| // Copyright 2015 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "cobalt/media/filters/h265_parser.h" |
| |
| #include <algorithm> |
| |
| #include "base/logging.h" |
| #include "base/stl_util.h" |
| #include "cobalt/media/base/decrypt_config.h" |
| #include "starboard/memory.h" |
| #include "starboard/types.h" |
| |
| namespace cobalt { |
| namespace media { |
| |
| #define READ_BITS_OR_RETURN(num_bits, out) \ |
| do { \ |
| int _out; \ |
| if (!br_.ReadBits(num_bits, &_out)) { \ |
| DVLOG(1) \ |
| << "Error in stream: unexpected EOS while trying to read " #out; \ |
| return kInvalidStream; \ |
| } \ |
| *out = _out; \ |
| } while (0) |
| |
| #define TRUE_OR_RETURN(a) \ |
| do { \ |
| if (!(a)) { \ |
| DVLOG(1) << "Error in stream: invalid value, expected " << #a; \ |
| return kInvalidStream; \ |
| } \ |
| } while (0) |
| |
| H265NALU::H265NALU() { SbMemorySet(this, 0, sizeof(*this)); } |
| |
| H265Parser::H265Parser() { Reset(); } |
| |
| H265Parser::~H265Parser() {} |
| |
| void H265Parser::Reset() { |
| stream_ = NULL; |
| bytes_left_ = 0; |
| encrypted_ranges_.clear(); |
| } |
| |
| void H265Parser::SetStream(const uint8_t* stream, off_t stream_size) { |
| std::vector<SubsampleEntry> subsamples; |
| SetEncryptedStream(stream, stream_size, subsamples); |
| } |
| |
| void H265Parser::SetEncryptedStream( |
| const uint8_t* stream, off_t stream_size, |
| const std::vector<SubsampleEntry>& subsamples) { |
| DCHECK(stream); |
| DCHECK_GT(stream_size, 0); |
| |
| stream_ = stream; |
| bytes_left_ = stream_size; |
| |
| encrypted_ranges_.clear(); |
| const uint8_t* start = stream; |
| const uint8_t* stream_end = stream_ + bytes_left_; |
| for (size_t i = 0; i < subsamples.size() && start < stream_end; ++i) { |
| start += subsamples[i].clear_bytes; |
| |
| const uint8_t* end = |
| std::min(start + subsamples[i].cypher_bytes, stream_end); |
| encrypted_ranges_.Add(start, end); |
| start = end; |
| } |
| } |
| |
| bool H265Parser::LocateNALU(off_t* nalu_size, off_t* start_code_size) { |
| // Find the start code of next NALU. |
| off_t nalu_start_off = 0; |
| off_t annexb_start_code_size = 0; |
| |
| if (!H264Parser::FindStartCodeInClearRanges( |
| stream_, bytes_left_, encrypted_ranges_, &nalu_start_off, |
| &annexb_start_code_size)) { |
| DVLOG(4) << "Could not find start code, end of stream?"; |
| return false; |
| } |
| |
| // Move the stream to the beginning of the NALU (pointing at the start code). |
| stream_ += nalu_start_off; |
| bytes_left_ -= nalu_start_off; |
| |
| const uint8_t* nalu_data = stream_ + annexb_start_code_size; |
| off_t max_nalu_data_size = bytes_left_ - annexb_start_code_size; |
| if (max_nalu_data_size <= 0) { |
| DVLOG(3) << "End of stream"; |
| return false; |
| } |
| |
| // Find the start code of next NALU; |
| // if successful, |nalu_size_without_start_code| is the number of bytes from |
| // after previous start code to before this one; |
| // if next start code is not found, it is still a valid NALU since there |
| // are some bytes left after the first start code: all the remaining bytes |
| // belong to the current NALU. |
| off_t next_start_code_size = 0; |
| off_t nalu_size_without_start_code = 0; |
| if (!H264Parser::FindStartCodeInClearRanges( |
| nalu_data, max_nalu_data_size, encrypted_ranges_, |
| &nalu_size_without_start_code, &next_start_code_size)) { |
| nalu_size_without_start_code = max_nalu_data_size; |
| } |
| *nalu_size = nalu_size_without_start_code + annexb_start_code_size; |
| *start_code_size = annexb_start_code_size; |
| return true; |
| } |
| |
| H265Parser::Result H265Parser::AdvanceToNextNALU(H265NALU* nalu) { |
| off_t start_code_size; |
| off_t nalu_size_with_start_code; |
| if (!LocateNALU(&nalu_size_with_start_code, &start_code_size)) { |
| DVLOG(4) << "Could not find next NALU, bytes left in stream: " |
| << bytes_left_; |
| return kEOStream; |
| } |
| |
| nalu->data = stream_ + start_code_size; |
| nalu->size = nalu_size_with_start_code - start_code_size; |
| DVLOG(4) << "NALU found: size=" << nalu_size_with_start_code; |
| |
| // Initialize bit reader at the start of found NALU. |
| if (!br_.Initialize(nalu->data, nalu->size)) return kEOStream; |
| |
| // Move parser state to after this NALU, so next time AdvanceToNextNALU |
| // is called, we will effectively be skipping it; |
| // other parsing functions will use the position saved |
| // in bit reader for parsing, so we don't have to remember it here. |
| stream_ += nalu_size_with_start_code; |
| bytes_left_ -= nalu_size_with_start_code; |
| |
| // Read NALU header, skip the forbidden_zero_bit, but check for it. |
| int data; |
| READ_BITS_OR_RETURN(1, &data); |
| TRUE_OR_RETURN(data == 0); |
| |
| READ_BITS_OR_RETURN(6, &nalu->nal_unit_type); |
| READ_BITS_OR_RETURN(6, &nalu->nuh_layer_id); |
| READ_BITS_OR_RETURN(3, &nalu->nuh_temporal_id_plus1); |
| |
| DVLOG(4) << "NALU type: " << static_cast<int>(nalu->nal_unit_type) |
| << " at: " << reinterpret_cast<const void*>(nalu->data) |
| << " size: " << nalu->size; |
| |
| return kOk; |
| } |
| |
| } // namespace media |
| } // namespace cobalt |