webrtc/modules/video_coding/include/video_coding.h

/*
 *  Copyright (c) 2012 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_INCLUDE_VIDEO_CODING_H_
#define WEBRTC_MODULES_VIDEO_CODING_INCLUDE_VIDEO_CODING_H_

#if defined(WEBRTC_WIN)
// This is a workaround on Windows due to the fact that some Windows
// headers define CreateEvent as a macro to either CreateEventW or CreateEventA.
// This can cause problems since we use that name as well and could
// declare them as one thing here whereas in another place a windows header
// may have been included and then implementing CreateEvent() causes compilation
// errors.  So for consistency, we include the main windows header here.
#include <windows.h>
#endif

#include "webrtc/modules/include/module.h"
#include "webrtc/modules/include/module_common_types.h"
#include "webrtc/modules/video_coding/include/video_coding_defines.h"
#include "webrtc/system_wrappers/include/event_wrapper.h"
#include "webrtc/video_frame.h"

namespace webrtc
{

class Clock;
class EncodedImageCallback;
class VideoEncoder;
class VideoDecoder;
struct CodecSpecificInfo;

class EventFactory {
 public:
  virtual ~EventFactory() {}

  virtual EventWrapper* CreateEvent() = 0;
};

class EventFactoryImpl : public EventFactory {
 public:
  virtual ~EventFactoryImpl() {}

  virtual EventWrapper* CreateEvent() {
    return EventWrapper::Create();
  }
};

// Used to indicate which decode with errors mode should be used.
enum VCMDecodeErrorMode {
  kNoErrors,                // Never decode with errors. Video will freeze
                            // if nack is disabled.
  kSelectiveErrors,         // Frames that are determined decodable in
                            // VCMSessionInfo may be decoded with missing
                            // packets. As not all incomplete frames will be
                            // decodable, video will freeze if nack is disabled.
  kWithErrors               // Release frames as needed. Errors may be
                            // introduced as some encoded frames may not be
                            // complete.
};

class VideoCodingModule : public Module
{
public:
    enum SenderNackMode {
        kNackNone,
        kNackAll,
        kNackSelective
    };

    enum ReceiverRobustness {
        kNone,
        kHardNack,
        kSoftNack,
        kReferenceSelection
    };

    static VideoCodingModule* Create(
        Clock* clock,
        VideoEncoderRateObserver* encoder_rate_observer,
        VCMQMSettingsCallback* qm_settings_callback);

    static VideoCodingModule* Create(Clock* clock, EventFactory* event_factory);

    static void Destroy(VideoCodingModule* module);

    // Get number of supported codecs
    //
    // Return value     : Number of supported codecs
    static uint8_t NumberOfCodecs();

    // Get supported codec settings with using id
    //
    // Input:
    //      - listId         : Id or index of the codec to look up
    //      - codec          : Memory where the codec settings will be stored
    //
    // Return value     : VCM_OK,              on success
    //                    VCM_PARAMETER_ERROR  if codec not supported or id too high
    static int32_t Codec(const uint8_t listId, VideoCodec* codec);

    // Get supported codec settings using codec type
    //
    // Input:
    //      - codecType      : The codec type to get settings for
    //      - codec          : Memory where the codec settings will be stored
    //
    // Return value     : VCM_OK,              on success
    //                    VCM_PARAMETER_ERROR  if codec not supported
    static int32_t Codec(VideoCodecType codecType, VideoCodec* codec);

    /*
    *   Sender
    */

    // Registers a codec to be used for encoding. Calling this
    // API multiple times overwrites any previously registered codecs.
    //
    // NOTE: Must be called on the thread that constructed the VCM instance.
    //
    // Input:
    //      - sendCodec      : Settings for the codec to be registered.
    //      - numberOfCores  : The number of cores the codec is allowed
    //                         to use.
    //      - maxPayloadSize : The maximum size each payload is allowed
    //                                to have. Usually MTU - overhead.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterSendCodec(const VideoCodec* sendCodec,
                                            uint32_t numberOfCores,
                                            uint32_t maxPayloadSize) = 0;

    // Get the current send codec in use.
    //
    // If a codec has not been set yet, the |id| property of the return value
    // will be 0 and |name| empty.
    //
    // NOTE: This method intentionally does not hold locks and minimizes data
    // copying.  It must be called on the thread where the VCM was constructed.
    virtual const VideoCodec& GetSendCodec() const = 0;

    // DEPRECATED: Use GetSendCodec() instead.
    //
    // API to get the current send codec in use.
    //
    // Input:
    //      - currentSendCodec : Address where the sendCodec will be written.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    //
    // NOTE: The returned codec information is not guaranteed to be current when
    // the call returns.  This method acquires a lock that is aligned with
    // video encoding, so it should be assumed to be allowed to block for
    // several milliseconds.
    virtual int32_t SendCodec(VideoCodec* currentSendCodec) const = 0;

    // DEPRECATED: Use GetSendCodec() instead.
    //
    // API to get the current send codec type
    //
    // Return value      : Codec type, on success.
    //                     kVideoCodecUnknown, on error or if no send codec is set
    // NOTE: Same notes apply as for SendCodec() above.
    virtual VideoCodecType SendCodec() const = 0;

    // Register an external encoder object. This can not be used together with
    // external decoder callbacks.
    //
    // Input:
    //      - externalEncoder : Encoder object to be used for encoding frames inserted
    //                          with the AddVideoFrame API.
    //      - payloadType     : The payload type bound which this encoder is bound to.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    // TODO(pbos): Remove return type when unused elsewhere.
    virtual int32_t RegisterExternalEncoder(VideoEncoder* externalEncoder,
                                            uint8_t payloadType,
                                            bool internalSource = false) = 0;

    // API to get currently configured encoder target bitrate in bits/s.
    //
    // Return value      : 0,   on success.
    //                     < 0, on error.
    virtual int Bitrate(unsigned int* bitrate) const = 0;

    // API to get currently configured encoder target frame rate.
    //
    // Return value      : 0,   on success.
    //                     < 0, on error.
    virtual int FrameRate(unsigned int* framerate) const = 0;

    // Sets the parameters describing the send channel. These parameters are inputs to the
    // Media Optimization inside the VCM and also specifies the target bit rate for the
    // encoder. Bit rate used by NACK should already be compensated for by the user.
    //
    // Input:
    //      - target_bitrate        : The target bitrate for VCM in bits/s.
    //      - lossRate              : Fractions of lost packets the past second.
    //                                (loss rate in percent = 100 * packetLoss / 255)
    //      - rtt                   : Current round-trip time in ms.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,         on error.
    virtual int32_t SetChannelParameters(uint32_t target_bitrate,
                                         uint8_t lossRate,
                                         int64_t rtt) = 0;

    // Sets the parameters describing the receive channel. These parameters are inputs to the
    // Media Optimization inside the VCM.
    //
    // Input:
    //      - rtt                   : Current round-trip time in ms.
    //                                with the most amount available bandwidth in a conference
    //                                scenario
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t SetReceiveChannelParameters(int64_t rtt) = 0;

    // Register a transport callback which will be called to deliver the encoded data and
    // side information.
    //
    // Input:
    //      - transport  : The callback object to register.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterTransportCallback(VCMPacketizationCallback* transport) = 0;

    // Register video output information callback which will be called to deliver information
    // about the video stream produced by the encoder, for instance the average frame rate and
    // bit rate.
    //
    // Input:
    //      - outputInformation  : The callback object to register.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterSendStatisticsCallback(
                                     VCMSendStatisticsCallback* sendStats) = 0;

    // Register a video protection callback which will be called to deliver
    // the requested FEC rate and NACK status (on/off).
    //
    // Input:
    //      - protection  : The callback object to register.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterProtectionCallback(VCMProtectionCallback* protection) = 0;

    // Enable or disable a video protection method.
    //
    // Input:
    //      - videoProtection  : The method to enable or disable.
    //      - enable           : True if the method should be enabled, false if
    //                           it should be disabled.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t SetVideoProtection(VCMVideoProtection videoProtection,
                                       bool enable) = 0;

    // Add one raw video frame to the encoder. This function does all the necessary
    // processing, then decides what frame type to encode, or if the frame should be
    // dropped. If the frame should be encoded it passes the frame to the encoder
    // before it returns.
    //
    // Input:
    //      - videoFrame        : Video frame to encode.
    //      - codecSpecificInfo : Extra codec information, e.g., pre-parsed in-band signaling.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t AddVideoFrame(
        const VideoFrame& videoFrame,
        const VideoContentMetrics* contentMetrics = NULL,
        const CodecSpecificInfo* codecSpecificInfo = NULL) = 0;

    // Next frame encoded should be an intra frame (keyframe).
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t IntraFrameRequest(int stream_index) = 0;

    // Frame Dropper enable. Can be used to disable the frame dropping when the encoder
    // over-uses its bit rate. This API is designed to be used when the encoded frames
    // are supposed to be stored to an AVI file, or when the I420 codec is used and the
    // target bit rate shouldn't affect the frame rate.
    //
    // Input:
    //      - enable            : True to enable the setting, false to disable it.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t EnableFrameDropper(bool enable) = 0;


    /*
    *   Receiver
    */

    // Register possible receive codecs, can be called multiple times for different codecs.
    // The module will automatically switch between registered codecs depending on the
    // payload type of incoming frames. The actual decoder will be created when needed.
    //
    // Input:
    //      - receiveCodec      : Settings for the codec to be registered.
    //      - numberOfCores     : Number of CPU cores that the decoder is allowed to use.
    //      - requireKeyFrame   : Set this to true if you don't want any delta frames
    //                            to be decoded until the first key frame has been decoded.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterReceiveCodec(const VideoCodec* receiveCodec,
                                         int32_t numberOfCores,
                                         bool requireKeyFrame = false) = 0;

    // Register an externally defined decoder/renderer object. Can be a decoder only or a
    // decoder coupled with a renderer. Note that RegisterReceiveCodec must be called to
    // be used for decoding incoming streams.
    //
    // Input:
    //      - externalDecoder        : The external decoder/renderer object.
    //      - payloadType            : The payload type which this decoder should be
    //                                 registered to.
    //
    virtual void RegisterExternalDecoder(VideoDecoder* externalDecoder,
                                         uint8_t payloadType) = 0;

    // Register a receive callback. Will be called whenever there is a new frame ready
    // for rendering.
    //
    // Input:
    //      - receiveCallback        : The callback object to be used by the module when a
    //                                 frame is ready for rendering.
    //                                 De-register with a NULL pointer.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterReceiveCallback(VCMReceiveCallback* receiveCallback) = 0;

    // Register a receive statistics callback which will be called to deliver information
    // about the video stream received by the receiving side of the VCM, for instance the
    // average frame rate and bit rate.
    //
    // Input:
    //      - receiveStats  : The callback object to register.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterReceiveStatisticsCallback(
                               VCMReceiveStatisticsCallback* receiveStats) = 0;

    // Register a decoder timing callback which will be called to deliver
    // information about the timing of the decoder in the receiving side of the
    // VCM, for instance the current and maximum frame decode latency.
    //
    // Input:
    //      - decoderTiming  : The callback object to register.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterDecoderTimingCallback(
        VCMDecoderTimingCallback* decoderTiming) = 0;

    // Register a frame type request callback. This callback will be called when the
    // module needs to request specific frame types from the send side.
    //
    // Input:
    //      - frameTypeCallback      : The callback object to be used by the module when
    //                                 requesting a specific type of frame from the send side.
    //                                 De-register with a NULL pointer.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t RegisterFrameTypeCallback(
                                  VCMFrameTypeCallback* frameTypeCallback) = 0;

    // Registers a callback which is called whenever the receive side of the VCM
    // encounters holes in the packet sequence and needs packets to be retransmitted.
    //
    // Input:
    //              - callback      : The callback to be registered in the VCM.
    //
    // Return value     : VCM_OK,     on success.
    //                    <0,         on error.
    virtual int32_t RegisterPacketRequestCallback(
                                        VCMPacketRequestCallback* callback) = 0;

    // Waits for the next frame in the jitter buffer to become complete
    // (waits no longer than maxWaitTimeMs), then passes it to the decoder for decoding.
    // Should be called as often as possible to get the most out of the decoder.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t Decode(uint16_t maxWaitTimeMs = 200) = 0;

    // Registers a callback which conveys the size of the render buffer.
    virtual int RegisterRenderBufferSizeCallback(
        VCMRenderBufferSizeCallback* callback) = 0;

    // Reset the decoder state to the initial state.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t ResetDecoder() = 0;

    // API to get the codec which is currently used for decoding by the module.
    //
    // Input:
    //      - currentReceiveCodec      : Settings for the codec to be registered.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t ReceiveCodec(VideoCodec* currentReceiveCodec) const = 0;

    // API to get the codec type currently used for decoding by the module.
    //
    // Return value      : codecy type,            on success.
    //                     kVideoCodecUnknown, on error or if no receive codec is registered
    virtual VideoCodecType ReceiveCodec() const = 0;

    // Insert a parsed packet into the receiver side of the module. Will be placed in the
    // jitter buffer waiting for the frame to become complete. Returns as soon as the packet
    // has been placed in the jitter buffer.
    //
    // Input:
    //      - incomingPayload      : Payload of the packet.
    //      - payloadLength        : Length of the payload.
    //      - rtpInfo              : The parsed header.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t IncomingPacket(const uint8_t* incomingPayload,
                                   size_t payloadLength,
                                   const WebRtcRTPHeader& rtpInfo) = 0;

    // Minimum playout delay (Used for lip-sync). This is the minimum delay required
    // to sync with audio. Not included in  VideoCodingModule::Delay()
    // Defaults to 0 ms.
    //
    // Input:
    //      - minPlayoutDelayMs   : Additional delay in ms.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t SetMinimumPlayoutDelay(uint32_t minPlayoutDelayMs) = 0;

    // Set the time required by the renderer to render a frame.
    //
    // Input:
    //      - timeMS        : The time in ms required by the renderer to render a frame.
    //
    // Return value      : VCM_OK, on success.
    //                     < 0,    on error.
    virtual int32_t SetRenderDelay(uint32_t timeMS) = 0;

    // The total delay desired by the VCM. Can be less than the minimum
    // delay set with SetMinimumPlayoutDelay.
    //
    // Return value      : Total delay in ms, on success.
    //                     < 0,               on error.
    virtual int32_t Delay() const = 0;

    // Returns the number of packets discarded by the jitter buffer due to being
    // too late. This can include duplicated packets which arrived after the
    // frame was sent to the decoder. Therefore packets which were prematurely
    // NACKed will be counted.
    virtual uint32_t DiscardedPackets() const = 0;


    // Robustness APIs

    // Set the receiver robustness mode. The mode decides how the receiver
    // responds to losses in the stream. The type of counter-measure (soft or
    // hard NACK, dual decoder, RPS, etc.) is selected through the
    // robustnessMode parameter. The errorMode parameter decides if it is
    // allowed to display frames corrupted by losses. Note that not all
    // combinations of the two parameters are feasible. An error will be
    // returned for invalid combinations.
    // Input:
    //      - robustnessMode : selected robustness mode.
    //      - errorMode      : selected error mode.
    //
    // Return value      : VCM_OK, on success;
    //                     < 0, on error.
    virtual int SetReceiverRobustnessMode(ReceiverRobustness robustnessMode,
                                          VCMDecodeErrorMode errorMode) = 0;

    // Set the decode error mode. The mode decides which errors (if any) are
    // allowed in decodable frames. Note that setting decode_error_mode to
    // anything other than kWithErrors without enabling nack will cause
    // long-term freezes (resulting from frequent key frame requests) if
    // packet loss occurs.
    virtual void SetDecodeErrorMode(VCMDecodeErrorMode decode_error_mode) = 0;

    // Sets the maximum number of sequence numbers that we are allowed to NACK
    // and the oldest sequence number that we will consider to NACK. If a
    // sequence number older than |max_packet_age_to_nack| is missing
    // a key frame will be requested. A key frame will also be requested if the
    // time of incomplete or non-continuous frames in the jitter buffer is above
    // |max_incomplete_time_ms|.
    virtual void SetNackSettings(size_t max_nack_list_size,
                                 int max_packet_age_to_nack,
                                 int max_incomplete_time_ms) = 0;

    // Setting a desired delay to the VCM receiver. Video rendering will be
    // delayed by at least desired_delay_ms.
    virtual int SetMinReceiverDelay(int desired_delay_ms) = 0;

    // Lets the sender suspend video when the rate drops below
    // |threshold_bps|, and turns back on when the rate goes back up above
    // |threshold_bps| + |window_bps|.
    virtual void SuspendBelowMinBitrate() = 0;

    // Returns true if SuspendBelowMinBitrate is engaged and the video has been
    // suspended due to bandwidth limitations; otherwise false.
    virtual bool VideoSuspended() const = 0;

    virtual void RegisterPreDecodeImageCallback(
        EncodedImageCallback* observer) = 0;
    virtual void RegisterPostEncodeImageCallback(
        EncodedImageCallback* post_encode_callback) = 0;
    // Releases pending decode calls, permitting faster thread shutdown.
    virtual void TriggerDecoderShutdown() = 0;
};

}  // namespace webrtc

#endif // WEBRTC_MODULES_VIDEO_CODING_INCLUDE_VIDEO_CODING_H_