summaryrefslogtreecommitdiffstats
path: root/dom/media/VideoUtils.h
blob: a2fa7208f58563f8ab5dc30c9cdb5d7eea85d7ab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef VideoUtils_h
#define VideoUtils_h

#include "AudioSampleFormat.h"
#include "MediaInfo.h"
#include "VideoLimits.h"
#include "mozilla/AbstractThread.h"
#include "mozilla/Attributes.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/MozPromise.h"
#include "mozilla/ReentrantMonitor.h"
#include "mozilla/RefPtr.h"
#include "mozilla/SharedThreadPool.h"
#include "mozilla/TaskQueue.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/gfx/Point.h"  // for gfx::IntSize
#include "mozilla/gfx/Types.h"
#include "nsCOMPtr.h"
#include "nsINamed.h"
#include "nsIThread.h"
#include "nsITimer.h"
#include "nsThreadUtils.h"
#include "prtime.h"

using mozilla::CheckedInt32;
using mozilla::CheckedInt64;
using mozilla::CheckedUint32;
using mozilla::CheckedUint64;

// This file contains stuff we'd rather put elsewhere, but which is
// dependent on other changes which we don't want to wait for. We plan to
// remove this file in the near future.

// This belongs in xpcom/monitor/Monitor.h, once we've made
// mozilla::Monitor non-reentrant.
namespace mozilla {

class MediaContainerType;

/**
 * ReentrantMonitorConditionallyEnter
 *
 * Enters the supplied monitor only if the conditional value |aEnter| is true.
 * E.g. Used to allow unmonitored read access on the decode thread,
 * and monitored access on all other threads.
 */
class MOZ_STACK_CLASS ReentrantMonitorConditionallyEnter {
 public:
  ReentrantMonitorConditionallyEnter(bool aEnter,
                                     ReentrantMonitor& aReentrantMonitor)
      : mReentrantMonitor(nullptr) {
    MOZ_COUNT_CTOR(ReentrantMonitorConditionallyEnter);
    if (aEnter) {
      mReentrantMonitor = &aReentrantMonitor;
      NS_ASSERTION(mReentrantMonitor, "null monitor");
      mReentrantMonitor->Enter();
    }
  }
  ~ReentrantMonitorConditionallyEnter(void) {
    if (mReentrantMonitor) {
      mReentrantMonitor->Exit();
    }
    MOZ_COUNT_DTOR(ReentrantMonitorConditionallyEnter);
  }

 private:
  // Restrict to constructor and destructor defined above.
  ReentrantMonitorConditionallyEnter();
  ReentrantMonitorConditionallyEnter(const ReentrantMonitorConditionallyEnter&);
  ReentrantMonitorConditionallyEnter& operator=(
      const ReentrantMonitorConditionallyEnter&);
  static void* operator new(size_t) noexcept(true);
  static void operator delete(void*);

  ReentrantMonitor* mReentrantMonitor;
};

// Shuts down a thread asynchronously.
class ShutdownThreadEvent : public Runnable {
 public:
  explicit ShutdownThreadEvent(nsIThread* aThread)
      : Runnable("ShutdownThreadEvent"), mThread(aThread) {}
  ~ShutdownThreadEvent() = default;
  NS_IMETHOD Run() override {
    mThread->Shutdown();
    mThread = nullptr;
    return NS_OK;
  }

 private:
  nsCOMPtr<nsIThread> mThread;
};

class MediaResource;

// Estimates the buffered ranges of a MediaResource using a simple
// (byteOffset/length)*duration method. Probably inaccurate, but won't
// do file I/O, and can be used when we don't have detailed knowledge
// of the byte->time mapping of a resource. aDurationUsecs is the duration
// of the media in microseconds. Estimated buffered ranges are stored in
// aOutBuffered. Ranges are 0-normalized, i.e. in the range of (0,duration].
media::TimeIntervals GetEstimatedBufferedTimeRanges(
    mozilla::MediaResource* aStream, int64_t aDurationUsecs);

double ToMicrosecondResolution(double aSeconds);
// Converts from number of audio frames (aFrames) to microseconds, given
// the specified audio rate (aRate).
CheckedInt64 FramesToUsecs(int64_t aFrames, uint32_t aRate);
// Converts from number of audio frames (aFrames) TimeUnit, given
// the specified audio rate (aRate).
media::TimeUnit FramesToTimeUnit(int64_t aFrames, uint32_t aRate);
// Perform aValue * aMul / aDiv, reducing the possibility of overflow due to
// aValue * aMul overflowing.
CheckedInt64 SaferMultDiv(int64_t aValue, uint64_t aMul, uint64_t aDiv);

// Converts from microseconds (aUsecs) to number of audio frames, given the
// specified audio rate (aRate). Stores the result in aOutFrames. Returns
// true if the operation succeeded, or false if there was an integer
// overflow while calulating the conversion.
CheckedInt64 UsecsToFrames(int64_t aUsecs, uint32_t aRate);

// Format TimeUnit as number of frames at given rate.
CheckedInt64 TimeUnitToFrames(const media::TimeUnit& aTime, uint32_t aRate);

// Converts milliseconds to seconds.
#define MS_TO_SECONDS(ms) ((double)(ms) / (PR_MSEC_PER_SEC))

// Converts seconds to milliseconds.
#define SECONDS_TO_MS(s) ((int)((s) * (PR_MSEC_PER_SEC)))

// Converts from seconds to microseconds. Returns failure if the resulting
// integer is too big to fit in an int64_t.
nsresult SecondsToUsecs(double aSeconds, int64_t& aOutUsecs);

// Scales the display rect aDisplay by aspect ratio aAspectRatio.
// Note that aDisplay must be validated by IsValidVideoRegion()
// before being used!
void ScaleDisplayByAspectRatio(gfx::IntSize& aDisplay, float aAspectRatio);

// Downmix Stereo audio samples to Mono.
// Input are the buffer contains stereo data and the number of frames.
void DownmixStereoToMono(mozilla::AudioDataValue* aBuffer, uint32_t aFrames);

// Decide the number of playback channels according to the
// given AudioInfo and the prefs that are being set.
uint32_t DecideAudioPlaybackChannels(const AudioInfo& info);

// Decide the sample-rate to use for audio output according to the
// given AudioInfo and the prefs that are being set.
uint32_t DecideAudioPlaybackSampleRate(const AudioInfo& info,
                                       bool aShouldResistFingerprinting);

bool IsDefaultPlaybackDeviceMono();

bool IsVideoContentType(const nsCString& aContentType);

// Returns true if it's safe to use aPicture as the picture to be
// extracted inside a frame of size aFrame, and scaled up to and displayed
// at a size of aDisplay. You should validate the frame, picture, and
// display regions before using them to display video frames.
bool IsValidVideoRegion(const gfx::IntSize& aFrame,
                        const gfx::IntRect& aPicture,
                        const gfx::IntSize& aDisplay);

// Template to automatically set a variable to a value on scope exit.
// Useful for unsetting flags, etc.
template <typename T>
class AutoSetOnScopeExit {
 public:
  AutoSetOnScopeExit(T& aVar, T aValue) : mVar(aVar), mValue(aValue) {}
  ~AutoSetOnScopeExit() { mVar = mValue; }

 private:
  T& mVar;
  const T mValue;
};

enum class MediaThreadType {
  SUPERVISOR,  // MediaFormatReader, RemoteDecoderManager, MediaDecodeTask and
               // others
  PLATFORM_DECODER,  // MediaDataDecoder
  PLATFORM_ENCODER,  // MediaDataEncoder
  WEBRTC_CALL_THREAD,
  WEBRTC_WORKER,
  MDSM,  // MediaDecoderStateMachine
};
// Returns the thread pool that is shared amongst all decoder state machines
// for decoding streams.
already_AddRefed<SharedThreadPool> GetMediaThreadPool(MediaThreadType aType);

enum H264_PROFILE {
  H264_PROFILE_UNKNOWN = 0,
  H264_PROFILE_BASE = 0x42,
  H264_PROFILE_MAIN = 0x4D,
  H264_PROFILE_EXTENDED = 0x58,
  H264_PROFILE_HIGH = 0x64,
};

enum H264_LEVEL {
  H264_LEVEL_1 = 10,
  H264_LEVEL_1_b = 11,
  H264_LEVEL_1_1 = 11,
  H264_LEVEL_1_2 = 12,
  H264_LEVEL_1_3 = 13,
  H264_LEVEL_2 = 20,
  H264_LEVEL_2_1 = 21,
  H264_LEVEL_2_2 = 22,
  H264_LEVEL_3 = 30,
  H264_LEVEL_3_1 = 31,
  H264_LEVEL_3_2 = 32,
  H264_LEVEL_4 = 40,
  H264_LEVEL_4_1 = 41,
  H264_LEVEL_4_2 = 42,
  H264_LEVEL_5 = 50,
  H264_LEVEL_5_1 = 51,
  H264_LEVEL_5_2 = 52
};

// Extracts the H.264/AVC profile and level from an H.264 codecs string.
// H.264 codecs parameters have a type defined as avc1.PPCCLL, where
// PP = profile_idc, CC = constraint_set flags, LL = level_idc.
// See
// http://blog.pearce.org.nz/2013/11/what-does-h264avc1-codecs-parameters.html
// for more details.
// Returns false on failure.
bool ExtractH264CodecDetails(const nsAString& aCodecs, uint8_t& aProfile,
                             uint8_t& aConstraint, uint8_t& aLevel);

struct VideoColorSpace {
  // Default values are set according to
  // https://www.webmproject.org/vp9/mp4/#optional-fields
  // and https://aomediacodec.github.io/av1-isobmff/#codecsparam
  gfx::CICP::ColourPrimaries mPrimaries = gfx::CICP::CP_BT709;
  gfx::CICP::TransferCharacteristics mTransfer = gfx::CICP::TC_BT709;
  gfx::CICP::MatrixCoefficients mMatrix = gfx::CICP::MC_BT709;
  gfx::ColorRange mRange = gfx::ColorRange::LIMITED;

  bool operator==(const VideoColorSpace& aOther) const {
    return mPrimaries == aOther.mPrimaries && mTransfer == aOther.mTransfer &&
           mMatrix == aOther.mMatrix && mRange == aOther.mRange;
  }
  bool operator!=(const VideoColorSpace& aOther) const {
    return !(*this == aOther);
  }
};

// Extracts the VPX codecs parameter string.
// See https://www.webmproject.org/vp9/mp4/#codecs-parameter-string
// for more details.
// Returns false on failure.
bool ExtractVPXCodecDetails(const nsAString& aCodec, uint8_t& aProfile,
                            uint8_t& aLevel, uint8_t& aBitDepth);
bool ExtractVPXCodecDetails(const nsAString& aCodec, uint8_t& aProfile,
                            uint8_t& aLevel, uint8_t& aBitDepth,
                            uint8_t& aChromaSubsampling,
                            mozilla::VideoColorSpace& aColorSpace);

// Extracts AV1 codecs parameter string.
// See https://aomediacodec.github.io/av1-isobmff/#codecsparam
// Returns false if the codec is invalid.
bool ExtractAV1CodecDetails(const nsAString& aCodec, uint8_t& aProfile,
                            uint8_t& aLevel, uint8_t& aTier, uint8_t& aBitDepth,
                            bool& aMonochrome, bool& aSubsamplingX,
                            bool& aSubsamplingY, uint8_t& aChromaSamplePosition,
                            mozilla::VideoColorSpace& aColorSpace);

// Use a cryptographic quality PRNG to generate raw random bytes
// and convert that to a base64 string.
nsresult GenerateRandomName(nsCString& aOutSalt, uint32_t aLength);

// This version returns a string suitable for use as a file or URL
// path. This is based on code from nsExternalAppHandler::SetUpTempFile.
nsresult GenerateRandomPathName(nsCString& aOutSalt, uint32_t aLength);

already_AddRefed<TaskQueue> CreateMediaDecodeTaskQueue(const char* aName);

// Iteratively invokes aWork until aCondition returns true, or aWork returns
// false. Use this rather than a while loop to avoid bogarting the task queue.
template <class Work, class Condition>
RefPtr<GenericPromise> InvokeUntil(Work aWork, Condition aCondition) {
  RefPtr<GenericPromise::Private> p = new GenericPromise::Private(__func__);

  if (aCondition()) {
    p->Resolve(true, __func__);
  }

  struct Helper {
    static void Iteration(const RefPtr<GenericPromise::Private>& aPromise,
                          Work aLocalWork, Condition aLocalCondition) {
      if (!aLocalWork()) {
        aPromise->Reject(NS_ERROR_FAILURE, __func__);
      } else if (aLocalCondition()) {
        aPromise->Resolve(true, __func__);
      } else {
        nsCOMPtr<nsIRunnable> r = NS_NewRunnableFunction(
            "InvokeUntil::Helper::Iteration",
            [aPromise, aLocalWork, aLocalCondition]() {
              Iteration(aPromise, aLocalWork, aLocalCondition);
            });
        AbstractThread::GetCurrent()->Dispatch(r.forget());
      }
    }
  };

  Helper::Iteration(p, aWork, aCondition);
  return p;
}

// Simple timer to run a runnable after a timeout.
class SimpleTimer : public nsITimerCallback, public nsINamed {
 public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSINAMED

  // Create a new timer to run aTask after aTimeoutMs milliseconds
  // on thread aTarget. If aTarget is null, task is run on the main thread.
  static already_AddRefed<SimpleTimer> Create(
      nsIRunnable* aTask, uint32_t aTimeoutMs,
      nsIEventTarget* aTarget = nullptr);
  void Cancel();

  NS_IMETHOD Notify(nsITimer* timer) override;

 private:
  virtual ~SimpleTimer() = default;
  nsresult Init(nsIRunnable* aTask, uint32_t aTimeoutMs,
                nsIEventTarget* aTarget);

  RefPtr<nsIRunnable> mTask;
  nsCOMPtr<nsITimer> mTimer;
};

void LogToBrowserConsole(const nsAString& aMsg);

bool ParseMIMETypeString(const nsAString& aMIMEType,
                         nsString& aOutContainerType,
                         nsTArray<nsString>& aOutCodecs);

bool ParseCodecsString(const nsAString& aCodecs,
                       nsTArray<nsString>& aOutCodecs);

bool IsH264CodecString(const nsAString& aCodec);

bool IsH265CodecString(const nsAString& aCodec);

bool IsAACCodecString(const nsAString& aCodec);

bool IsVP8CodecString(const nsAString& aCodec);

bool IsVP9CodecString(const nsAString& aCodec);

bool IsAV1CodecString(const nsAString& aCodec);

// Try and create a TrackInfo with a given codec MIME type.
UniquePtr<TrackInfo> CreateTrackInfoWithMIMEType(
    const nsACString& aCodecMIMEType);

// Try and create a TrackInfo with a given codec MIME type, and optional extra
// parameters from a container type (its MIME type and codecs are ignored).
UniquePtr<TrackInfo> CreateTrackInfoWithMIMETypeAndContainerTypeExtraParameters(
    const nsACString& aCodecMIMEType, const MediaContainerType& aContainerType);

namespace detail {

// aString should start with aMajor + '/'.
constexpr bool StartsWithMIMETypeMajor(const char* aString, const char* aMajor,
                                       size_t aMajorRemaining) {
  return (aMajorRemaining == 0 && *aString == '/') ||
         (*aString == *aMajor &&
          StartsWithMIMETypeMajor(aString + 1, aMajor + 1,
                                  aMajorRemaining - 1));
}

// aString should only contain [a-z0-9\-\.] and a final '\0'.
constexpr bool EndsWithMIMESubtype(const char* aString, size_t aRemaining) {
  return aRemaining == 0 || (((*aString >= 'a' && *aString <= 'z') ||
                              (*aString >= '0' && *aString <= '9') ||
                              *aString == '-' || *aString == '.') &&
                             EndsWithMIMESubtype(aString + 1, aRemaining - 1));
}

// Simple MIME-type literal string checker with a given (major) type.
// Only accepts "{aMajor}/[a-z0-9\-\.]+".
template <size_t MajorLengthPlus1>
constexpr bool IsMIMETypeWithMajor(const char* aString, size_t aLength,
                                   const char (&aMajor)[MajorLengthPlus1]) {
  return aLength > MajorLengthPlus1 &&  // Major + '/' + at least 1 char
         StartsWithMIMETypeMajor(aString, aMajor, MajorLengthPlus1 - 1) &&
         EndsWithMIMESubtype(aString + MajorLengthPlus1,
                             aLength - MajorLengthPlus1);
}

}  // namespace detail

// Simple MIME-type string checker.
// Only accepts lowercase "{application,audio,video}/[a-z0-9\-\.]+".
// Add more if necessary.
constexpr bool IsMediaMIMEType(const char* aString, size_t aLength) {
  return detail::IsMIMETypeWithMajor(aString, aLength, "application") ||
         detail::IsMIMETypeWithMajor(aString, aLength, "audio") ||
         detail::IsMIMETypeWithMajor(aString, aLength, "video");
}

// Simple MIME-type string literal checker.
// Only accepts lowercase "{application,audio,video}/[a-z0-9\-\.]+".
// Add more if necessary.
template <size_t LengthPlus1>
constexpr bool IsMediaMIMEType(const char (&aString)[LengthPlus1]) {
  return IsMediaMIMEType(aString, LengthPlus1 - 1);
}

// Simple MIME-type string checker.
// Only accepts lowercase "{application,audio,video}/[a-z0-9\-\.]+".
// Add more if necessary.
inline bool IsMediaMIMEType(const nsACString& aString) {
  return IsMediaMIMEType(aString.Data(), aString.Length());
}

enum class StringListRangeEmptyItems {
  // Skip all empty items (empty string will process nothing)
  // E.g.: "a,,b" -> ["a", "b"], "" -> nothing
  Skip,
  // Process all, except if string is empty
  // E.g.: "a,,b" -> ["a", "", "b"], "" -> nothing
  ProcessEmptyItems,
  // Process all, including 1 empty item in an empty string
  // E.g.: "a,,b" -> ["a", "", "b"], "" -> [""]
  ProcessAll
};

template <typename String,
          StringListRangeEmptyItems empties = StringListRangeEmptyItems::Skip>
class StringListRange {
  using CharType = typename String::char_type;
  using Pointer = const CharType*;

 public:
  // Iterator into range, trims items and optionally skips empty items.
  class Iterator {
   public:
    bool operator!=(const Iterator& a) const {
      return mStart != a.mStart || mEnd != a.mEnd;
    }
    Iterator& operator++() {
      SearchItemAt(mComma + 1);
      return *this;
    }
    // DereferencedType should be 'const nsDependent[C]String' pointing into
    // mList (which is 'const ns[C]String&').
    using DereferencedType = decltype(Substring(Pointer(), Pointer()));
    DereferencedType operator*() { return Substring(mStart, mEnd); }

   private:
    friend class StringListRange;
    Iterator(const CharType* aRangeStart, uint32_t aLength)
        : mRangeEnd(aRangeStart + aLength),
          mStart(nullptr),
          mEnd(nullptr),
          mComma(nullptr) {
      SearchItemAt(aRangeStart);
    }
    void SearchItemAt(Pointer start) {
      // First, skip leading whitespace.
      for (Pointer p = start;; ++p) {
        if (p >= mRangeEnd) {
          if (p > mRangeEnd +
                      (empties != StringListRangeEmptyItems::Skip ? 1 : 0)) {
            p = mRangeEnd +
                (empties != StringListRangeEmptyItems::Skip ? 1 : 0);
          }
          mStart = mEnd = mComma = p;
          return;
        }
        auto c = *p;
        if (c == CharType(',')) {
          // Comma -> Empty item -> Skip or process?
          if (empties != StringListRangeEmptyItems::Skip) {
            mStart = mEnd = mComma = p;
            return;
          }
        } else if (c != CharType(' ')) {
          mStart = p;
          break;
        }
      }
      // Find comma, recording start of trailing space.
      Pointer trailingWhitespace = nullptr;
      for (Pointer p = mStart + 1;; ++p) {
        if (p >= mRangeEnd) {
          mEnd = trailingWhitespace ? trailingWhitespace : p;
          mComma = p;
          return;
        }
        auto c = *p;
        if (c == CharType(',')) {
          mEnd = trailingWhitespace ? trailingWhitespace : p;
          mComma = p;
          return;
        }
        if (c == CharType(' ')) {
          // Found a whitespace -> Record as trailing if not first one.
          if (!trailingWhitespace) {
            trailingWhitespace = p;
          }
        } else {
          // Found a non-whitespace -> Reset trailing whitespace if needed.
          if (trailingWhitespace) {
            trailingWhitespace = nullptr;
          }
        }
      }
    }
    const Pointer mRangeEnd;
    Pointer mStart;
    Pointer mEnd;
    Pointer mComma;
  };

  explicit StringListRange(const String& aList) : mList(aList) {}
  Iterator begin() const {
    return Iterator(
        mList.Data() +
            ((empties == StringListRangeEmptyItems::ProcessEmptyItems &&
              mList.Length() == 0)
                 ? 1
                 : 0),
        mList.Length());
  }
  Iterator end() const {
    return Iterator(mList.Data() + mList.Length() +
                        (empties != StringListRangeEmptyItems::Skip ? 1 : 0),
                    0);
  }

 private:
  const String& mList;
};

template <StringListRangeEmptyItems empties = StringListRangeEmptyItems::Skip,
          typename String>
StringListRange<String, empties> MakeStringListRange(const String& aList) {
  return StringListRange<String, empties>(aList);
}

template <StringListRangeEmptyItems empties = StringListRangeEmptyItems::Skip,
          typename ListString, typename ItemString>
static bool StringListContains(const ListString& aList,
                               const ItemString& aItem) {
  for (const auto& listItem : MakeStringListRange<empties>(aList)) {
    if (listItem.Equals(aItem)) {
      return true;
    }
  }
  return false;
}

inline void AppendStringIfNotEmpty(nsACString& aDest, nsACString&& aSrc) {
  if (!aSrc.IsEmpty()) {
    aDest.Append("\n"_ns);
    aDest.Append(aSrc);
  }
}

// Returns true if we're running on a cellular connection; 2G, 3G, etc.
// Main thread only.
bool OnCellularConnection();

inline gfx::YUVColorSpace DefaultColorSpace(const gfx::IntSize& aSize) {
  return aSize.height < 720 ? gfx::YUVColorSpace::BT601
                            : gfx::YUVColorSpace::BT709;
}

bool IsWaveMimetype(const nsACString& aMimeType);

void DetermineResolutionForTelemetry(const MediaInfo& aInfo,
                                     nsCString& aResolutionOut);

}  // end namespace mozilla

#endif