packager_util.cc

// Copyright 2014 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/app/packager_util.h"

#include <gflags/gflags.h>
#include <iostream>

#include "packager/app/fixed_key_encryption_flags.h"
#include "packager/app/playready_key_encryption_flags.h"
#include "packager/app/mpd_flags.h"
#include "packager/app/muxer_flags.h"
#include "packager/app/widevine_encryption_flags.h"
#include "packager/base/logging.h"
#include "packager/base/strings/string_number_conversions.h"
#include "packager/media/base/fixed_key_source.h"
#include "packager/media/base/muxer_options.h"
#include "packager/media/base/playready_key_source.h"
#include "packager/media/base/request_signer.h"
#include "packager/media/base/widevine_key_source.h"
#include "packager/media/chunking/chunking_handler.h"
#include "packager/media/crypto/encryption_handler.h"
#include "packager/media/file/file.h"
#include "packager/mpd/base/mpd_options.h"

DEFINE_bool(mp4_use_decoding_timestamp_in_timeline,
            false,
            "If set, decoding timestamp instead of presentation timestamp will "
            "be used when generating media timeline, e.g. timestamps in sidx "
            "and mpd. This is to workaround a Chromium bug that decoding "
            "timestamp is used in buffered range, https://crbug.com/398130.");
DEFINE_bool(dump_stream_info, false, "Dump demuxed stream info.");

namespace shaka {
namespace media {
namespace {

FourCC GetProtectionScheme(const std::string& protection_scheme) {
  if (protection_scheme == "cenc") {
    return FOURCC_cenc;
  } else if (protection_scheme == "cens") {
    return FOURCC_cens;
  } else if (protection_scheme == "cbc1") {
    return FOURCC_cbc1;
  } else if (protection_scheme == "cbcs") {
    return FOURCC_cbcs;
  } else {
    LOG(ERROR) << "Unknown protection scheme: " << protection_scheme;
    return FOURCC_NULL;
  }
}

}  // namespace

std::unique_ptr<RequestSigner> CreateSigner() {
  std::unique_ptr<RequestSigner> signer;

  if (!FLAGS_aes_signing_key.empty()) {
    signer.reset(AesRequestSigner::CreateSigner(
        FLAGS_signer, FLAGS_aes_signing_key, FLAGS_aes_signing_iv));
    if (!signer) {
      LOG(ERROR) << "Cannot create an AES signer object from '"
                 << FLAGS_aes_signing_key << "':'" << FLAGS_aes_signing_iv
                 << "'.";
      return std::unique_ptr<RequestSigner>();
    }
  } else if (!FLAGS_rsa_signing_key_path.empty()) {
    std::string rsa_private_key;
    if (!File::ReadFileToString(FLAGS_rsa_signing_key_path.c_str(),
                                &rsa_private_key)) {
      LOG(ERROR) << "Failed to read from '" << FLAGS_rsa_signing_key_path
                 << "'.";
      return std::unique_ptr<RequestSigner>();
    }
    signer.reset(RsaRequestSigner::CreateSigner(FLAGS_signer, rsa_private_key));
    if (!signer) {
      LOG(ERROR) << "Cannot create a RSA signer object from '"
                 << FLAGS_rsa_signing_key_path << "'.";
      return std::unique_ptr<RequestSigner>();
    }
  }
  return signer;
}

std::unique_ptr<KeySource> CreateEncryptionKeySource() {
  std::unique_ptr<KeySource> encryption_key_source;
  if (FLAGS_enable_widevine_encryption) {
    std::unique_ptr<WidevineKeySource> widevine_key_source(
        new WidevineKeySource(FLAGS_key_server_url, FLAGS_include_common_pssh));
    if (!FLAGS_signer.empty()) {
      std::unique_ptr<RequestSigner> request_signer(CreateSigner());
      if (!request_signer)
        return std::unique_ptr<KeySource>();
      widevine_key_source->set_signer(std::move(request_signer));
    }

    std::vector<uint8_t> content_id;
    if (!base::HexStringToBytes(FLAGS_content_id, &content_id)) {
      LOG(ERROR) << "Invalid content_id hex string specified.";
      return std::unique_ptr<KeySource>();
    }
    Status status = widevine_key_source->FetchKeys(content_id, FLAGS_policy);
    if (!status.ok()) {
      LOG(ERROR) << "Widevine encryption key source failed to fetch keys: "
                 << status.ToString();
      return std::unique_ptr<KeySource>();
    }
    encryption_key_source = std::move(widevine_key_source);
  } else if (FLAGS_enable_fixed_key_encryption) {
    encryption_key_source = FixedKeySource::CreateFromHexStrings(
        FLAGS_key_id, FLAGS_key, FLAGS_pssh, FLAGS_iv);
  } else if (FLAGS_enable_playready_encryption) {
    if (!FLAGS_playready_key_id.empty() && !FLAGS_playready_key.empty()) {
      encryption_key_source = PlayReadyKeySource::CreateFromKeyAndKeyId(
          FLAGS_playready_key_id, FLAGS_playready_key);
    } else if (!FLAGS_playready_server_url.empty() &&
               !FLAGS_program_identifier.empty()) {
      std::unique_ptr<PlayReadyKeySource> playready_key_source;
      if (!FLAGS_client_cert_file.empty() &&
          !FLAGS_client_cert_private_key_file.empty() &&
          !FLAGS_client_cert_private_key_password.empty()) {
        playready_key_source.reset(new PlayReadyKeySource(
            FLAGS_playready_server_url,
            FLAGS_client_cert_file,
            FLAGS_client_cert_private_key_file,
            FLAGS_client_cert_private_key_password));
      } else {
        playready_key_source.reset(new PlayReadyKeySource(
            FLAGS_playready_server_url));
      }
      if (!FLAGS_ca_file.empty()) {
        playready_key_source->SetCaFile(FLAGS_ca_file);
      }
      playready_key_source->FetchKeysWithProgramIdentifier(FLAGS_program_identifier);
      encryption_key_source = std::move(playready_key_source);
    } else {
      LOG(ERROR) << "Error creating PlayReady key source.";
      return std::unique_ptr<KeySource>();
    }
  }
  return encryption_key_source;
}

std::unique_ptr<KeySource> CreateDecryptionKeySource() {
  std::unique_ptr<KeySource> decryption_key_source;
  if (FLAGS_enable_widevine_decryption) {
    std::unique_ptr<WidevineKeySource> widevine_key_source(
        new WidevineKeySource(FLAGS_key_server_url, FLAGS_include_common_pssh));
    if (!FLAGS_signer.empty()) {
      std::unique_ptr<RequestSigner> request_signer(CreateSigner());
      if (!request_signer)
        return std::unique_ptr<KeySource>();
      widevine_key_source->set_signer(std::move(request_signer));
    }

    decryption_key_source = std::move(widevine_key_source);
  } else if (FLAGS_enable_fixed_key_decryption) {
    const char kNoPssh[] = "";
    const char kNoIv[] = "";
    decryption_key_source = FixedKeySource::CreateFromHexStrings(
        FLAGS_key_id, FLAGS_key, kNoPssh, kNoIv);
  }
  return decryption_key_source;
}

ChunkingOptions GetChunkingOptions() {
  ChunkingOptions chunking_options;
  chunking_options.segment_duration_in_seconds = FLAGS_segment_duration;
  chunking_options.subsegment_duration_in_seconds = FLAGS_fragment_duration;
  chunking_options.segment_sap_aligned = FLAGS_segment_sap_aligned;
  chunking_options.subsegment_sap_aligned = FLAGS_fragment_sap_aligned;
  return chunking_options;
}

EncryptionOptions GetEncryptionOptions() {
  EncryptionOptions encryption_options;
  encryption_options.clear_lead_in_seconds = FLAGS_clear_lead;
  encryption_options.protection_scheme =
      GetProtectionScheme(FLAGS_protection_scheme);
  encryption_options.max_sd_pixels = FLAGS_max_sd_pixels;
  encryption_options.max_hd_pixels = FLAGS_max_hd_pixels;
  encryption_options.max_uhd1_pixels = FLAGS_max_uhd1_pixels;
  encryption_options.crypto_period_duration_in_seconds =
      FLAGS_crypto_period_duration;
  return encryption_options;
}

MuxerOptions GetMuxerOptions() {
  MuxerOptions muxer_options;
  muxer_options.num_subsegments_per_sidx = FLAGS_num_subsegments_per_sidx;
  muxer_options.webm_subsample_encryption = FLAGS_webm_subsample_encryption;
  if (FLAGS_mp4_use_decoding_timestamp_in_timeline) {
    LOG(WARNING) << "Flag --mp4_use_decoding_timestamp_in_timeline is set. "
                    "Note that it is a temporary hack to workaround Chromium "
                    "bug https://crbug.com/398130. The flag may be removed "
                    "when the Chromium bug is fixed.";
  }
  muxer_options.mp4_use_decoding_timestamp_in_timeline =
      FLAGS_mp4_use_decoding_timestamp_in_timeline;
  muxer_options.temp_dir = FLAGS_temp_dir;
  return muxer_options;
}

MpdOptions GetMpdOptions(bool on_demand_profile) {
  MpdOptions mpd_options;
  mpd_options.dash_profile =
      on_demand_profile ? DashProfile::kOnDemand : DashProfile::kLive;
  mpd_options.mpd_type = (on_demand_profile || FLAGS_generate_static_mpd)
                             ? MpdType::kStatic
                             : MpdType::kDynamic;
  mpd_options.availability_time_offset = FLAGS_availability_time_offset;
  mpd_options.minimum_update_period = FLAGS_minimum_update_period;
  mpd_options.min_buffer_time = FLAGS_min_buffer_time;
  mpd_options.time_shift_buffer_depth = FLAGS_time_shift_buffer_depth;
  mpd_options.suggested_presentation_delay = FLAGS_suggested_presentation_delay;
  mpd_options.default_language = FLAGS_default_language;
  return mpd_options;
}

}  // namespace media
}  // namespace shaka