jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2021, Hunter Salyer <thefalsehonesty@gmail.com>
3 * Copyright (c) 2022, Gregory Bertilson <zaggy1024@gmail.com>
4 *
5 * SPDX-License-Identifier: BSD-2-Clause
6 */
7
8#include <AK/Function.h>
9#include <LibCore/ArgsParser.h>
10#include <LibMain/Main.h>
11#include <LibVideo/Containers/Matroska/Reader.h>
12
13#define TRY_PARSE(expression) \
14 ({ \
15 auto&& _temporary_result = ((expression)); \
16 if (_temporary_result.is_error()) [[unlikely]] { \
17 outln("Encountered a parsing error: {}", _temporary_result.error().string_literal()); \
18 return Error::from_string_literal("Failed to parse :("); \
19 } \
20 static_assert(!::AK::Detail::IsLvalueReference<decltype(_temporary_result.release_value())>, \
21 "Do not return a reference from a fallible expression"); \
22 _temporary_result.release_value(); \
23 })
24
25ErrorOr<int> serenity_main(Main::Arguments arguments)
26{
27 StringView filename;
28 bool blocks = false;
29 bool cues = false;
30 u64 track_number = 0;
31
32 Core::ArgsParser args_parser;
33 args_parser.add_option(blocks, "Print blocks for each track.", "blocks", 'b');
34 args_parser.add_option(cues, "Print cue points for each track.", "cues", 'c');
35 args_parser.add_option<u64>(track_number, "Specify a track number to print info for, omit to print all of them.", "track", 't', "tracknumber");
36 args_parser.add_positional_argument(filename, "The video file to display.", "filename", Core::ArgsParser::Required::Yes);
37 args_parser.parse(arguments);
38
39 auto reader = TRY_PARSE(Video::Matroska::Reader::from_file(filename));
40
41 outln("DocType is {}", reader.header().doc_type.characters());
42 outln("DocTypeVersion is {}", reader.header().doc_type_version);
43 auto segment_information = TRY_PARSE(reader.segment_information());
44 outln("Timestamp scale is {}", segment_information.timestamp_scale());
45 outln("Muxing app is \"{}\"", segment_information.muxing_app().as_string().to_deprecated_string().characters());
46 outln("Writing app is \"{}\"", segment_information.writing_app().as_string().to_deprecated_string().characters());
47
48 outln("Document has {} tracks", TRY_PARSE(reader.track_count()));
49 TRY_PARSE(reader.for_each_track([&](Video::Matroska::TrackEntry const& track_entry) -> Video::DecoderErrorOr<IterationDecision> {
50 if (track_number != 0 && track_entry.track_number() != track_number)
51 return IterationDecision::Continue;
52
53 outln("\tTrack #{} with TrackID {}", track_entry.track_number(), track_entry.track_uid());
54 outln("\tTrack has TrackType {}", static_cast<u8>(track_entry.track_type()));
55 outln("\tTrack has Language \"{}\"", track_entry.language().characters());
56 outln("\tTrack has CodecID \"{}\"", track_entry.codec_id().characters());
57 outln("\tTrack has TrackTimestampScale {}", track_entry.timestamp_scale());
58 outln("\tTrack has CodecDelay {}", track_entry.codec_delay());
59
60 if (track_entry.track_type() == Video::Matroska::TrackEntry::TrackType::Video) {
61 auto const video_track = track_entry.video_track().value();
62 outln("\t\tVideo is {} pixels wide by {} pixels tall", video_track.pixel_width, video_track.pixel_height);
63 } else if (track_entry.track_type() == Video::Matroska::TrackEntry::TrackType::Audio) {
64 auto const audio_track = track_entry.audio_track().value();
65 outln("\t\tAudio has {} channels with a bit depth of {}", audio_track.channels, audio_track.bit_depth);
66 }
67
68 if (cues) {
69 auto const& cue_points = TRY(reader.cue_points_for_track(track_entry.track_number()));
70
71 if (cue_points.has_value()) {
72 outln("\tCues points:");
73
74 for (auto const& cue_point : cue_points.value()) {
75 outln("\t\tCue point at {}ms:", cue_point.timestamp().to_milliseconds());
76 auto const& track_position = cue_point.position_for_track(track_entry.track_number());
77
78 if (!track_position.has_value()) {
79 outln("\t\t\tCue point has no positions for this track, this should not happen");
80 continue;
81 }
82 outln("\t\t\tCluster position {}", track_position->cluster_position());
83 outln("\t\t\tBlock offset {}", track_position->block_offset());
84 }
85 } else {
86 outln("\tNo cue points exist for this track");
87 }
88 }
89
90 if (blocks) {
91 outln("\tBlocks:");
92 auto iterator = TRY(reader.create_sample_iterator(track_entry.track_number()));
93
94 while (true) {
95 auto block_result = iterator.next_block();
96 if (block_result.is_error()) {
97 if (block_result.error().category() == Video::DecoderErrorCategory::EndOfStream)
98 break;
99 return block_result.release_error();
100 }
101 auto block = block_result.release_value();
102 outln("\t\tBlock at timestamp {}ms:", block.timestamp().to_milliseconds());
103 if (block.only_keyframes())
104 outln("\t\t\tThis block contains only keyframes");
105 outln("\t\t\tContains {} frames", block.frame_count());
106 outln("\t\t\tLacing is {}", static_cast<u8>(block.lacing()));
107 }
108 }
109
110 if (track_number != 0)
111 return IterationDecision::Break;
112
113 return IterationDecision::Continue;
114 }));
115
116 return 0;
117}