modules/rtp_rtcp/source/rtp_format_vp8.h - src - Git at Google

 /*
  *  Copyright (c) 2011 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.
  */

 /*
  * This file contains the declaration of the VP8 packetizer class.
  * A packetizer object is created for each encoded video frame. The
  * constructor is called with the payload data and size,
  * together with the fragmentation information and a packetizer mode
  * of choice. Alternatively, if no fragmentation info is available, the
  * second constructor can be used with only payload data and size; in that
  * case the mode kEqualSize is used.
  *
  * After creating the packetizer, the method NextPacket is called
  * repeatedly to get all packets for the frame. The method returns
  * false as long as there are more packets left to fetch.
  */

 #ifndef MODULES_RTP_RTCP_SOURCE_RTP_FORMAT_VP8_H_
 #define MODULES_RTP_RTCP_SOURCE_RTP_FORMAT_VP8_H_

 #include <queue>
 #include <string>
 #include <vector>

 #include "modules/include/module_common_types.h"
 #include "modules/rtp_rtcp/source/rtp_format.h"
 #include "rtc_base/constructormagic.h"
 #include "typedefs.h"  // NOLINT(build/include)

 namespace webrtc {

 // Packetizer for VP8.
 class RtpPacketizerVp8 : public RtpPacketizer {
  public:
   // Initialize with payload from encoder.
   // The payload_data must be exactly one encoded VP8 frame.
   RtpPacketizerVp8(const RTPVideoHeaderVP8& hdr_info,
                    size_t max_payload_len,
                    size_t last_packet_reduction_len);

   ~RtpPacketizerVp8() override;

   size_t SetPayloadData(const uint8_t* payload_data,
                         size_t payload_size,
                         const RTPFragmentationHeader* fragmentation) override;

   // Get the next payload with VP8 payload header.
   // Write payload and set marker bit of the |packet|.
   // Returns true on success, false otherwise.
   bool NextPacket(RtpPacketToSend* packet) override;

   std::string ToString() override;

  private:
   typedef struct {
     size_t payload_start_pos;
     size_t size;
     bool first_packet;
   } InfoStruct;
   typedef std::queue<InfoStruct> InfoQueue;

   static const int kXBit = 0x80;
   static const int kNBit = 0x20;
   static const int kSBit = 0x10;
   static const int kPartIdField = 0x0F;
   static const int kKeyIdxField = 0x1F;
   static const int kIBit = 0x80;
   static const int kLBit = 0x40;
   static const int kTBit = 0x20;
   static const int kKBit = 0x10;
   static const int kYBit = 0x20;

   // Calculate all packet sizes and load to packet info queue.
   int GeneratePackets();

   // Splits given part of payload to packets with a given capacity. The last
   // packet should be reduced by last_packet_reduction_len_.
   void GeneratePacketsSplitPayloadBalanced(size_t payload_len, size_t capacity);

   // Insert packet into packet queue.
   void QueuePacket(size_t start_pos, size_t packet_size, bool first_packet);

   // Write the payload header and copy the payload to the buffer.
   // The info in packet_info determines which part of the payload is written
   // and what to write in the header fields.
   int WriteHeaderAndPayload(const InfoStruct& packet_info,
                             uint8_t* buffer,
                             size_t buffer_length) const;

   // Write the X field and the appropriate extension fields to buffer.
   // The function returns the extension length (including X field), or -1
   // on error.
   int WriteExtensionFields(uint8_t* buffer, size_t buffer_length) const;

   // Set the I bit in the x_field, and write PictureID to the appropriate
   // position in buffer. The function returns 0 on success, -1 otherwise.
   int WritePictureIDFields(uint8_t* x_field,
                            uint8_t* buffer,
                            size_t buffer_length,
                            size_t* extension_length) const;

   // Set the L bit in the x_field, and write Tl0PicIdx to the appropriate
   // position in buffer. The function returns 0 on success, -1 otherwise.
   int WriteTl0PicIdxFields(uint8_t* x_field,
                            uint8_t* buffer,
                            size_t buffer_length,
                            size_t* extension_length) const;

   // Set the T and K bits in the x_field, and write TID, Y and KeyIdx to the
   // appropriate position in buffer. The function returns 0 on success,
   // -1 otherwise.
   int WriteTIDAndKeyIdxFields(uint8_t* x_field,
                               uint8_t* buffer,
                               size_t buffer_length,
                               size_t* extension_length) const;

   // Write the PictureID from codec_specific_info_ to buffer. One or two
   // bytes are written, depending on magnitude of PictureID. The function
   // returns the number of bytes written.
   int WritePictureID(uint8_t* buffer, size_t buffer_length) const;

   // Calculate and return length (octets) of the variable header fields in
   // the next header (i.e., header length in addition to vp8_header_bytes_).
   size_t PayloadDescriptorExtraLength() const;

   // Calculate and return length (octets) of PictureID field in the next
   // header. Can be 0, 1, or 2.
   size_t PictureIdLength() const;

   // Check whether each of the optional fields will be included in the header.
   bool XFieldPresent() const;
   bool TIDFieldPresent() const;
   bool KeyIdxFieldPresent() const;
   bool TL0PicIdxFieldPresent() const;
   bool PictureIdPresent() const { return (PictureIdLength() > 0); }

   const uint8_t* payload_data_;
   size_t payload_size_;
   const size_t vp8_fixed_payload_descriptor_bytes_;  // Length of VP8 payload
                                                      // descriptors' fixed part.
   const RTPVideoHeaderVP8 hdr_info_;
   const size_t max_payload_len_;
   const size_t last_packet_reduction_len_;
   InfoQueue packets_;

   RTC_DISALLOW_COPY_AND_ASSIGN(RtpPacketizerVp8);
 };

 // Depacketizer for VP8.
 class RtpDepacketizerVp8 : public RtpDepacketizer {
  public:
   ~RtpDepacketizerVp8() override = default;

   bool Parse(ParsedPayload* parsed_payload,
              const uint8_t* payload_data,
              size_t payload_data_length) override;
 };
 }  // namespace webrtc
 #endif  // MODULES_RTP_RTCP_SOURCE_RTP_FORMAT_VP8_H_
	/*
	* Copyright (c) 2011 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.
	*/

	/*
	* This file contains the declaration of the VP8 packetizer class.
	* A packetizer object is created for each encoded video frame. The
	* constructor is called with the payload data and size,
	* together with the fragmentation information and a packetizer mode
	* of choice. Alternatively, if no fragmentation info is available, the
	* second constructor can be used with only payload data and size; in that
	* case the mode kEqualSize is used.
	*
	* After creating the packetizer, the method NextPacket is called
	* repeatedly to get all packets for the frame. The method returns
	* false as long as there are more packets left to fetch.
	*/

	#ifndef MODULES_RTP_RTCP_SOURCE_RTP_FORMAT_VP8_H_
	#define MODULES_RTP_RTCP_SOURCE_RTP_FORMAT_VP8_H_

	#include <queue>
	#include <string>
	#include <vector>

	#include "modules/include/module_common_types.h"
	#include "modules/rtp_rtcp/source/rtp_format.h"
	#include "rtc_base/constructormagic.h"
	#include "typedefs.h" // NOLINT(build/include)

	namespace webrtc {

	// Packetizer for VP8.
	class RtpPacketizerVp8 : public RtpPacketizer {
	public:
	// Initialize with payload from encoder.
	// The payload_data must be exactly one encoded VP8 frame.
	RtpPacketizerVp8(const RTPVideoHeaderVP8& hdr_info,
	size_t max_payload_len,
	size_t last_packet_reduction_len);

	~RtpPacketizerVp8() override;

	size_t SetPayloadData(const uint8_t* payload_data,
	size_t payload_size,
	const RTPFragmentationHeader* fragmentation) override;

	// Get the next payload with VP8 payload header.
	// Write payload and set marker bit of the \|packet\|.
	// Returns true on success, false otherwise.
	bool NextPacket(RtpPacketToSend* packet) override;

	std::string ToString() override;

	private:
	typedef struct {
	size_t payload_start_pos;
	size_t size;
	bool first_packet;
	} InfoStruct;
	typedef std::queue<InfoStruct> InfoQueue;

	static const int kXBit = 0x80;
	static const int kNBit = 0x20;
	static const int kSBit = 0x10;
	static const int kPartIdField = 0x0F;
	static const int kKeyIdxField = 0x1F;
	static const int kIBit = 0x80;
	static const int kLBit = 0x40;
	static const int kTBit = 0x20;
	static const int kKBit = 0x10;
	static const int kYBit = 0x20;

	// Calculate all packet sizes and load to packet info queue.
	int GeneratePackets();

	// Splits given part of payload to packets with a given capacity. The last
	// packet should be reduced by last_packet_reduction_len_.
	void GeneratePacketsSplitPayloadBalanced(size_t payload_len, size_t capacity);

	// Insert packet into packet queue.
	void QueuePacket(size_t start_pos, size_t packet_size, bool first_packet);

	// Write the payload header and copy the payload to the buffer.
	// The info in packet_info determines which part of the payload is written
	// and what to write in the header fields.
	int WriteHeaderAndPayload(const InfoStruct& packet_info,
	uint8_t* buffer,
	size_t buffer_length) const;

	// Write the X field and the appropriate extension fields to buffer.
	// The function returns the extension length (including X field), or -1
	// on error.
	int WriteExtensionFields(uint8_t* buffer, size_t buffer_length) const;

	// Set the I bit in the x_field, and write PictureID to the appropriate
	// position in buffer. The function returns 0 on success, -1 otherwise.
	int WritePictureIDFields(uint8_t* x_field,
	uint8_t* buffer,
	size_t buffer_length,
	size_t* extension_length) const;

	// Set the L bit in the x_field, and write Tl0PicIdx to the appropriate
	// position in buffer. The function returns 0 on success, -1 otherwise.
	int WriteTl0PicIdxFields(uint8_t* x_field,
	uint8_t* buffer,
	size_t buffer_length,
	size_t* extension_length) const;

	// Set the T and K bits in the x_field, and write TID, Y and KeyIdx to the
	// appropriate position in buffer. The function returns 0 on success,
	// -1 otherwise.
	int WriteTIDAndKeyIdxFields(uint8_t* x_field,
	uint8_t* buffer,
	size_t buffer_length,
	size_t* extension_length) const;

	// Write the PictureID from codec_specific_info_ to buffer. One or two
	// bytes are written, depending on magnitude of PictureID. The function
	// returns the number of bytes written.
	int WritePictureID(uint8_t* buffer, size_t buffer_length) const;

	// Calculate and return length (octets) of the variable header fields in
	// the next header (i.e., header length in addition to vp8_header_bytes_).
	size_t PayloadDescriptorExtraLength() const;

	// Calculate and return length (octets) of PictureID field in the next
	// header. Can be 0, 1, or 2.
	size_t PictureIdLength() const;

	// Check whether each of the optional fields will be included in the header.
	bool XFieldPresent() const;
	bool TIDFieldPresent() const;
	bool KeyIdxFieldPresent() const;
	bool TL0PicIdxFieldPresent() const;
	bool PictureIdPresent() const { return (PictureIdLength() > 0); }

	const uint8_t* payload_data_;
	size_t payload_size_;
	const size_t vp8_fixed_payload_descriptor_bytes_; // Length of VP8 payload
	// descriptors' fixed part.
	const RTPVideoHeaderVP8 hdr_info_;
	const size_t max_payload_len_;
	const size_t last_packet_reduction_len_;
	InfoQueue packets_;

	RTC_DISALLOW_COPY_AND_ASSIGN(RtpPacketizerVp8);
	};

	// Depacketizer for VP8.
	class RtpDepacketizerVp8 : public RtpDepacketizer {
	public:
	~RtpDepacketizerVp8() override = default;

	bool Parse(ParsedPayload* parsed_payload,
	const uint8_t* payload_data,
	size_t payload_data_length) override;
	};
	} // namespace webrtc
	#endif // MODULES_RTP_RTCP_SOURCE_RTP_FORMAT_VP8_H_