Add a webrtc{en,de}coderfactory implementation for VideoToolbox

webrtc/modules/video_coding/codecs/h264/h264_video_toolbox_nalu.h

-/*
- *  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.
- *
- */
-
-#ifndef WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_H264_VIDEO_TOOLBOX_NALU_H_
-#define WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_H264_VIDEO_TOOLBOX_NALU_H_
-
-#include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
-
-#if defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
-
-#include <CoreMedia/CoreMedia.h>
-
-#include "webrtc/base/buffer.h"
-#include "webrtc/modules/include/module_common_types.h"
-
-namespace webrtc {
-
-// Converts a sample buffer emitted from the VideoToolbox encoder into a buffer
-// suitable for RTP. The sample buffer is in avcc format whereas the rtp buffer
-// needs to be in Annex B format. Data is written directly to |annexb_buffer|
-// and a new RTPFragmentationHeader is returned in |out_header|.
-bool H264CMSampleBufferToAnnexBBuffer(
-    CMSampleBufferRef avcc_sample_buffer,
-    bool is_keyframe,
-    rtc::Buffer* annexb_buffer,
-    webrtc::RTPFragmentationHeader** out_header);
-
-// Converts a buffer received from RTP into a sample buffer suitable for the
-// VideoToolbox decoder. The RTP buffer is in annex b format whereas the sample
-// buffer is in avcc format.
-// If |is_keyframe| is true then |video_format| is ignored since the format will
-// be read from the buffer. Otherwise |video_format| must be provided.
-// Caller is responsible for releasing the created sample buffer.
-bool H264AnnexBBufferToCMSampleBuffer(const uint8_t* annexb_buffer,
-                                      size_t annexb_buffer_size,
-                                      CMVideoFormatDescriptionRef video_format,
-                                      CMSampleBufferRef* out_sample_buffer);
-
-// Returns true if the type of the first NALU in the supplied Annex B buffer is
-// the SPS type.
-bool H264AnnexBBufferHasVideoFormatDescription(const uint8_t* annexb_buffer,
-                                               size_t annexb_buffer_size);
-
-// Returns a video format description created from the sps/pps information in
-// the Annex B buffer. If there is no such information, nullptr is returned.
-// The caller is responsible for releasing the description.
-CMVideoFormatDescriptionRef CreateVideoFormatDescription(
-    const uint8_t* annexb_buffer,
-    size_t annexb_buffer_size);
-
-// Helper class for reading NALUs from an RTP Annex B buffer.
-class AnnexBBufferReader final {
- public:
-  AnnexBBufferReader(const uint8_t* annexb_buffer, size_t length);
-  ~AnnexBBufferReader() {}
-  AnnexBBufferReader(const AnnexBBufferReader& other) = delete;
-  void operator=(const AnnexBBufferReader& other) = delete;
-
-  // Returns a pointer to the beginning of the next NALU slice without the
-  // header bytes and its length. Returns false if no more slices remain.
-  bool ReadNalu(const uint8_t** out_nalu, size_t* out_length);
-
-  // Returns the number of unread NALU bytes, including the size of the header.
-  // If the buffer has no remaining NALUs this will return zero.
-  size_t BytesRemaining() const;
-
- private:
-  // Returns the the next offset that contains NALU data.
-  size_t FindNextNaluHeader(const uint8_t* start,
-                            size_t length,
-                            size_t offset) const;
-
-  const uint8_t* const start_;
-  size_t offset_;
-  size_t next_offset_;
-  const size_t length_;
-};
-
-// Helper class for writing NALUs using avcc format into a buffer.
-class AvccBufferWriter final {
- public:
-  AvccBufferWriter(uint8_t* const avcc_buffer, size_t length);
-  ~AvccBufferWriter() {}
-  AvccBufferWriter(const AvccBufferWriter& other) = delete;
-  void operator=(const AvccBufferWriter& other) = delete;
-
-  // Writes the data slice into the buffer. Returns false if there isn't
-  // enough space left.
-  bool WriteNalu(const uint8_t* data, size_t data_size);
-
-  // Returns the unused bytes in the buffer.
-  size_t BytesRemaining() const;
-
- private:
-  uint8_t* const start_;
-  size_t offset_;
-  const size_t length_;
-};
-
-}  // namespace webrtc
-
-#endif  // defined(WEBRTC_VIDEO_TOOLBOX_SUPPORTED)
-#endif  // WEBRTC_MODULES_VIDEO_CODING_CODECS_H264_H264_VIDEO_TOOLBOX_NALU_H_