| // Copyright 2014 The Chromium Authors |
| // 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 "media/midi/message_util.h" |
| #include "media/midi/usb_midi_device.h" |
| |
| 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) { |
| 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 + std::size(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 + std::size(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 |