shaka-packager/packager/app/crypto_flags.cc

89 lines
2.5 KiB
C++

// Copyright 2017 Google LLC. 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/crypto_flags.h>
#include <cstdio>
#include <absl/flags/flag.h>
ABSL_FLAG(std::string,
protection_scheme,
"cenc",
"Specify a protection scheme, 'cenc' or 'cbc1' or pattern-based "
"protection schemes 'cens' or 'cbcs'.");
ABSL_FLAG(
int32_t,
crypt_byte_block,
1,
"Specify the count of the encrypted blocks in the protection pattern, "
"where block is of size 16-bytes. There are three common "
"patterns (crypt_byte_block:skip_byte_block): 1:9 (default), 5:5, 10:0. "
"Apply to video streams with 'cbcs' and 'cens' protection schemes only; "
"ignored otherwise.");
ABSL_FLAG(
int32_t,
skip_byte_block,
9,
"Specify the count of the unencrypted blocks in the protection pattern. "
"Apply to video streams with 'cbcs' and 'cens' protection schemes only; "
"ignored otherwise.");
ABSL_FLAG(bool,
vp9_subsample_encryption,
true,
"Enable VP9 subsample encryption.");
ABSL_FLAG(std::string,
playready_extra_header_data,
"",
"Extra XML data to add to PlayReady headers.");
bool ValueNotGreaterThanTen(const char* flagname, int32_t value) {
if (value > 10) {
fprintf(stderr, "ERROR: %s must not be greater than 10.\n", flagname);
return false;
}
if (value < 0) {
fprintf(stderr, "ERROR: %s must be non-negative.\n", flagname);
return false;
}
return true;
}
bool ValueIsXml(const char* flagname, const std::string& value) {
if (value.empty())
return true;
if (value[0] != '<' || value[value.size() - 1] != '>') {
fprintf(stderr, "ERROR: %s must be valid XML.\n", flagname);
return false;
}
return true;
}
namespace shaka {
bool ValidateCryptoFlags() {
bool success = true;
auto crypt_byte_block = absl::GetFlag(FLAGS_crypt_byte_block);
if (!ValueNotGreaterThanTen("crypt_byte_block", crypt_byte_block)) {
success = false;
}
auto skip_byte_block = absl::GetFlag(FLAGS_skip_byte_block);
if (!ValueNotGreaterThanTen("skip_byte_block", skip_byte_block)) {
success = false;
}
auto playready_extra_header_data =
absl::GetFlag(FLAGS_playready_extra_header_data);
if (!ValueIsXml("playready_extra_header_data", playready_extra_header_data)) {
success = false;
}
return success;
}
} // namespace shaka