sample_muxer: added support for WebVTT chapters
Change-Id: Ic5ab8097c0981ef300eadc4a3c151f63b2aad81d
diff --git a/sample_muxer.cpp b/sample_muxer.cpp
index 62659ce..1e84410 100644
--- a/sample_muxer.cpp
+++ b/sample_muxer.cpp
@@ -63,6 +63,8 @@
"add WebVTT descriptions as metadata track\n");
printf(" -webvtt-metadata <vttfile> "
"add WebVTT subtitles as metadata track\n");
+ printf(" -webvtt-chapters <vttfile> "
+ "add WebVTT chapters as MKV chapters element\n");
}
struct MetadataFile {
@@ -98,13 +100,14 @@
metadata_files_t* metadata_files) {
int& i = *argv_index;
- enum { kCount = 4 };
+ enum { kCount = 5 };
struct Arg { const char* name; SampleMuxerMetadata::Kind kind; };
const Arg args[kCount] = {
{ "-webvtt-subtitles", SampleMuxerMetadata::kSubtitles },
{ "-webvtt-captions", SampleMuxerMetadata::kCaptions },
{ "-webvtt-descriptions", SampleMuxerMetadata::kDescriptions },
- { "-webvtt-metadata", SampleMuxerMetadata::kMetadata }
+ { "-webvtt-metadata", SampleMuxerMetadata::kMetadata },
+ { "-webvtt-chapters", SampleMuxerMetadata::kChapters }
};
for (int idx = 0; idx < kCount; ++idx) {
@@ -147,8 +150,8 @@
uint64 max_cluster_duration = 0;
uint64 max_cluster_size = 0;
bool switch_tracks = false;
- int audio_track_number = 0; // 0 tells muxer to decide.
- int video_track_number = 0; // 0 tells muxer to decide.
+ int audio_track_number = 0; // 0 tells muxer to decide.
+ int video_track_number = 0; // 0 tells muxer to decide.
bool chunking = false;
const char* chunk_name = NULL;
@@ -291,8 +294,8 @@
// Set Tracks element attributes
const mkvparser::Tracks* const parser_tracks = parser_segment->GetTracks();
unsigned long i = 0;
- uint64 vid_track = 0; // no track added
- uint64 aud_track = 0; // no track added
+ uint64 vid_track = 0; // no track added
+ uint64 aud_track = 0; // no track added
using mkvparser::Track;
@@ -408,6 +411,9 @@
if (!LoadMetadataFiles(metadata_files, &metadata))
return EXIT_FAILURE;
+ if (!metadata.AddChapters())
+ return EXIT_FAILURE;
+
// Set Cues element attributes
mkvmuxer::Cues* const cues = muxer_segment.GetCues();
cues->set_output_block_number(output_cues_block_number);
@@ -427,8 +433,7 @@
long status = cluster->GetFirst(block_entry);
- if (status)
- {
+ if (status) {
printf("\n Could not get first block of cluster.\n");
return EXIT_FAILURE;
}
@@ -483,8 +488,7 @@
status = cluster->GetNext(block_entry, block_entry);
- if (status)
- {
+ if (status) {
printf("\n Could not get next block of cluster.\n");
return EXIT_FAILURE;
}
@@ -498,7 +502,10 @@
if (!metadata.Write(-1))
return EXIT_FAILURE;
- muxer_segment.Finalize();
+ if (!muxer_segment.Finalize()) {
+ printf("Finalization of segment failed.\n");
+ return EXIT_FAILURE;
+ }
delete [] data;
delete parser_segment;
diff --git a/sample_muxer_metadata.cc b/sample_muxer_metadata.cc
index 4066670..c3a2e3f 100644
--- a/sample_muxer_metadata.cc
+++ b/sample_muxer_metadata.cc
@@ -16,6 +16,9 @@
}
bool SampleMuxerMetadata::Load(const char* file, Kind kind) {
+ if (kind == kChapters)
+ return LoadChapters(file);
+
mkvmuxer::uint64 track_num;
if (!AddTrack(kind, &track_num)) {
@@ -26,6 +29,21 @@
return Parse(file, kind, track_num);
}
+bool SampleMuxerMetadata::AddChapters() {
+ typedef cue_list_t::const_iterator iter_t;
+ iter_t i = chapter_cues_.begin();
+ const iter_t j = chapter_cues_.end();
+
+ while (i != j) {
+ const cue_t& chapter = *i++;
+
+ if (!AddChapter(chapter))
+ return false;
+ }
+
+ return true;
+}
+
bool SampleMuxerMetadata::Write(mkvmuxer::int64 time_ns) {
typedef cues_set_t::iterator iter_t;
@@ -49,6 +67,129 @@
return true;
}
+bool SampleMuxerMetadata::LoadChapters(const char* file) {
+ if (!chapter_cues_.empty()) {
+ printf("Support for more than one chapters file is not yet implemented\n");
+ return false;
+ }
+
+ cue_list_t cues;
+
+ if (!ParseChapters(file, &cues))
+ return false;
+
+ // TODO(matthewjheaney): support more than one chapters file
+ chapter_cues_.swap(cues);
+
+ return true;
+}
+
+bool SampleMuxerMetadata::ParseChapters(
+ const char* file,
+ cue_list_t* cues_ptr) {
+ cue_list_t& cues = *cues_ptr;
+ cues.clear();
+
+ libwebvtt::VttReader r;
+ int e = r.Open(file);
+
+ if (e) {
+ printf("Unable to open WebVTT file: \"%s\"\n", file);
+ return false;
+ }
+
+ libwebvtt::Parser p(&r);
+ e = p.Init();
+
+ if (e < 0) { // error
+ printf("Error parsing WebVTT file: \"%s\"\n", file);
+ return false;
+ }
+
+ libwebvtt::Time t;
+ t.hours = -1;
+
+ for (;;) {
+ cue_t c;
+ e = p.Parse(&c);
+
+ if (e < 0) { // error
+ printf("Error parsing WebVTT file: \"%s\"\n", file);
+ return false;
+ }
+
+ if (e > 0) // EOF
+ return true;
+
+ if (c.start_time < t) {
+ printf("bad WebVTT cue timestamp (out-of-order)\n");
+ return false;
+ }
+
+ if (c.stop_time < c.start_time) {
+ printf("bad WebVTT cue timestamp (stop < start)\n");
+ return false;
+ }
+
+ t = c.start_time;
+ cues.push_back(c);
+ }
+}
+
+bool SampleMuxerMetadata::AddChapter(const cue_t& cue) {
+ // TODO(matthewjheaney): support language and country
+
+ mkvmuxer::Chapter* const chapter = segment_->AddChapter();
+
+ if (chapter == NULL) {
+ printf("Unable to add chapter\n");
+ return false;
+ }
+
+ if (cue.identifier.empty()) {
+ chapter->set_id(NULL);
+ } else {
+ const char* const id = cue.identifier.c_str();
+ if (!chapter->set_id(id)) {
+ printf("Unable to set chapter id\n");
+ return false;
+ }
+ }
+
+ typedef libwebvtt::presentation_t time_ms_t;
+ const time_ms_t start_time_ms = cue.start_time.presentation();
+ const time_ms_t stop_time_ms = cue.stop_time.presentation();
+
+ enum { kNsPerMs = 1000000 };
+ const mkvmuxer::uint64 start_time_ns = start_time_ms * kNsPerMs;
+ const mkvmuxer::uint64 stop_time_ns = stop_time_ms * kNsPerMs;
+
+ chapter->set_time(*segment_, start_time_ns, stop_time_ns);
+
+ typedef libwebvtt::Cue::payload_t::const_iterator iter_t;
+ iter_t i = cue.payload.begin();
+ const iter_t j = cue.payload.end();
+
+ string title;
+
+ for (;;) {
+ title += *i++;
+
+ if (i == j)
+ break;
+
+ enum { kLF = '\x0A' };
+ title += kLF;
+ }
+
+ if (!chapter->add_string(title.c_str(), NULL, NULL)) {
+ printf("Unable to set chapter title\n");
+ return false;
+ }
+
+ return true;
+}
+
bool SampleMuxerMetadata::AddTrack(
Kind kind,
mkvmuxer::uint64* track_num) {
diff --git a/sample_muxer_metadata.h b/sample_muxer_metadata.h
index a714721..353cf19 100644
--- a/sample_muxer_metadata.h
+++ b/sample_muxer_metadata.h
@@ -21,7 +21,8 @@
kSubtitles,
kCaptions,
kDescriptions,
- kMetadata
+ kMetadata,
+ kChapters
};
SampleMuxerMetadata();
@@ -31,10 +32,12 @@
bool Init(mkvmuxer::Segment* segment);
// Parse the WebVTT file |filename| having the indicated |kind|, and
- // create a corresponding track in the segment. Returns false on
- // error.
+ // create a corresponding track (or chapters element) in the
+ // segment. Returns false on error.
bool Load(const char* filename, Kind kind);
+ bool AddChapters();
+
// Write any WebVTT cues whose time is less or equal to |time_ns| as
// a metadata block in its corresponding track. If |time_ns| is
// negative, write all remaining cues. Returns false on error.
@@ -74,6 +77,21 @@
};
typedef std::multiset<SortableCue> cues_set_t;
+ typedef std::list<cue_t> cue_list_t;
+
+ // Parse the WebVTT cues in the named |file|, returning false on
+ // error. We handle chapters as a special case, because they are
+ // stored in their own, dedicated level-1 element.
+ bool LoadChapters(const char* file);
+
+ // Parse the WebVTT chapters in |file| to populate |cues|. Returns
+ // false on error.
+ static bool ParseChapters(const char* file,
+ cue_list_t* cues);
+
+ // Adds WebVTT cue |chapter| to the chapters element of the output
+ // file's segment element. Returns false on error.
+ bool AddChapter(const cue_t& chapter);
// Add a metadata track to the segment having the indicated |kind|,
// returning the |track_num| that has been chosen for this track.
@@ -105,6 +123,10 @@
// Set of cues ordered by time and then by track number.
cues_set_t cues_set_;
+ // The cues that will be used to populate the Chapters level-1
+ // element of the output file.
+ cue_list_t chapter_cues_;
+
// Disable copy ctor and copy assign.
SampleMuxerMetadata(const SampleMuxerMetadata&);
SampleMuxerMetadata& operator=(const SampleMuxerMetadata&);
