From beac7bae62a30662215386ba6d567248fe3bcd58 Mon Sep 17 00:00:00 2001 From: Kongqun Yang Date: Thu, 17 Apr 2014 15:51:39 -0700 Subject: [PATCH] Add AUTHORS, CONTRIBUTORS, CONTRIBUTING.md, and README.md CONTRIBUTING.md and README.md use GitHub Flavored Markdown, tested @ http://md.mouse.vc/ Change-Id: Ib01b9bcd8c7dac240de6d25ff443e7cdc296d780 --- AUTHORS | 17 +++ CONTRIBUTING.md | 58 ++++++++++ CONTRIBUTORS | 27 +++++ README.md | 295 ++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 397 insertions(+) create mode 100644 AUTHORS create mode 100644 CONTRIBUTING.md create mode 100644 CONTRIBUTORS create mode 100644 README.md diff --git a/AUTHORS b/AUTHORS new file mode 100644 index 0000000000..4e723be0d6 --- /dev/null +++ b/AUTHORS @@ -0,0 +1,17 @@ +# This is the official list of edash-packager authors for copyright purposes. +# This file is distinct from the CONTRIBUTORS files. +# See the latter for an explanation. +# +# Names should be added to this file with one of the following patterns: +# +# For individual contributors: +# Name +# +# For corporate contributors: +# Organization +# See examples below or python fnmatch module documentation for more information. +# +# Please keep the list sorted. + +Google Inc. <*@google.com> +The Chromium Authors <*@chromium.org> diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md new file mode 100644 index 0000000000..e8ee028500 --- /dev/null +++ b/CONTRIBUTING.md @@ -0,0 +1,58 @@ +# How to contribute # + +We'd love to accept your patches and contributions to this project. There are +just a few small guidelines you need to follow. + + +## Contributor License Agreement ## + +Contributions to any Google project must be accompanied by a Contributor +License Agreement. This is not a copyright **assignment**, it simply gives +Google permission to use and redistribute your contributions as part of the +project. + + * If you are an individual writing original source code and you're sure you + own the intellectual property, then you'll need to sign an [individual + CLA][]. + + * If you work for a company that wants to allow you to contribute your work, + then you'll need to sign a [corporate CLA][]. + +You generally only need to submit a CLA once, so if you've already submitted +one (even if it was for a different project), you probably don't need to do it +again. + +[individual CLA]: https://developers.google.com/open-source/cla/individual +[corporate CLA]: https://developers.google.com/open-source/cla/corporate + +Once your CLA is submitted (or if you already submitted one for +another Google project), make a commit adding yourself to the +[AUTHORS][] and [CONTRIBUTORS][] files. This commit can be part +of your first [pull request][]. + +[AUTHORS]: AUTHORS +[CONTRIBUTORS]: CONTRIBUTORS + + +## Submitting a patch ## + + 1. It's generally best to start by opening a new issue describing the bug or + feature you're intending to fix. Even if you think it's relatively minor, + it's helpful to know what people are working on. Mention in the initial + issue that you are planning to work on that bug or feature so that it can + be assigned to you. + + 1. Follow the normal process of [forking][] the project, and setup a new + branch to work in. It's important that each group of changes be done in + separate branches in order to ensure that a pull request only includes the + commits related to that bug or feature. + + 1. Do your best to have [well-formed commit messages][] for each change. + This provides consistency throughout the project, and ensures that commit + messages are able to be formatted properly by various git tools. + + 1. Finally, push the commits to your fork and submit a [pull request][]. + +[forking]: https://help.github.com/articles/fork-a-repo +[well-formed commit messages]: http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html +[pull request]: https://help.github.com/articles/creating-a-pull-request diff --git a/CONTRIBUTORS b/CONTRIBUTORS new file mode 100644 index 0000000000..765f8e58e1 --- /dev/null +++ b/CONTRIBUTORS @@ -0,0 +1,27 @@ +# People who have agreed to one of the CLAs and can contribute patches. +# The AUTHORS file lists the copyright holders; this file +# lists people. For example, Google employees are listed here +# but not in AUTHORS, because Google holds the copyright. +# +# Names should be added to this file only after verifying that +# the individual or the individual's organization has agreed to +# the appropriate Contributor License Agreement, found here: +# +# https://developers.google.com/open-source/cla/individual +# https://developers.google.com/open-source/cla/corporate +# +# The agreement for individuals can be filled out on the web. +# +# When adding J Random Contributor's name to this file, +# either J's name or J's organization's name should be +# added to the AUTHORS file, depending on whether the +# individual or corporate CLA was used. +# +# Names should be added to this file as: +# Name +# +# Please keep the list sorted. + +Kongqun Yang +Rintaro Kuroiwa +Thomas Inskip diff --git a/README.md b/README.md new file mode 100644 index 0000000000..bccfb44622 --- /dev/null +++ b/README.md @@ -0,0 +1,295 @@ +Media packaging SDK is intended for C++ programmers writing DASH packager application with common encryption support. + +This document provides the information needed to create a DASH packager that is able to remux and encrypt a video into fragmented ISO BMFF format with CENC support. The DASH packaging API is also designed in such a way for easy extension to more source and destination formats. + +# Setting up for development # + +1. Packager source is managed by Git at https://www.github.com/google/edash-packager. We use gclient tool from Chromium to manage third_party libraries. You will need Git and Subversion (for third_party libraries) installed on your machine to access the source code. + +2. Pull gclient and ninja from Chrome Depot Tools: +```Shell +git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git +``` +Add depot_tools to your PATH, for example, in linux: +```Shell +$ export PATH="$PATH":`pwd`/depot_tools +``` +You may want to add this to your .bashrc file or your shell's equivalent so that you don’t need to reset your $PATH manually each time you open a new shell. + +3. Get the source +```Shell +mkdir packager +cd packager +gclient config https://www.github.com/google/edash-packager.git --name=src +gclient sync +``` + +4. Build +We use ninja to build our code: +``` +ninja -C src/out/{Debug/Release} [Module] +``` +Module is optional. If not specified, build all, e.g. +``` +ninja -C src/out/Debug # build all modules in Debug mode +ninja -C src/out/Release # build all modules in Release mode +ninja -C src/out/Release mp4 # build mp4 module in Debug mode +``` +Refer to ninja manual for details.
+We also provide a mechanism to change build configurations, for example, developers can change build system to “make” by overriding GYP_GENERATORS using gyp_packager.py script, i.e. +```Shell +GYP_GENERATORS='make' src/gyp_packager.py +``` +Another example, developers can also enable clang by overriding GYP_DEFINE. +```Shell +GYP_DEFINES='clang=1' src/gyp_packager.py +``` +Take note that clang needs to be setup for the first time if it is not setup yet. +```Shell +src/tools/clang/scripts/update.sh +``` + +#Design overview# + +Major modules are described below: + +Demuxer is responsible for extracting elementary stream samples from a multimedia file, e.g. an ISO BMFF file. The demuxed streams can be fed into a muxer to generate multimedia files. For encrypted media, the user should implement the abstract DecryptorSource interface, which is used by Demuxer to decrypt the streams. The concrete DecryptorSource implementation wraps the fetching and management of decryption keys. + +Demuxer reads from source through the File interface. A concrete LocalFile class is already implemented. The user may also implements his own File class if they want to read/write using a different kinds of protocol, e.g. network storage, http etc. + +Muxer is responsible for taking elementary stream samples and producing media segments. An optional EncryptorSource can be provided to Muxer to generate encrypted outputs. Muxer writes to output using the same File interface as Demuxer. + +Demuxer and Muxer are connected using MediaStream. MediaStream wraps the elementary streams and is responsible for the interaction between Demuxer and Muxer. A demuxer can transmits multiple MediaStreams; similarly, A muxer is able to accept and mux multiple MediaStreams, not necessarily from the same Demuxer. + +MPDBuilder is responsible for the creation of Media Presentation Description as specified in ISO/IEC 23009-1 DASH MPD spec. + +The only source format supported for now is ISO BMFF; the only output format supported right now is fragmented ISO BMFF with CENC. Support for more formats will be added soon. + +##Creating DecryptorSource## + +Not implemented yet. Not needed for now. + +##Creating Demuxer## + +```C++ + // Create a demuxer from |input_media_file|. At this moment we support + // MP4 (ISO BMFF) only. + // |input_media_file| could be any supported files, e.g. if the user has + // implemented a network file interface with prefix “network”, + // |input_media_file| with value “network://xxxx” would open a network + // file automatically. + // |decryptor_source| should be NULL if the input media is not encrypted. + Demuxer demuxer(input_media_file, decryptor_source); +``` + +##Creating MpdBuilder## + +```C++ +MpdBuilder mpd_builder(MpdBuiler::kStatic); // kStatic profile for VOD. +Using MpdBuilder Instance +mpd_builder.AddBaseUrl(“http://foo.com/bar”); // Add a element. +AdaptationSet* video_adaptation_set = mpd_builder.AddAdaptationSet(); + +// Create MediaInfo object. +Representation* representation = + video_adaptation_set->AddRepresentation(media_info_object); +assert(representation); // Make sure it succeeded. +// |representation| is owned by |video_adatptation_set|, no additional +// operations are required to generate a valid MPD. + +std::cout << mpd_builder.ToString() << std::endl; // Print the MPD to stdout. +MpdWriter: MpdBuilder Wrapper class +// Get file names with MediaInfo protobuf, i.e. media_info_files (array). +MpdWrite mpd_writer; +for (size_t i = 0; i < n; ++i) + mpd_writer.AddFile(media_info_files[i]); + +mpd_writer.WriteMpdToFile(“output_file_name.mpd”); +``` + +##Creating Muxer## + +```C++ + // See below for muxer options. + MuxerOptions options; + + // Create a MP4Muxer with options specified by |options|. + mp4::MP4Muxer muxer(options); +``` + +###Muxer Options:### + +```C++ + // Generate a single segment for each media presentation. This option + // should be set for on demand profile. + options.single_segment = true; + + // Segment duration in seconds. If single_segment is specified, this parameter + // sets the duration of a subsegment; otherwise, this parameter sets the + // duration of a segment. A segment can contain one to many fragments. + options.segment_duration = 10.0; + + // Fragment duration in seconds. Should not be larger than the segment + // duration. + options.fragment_duration = 2.0; + + // Force segments to begin with stream access points. Segment duration may + // not be exactly what asked by segment_duration. + options.segment_sap_aligned = true; + + // Force fragments to begin with stream access points. Fragment duration + // may not be exactly what asked by segment_duration. Imply + // segment_sap_aligned. + options.fragment_sap_aligned = true; + + // Set to true to normalize the presentation timestamps to start from zero. + options.normalize_presentation_timestamp = true; + + // For ISO BMFF only. + // Set the number of subsegments in each SIDX box. If 0, a single SIDX box + // is used per segment. If -1, no SIDX box is used. Otherwise, the Muxer + // will pack N subsegments in the root SIDX of the segment, with + // segment_duration/N/fragment_duration fragments per subsegment. + options.num_subsegments_per_sidx = 1; + + // Output file name. If segment_template is not specified, the Muxer + // generates this single output file with all segments concatenated; + // Otherwise, it specifies the init segment name. + options.output_file_name = …; + + // Specify output segment name pattern for generated segments. It can + // furthermore be configured by using a subset of the SegmentTemplate + // identifiers: $RepresentationID$, $Number$, $Bandwidth$ and $Time. + // Optional. + options.segment_template = …; + + // Specify the temporary file for on demand media file creation. + options.temp_file_name = …; +``` + +##Creating EncryptorSource## + +```C++ +// An EncryptorSource is optional. The stream won’t be encrypted if an +// EncryptorSource is not provided. +// There are several different EncryptorSource implementations. +``` + +###FixedEncryptorSource### + +```C++ +// Users can use FixedEncryptorSource if they have encryption keys already. +scoped_ptr encryptor_source( + new FixedEncryptorSource(key_id, key, pssh)); +``` + +###WidevineEncryptorSource### + +```C++ +// Users may also use WidevineEncryptorSource to fetch keys from Widevine +// common encryption server. + +// A request signer is required to sign the common encryption request. +scoped_ptr signer( + RsaRequestSigner::CreateSigner(signer, pkcs1_rsa_private_key)); +if (!signer) { … } + +scoped_ptr encryptor_source(new WidevineEncryptorSource( + server_url, content_id, track_type, signer.Pass())); +``` + +After creating the encryptor source, + +```C++ +// Intialize encryptor source. +status = encryptor_source->Initialize(); +if (!status.ok()) { … } + +// Set encryptor source to muxer. +muxer->SetEncryptorSource(encryptor_source.get(), clear_lead); +``` + +##Connecting Demuxer and Muxer## + +```C++ + // Initialize the demuxer. + status = demuxer.Initialize(); + if (!status.ok()) { … } + + // After intializing the demuxer, we can query demuxer streams + // using demuxer.streams(). + // The function below adds the first stream into muxer, which sets up + // the connection between Demuxer and Muxer. + status = muxer.AddStream(demuxer.streams()[0]); + if (!status.ok()) { … } +``` + +##Starting Remuxing## + +```C++ + // Starts remuxing process. It runs until completion or abort due to error. + status = demuxer.Run(); + if (!status.ok()) { … } +``` + +#Packager API detail# + +Doxygen API documentation coming soon. + +#Driver Program Sample Usage# + +Sample driver programs packager_main and mpd_generator are written using the SDK. Some sample usages: + +Run the program without arguments will display the help page with the list of command line arguments: +```Shell +packager_main +``` + +Dump stream info: +```Shell +packager_main sintel.mp4 --dump_stream_info +``` + +Demux audio from the input and generate a fragmented mp4: +```Shell +packager_main sintel.mp4 --stream audio --output "fragmented_sintel.mp4" +``` + +Demux the first stream from the input and generate a fragmented mp4: +```Shell +packager_main sintel.mp4 --stream 0 --output "fragmented_sintel.mp4" +``` + +Demux video from the input and generate an encrypted fragmented mp4 using widevine encryption with RSA signing key file "widevine_test_private.der": +```Shell +packager_main sintel.mp4 \ +--stream video \ +--output "encrypted_sintel.mp4" \ +--enable_widevine_encryption \ +--server_url "license.uat.widevine.com/cenc/getcontentkey/widevine_test" \ +--content_id "content_sintel" \ +--signer "widevine_test" \ +--rsa_signing_key_path "widevine_test_private.der" +``` + +The program also supports AES signing. +```Shell +packager_main sintel.mp4 \ +--stream video \ +--output "encrypted_sintel.mp4" \ +--enable_widevine_encryption \ +--server_url "license.uat.widevine.com/cenc/getcontentkey/widevine_test" \ +--content_id "content_sintel" \ +--signer "widevine_test" \ +--aes_signing_key "1ae8ccd0e7985cc0b6203a55855a1034afc252980e970ca90e5202689f947ab9" \ +--aes_signing_iv "d58ce954203b7c9a9a9d467f59839249" +``` + +By default, packager_main will output MediaInfo files. “.media_info” file extension is appended to the output media files. The MediaInfo files can be passed to mpd_generator to generate an MPD. mpd_generator uses MpdWriter. +```Shell +mpd_generator \ +--base_urls "http://foo.com/bar1,http://foo.com/bar2" \ +--input "encrypted_sintel.mp4.media_info" \ +--output "example.mpd" +``` +