/// sub_fragments, body, image, or newline will be set.
struct TextFragment {
TextFragment() {}
TextFragment(const TextFragmentStyle& style,
@ -90,6 +90,9 @@ struct TextFragment {
: style(style), body(body) {}
TextFragment(const TextFragmentStyle& style, const std::string& body)
: style(style), body(body) {}
TextFragment(const TextFragmentStyle& style,
const std::vector<uint8_t>& image)
: style(style), image(image) {}
TextFragment(const TextFragmentStyle& style, bool newline)
: style(style), newline(newline) {}
@ -97,6 +100,8 @@ struct TextFragment {
std::vector<TextFragment> sub_fragments;
std::string body;
/// PNG image data.
std::vector<uint8_t> image;
bool newline = false;
bool is_empty() const;

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@ -6,6 +6,7 @@
#include "packager/media/formats/ttml/ttml_generator.h"
#include "packager/base/base64.h"
#include "packager/base/strings/stringprintf.h"
#include "packager/media/base/rcheck.h"
@ -87,12 +88,19 @@ bool TtmlGenerator::Dump(std::string* result) const {
}
RCHECK(root.AddChild(std::move(head)));
size_t image_count = 0;
xml::XmlNode metadata("metadata");
xml::XmlNode body("body");
xml::XmlNode div("div");
for (const auto& sample : samples_) {
RCHECK(AddSampleToXml(sample, &div));
RCHECK(AddSampleToXml(sample, &div, &metadata, &image_count));
}
RCHECK(body.AddChild(std::move(div)));
if (image_count > 0) {
RCHECK(root.SetStringAttribute(
"xmlns:smpte", "http://www.smpte-ra.org/schemas/2052-1/2010/smpte-tt"));
RCHECK(root.AddChild(std::move(metadata)));
}
RCHECK(root.AddChild(std::move(body)));
*result = root.ToString(/* comment= */ "");
@ -100,14 +108,16 @@ bool TtmlGenerator::Dump(std::string* result) const {
}
bool TtmlGenerator::AddSampleToXml(const TextSample& sample,
xml::XmlNode* body) const {
xml::XmlNode* body,
xml::XmlNode* metadata,
size_t* image_count) const {
xml::XmlNode p("p");
RCHECK(p.SetStringAttribute("xml:space", "preserve"));
RCHECK(p.SetStringAttribute("begin",
ToTtmlTime(sample.start_time(), time_scale_)));
RCHECK(
p.SetStringAttribute("end", ToTtmlTime(sample.EndTime(), time_scale_)));
RCHECK(ConvertFragmentToXml(sample.body(), &p));
RCHECK(ConvertFragmentToXml(sample.body(), &p, metadata, image_count));
if (!sample.id().empty())
RCHECK(p.SetStringAttribute("xml:id", sample.id()));
@ -151,7 +161,9 @@ bool TtmlGenerator::AddSampleToXml(const TextSample& sample,
}
bool TtmlGenerator::ConvertFragmentToXml(const TextFragment& body,
xml::XmlNode* parent) const {
xml::XmlNode* parent,
xml::XmlNode* metadata,
size_t* image_count) const {
if (body.newline) {
xml::XmlNode br("br");
return parent->AddChild(std::move(br));
@ -179,9 +191,23 @@ bool TtmlGenerator::ConvertFragmentToXml(const TextFragment& body,
if (!body.body.empty()) {
node->AddContent(body.body);
} else if (!body.image.empty()) {
std::string image_data(body.image.begin(), body.image.end());
std::string base64_data;
base::Base64Encode(image_data, &base64_data);
std::string id = "img_" + std::to_string(++*image_count);
xml::XmlNode image_xml("smpte:image");
RCHECK(image_xml.SetStringAttribute("imagetype", "PNG"));
RCHECK(image_xml.SetStringAttribute("encoding", "Base64"));
RCHECK(image_xml.SetStringAttribute("xml:id", id));
image_xml.SetContent(base64_data);
RCHECK(metadata->AddChild(std::move(image_xml)));
RCHECK(node->SetStringAttribute("smpte:backgroundImage", "#" + id));
} else {
for (const auto& frag : body.sub_fragments) {
if (!ConvertFragmentToXml(frag, node))
if (!ConvertFragmentToXml(frag, node, metadata, image_count))
return false;
}
}

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@ -35,9 +35,14 @@ class TtmlGenerator {
bool Dump(std::string* result) const;
private:
bool AddSampleToXml(const TextSample& sample, xml::XmlNode* body) const;
bool AddSampleToXml(const TextSample& sample,
xml::XmlNode* body,
xml::XmlNode* metadata,
size_t* image_count) const;
bool ConvertFragmentToXml(const TextFragment& fragment,
xml::XmlNode* parent) const;
xml::XmlNode* parent,
xml::XmlNode* metadata,
size_t* image_count) const;
std::list<TextSample> samples_;
std::map<std::string, TextRegion> regions_;

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@ -322,6 +322,32 @@ TEST_F(TtmlMuxerTest, HandlesReset) {
ASSERT_EQ(results, kExpectedOutput2);
}
TEST_F(TtmlMuxerTest, HandlesImage) {
const char* kExpectedOutput =
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
"<tt xmlns=\"http://www.w3.org/ns/ttml\" "
"xmlns:tts=\"http://www.w3.org/ns/ttml#styling\" xml:lang=\"\" "
"xmlns:smpte=\"http://www.smpte-ra.org/schemas/2052-1/2010/smpte-tt\">\n"
" <head/>\n"
" <metadata>\n"
" <smpte:image imagetype=\"PNG\" encoding=\"Base64\" xml:id=\"img_1\">"
"AQID</smpte:image>\n"
" </metadata>\n"
" <body>\n"
" <div>\n"
" <p xml:space=\"preserve\" begin=\"00:00:05.00\" "
"end=\"00:00:06.00\" smpte:backgroundImage=\"#img_1\" xml:id=\"foo\"/>\n"
" </div>\n"
" </body>\n"
"</tt>\n";
TestProperties properties;
properties.id = "foo";
properties.body.image = {1, 2, 3};
ParseSingleCue(kExpectedOutput, properties);
}
} // namespace ttml
} // namespace media
} // namespace shaka