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/*
* Copyright (c) 2019 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.
*/
#include "api/audio/channel_layout.h"
#include <stddef.h>
#include <iterator>
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
namespace webrtc {
static const int kLayoutToChannels[] = {
0, // CHANNEL_LAYOUT_NONE
0, // CHANNEL_LAYOUT_UNSUPPORTED
1, // CHANNEL_LAYOUT_MONO
2, // CHANNEL_LAYOUT_STEREO
3, // CHANNEL_LAYOUT_2_1
3, // CHANNEL_LAYOUT_SURROUND
4, // CHANNEL_LAYOUT_4_0
4, // CHANNEL_LAYOUT_2_2
4, // CHANNEL_LAYOUT_QUAD
5, // CHANNEL_LAYOUT_5_0
6, // CHANNEL_LAYOUT_5_1
5, // CHANNEL_LAYOUT_5_0_BACK
6, // CHANNEL_LAYOUT_5_1_BACK
7, // CHANNEL_LAYOUT_7_0
8, // CHANNEL_LAYOUT_7_1
8, // CHANNEL_LAYOUT_7_1_WIDE
2, // CHANNEL_LAYOUT_STEREO_DOWNMIX
3, // CHANNEL_LAYOUT_2POINT1
4, // CHANNEL_LAYOUT_3_1
5, // CHANNEL_LAYOUT_4_1
6, // CHANNEL_LAYOUT_6_0
6, // CHANNEL_LAYOUT_6_0_FRONT
6, // CHANNEL_LAYOUT_HEXAGONAL
7, // CHANNEL_LAYOUT_6_1
7, // CHANNEL_LAYOUT_6_1_BACK
7, // CHANNEL_LAYOUT_6_1_FRONT
7, // CHANNEL_LAYOUT_7_0_FRONT
8, // CHANNEL_LAYOUT_7_1_WIDE_BACK
8, // CHANNEL_LAYOUT_OCTAGONAL
0, // CHANNEL_LAYOUT_DISCRETE
3, // CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC
5, // CHANNEL_LAYOUT_4_1_QUAD_SIDE
0, // CHANNEL_LAYOUT_BITSTREAM
};
// The channel orderings for each layout as specified by FFmpeg. Each value
// represents the index of each channel in each layout. Values of -1 mean the
// channel at that index is not used for that layout. For example, the left side
// surround sound channel in FFmpeg's 5.1 layout is in the 5th position (because
// the order is L, R, C, LFE, LS, RS), so
// kChannelOrderings[CHANNEL_LAYOUT_5_1][SIDE_LEFT] = 4;
static const int kChannelOrderings[CHANNEL_LAYOUT_MAX + 1][CHANNELS_MAX + 1] = {
// FL | FR | FC | LFE | BL | BR | FLofC | FRofC | BC | SL | SR
// CHANNEL_LAYOUT_NONE
{-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_UNSUPPORTED
{-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_MONO
{-1, -1, 0, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_STEREO
{0, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_2_1
{0, 1, -1, -1, -1, -1, -1, -1, 2, -1, -1},
// CHANNEL_LAYOUT_SURROUND
{0, 1, 2, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_4_0
{0, 1, 2, -1, -1, -1, -1, -1, 3, -1, -1},
// CHANNEL_LAYOUT_2_2
{0, 1, -1, -1, -1, -1, -1, -1, -1, 2, 3},
// CHANNEL_LAYOUT_QUAD
{0, 1, -1, -1, 2, 3, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_5_0
{0, 1, 2, -1, -1, -1, -1, -1, -1, 3, 4},
// CHANNEL_LAYOUT_5_1
{0, 1, 2, 3, -1, -1, -1, -1, -1, 4, 5},
// FL | FR | FC | LFE | BL | BR | FLofC | FRofC | BC | SL | SR
// CHANNEL_LAYOUT_5_0_BACK
{0, 1, 2, -1, 3, 4, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_5_1_BACK
{0, 1, 2, 3, 4, 5, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_7_0
{0, 1, 2, -1, 5, 6, -1, -1, -1, 3, 4},
// CHANNEL_LAYOUT_7_1
{0, 1, 2, 3, 6, 7, -1, -1, -1, 4, 5},
// CHANNEL_LAYOUT_7_1_WIDE
{0, 1, 2, 3, -1, -1, 6, 7, -1, 4, 5},
// CHANNEL_LAYOUT_STEREO_DOWNMIX
{0, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_2POINT1
{0, 1, -1, 2, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_3_1
{0, 1, 2, 3, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_4_1
{0, 1, 2, 4, -1, -1, -1, -1, 3, -1, -1},
// CHANNEL_LAYOUT_6_0
{0, 1, 2, -1, -1, -1, -1, -1, 5, 3, 4},
// CHANNEL_LAYOUT_6_0_FRONT
{0, 1, -1, -1, -1, -1, 4, 5, -1, 2, 3},
// FL | FR | FC | LFE | BL | BR | FLofC | FRofC | BC | SL | SR
// CHANNEL_LAYOUT_HEXAGONAL
{0, 1, 2, -1, 3, 4, -1, -1, 5, -1, -1},
// CHANNEL_LAYOUT_6_1
{0, 1, 2, 3, -1, -1, -1, -1, 6, 4, 5},
// CHANNEL_LAYOUT_6_1_BACK
{0, 1, 2, 3, 4, 5, -1, -1, 6, -1, -1},
// CHANNEL_LAYOUT_6_1_FRONT
{0, 1, -1, 6, -1, -1, 4, 5, -1, 2, 3},
// CHANNEL_LAYOUT_7_0_FRONT
{0, 1, 2, -1, -1, -1, 5, 6, -1, 3, 4},
// CHANNEL_LAYOUT_7_1_WIDE_BACK
{0, 1, 2, 3, 4, 5, 6, 7, -1, -1, -1},
// CHANNEL_LAYOUT_OCTAGONAL
{0, 1, 2, -1, 5, 6, -1, -1, 7, 3, 4},
// CHANNEL_LAYOUT_DISCRETE
{-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC
{0, 1, 2, -1, -1, -1, -1, -1, -1, -1, -1},
// CHANNEL_LAYOUT_4_1_QUAD_SIDE
{0, 1, -1, 4, -1, -1, -1, -1, -1, 2, 3},
// CHANNEL_LAYOUT_BITSTREAM
{-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1},
// FL | FR | FC | LFE | BL | BR | FLofC | FRofC | BC | SL | SR
};
int ChannelLayoutToChannelCount(ChannelLayout layout) {
RTC_DCHECK_LT(static_cast<size_t>(layout), std::size(kLayoutToChannels));
RTC_DCHECK_LE(kLayoutToChannels[layout], kMaxConcurrentChannels);
return kLayoutToChannels[layout];
}
// Converts a channel count into a channel layout.
ChannelLayout GuessChannelLayout(int channels) {
switch (channels) {
case 1:
return CHANNEL_LAYOUT_MONO;
case 2:
return CHANNEL_LAYOUT_STEREO;
case 3:
return CHANNEL_LAYOUT_SURROUND;
case 4:
return CHANNEL_LAYOUT_QUAD;
case 5:
return CHANNEL_LAYOUT_5_0;
case 6:
return CHANNEL_LAYOUT_5_1;
case 7:
return CHANNEL_LAYOUT_6_1;
case 8:
return CHANNEL_LAYOUT_7_1;
default:
RTC_DLOG(LS_WARNING) << "Unsupported channel count: " << channels;
}
return CHANNEL_LAYOUT_UNSUPPORTED;
}
int ChannelOrder(ChannelLayout layout, Channels channel) {
RTC_DCHECK_LT(static_cast<size_t>(layout), std::size(kChannelOrderings));
RTC_DCHECK_LT(static_cast<size_t>(channel), std::size(kChannelOrderings[0]));
return kChannelOrderings[layout][channel];
}
const char* ChannelLayoutToString(ChannelLayout layout) {
switch (layout) {
case CHANNEL_LAYOUT_NONE:
return "NONE";
case CHANNEL_LAYOUT_UNSUPPORTED:
return "UNSUPPORTED";
case CHANNEL_LAYOUT_MONO:
return "MONO";
case CHANNEL_LAYOUT_STEREO:
return "STEREO";
case CHANNEL_LAYOUT_2_1:
return "2.1";
case CHANNEL_LAYOUT_SURROUND:
return "SURROUND";
case CHANNEL_LAYOUT_4_0:
return "4.0";
case CHANNEL_LAYOUT_2_2:
return "QUAD_SIDE";
case CHANNEL_LAYOUT_QUAD:
return "QUAD";
case CHANNEL_LAYOUT_5_0:
return "5.0";
case CHANNEL_LAYOUT_5_1:
return "5.1";
case CHANNEL_LAYOUT_5_0_BACK:
return "5.0_BACK";
case CHANNEL_LAYOUT_5_1_BACK:
return "5.1_BACK";
case CHANNEL_LAYOUT_7_0:
return "7.0";
case CHANNEL_LAYOUT_7_1:
return "7.1";
case CHANNEL_LAYOUT_7_1_WIDE:
return "7.1_WIDE";
case CHANNEL_LAYOUT_STEREO_DOWNMIX:
return "STEREO_DOWNMIX";
case CHANNEL_LAYOUT_2POINT1:
return "2POINT1";
case CHANNEL_LAYOUT_3_1:
return "3.1";
case CHANNEL_LAYOUT_4_1:
return "4.1";
case CHANNEL_LAYOUT_6_0:
return "6.0";
case CHANNEL_LAYOUT_6_0_FRONT:
return "6.0_FRONT";
case CHANNEL_LAYOUT_HEXAGONAL:
return "HEXAGONAL";
case CHANNEL_LAYOUT_6_1:
return "6.1";
case CHANNEL_LAYOUT_6_1_BACK:
return "6.1_BACK";
case CHANNEL_LAYOUT_6_1_FRONT:
return "6.1_FRONT";
case CHANNEL_LAYOUT_7_0_FRONT:
return "7.0_FRONT";
case CHANNEL_LAYOUT_7_1_WIDE_BACK:
return "7.1_WIDE_BACK";
case CHANNEL_LAYOUT_OCTAGONAL:
return "OCTAGONAL";
case CHANNEL_LAYOUT_DISCRETE:
return "DISCRETE";
case CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC:
return "STEREO_AND_KEYBOARD_MIC";
case CHANNEL_LAYOUT_4_1_QUAD_SIDE:
return "4.1_QUAD_SIDE";
case CHANNEL_LAYOUT_BITSTREAM:
return "BITSTREAM";
}
RTC_DCHECK_NOTREACHED() << "Invalid channel layout provided: " << layout;
return "";
}
} // namespace webrtc
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