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// Copyright 2014 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.
#include "media/midi/usb_midi_output_stream.h"
#include "base/logging.h"
#include "base/macros.h"
#include "media/midi/midi_message_util.h"
#include "media/midi/usb_midi_device.h"
namespace media {
namespace midi {
UsbMidiOutputStream::UsbMidiOutputStream(const UsbMidiJack& jack)
: jack_(jack), pending_size_(0), is_sending_sysex_(false) {}
void UsbMidiOutputStream::Send(const std::vector<uint8_t>& data) {
// To prevent link errors caused by DCHECK_*.
const size_t kPacketContentSize = UsbMidiOutputStream::kPacketContentSize;
DCHECK_LT(jack_.cable_number, 16u);
std::vector<uint8_t> data_to_send;
size_t current = 0;
size_t size = GetSize(data);
while (current < size) {
uint8_t first_byte = Get(data, current);
if (first_byte == kSysExByte || is_sending_sysex_) {
// System Exclusive messages
if (!PushSysExMessage(data, ¤t, &data_to_send))
break;
} else if ((first_byte & kSysMessageBitMask) == kSysMessageBitPattern) {
if (first_byte & 0x08) {
// System Real-Time messages
PushSysRTMessage(data, ¤t, &data_to_send);
} else {
// System Common messages
if (!PushSysCommonMessage(data, ¤t, &data_to_send))
break;
}
} else if (first_byte & 0x80) {
if (!PushChannelMessage(data, ¤t, &data_to_send))
break;
} else {
// Unknown messages
DVLOG(1) << "Unknown byte: " << static_cast<unsigned int>(first_byte);
++current;
}
}
if (data_to_send.size() > 0)
jack_.device->Send(jack_.endpoint_number(), data_to_send);
DCHECK_LE(current, size);
DCHECK_LE(size - current, kPacketContentSize);
// Note that this can be a self-copying and the iteration order is important.
for (size_t i = current; i < size; ++i)
pending_data_[i - current] = Get(data, i);
pending_size_ = size - current;
}
size_t UsbMidiOutputStream::GetSize(const std::vector<uint8_t>& data) const {
return data.size() + pending_size_;
}
uint8_t UsbMidiOutputStream::Get(const std::vector<uint8_t>& data,
size_t index) const {
DCHECK_LT(index, GetSize(data));
if (index < pending_size_)
return pending_data_[index];
return data[index - pending_size_];
}
bool UsbMidiOutputStream::PushSysExMessage(const std::vector<uint8_t>& data,
size_t* current,
std::vector<uint8_t>* data_to_send) {
size_t index = *current;
size_t message_size = 0;
const size_t kMessageSizeMax = 3;
uint8_t message[kMessageSizeMax] = {};
while (index < GetSize(data)) {
if (message_size == kMessageSizeMax) {
// We can't find the end-of-message mark in the three bytes.
*current = index;
data_to_send->push_back((jack_.cable_number << 4) | 0x4);
data_to_send->insert(data_to_send->end(),
message,
message + arraysize(message));
is_sending_sysex_ = true;
return true;
}
uint8_t byte = Get(data, index);
if ((byte & kSysRTMessageBitMask) == kSysRTMessageBitPattern) {
// System Real-Time messages interleaved in a SysEx message
PushSysRTMessage(data, &index, data_to_send);
continue;
}
message[message_size] = byte;
++message_size;
if (byte == kEndOfSysExByte) {
uint8_t code_index = static_cast<uint8_t>(message_size) + 0x4;
DCHECK(code_index == 0x5 || code_index == 0x6 || code_index == 0x7);
data_to_send->push_back((jack_.cable_number << 4) | code_index);
data_to_send->insert(data_to_send->end(),
message,
message + arraysize(message));
*current = index + 1;
is_sending_sysex_ = false;
return true;
}
++index;
}
return false;
}
bool UsbMidiOutputStream::PushSysCommonMessage(
const std::vector<uint8_t>& data,
size_t* current,
std::vector<uint8_t>* data_to_send) {
size_t index = *current;
uint8_t first_byte = Get(data, index);
DCHECK_LE(0xf1, first_byte);
DCHECK_LE(first_byte, 0xf7);
DCHECK_EQ(0xf0, first_byte & 0xf8);
// There are only 6 message types (0xf1 - 0xf7), so the table size is 8.
const size_t message_size_table[8] = {
0, 2, 3, 2, 1, 1, 1, 0,
};
size_t message_size = message_size_table[first_byte & 0x07];
DCHECK_NE(0u, message_size);
DCHECK_LE(message_size, 3u);
if (GetSize(data) < index + message_size) {
// The message is incomplete.
return false;
}
uint8_t code_index =
message_size == 1 ? 0x5 : static_cast<uint8_t>(message_size);
data_to_send->push_back((jack_.cable_number << 4) | code_index);
for (size_t i = index; i < index + 3; ++i)
data_to_send->push_back(i < index + message_size ? Get(data, i) : 0);
*current += message_size;
return true;
}
void UsbMidiOutputStream::PushSysRTMessage(const std::vector<uint8_t>& data,
size_t* current,
std::vector<uint8_t>* data_to_send) {
size_t index = *current;
uint8_t first_byte = Get(data, index);
DCHECK_LE(0xf8, first_byte);
DCHECK_LE(first_byte, 0xff);
data_to_send->push_back((jack_.cable_number << 4) | 0x5);
data_to_send->push_back(first_byte);
data_to_send->push_back(0);
data_to_send->push_back(0);
*current += 1;
}
bool UsbMidiOutputStream::PushChannelMessage(
const std::vector<uint8_t>& data,
size_t* current,
std::vector<uint8_t>* data_to_send) {
size_t index = *current;
uint8_t first_byte = Get(data, index);
DCHECK_LE(0x80, (first_byte & 0xf0));
DCHECK_LE((first_byte & 0xf0), 0xe0);
// There are only 7 message types (0x8-0xe in the higher four bits), so the
// table size is 8.
const size_t message_size_table[8] = {
3, 3, 3, 3, 2, 3, 3, 0,
};
uint8_t code_index = first_byte >> 4;
DCHECK_LE(0x08, code_index);
DCHECK_LE(code_index, 0x0e);
size_t message_size = message_size_table[code_index & 0x7];
DCHECK_NE(0u, message_size);
DCHECK_LE(message_size, 3u);
if (GetSize(data) < index + message_size) {
// The message is incomplete.
return false;
}
data_to_send->push_back((jack_.cable_number << 4) | code_index);
for (size_t i = index; i < index + 3; ++i)
data_to_send->push_back(i < index + message_size ? Get(data, i) : 0);
*current += message_size;
return true;
}
} // namespace midi
} // namespace media
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