Reland of Split iOS sdk in to separate targets

webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.cc

+/*
+ *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ *
+ */
+
+#include "webrtc/sdk/objc/Framework/Classes/VideoToolbox/nalu_rewriter.h"
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <memory>
+#include <vector>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/logging.h"
+
+namespace webrtc {
+
+using H264::kAud;
+using H264::kSps;
+using H264::NaluIndex;
+using H264::NaluType;
+using H264::ParseNaluType;
+
+const char kAnnexBHeaderBytes[4] = {0, 0, 0, 1};
+const size_t kAvccHeaderByteSize = sizeof(uint32_t);
+
+bool H264CMSampleBufferToAnnexBBuffer(
+    CMSampleBufferRef avcc_sample_buffer,
+    bool is_keyframe,
+    rtc::Buffer* annexb_buffer,
+    webrtc::RTPFragmentationHeader** out_header) {
+  RTC_DCHECK(avcc_sample_buffer);
+  RTC_DCHECK(out_header);
+  *out_header = nullptr;
+
+  // Get format description from the sample buffer.
+  CMVideoFormatDescriptionRef description =
+      CMSampleBufferGetFormatDescription(avcc_sample_buffer);
+  if (description == nullptr) {
+    LOG(LS_ERROR) << "Failed to get sample buffer's description.";
+    return false;
+  }
+
+  // Get parameter set information.
+  int nalu_header_size = 0;
+  size_t param_set_count = 0;
+  OSStatus status = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(
+      description, 0, nullptr, nullptr, &param_set_count, &nalu_header_size);
+  if (status != noErr) {
+    LOG(LS_ERROR) << "Failed to get parameter set.";
+    return false;
+  }
+  RTC_CHECK_EQ(nalu_header_size, kAvccHeaderByteSize);
+  RTC_DCHECK_EQ(param_set_count, 2);
+
+  // Truncate any previous data in the buffer without changing its capacity.
+  annexb_buffer->SetSize(0);
+
+  size_t nalu_offset = 0;
+  std::vector<size_t> frag_offsets;
+  std::vector<size_t> frag_lengths;
+
+  // Place all parameter sets at the front of buffer.
+  if (is_keyframe) {
+    size_t param_set_size = 0;
+    const uint8_t* param_set = nullptr;
+    for (size_t i = 0; i < param_set_count; ++i) {
+      status = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(
+          description, i, &param_set, &param_set_size, nullptr, nullptr);
+      if (status != noErr) {
+        LOG(LS_ERROR) << "Failed to get parameter set.";
+        return false;
+      }
+      // Update buffer.
+      annexb_buffer->AppendData(kAnnexBHeaderBytes, sizeof(kAnnexBHeaderBytes));
+      annexb_buffer->AppendData(reinterpret_cast<const char*>(param_set),
+                                param_set_size);
+      // Update fragmentation.
+      frag_offsets.push_back(nalu_offset + sizeof(kAnnexBHeaderBytes));
+      frag_lengths.push_back(param_set_size);
+      nalu_offset += sizeof(kAnnexBHeaderBytes) + param_set_size;
+    }
+  }
+
+  // Get block buffer from the sample buffer.
+  CMBlockBufferRef block_buffer =
+      CMSampleBufferGetDataBuffer(avcc_sample_buffer);
+  if (block_buffer == nullptr) {
+    LOG(LS_ERROR) << "Failed to get sample buffer's block buffer.";
+    return false;
+  }
+  CMBlockBufferRef contiguous_buffer = nullptr;
+  // Make sure block buffer is contiguous.
+  if (!CMBlockBufferIsRangeContiguous(block_buffer, 0, 0)) {
+    status = CMBlockBufferCreateContiguous(
+        nullptr, block_buffer, nullptr, nullptr, 0, 0, 0, &contiguous_buffer);
+    if (status != noErr) {
+      LOG(LS_ERROR) << "Failed to flatten non-contiguous block buffer: "
+                    << status;
+      return false;
+    }
+  } else {
+    contiguous_buffer = block_buffer;
+    // Retain to make cleanup easier.
+    CFRetain(contiguous_buffer);
+    block_buffer = nullptr;
+  }
+
+  // Now copy the actual data.
+  char* data_ptr = nullptr;
+  size_t block_buffer_size = CMBlockBufferGetDataLength(contiguous_buffer);
+  status = CMBlockBufferGetDataPointer(contiguous_buffer, 0, nullptr, nullptr,
+                                       &data_ptr);
+  if (status != noErr) {
+    LOG(LS_ERROR) << "Failed to get block buffer data.";
+    CFRelease(contiguous_buffer);
+    return false;
+  }
+  size_t bytes_remaining = block_buffer_size;
+  while (bytes_remaining > 0) {
+    // The size type here must match |nalu_header_size|, we expect 4 bytes.
+    // Read the length of the next packet of data. Must convert from big endian
+    // to host endian.
+    RTC_DCHECK_GE(bytes_remaining, (size_t)nalu_header_size);
+    uint32_t* uint32_data_ptr = reinterpret_cast<uint32_t*>(data_ptr);
+    uint32_t packet_size = CFSwapInt32BigToHost(*uint32_data_ptr);
+    // Update buffer.
+    annexb_buffer->AppendData(kAnnexBHeaderBytes, sizeof(kAnnexBHeaderBytes));
+    annexb_buffer->AppendData(data_ptr + nalu_header_size, packet_size);
+    // Update fragmentation.
+    frag_offsets.push_back(nalu_offset + sizeof(kAnnexBHeaderBytes));
+    frag_lengths.push_back(packet_size);
+    nalu_offset += sizeof(kAnnexBHeaderBytes) + packet_size;
+
+    size_t bytes_written = packet_size + sizeof(kAnnexBHeaderBytes);
+    bytes_remaining -= bytes_written;
+    data_ptr += bytes_written;
+  }
+  RTC_DCHECK_EQ(bytes_remaining, (size_t)0);
+
+  std::unique_ptr<webrtc::RTPFragmentationHeader> header;
+  header.reset(new webrtc::RTPFragmentationHeader());
+  header->VerifyAndAllocateFragmentationHeader(frag_offsets.size());
+  RTC_DCHECK_EQ(frag_lengths.size(), frag_offsets.size());
+  for (size_t i = 0; i < frag_offsets.size(); ++i) {
+    header->fragmentationOffset[i] = frag_offsets[i];
+    header->fragmentationLength[i] = frag_lengths[i];
+    header->fragmentationPlType[i] = 0;
+    header->fragmentationTimeDiff[i] = 0;
+  }
+  *out_header = header.release();
+  CFRelease(contiguous_buffer);
+  return true;
+}
+
+bool H264AnnexBBufferToCMSampleBuffer(const uint8_t* annexb_buffer,
+                                      size_t annexb_buffer_size,
+                                      CMVideoFormatDescriptionRef video_format,
+                                      CMSampleBufferRef* out_sample_buffer) {
+  RTC_DCHECK(annexb_buffer);
+  RTC_DCHECK(out_sample_buffer);
+  RTC_DCHECK(video_format);
+  *out_sample_buffer = nullptr;
+
+  AnnexBBufferReader reader(annexb_buffer, annexb_buffer_size);
+  if (H264AnnexBBufferHasVideoFormatDescription(annexb_buffer,
+                                                annexb_buffer_size)) {
+    // Advance past the SPS and PPS.
+    const uint8_t* data = nullptr;
+    size_t data_len = 0;
+    if (!reader.ReadNalu(&data, &data_len)) {
+      LOG(LS_ERROR) << "Failed to read SPS";
+      return false;
+    }
+    if (!reader.ReadNalu(&data, &data_len)) {
+      LOG(LS_ERROR) << "Failed to read PPS";
+      return false;
+    }
+  }
+
+  // Allocate memory as a block buffer.
+  // TODO(tkchin): figure out how to use a pool.
+  CMBlockBufferRef block_buffer = nullptr;
+  OSStatus status = CMBlockBufferCreateWithMemoryBlock(
+      nullptr, nullptr, reader.BytesRemaining(), nullptr, nullptr, 0,
+      reader.BytesRemaining(), kCMBlockBufferAssureMemoryNowFlag,
+      &block_buffer);
+  if (status != kCMBlockBufferNoErr) {
+    LOG(LS_ERROR) << "Failed to create block buffer.";
+    return false;
+  }
+
+  // Make sure block buffer is contiguous.
+  CMBlockBufferRef contiguous_buffer = nullptr;
+  if (!CMBlockBufferIsRangeContiguous(block_buffer, 0, 0)) {
+    status = CMBlockBufferCreateContiguous(
+        nullptr, block_buffer, nullptr, nullptr, 0, 0, 0, &contiguous_buffer);
+    if (status != noErr) {
+      LOG(LS_ERROR) << "Failed to flatten non-contiguous block buffer: "
+                    << status;
+      CFRelease(block_buffer);
+      return false;
+    }
+  } else {
+    contiguous_buffer = block_buffer;
+    block_buffer = nullptr;
+  }
+
+  // Get a raw pointer into allocated memory.
+  size_t block_buffer_size = 0;
+  char* data_ptr = nullptr;
+  status = CMBlockBufferGetDataPointer(contiguous_buffer, 0, nullptr,
+                                       &block_buffer_size, &data_ptr);
+  if (status != kCMBlockBufferNoErr) {
+    LOG(LS_ERROR) << "Failed to get block buffer data pointer.";
+    CFRelease(contiguous_buffer);
+    return false;
+  }
+  RTC_DCHECK(block_buffer_size == reader.BytesRemaining());
+
+  // Write Avcc NALUs into block buffer memory.
+  AvccBufferWriter writer(reinterpret_cast<uint8_t*>(data_ptr),
+                          block_buffer_size);
+  while (reader.BytesRemaining() > 0) {
+    const uint8_t* nalu_data_ptr = nullptr;
+    size_t nalu_data_size = 0;
+    if (reader.ReadNalu(&nalu_data_ptr, &nalu_data_size)) {
+      writer.WriteNalu(nalu_data_ptr, nalu_data_size);
+    }
+  }
+
+  // Create sample buffer.
+  status = CMSampleBufferCreate(nullptr, contiguous_buffer, true, nullptr,
+                                nullptr, video_format, 1, 0, nullptr, 0,
+                                nullptr, out_sample_buffer);
+  if (status != noErr) {
+    LOG(LS_ERROR) << "Failed to create sample buffer.";
+    CFRelease(contiguous_buffer);
+    return false;
+  }
+  CFRelease(contiguous_buffer);
+  return true;
+}
+
+bool H264AnnexBBufferHasVideoFormatDescription(const uint8_t* annexb_buffer,
+                                               size_t annexb_buffer_size) {
+  RTC_DCHECK(annexb_buffer);
+  RTC_DCHECK_GT(annexb_buffer_size, 4);
+
+  // The buffer we receive via RTP has 00 00 00 01 start code artifically
+  // embedded by the RTP depacketizer. Extract NALU information.
+  // TODO(tkchin): handle potential case where sps and pps are delivered
+  // separately.
+  NaluType first_nalu_type = ParseNaluType(annexb_buffer[4]);
+  bool is_first_nalu_type_sps = first_nalu_type == kSps;
+  if (is_first_nalu_type_sps)
+    return true;
+  bool is_first_nalu_type_aud = first_nalu_type == kAud;
+  // Start code + access unit delimiter + start code = 4 + 2 + 4 = 10.
+  if (!is_first_nalu_type_aud || annexb_buffer_size <= 10u)
+    return false;
+  NaluType second_nalu_type = ParseNaluType(annexb_buffer[10]);
+  bool is_second_nalu_type_sps = second_nalu_type == kSps;
+  return is_second_nalu_type_sps;
+}
+
+CMVideoFormatDescriptionRef CreateVideoFormatDescription(
+    const uint8_t* annexb_buffer,
+    size_t annexb_buffer_size) {
+  if (!H264AnnexBBufferHasVideoFormatDescription(annexb_buffer,
+                                                 annexb_buffer_size)) {
+    return nullptr;
+  }
+  AnnexBBufferReader reader(annexb_buffer, annexb_buffer_size);
+  CMVideoFormatDescriptionRef description = nullptr;
+  OSStatus status = noErr;
+  // Parse the SPS and PPS into a CMVideoFormatDescription.
+  const uint8_t* param_set_ptrs[2] = {};
+  size_t param_set_sizes[2] = {};
+  // Skip AUD.
+  if (ParseNaluType(annexb_buffer[4]) == kAud) {
+    if (!reader.ReadNalu(&param_set_ptrs[0], &param_set_sizes[0])) {
+      LOG(LS_ERROR) << "Failed to read AUD";
+      return nullptr;
+    }
+  }
+  if (!reader.ReadNalu(&param_set_ptrs[0], &param_set_sizes[0])) {
+    LOG(LS_ERROR) << "Failed to read SPS";
+    return nullptr;
+  }
+  if (!reader.ReadNalu(&param_set_ptrs[1], &param_set_sizes[1])) {
+    LOG(LS_ERROR) << "Failed to read PPS";
+    return nullptr;
+  }
+  status = CMVideoFormatDescriptionCreateFromH264ParameterSets(
+      kCFAllocatorDefault, 2, param_set_ptrs, param_set_sizes, 4,
+      &description);
+  if (status != noErr) {
+    LOG(LS_ERROR) << "Failed to create video format description.";
+    return nullptr;
+  }
+  return description;
+}
+
+AnnexBBufferReader::AnnexBBufferReader(const uint8_t* annexb_buffer,
+                                       size_t length)
+    : start_(annexb_buffer), length_(length) {
+  RTC_DCHECK(annexb_buffer);
+  offsets_ = H264::FindNaluIndices(annexb_buffer, length);
+  offset_ = offsets_.begin();
+}
+
+bool AnnexBBufferReader::ReadNalu(const uint8_t** out_nalu,
+                                  size_t* out_length) {
+  RTC_DCHECK(out_nalu);
+  RTC_DCHECK(out_length);
+  *out_nalu = nullptr;
+  *out_length = 0;
+
+  if (offset_ == offsets_.end()) {
+    return false;
+  }
+  *out_nalu = start_ + offset_->payload_start_offset;
+  *out_length = offset_->payload_size;
+  ++offset_;
+  return true;
+}
+
+size_t AnnexBBufferReader::BytesRemaining() const {
+  if (offset_ == offsets_.end()) {
+    return 0;
+  }
+  return length_ - offset_->start_offset;
+}
+
+AvccBufferWriter::AvccBufferWriter(uint8_t* const avcc_buffer, size_t length)
+    : start_(avcc_buffer), offset_(0), length_(length) {
+  RTC_DCHECK(avcc_buffer);
+}
+
+bool AvccBufferWriter::WriteNalu(const uint8_t* data, size_t data_size) {
+  // Check if we can write this length of data.
+  if (data_size + kAvccHeaderByteSize > BytesRemaining()) {
+    return false;
+  }
+  // Write length header, which needs to be big endian.
+  uint32_t big_endian_length = CFSwapInt32HostToBig(data_size);
+  memcpy(start_ + offset_, &big_endian_length, sizeof(big_endian_length));
+  offset_ += sizeof(big_endian_length);
+  // Write data.
+  memcpy(start_ + offset_, data, data_size);
+  offset_ += data_size;
+  return true;
+}
+
+size_t AvccBufferWriter::BytesRemaining() const {
+  return length_ - offset_;
+}
+
+}  // namespace webrtc