// Copyright (c) 2010 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.

// Protocol for video messages.

syntax = "proto2";

option optimize_for = LITE_RUNTIME;

package remoting;

// A message that gets sent to the client after the client is connected to the
// host. It contains information that the client needs to know about the host.
// NEXT ID: 3
// TODO(sergeyu): Move to the control channel.
message InitClientMessage {
  required int32 width = 1;
  required int32 height = 2;
}

// TODO(ajwong): Determine if these fields should be optional or required.
message VideoPacketFormat {
  // Identifies how the image was encoded.
  enum Encoding {
    ENCODING_INVALID = -1;
    ENCODING_VERBATIM = 0;
    ENCODING_ZLIB = 1;
    ENCODING_VP8 = 2;
  };

  // X,Y coordinates (in screen pixels) for origin of this update.
  optional int32 x = 1;
  optional int32 y = 2;

  // Width, height (in screen pixels) for this update.
  optional int32 width = 3;
  optional int32 height = 4;

  // The encoding used for this image update.
  optional Encoding encoding = 5 [default = ENCODING_INVALID];
}

message VideoPacket {
  // Bitmasks for use in the flags field below.
  //
  // The encoder may fragment one update into multiple packets depending on
  // how the encoder outputs data.  Thus, one update can logically consist of
  // multiple packets.  The FIRST_PACKET and LAST_PACKET flags are used to
  // indicate the start and end of a logical update.  Here are notable
  // consequences:
  //  * Both FIRST_PACKET and LAST_PACKET may be set if an update is only
  //    one packet long.
  //  * The VideoPacketFormat is only supplied in a FIRST_PACKET.
  //  * An local update cannot change format between a FIRST_PACKET and
  //    a LAST_PACKET.
  //  * All packets in one logical update must be processed in order, and
  //    packets may not be skipped.
  enum Flags {
    FIRST_PACKET = 1;
    LAST_PACKET = 2;
  }
  optional int32 flags = 1 [default = 0];

  // The sequence number of the partial data for updating a rectangle.
  optional int32 sequence_number = 2 [default = 0];

  optional int32 timestamp = 3 [default = 0];

  // This is provided on the first packet of the rectangle data, when
  // the flags has FIRST_PACKET set.
  optional VideoPacketFormat format = 4;

  optional bytes data = 5;
}