shaka-packager/packager/hls/base/master_playlist.cc

210 lines
7.7 KiB
C++

// Copyright 2016 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#include "packager/hls/base/master_playlist.h"
#include <inttypes.h>
#include "packager/base/files/file_path.h"
#include "packager/base/strings/string_number_conversions.h"
#include "packager/base/strings/stringprintf.h"
#include "packager/file/file.h"
#include "packager/hls/base/media_playlist.h"
#include "packager/version/version.h"
namespace shaka {
namespace hls {
namespace {
void AppendMediaTag(const std::string& base_url,
const std::string& group_id,
const MediaPlaylist* audio_playlist,
const std::string& language,
bool is_default,
bool is_autoselect,
std::string* out) {
DCHECK(audio_playlist);
DCHECK(out);
out->append("#EXT-X-MEDIA:TYPE=AUDIO");
base::StringAppendF(out, ",URI=\"%s\"",
(base_url + audio_playlist->file_name()).c_str());
base::StringAppendF(out, ",GROUP-ID=\"%s\"", group_id.c_str());
if (!language.empty())
base::StringAppendF(out, ",LANGUAGE=\"%s\"", language.c_str());
base::StringAppendF(out, ",NAME=\"%s\"", audio_playlist->name().c_str());
if (is_default)
base::StringAppendF(out, ",DEFAULT=YES");
if (is_autoselect)
base::StringAppendF(out, ",AUTOSELECT=YES");
base::StringAppendF(out, ",CHANNELS=\"%d\"",
audio_playlist->GetNumChannels());
out->append("\n");
}
void AppendStreamInfoTag(uint64_t bitrate,
const std::string& codecs,
uint32_t width,
uint32_t height,
const std::string* audio_group_id,
const std::string& base_url,
const std::string& file_name,
std::string* out) {
DCHECK(out);
base::StringAppendF(out, "#EXT-X-STREAM-INF:");
base::StringAppendF(out, "BANDWIDTH=%" PRIu64, bitrate);
base::StringAppendF(out, ",CODECS=\"%s\"", codecs.c_str());
base::StringAppendF(out, ",RESOLUTION=%" PRIu32 "x%" PRIu32, width, height);
if (audio_group_id) {
base::StringAppendF(out, ",AUDIO=\"%s\"", audio_group_id->c_str());
}
base::StringAppendF(out, "\n%s%s\n", base_url.c_str(), file_name.c_str());
}
} // namespace
MasterPlaylist::MasterPlaylist(const std::string& file_name,
const std::string& default_language)
: file_name_(file_name), default_language_(default_language) {}
MasterPlaylist::~MasterPlaylist() {}
void MasterPlaylist::AddMediaPlaylist(MediaPlaylist* media_playlist) {
DCHECK(media_playlist);
switch (media_playlist->stream_type()) {
case MediaPlaylist::MediaPlaylistStreamType::kAudio: {
const std::string& group_id = media_playlist->group_id();
audio_playlist_groups_[group_id].push_back(media_playlist);
break;
}
case MediaPlaylist::MediaPlaylistStreamType::kVideo: {
video_playlists_.push_back(media_playlist);
break;
}
default: {
NOTIMPLEMENTED() << static_cast<int>(media_playlist->stream_type())
<< " not handled.";
break;
}
}
// Sometimes we need to iterate over all playlists, so keep a collection
// of all playlists to make iterating easier.
all_playlists_.push_back(media_playlist);
}
bool MasterPlaylist::WriteMasterPlaylist(const std::string& base_url,
const std::string& output_dir) {
// TODO(rkuroiwa): Handle audio only.
std::string audio_output;
std::string video_output;
for (const auto& group_id_audio_playlists : audio_playlist_groups_) {
const std::string& group_id = group_id_audio_playlists.first;
const std::list<const MediaPlaylist*>& audio_playlists =
group_id_audio_playlists.second;
// Tracks the language of the playlist in this group.
// According to HLS spec: https://goo.gl/MiqjNd 4.3.4.1.1. Rendition Groups
// - A Group MUST NOT have more than one member with a DEFAULT attribute of
// YES.
// - Each EXT-X-MEDIA tag with an AUTOSELECT=YES attribute SHOULD have a
// combination of LANGUAGE[RFC5646], ASSOC-LANGUAGE, FORCED, and
// CHARACTERISTICS attributes that is distinct from those of other
// AUTOSELECT=YES members of its Group.
// We tag the first rendition encountered with a particular language with
// 'AUTOSELECT'; it is tagged with 'DEFAULT' too if the language matches
// |default_language_|.
std::set<std::string> languages;
uint64_t max_audio_bitrate = 0;
for (const MediaPlaylist* audio_playlist : audio_playlists) {
bool is_default = false;
bool is_autoselect = false;
const std::string language = audio_playlist->GetLanguage();
if (languages.find(language) == languages.end()) {
is_default = !language.empty() && language == default_language_;
is_autoselect = true;
languages.insert(language);
}
AppendMediaTag(base_url, group_id, audio_playlist, language, is_default,
is_autoselect, &audio_output);
const uint64_t audio_bitrate = audio_playlist->Bitrate();
if (audio_bitrate > max_audio_bitrate)
max_audio_bitrate = audio_bitrate;
}
for (const MediaPlaylist* video_playlist : video_playlists_) {
const std::string& video_codec = video_playlist->codec();
const uint64_t video_bitrate = video_playlist->Bitrate();
// Assume all codecs are the same for same group ID.
const std::string& audio_codec = audio_playlists.front()->codec();
uint32_t video_width;
uint32_t video_height;
CHECK(video_playlist->GetDisplayResolution(&video_width, &video_height));
AppendStreamInfoTag(video_bitrate + max_audio_bitrate,
video_codec + "," + audio_codec,
video_width,
video_height,
&group_id,
base_url,
video_playlist->file_name(),
&video_output);
}
}
if (audio_playlist_groups_.empty()) {
for (const MediaPlaylist* video_playlist : video_playlists_) {
const std::string& video_codec = video_playlist->codec();
const uint64_t video_bitrate = video_playlist->Bitrate();
uint32_t video_width;
uint32_t video_height;
CHECK(video_playlist->GetDisplayResolution(&video_width, &video_height));
AppendStreamInfoTag(video_bitrate,
video_codec,
video_width,
video_height,
nullptr,
base_url,
video_playlist->file_name(),
&video_output);
}
}
const std::string version = GetPackagerVersion();
std::string version_line;
if (!version.empty()) {
version_line =
base::StringPrintf("## Generated with %s version %s\n",
GetPackagerProjectUrl().c_str(), version.c_str());
}
std::string content =
"#EXTM3U\n" + version_line + audio_output + video_output;
// Skip if the playlist is already written.
if (content == written_playlist_)
return true;
std::string file_path =
base::FilePath::FromUTF8Unsafe(output_dir)
.Append(base::FilePath::FromUTF8Unsafe(file_name_))
.AsUTF8Unsafe();
if (!File::WriteFileAtomically(file_path.c_str(), content)) {
LOG(ERROR) << "Failed to write master playlist to: " << file_path;
return false;
}
written_playlist_ = content;
return true;
}
} // namespace hls
} // namespace shaka